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Advanced Higher Health and Food Technology
Content
Content
The Food Chain
Elaboration
The process of events from production of food
through to its consumption to include:
 Food hygiene and safety issues at each stage in the
food chain – primary producers, primary/initial
processing, final/secondary processing or
manufacturing, transportation, retail, consumer to
include:
- types of bacteria and possible sources which may increase
the risk of food poisoning within the food chain
- control and prevention of microbial growth though out the
food chain.
- Current Food Safety Legislation such as Food Safety Act
1990,
Food Hygiene (Scotland) Regulations 2006
- the Hazard Analysis critical Control Point
system
- the role of the Environment Health Department
 Products design and quality to include:
- market research (reasons for use, benefits to
manufacturer, methods of obtain data)
- stages in product development (concept
generation, concept screening, development
of prototype, product testing, packaging
design, first production run, marketing plan,
product launch)
- quality assurance and quality control
- use of computer technology in food
production
Food Politics
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Food Science
The chemical structure of
the main nutrients
EU Directives
The role of the Food Standard Agency
The role of DEFRA/SEERAD
Food, nutrition and health issues/policies in Scotland
and in the UK --- current reports should accessed, eg
Hungry for Success, Eating for Health --- meeting the
Challenge, Food Standard Agency reports.
The impact of nutrition/health, culture, social,
economic, and environment factors (eg Fair Trade)
on food availability, selection and consumption
patterns
The chemical structure of:
 Carbohydrates (sugar, starch, Non Starch
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Polysaccharides) --- monosaccharides, disaccharides
and polysaccharides
Fats and oils --- fatty acids and glycerol; unsaturated,
monounsaturated, poly unsaturated; essential fatty
acids; trans and cis fatty acids
Proteins --- amino acids
Content
Elaboration
Food Science
The properties and uses of:
The nature of food
 Carbohydrates --- solubility, inversion, crystallisation,
constituents in relation to
caramelisation, retrogradation of starch pectin gel
their properties and uses in
formation
food manufacture
 Fats and oils --- melting characteristics, plasticity
related to creaming and shortening properties,
hydrogenation of oils, smoke point related to uses as a
cooking medium, colloidal systems, emulsifying
agents and stabilisers, hydrolytic and oxidative
rancidity
Nutrients and their on
In depth study of nutrients, their function and the effect on the
their on the health and
health and development of individuals at different life
development of
stages/special circumstances --- pregnancy and lactation,
individuals
infant/young children, teenagers, adults, elderly vegetarians,
weight reduction, sports performance:
 Main nutrients --- protein, fats and carbohydrates --functions and effect on health and development
 Micronutrients --- functions and effect on health and
development
 Anti-oxidants --- role in health
 Inter-relationship of nutrients
 Factors affecting absorption of nutrients
Health and dietary diseases ---- coronary heart disease,
obesity, hypertension, cancer, diabetes, anaemia, bowel
disorders, osteomalacia, osteoporosis, dental decay.
Food Commodities
Composition and properties of the following goods in raw an
cooked state:
 Fruit and vegetables --- structure and texture, changes
during ripening and cooking, plant pigments and
enzymic browning, sensory qualities, relationship to
health
 Meat and fish --- structure and texture, post-mortem
changes, changes during cooking, meat and fish
colour, meat tenderness, sensory qualities, relationship
to health
 Dairy food, milk and milk products and eggs --constituents, uses in food preparation, changes during
cooking, sensory qualities, relationship to health
 Cereals and baked goods --- types, function and uses
of : rice and pasta, flour, fats, and shortenings, sugar,
raising agents; changes during cooking, sensory
qualities, relationship to health
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Biochemistry, preservation 
and processing
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The role of micro-organisms and enzymes in the
development of flavours and textures in food
Beneficial effects of micro-organisms and enzymes
related to specific foodstuffs: cheese yoghurt, alcoholic
drinks, bread
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Adverse effect of micro-organisms and enzymes in the
development of flavours and textures in food
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Physical and chemical changes in foodstuffs are
preservation affecting structure, texture, colour and
nutritive value
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Food additives --- preservation, anti-oxidants,
emulsifiers, specific commercial additives, ie antifoaming agents, colour, bleaches, flavour enhancers,
nutritional additives
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The benefits of additives and safeguards regarding their
use
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Organic foods
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Genetic modification of foods
Content
Elaboration
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Food irradiation
Biochemistry, preservation 
Functional food (health promoting food)
and processing
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Fast foods
--- reasons for growth of the fast food industry
continued
--- role of technology
--- impact of fast food on food habits
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--- in a social context, eg school, hospital
Psychology of food
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Influence on food product development
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Influence on consumers
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Consumers attitude to food issues
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Role/influence of the media
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Consumer behaviour
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UNIT : RESOURCE MANAGEMENT
CONTEXT
The Food Chain
CONTENT
The processes of events from production of
food through to its consumption to include:
Food hygiene and safety issues at each stage in
the Food chain
Steps taken throughout the food chain to ensure the provision of safe food.
1. PRIMARY PRODUCERS
These include farmers, horticulturalists, fishermen. In all areas strict controls are necessary.
The following outline some areas in farming where controls are needed:
 Strict control procedures should be used by primary producers eg storage of eggs to prevent infection
with salmonella prior to hatching
 Poultry reared for meat on farms are at risk of Campylobacter infection unless precautions are taken
to prevent this. These precautions could include, for example, improving the cleaning of chicken
houses between different flocks and daily sanitisation of feeding water.
 The safety precautions in the UK food chain are designed to minimise any potential risk from Bovine
Spongiform Encephalopathy (BSE). Feeding cattle (or any other farm animal) with material that
includes processed body parts of cattle or sheep is illegal. Only cattle under 30 months old can be
used for food.
 All incidences of TB brucellosis, salmonella and bovine sprongiform encephalopathy (BSE) must be
reported.
 Use of pesticides and veterinary medicines such as antibiotics need control to minimise residue in
food.
 Microbiologists are concerned about the use of antibiotics as growth promoters in some feedstuffs
because of the risk that they may lead to the development of antibiotic resistant strains of bacteria
which mau be transmitted to humans. These are being reduced or removed
 Milk fresh from cow is around 37C. This is cooled to 4C and stored in clean tanks. Tanks are
insulated to retain temperature. Tanks are transported at this temperature.
 Animal health regulations are now being enforced by Trading Standards eg animal movement records/
markets
2. INITIAL PROCESSING/ PRIMARY PROCESSORS
Slaughter Houses
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These must comply with the Poultry, Meat, Farmed Game Bird and Rabbit Meat (Hygiene and
Inspection) Regulations 1995.
The regulations outline the standard of hygiene for the slaughterhouse, temperature control, how
and for how long the carcasses should be stored.
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These controls will contribute to the prevention of microbiological contamination, particularly
salmonella (optimum temp 37C) and E Coli (optimum temp 37C).
Also helps to prevent cross contamination occurring especially when gutting.
The Meat Hygiene Service(MHS)ensures that the meat industry safeguards the health of the
public, and the health and welfare of animals at the point of slaughter, through enforcement of
legislation in approved fresh meat premises
Official controls require specific inspection of all animals, carcases and offal and risk based audits
to ensure that EU food hygiene regulations are met. The MHS undertakes this work on behalf of
the Food Standards Agency
The Clean Livestock policy sets out the standards for acceptable levels of cleanliness for cattle
and sheep being presented for slaughter. It was published in 1997 to improve hygiene standards
following the outbreak of E Coli in 1996 in Scotland
Dairies
Processing is subject to special supervision, strict controls. Milk is heat treated to make if safe for the
consumer. HACCP procedures must be in place.
3. FINAL/SECONDARY PROCESSING or MANUFACTURING
Quality management systems are set up to reduce the risk of microbiological contamination. Quality
systems include
 HACCP which focus on identifying risks/hazards during food manufacture and putting controls in
place to ensure safe food
 ISO (International Standards Association) - sets quality management standards to be followed to
assure quality of product at all stages
Manufacturer’s Responsibilities – examples of
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The storage, preparation and cooking of, for example, meat, chicken – a proper HACCP system
should be set up to minimise the risk of micro-biological contamination.
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Chickens are “high risk” products, a structured system, using written records of hazard analysis,
should be used to set up effective control.
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All controls must be monitored rigorously to ensure they are working effectively and that the food
is safe.
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Specific points may include, separate storage areas for raw and cooked foods, and the use of rapid
cooling – chill blasting to enable foods to be stored at low risk temperatures quickly.
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Salmonella and E Coli are the main ones to watch as well as clostridium (optimum temp 43-37C)
during “bulk cooking”.
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A minimum centre temperature of 75C required to ensure bacteria is killed and this should be
checked with a food probe.
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The importance of staff training in general hygiene practices and specifically in relation to
personal hygiene, particularly the prevention of staphylococcus aureus food poisoning.
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4. TRANSPORTATION/ DISTRIBUTION
Quality and safety of food must be maintained during transportation and distribution by checking
operating procedures to ensure food products are preserved correctly and that monitoring procedures are
carried out. There are three international bodies responsible for implementing quality standards:
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European Union’s Legislation on the preservation of hygiene and safety of food.
International Standards Organisation (ISO).
Codex Alimenarius established in 1962 by the Word Health Organisation and the Food
Agriculture Organisation.
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Cleanliness of lorry is vital, sanitised between trips.
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Cramped conditions, e.g. in transport of chickens/cows may spread infection.
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Temperature of transport system very important, refrigerated lorries with temperatures below 5C
and a system of monitoring temperature control essential to ensure safe food for the consumer.
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Products must be kept free from external pollutants e.g. dust, moisture, unsuitable temperatures,
odours, rodents and insect pests.
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To help ensure this happens, packaging should not be physically bruised, broken or bent. Product
must be delivered in perfect condition with packaging fully intact.
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All transportation vehicles should be clean, damp, mould and odour free to help prevent
contamination from insects, etc., and clostridium perfringens.
RETAILER
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The retailer must ensure all foods received have been transported at the correct temperature, are
within the use by date and that all packaging is intact.
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Once in the store they must be kept from raw meats (E Coli) and if chilled, below 8C or les or if
hot, above 63C (listeria/staphylococcus aureus).
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Frozen food must be kept frozen to prevent the product thawing before it reaches the consumer
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Excess humidity can lead to the growth of moulds and bacteria on meat and fungus on fruit,
vegetables and dry cereals
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The Food Hygiene (Scotland) Regulations 2006 should be followed in relation to cleanliness,
maintenance and repair of food premises, layout and design, prevention of cross-contamination,
accessibility to wash basins, ventilation, toilet facilities, lighting and personal hygiene facilities.
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Foodstuffs must be handled by trained staff.
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Foods must be stored correctly, cooked and raw foods must be stored separately to avoid
possibility of cross contamination.
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CONSUMER
This is the final part of the food chain. the consumer must be aware of the dangers of poor food
preparation, storage, transportation from shop, cooking.
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Purchase – foods within correct shelf life and in good condition, packaged carefully to avoid
damage from shop to home.
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Transport – frozen or chilled foods to be purchased at end of shopping and transported to the
home as quickly as possible. A cool bag is ideal to help food remain chilled.
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Storage – refrigerated or frozen at correct temperatures. Food wrapped. Cooked and raw foods
stored away from one another i.e. raw at bottom of refrigerator, cooked above. This will avoid
any cross contamination. Rotate stock to avoid out of date products. Fridge temperature should
be less than 4C.
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Cooking/Reheating – according to instructions for appropriate time and to safe temperatures.
Food should only be reheated once.
Consumers have a responsibility to be knowledgeable about current hygiene and safety practices. DEFRA
produces advisory leaflets.
Note that the following Food Legislation can be enforced at various stages in the food chain
Food Safety Act 1990
Food Hygiene (Scotland) Regulations 2006
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Resource Management
Content
The Food Chain
Elaboration
The process of events from production of food
through to its consumption to include:
Food Hygiene and Safety issues at each stage in the
food chain to include Food Safety Legislation
HACCP system
Environmental Health Department
Food Safety Act 1990
The Food Safety Act 1990 was introduced to take account of the changes in food technology and eating
habits. It was designed to help reduce the number of cases of contamination and food poisoning. It applies
to food businesses throughout the UK.
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Aims to ensure all food produced for sale is safe to eat, reaches quality expectations and is not
misleadingly presented
Covers the whole food chain from the farm or factory to point of sale – ensures safe food for
consumers.
In particular it covers sources from which the food is derived and articles which come into contact
with the food so the consumer is protected throughout the food chain
It covers farmers directly so ensures safe primary production
Makes it an offence to sell food which is injurious to health, unfit to eat or contaminated.
All in the food business must conform to this Act, and food premises must be registered – ensures
good hygiene standards for consumers
All food handlers have to undergo food hygiene training therefore the consumer should be
protected from the risk of food poisoning
Provides legal powers and penalties to enforce the act. These duties are carried out by
Environmental Health departments in relation to food hygiene issues and by trading standards in
relation to food labelling etc.
Enforcement officers have the right to inspect food sources and to take action when an offence has
been committed
Food labelling must be accurate – this relates to storage/cooking instructions and possible
ingredients/ additives which may cause allergies
Enables us to fit in with the requirements of the EU and to meet their food safety requirements
Allows us to keep pace with technological change and so ensure food developments do not put
safety of the consumer at risk
“Due Diligence”
It is a defence for a person handling food to prove that they took all reasonable precautions and exercised
all due diligence to avoid committing an offence either by themselves or a person under their control.
Due diligence is the principal defence under the Food Safety Act 1990, and enables the defendant to be
acquitted of an offence if they prove that they ‘took all reasonable precautions and exercised all due
diligence to avoid committing the offence.’
To prove that reasonable precautions have been taken involves setting up a system of procedures and
controls, being aware of the likely hazards and risks and checking that these systems are operated
properly.
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Clear, written records referring to hazard analysis, training, temperatures, pest control, testing, cleaning
schedules and codes of practice are essential.
It may be acceptable for a food operator to prove than someone else, not under their control was
responsible, that they were relying on information provided, that reasonable
checks were made and they could not reasonably know that an offence was being committed
Food Hygiene (Scotland) Regulations 2006
These regulations are designed to ensure that food hygiene regulations in Scotland meet the requirements
of being a member of the European Community
 Anyone who processes or sells food is covered by these regulations and are legally bound to
make sure they carry out their operations safely and hygienically
 Anyone who owns, manages or works in a food business, apart from those working in primary
food production such as harvesting, slaughtering or milking, is affected by these regulations.
 The regulations apply to all premises, from restaurants and supermarkets to vans, vending
machines and village halls. Whether food is sold publicly or privately, in a hotel or in a
marquee, for profit or fund-raising these regulations must be observed.
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The main points of the regulations are to ensure
1. Owners of a food business must carry out a risk assessment of their business in order to ensure
food safety and hygiene. The one that is most widely used by food businesses is known as Hazard
analysis Critical Control Point (HACCP)
 They ensure that all sellers/processors of food must identify all steps in their activities which are
critical to food safety – emphasis on controlling risk thus reducing risk to the consumer
 Also ensure that adequate safety controls are in place, maintained and reviewed
 This is undertaken by implementing the Hazard Analysis Critical Control point (HACCP) system
2. General food hygiene
The aim to set out basic hygiene principles to control food safety risks. All food must be fit for human
consumption and protected to minimise risk of infection
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The regulations deal with the following areas:
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Premises – their construction and design should allow for good cleaning and maintenance,
have good ventilation and lighting, good drainage, have adequate hand washing facilities,
removal and storage of waste shod be well planned, toilet facilities should be away from
food preparation areas.
Food preparation rooms – should have floors, doors, walls, ceilings and work surfaces
that are easy to clean,
Equipment – should be designed for ease of cleaning, maintenance and well installed.
Transport used to carry food – must be kept clean and well maintained, have food stuffs
stored and protected to reduce the risk of contamination
Hygiene of food handlers – good personal hygiene, routine hand washing, protective
clothing, cover cuts appropriately, no jewellery or nail polish, no smoking.
Fitness for work – specific medical conditions which will make food handlers likely to
contaminate food legally must be excluded from any food handling e.g. diarrhoea, pus
containing sores, vomiting, any form of food poisoning. Food handlers if known or
suspected of carrying any disease or infection, must not be permitted to work.
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Preventing food contamination – cooked and raw foods kept apart during preparation
and storage, place food safely, open food to be 45cm from the ground, cover open food
while exposed, store food at correct temperatures, i.e. refrigerators below 5C.
Training and supervising food handlers – instruction and/or training in food hygiene
matters to the level appropriate for their job. Staff must be adequately trained and
supervised in matters relating to food safety
HAZARD ANALYSIS CRITICAL CONTROL POINT (HACCP)
This system operates from purchase of raw materials to service to the customer.
There are seven stages involved in the HACCP system
Seven stages of HACCP
1. Conduct a hazard analysis
2. Decide on the Critical Control Points
3. Establish a tolerance level
4. Establish a monitoring system
5. Establish what action should be taken to correct the hazard if it occurs
6. Establish procedures to check that the HACCP system works effectively
Recordakeeping
review of procedures
1. 7.
Conduct
hazardand
analysis
Potential hazards associated with a food, and measures to control those hazards, are identified during
hazard analysis.
Hazards could be:
a. Contamination in the following ways  Biological such as bacteria, moulds, viruses
 Chemical such as cleaning chemicals or pesticides
 Physical such as foreign bodies like glass, pests, metal
b. Temperature control during storage
Bacteria and mould will multiply in foods if they are stored at higher temperatures than
recommended or are left in warm conditions for too long
c. Inadequate cooking
If food has not had sufficient cooking time or has not reached the correct temperature then bacteria
may survive.
Personal hygiene, cleaning and disinfecting of equipment, waste disposal and pest
control are important at each step of HACCP. By identifying the stages where
potential hazards might occur, controls can be put in place which can prevent
bacterial growth or contamination
2. Decide on the Critical Control Points
These are the points in food production – from its raw state through processing and distribution to
the consumer - at which the potential hazard can be controlled or eliminated. At each step of
production there are likely to several hazards.
If a failure to control any hazard at this point could cause food poisoning or a serious food
complaint (eg glass in food) then this step is called a critical control point and the hazard must
be controlled or eliminated. An example of a critical control point would be temperature control
with a high risk food such as chicken, food safety would be maintained by keeping temperatures
below 5ºC.
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If the hazard does not carry a food poisoning risk, then good hygiene practice at this step should
be sufficient to ensure good food safety – this is called a control point
3. Establish a tolerance level
Controls must be implemented to eliminate the hazard or to reduce it too a safe level. This stage
establishes preventative measures with critical limits for each control point. For a cooked food,
for example , this might include setting the minimum cooking temperature and time required to
ensure the elimination of food poisoning bacteria.
4. Establish a monitoring system
Procedures must be established to monitor the steps. Monitoring involves checking to make sure
that controls are effective and that they are being implemented throughout food production. Such
procedures might include determining how, and by whom, cooking time and temperature should
be monitored. Time and temperature are two very important factors and they should be precise
and relatively easy to monitor.
Examples of monitoring include
 Checking the temperature of the refrigerator frequently
 Checking that staff wash their hands on entering the food preparation area
 Checking that the core temperature of a joint of meat reaches 75ºC
 Checking that the equipment has been thoroughly cleaned and disinfected
5. Establish what action should be taken to correct the hazard if it occurs
When monitoring has revealed a problem or a complaint is received, then action to correct the
hazard must be taken (corrective action) Some examples of corrective action include:
 Disposing of food if minimum cooking temperature has not been met
 Rejecting out of date stock
6. Establish procedures to check that the HACCP system works effectively
An example of this could be a testing time and temperature recording device to verify that a
cooking unit is working properly.
7. Record keeping and review of procedures
This would include records of hazards and their control, the monitoring that has taken place and
any action taken to correct potential problems. Documentation of the system is not a legal
requirement but detailed and accurate documentation will assist a defence of “due diligence” in
the event of a prosecution.
A review of procedures may be required if :
 The product or the controls are not satisfactory
 The method of preparation changes
 New equipment is introduced
Advantages of the HACCP system
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Hazards are identified and controlled before production and at each stage of the process from raw
materials through to the sale of the product. This should result in safe food for consumers so that
they are not put at risk
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Many food poisoning incidents result from poor practices which are only discovered after an
outbreak. By identifying hazards, the likelihood of such problems would be reduced
 It ensures that food companies do not break the law and face prosecution.
 Helps food companies compete more effectively in the world market
 Record keeping allows investigators to see how well a firm is complying with food safety laws.
Stages of manufacture and HACCP
The stages of manufacture involved in food production will vary according to the final food product.
A basic outline of the stages involved in food production is given below. All these stages have to be
closely looked at for potential hazards using the HACCP system.
1. Purchase of ingredients.
2. Delivery of ingredients
3. Storage of ingredients
4. Preparation of ingredients
5. Cooking of ingredients
6. Chilled storage
7. Packaging
8. Distribution
Stages in food production where HACCP is implemented
Stage
1. Purchase of
ingredients
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2. Delivery of
ingredients
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3. Storage of
ingredients
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4. Preparation of
ingredients
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Importance of HACCP to each stage
Raw materials which are purchased may contain harmful foreign bodies eg
flour could contain weevils
High risk foods, such as fish, meat, cream can present a hazard to health as
they could be contaminated by bacteria
Ingredients should be purchased from a reputable supplier to guarantee
quality and safety
Checks should be in place to ensure that high risk foods are delivered at
temperatures between 0 – 4º C
Check temperature and condition of delivery vehicle
Date marks of dry stores / fats should be checked to ensure that there is
sufficient time remaining before they can be used
Checks should be in place to ensure that high risk foods such as chicken,
cream are stored at temperatures between 0 – 4ºC to prevent bacterial
growth
Dry stores should be stored in a cool place and in sealed containers
Stock rotation system should be used to ensure that the FIFO (First In First
Out) system applies
Use foods within the date mark
Containers should be sealed, to prevent the entry of pests, and labelled
Storage areas should be kept clean and free from dust and food debris that
could attract pests
Raw and cooked ingredients should be kept separate to prevent cross
contamination
Food handlers should follow strict food hygiene rules to avoid possible
contamination of ingredients and wear protective clothing.
Equipment must be well cleaned and maintained to prevent possible
contamination from equipment
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Work surfaces and areas must be kept clean to avoid possible cross
contamination
 Limit handling times during preparation especially of high risk foods
 Check no foreign bodies have entered the food during preparation as these
could cause the consumer to choke eg fish bones
Stage
5. Cooking of
ingredients
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6. Chilled storage /
cooling
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7.Packaging
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8.Distribution
Importance of HACCP to each stage
Cooking times and temperatures must be checked
Products must be thoroughly cooked to destroy bacteria
Routine temperature checks using food probes to check core temperatures at
least 75ºC at centre
Cooked food must be cooled or chilled rapidly so that the danger zone is
quickly passed through to prevent the growth of harmful bacteria
High risk foods such as cream must be refrigerated at between 0 –
4º C immediately after preparation
No contact with raw food to prevent cross contamination
Packaging should be sealed to protect food from contamination or physical
contamination
Packaging may have to withstand chilling temperatures without breaking up
when refrigerated
Packaging should be labelled to indicate how the product should be stored
safely before eating
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High risk food / cook chill foods should be distributed to retail outlets in
refrigerated vehicle at between 0-4º C
 Temperature of vehicle should be checked and recorded before food is
loaded into it at the factory and removed from it before unloading at the
retailers
The Food Hygiene (Scotland) Regulations 2006 also ensure that the correct temperatures are
maintained during food production (replaces Food Safety (Temperature Control) Regulations
1995)
 Regulations cover all food stuffs including raw materials and ingredients
 They apply to all stages from transport, preparation, processing, storage, manufacturing,
catering and retailing
 States that the maximum temperature of 8º C is the specific requirement for all foods that could
support the development of harmful pathogenic micro-organisms or the formation of toxins
this helps protect the consumer from food poisoning
 Even if food is kept below 8ºC, if it is known to support the growth of pathogenic bacteria at
say 5ºC the law is breached
 Food which is to be reheated before serving must reach a temperature of not less than 82º C
 Cooked food which is to be kept hot for more than 2 hours must be kept above 63º C to
prevent the growth of pathogens or the formation of toxins
 A food business responsible for cooling food that will be kept at chill temperatures must cool
the food as quickly as possible after cooking. Cooling is a critical step to food safety
especially for ‘high risk’ foods.
 Environmental Health Officers enforce the regulation by:
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checking temperatures of cold rooms, refrigerators and chilled cabinets.
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recording temperatures between packs of food
probing food for centre temperature.
Quick Frozen Foodstuffs Regulations 1990
 Required frozen foods to be stored at - 18 ºC and transported at between minus 15-18º C
THE ROLE and RESPONSIBILITIES of the ENVIRONMENTAL HEALTH DEPARTMENT
Environmental Health Departments employ Environmental Health Officers who protect the interests of
the consumer.
Environmental Health Officers (EHO) has responsibility for –
 enforcing the Food Safety Act 1990 in relation to the local community and so ensuring that consumers
is protected against the risk of food poisoning
 enforcing hygiene regulations covering food premises and for general food safety.
Procedure for Enforcement:
 officers can enter food premises such as food manufacturers, retail outlets and restaurants on a
routine inspection or to investigate complaints.
 officers will identify potential hazards in the food chain and carry out risk assessment
 officers can inspect food to see if it is safe and retain, seize or condemn food
 when officers enter food premises they can take away food samples to be tested and make videos to
record what they see
 failure to comply with food hygiene regulations may result in the service of an improvement notice,
which specifies the contravention, the improvements required and the time allowed to make the
improvements. Failure to comply with an improvement notice is an offence.
 a prohibition notice could also be issued if there is a risk of injury or harm to consumer’s health. The
officer has to ask the courts permission to prevent, for example, the use of a specific piece of
equipment or a process. When the business has undertaken the action requested to prevent any food
safety issues then the officer will grant a certificate to the business.
 if the officer is satisfied that there is an imminent risk of injury to health an emergency prohibition
notice may be served and this could mean that premises would be closed immediately.
 after doing this, an application for an emergency prohibition order must be made to the court within
three days of serving the emergency prohibition notice. Once all the required action has been
undertaken to ensure that the food business is no longer a food safety risk, then a certificate will be
issued and the business can re-open.
As well as enforcing legislation the Environmental Health Department
 works closely with schools and community organisations providing advice, training and support
on local environment, public health and food safety issues. This is very useful in protecting the
interests of consumers as this helps raise consumers awareness of their function and informs
them of actions or steps to take when issues arise.
 Gives advice to businesses on food laws and regulations
 Offers food hygiene courses to food handlers
There are numerous food opening daily therefore enforcing the Act is difficult and may mean that the
consumer may not always be fully protected
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Content
The food chain
Resource Management
Elaboration
Product design and quality to include:
 Market research (reasons for use, benefits to
manufacturer, methods of obtaining data
 Stages in product development(concept
generation, concept screening ,development of
prototype, product testing, packaging, first
production run, marketing plan, product
launch)
 Quality assurance and quality control
 Use of computer technology in food
production
Product Design
Food products today are very different from those of 20 years ago – consumers tastes and diet change
over time and foods go in and out of fashion. People lead busier lives so they may buy more ready
made meals, or eat out more rather than cooking for themselves.
Consumers now expect to find a wide range of ingredients and products due to:
- increased foreign travel
- a multi cultural community with many different traditional cuisines
- the many cookery programmes on television which encourage the use of new ingredients
Many consumers now take a greater interest in the food they eat. This can be due to:
- a demand for healthier foods linked to health concerns linked to salt, sugar and fat intake
- an increase in concern for the environment, hence the purchase of organic, Fair Trade foods and
GM free foods.
To be successful a food product has to appeal to the target market. Manufacturers spend considerable time
working on a product development strategy to ensure that the product will sell well.
Market research
Market research may be carried out by a manufacturer:
 Before the development of a new product
 Throughout the development of a new product
 After the launch of a new product
 For existing product evaluation – if the product has been available for some time and sales have
dropped
Reasons for use
Manufacturers use market research to find out :
 The ideas from market analysis which could be developed , perhaps even trialling of popular
products for example, why chocolate flavour is popular, looking for something similar but new
 Consumers opinions regarding a suitable product - if there is need for a certain product and will it
be marketable and sell eg
- whether it is cheap, attractive, convenient
- snack type foods
- for a special group eg consumers on a weight reduction diet
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

If there is a gap in the market – this helps find out if there is a need for a product or service
About the competition from other manufacturers To find out about the competition, what is available
and what could be adapted
 The market trends – which foods are popular at a particular time
 It could also be used to evaluate the product, gaining important public opinions on for example, its
sensory qualities, cost, packaging etc. Market research for product evaluation will look at aspects of
the product. The public may be asked to judge or comment on sensory properties :

appearance – how the food looks (does it look fresh, healthy, appetising?) and its colour, for instance
blue custard might be rejected because it is not what we expect; combinations of colours are more
aesthetically appealing.
 texture/consistency – how the food tastes in the mouth, e.g. crunchy, smooth, rough, dry
 smell – this matters because if something smells off putting, then people will not want to eat it
 taste/flavour – detected by the taste buds in the mouth, i.e. fruit, sharp, sweet, sour, saltiness,
bitterness; the flavour of food is a combination of taste and smell.
Other aspects of product evaluation may be concerned with gaining public opinion on:
 acceptability of price, i.e. will the consumer pay a certain price for the product? Will it be for money
 packaging – what shape and size of packaging will the consumer prefer for the product
 method of cooking or reheating the product – microwave, oven, grill, etc. (container/packaging may
have to suit all of these)
The benefits of market research to manufacturers and retailers are:


Helps food businesses plan how they will promote and advertise a product
Market research will help the food industry find out if a new product is a good idea before they
spend too much money on product development
Market research should ensure that the development of the product is profitable. Manufacturers
will not make a loss and retailers will have a good turnover of goods
Manufacturers will keep track of market trends ie what the consumer wants, what meets their
needs and how much they are willing to spend. They will then be able to provide a product
which will sell well and profit margins will increase
Competition from other manufacturers will be identified allowing the manufacturer to make a
decision whether it is viable to continue with the product.
Market research is used to gain public opinion on cost of product so the manufacturer and
consumer can assess if they think the product is value for money and economical to produce




Methods of obtaining data

direct and indirect
direct research from the public using the telephone, personal and group interviews, tasting and
testing sessions, questionnaires
- indirect research where existing information is used, including reports such as Social Trends
(HMSO publication), computer databases, CD –ROMs, collecting sales information.
-

Qualitative and quantitative
quantitative –
Information is gathered using large numbers of people, by questionnaires and interviews
(normally 200 – eg telephone survey)
- qualitative –
Asking small numbers of people about their likes and dislikes, for their
-
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opinions on products and how to increase product appeal.
Used to increase understanding by more in depth, focussed market research.
Stages in product development
Concept generation
 This is an important initial stage as it involves developing ideas for new products. Without it, the
development process cannot take place
 It is a thinking stage – thinking up new ideas, perhaps even looking for a gap in the market. Ideas
may come from:
- people brainstorming in teams or individually
- looking at competitors products – this could involve evaluating a range of existing and similar
products
- consumer research which will show consumers needs and preferences
- consultants who are specialists in developing ideas
- ideas from recipes books and magazines. Looking at some of the long term established tried and
tested recipes, and those from other cultures may provide inspiration
- new ingredients and technology
- food fashion trends – often set by celebrity chefs and restaurants
- government guidelines and health recommendations – this may result in manufacturers
designing products with nutrition in mind eg reduced fat products
- the need to improve, update or relaunch existing products
 Manufacturers do not want to replicate something which is already on the market, they must put a
new slant on it
 Factors such as cost, portion size, methods of / processing manufacturing, cooking/ reheating for
the consumer flavour, texture and appearance will be considered at this stage
 Particular target groups eg children, times of the day eg breakfast, celebratory occasions and
particular times of the year eg seasonal salads may also have to be considered
Concept Screening – this is a stage where ideas are refined and screened for feasibility
 Consider all ideas, keep some and discard some
 This stage is important as it allows the production process to move away from initial ideas to
actual development issues
 Allows the manufacturer to develop a specification against which to develop ideas
 The best ideas are taken forward. Clear decisions are made on which ideas meet the specification
and should be further tested
 Specification allows manufacturer to eliminate ideas that might be costly, difficult to process/not
meet other constraints. The commercial viability of the product will be looked at eg whether the
projected sales value will cover the cost of production, ingredients, packaging and still make
sufficient profit for the manufacturer
 Allows product ideas to be generated so that a prototype can be developed.
Development of a prototype
 This is an example or specimen of what the product will be like
 This would be done in a test kitchen and the prototype is developed here and measured against the
specification
 Evaluation is an important part of the development process eg
- sensory evaluation The prototype will be tested for appeal, perhaps using a small
experienced team to carry out a sensory evaluation , and it may be further
modified, accepted or rejected
- nutritional and attribute analysis by looking at the qualities and characteristics of the product
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-
disassembly of the product to take a closer look at for example at the proportion and
combination of ingredients and learning from what is observed
Product testing
 Many manufacturers test new products on potential consumers before moving on to large scale
production, so various opinions can be obtained for example by using consumer panels to carry
out a sensory evaluation
 This would allow the product, or a range of products, to be further refined or eliminated as a
result of consumer opinions. The most suitable solution being kept.
Packaging design
 This is when the packaging design team would consider the image of the product and the target
market and start to create a design which will attract customers and help to sell the product.
 The type of packaging will be investigated, tested and costed.
 Legal labels will be designed and produced
First production run
 This allows for the production of an actual product for the first time as a full production run so the
item can be assessed under factory conditions
 It enables the quality assurance team to test the product to ensure quality, safeguard staff health
and uniformity of standards during the manufacturing processes
 It allows the manufacturer to maintain food safety standards and to consider the HACCP issues
 This stage allows for potential production problems to be sorted out before large scale production
begins as this may in future result in ‘down time’ when production has to be stopped
 This is a vital stage as it is here that changes may take place which could affect other aspects of
the product e.g. changes to the ingredients will result in changes having to be made to the
ingredients list on the label
Marketing plan
 This allows for a range of activities to be developed to promote the product e.g. where it will be
sold, position in the shop, special introductory offers etc
 This is important as it may help determine the initial price of the product e.g. low to attract new
customers, higher to denote quality
 Packaging can now be finalised to take account of marketing plans
Product launch
 It may be launched in one region initially(piloted) to allow its performance to be monitored
before a national launch is considered and the plan can be adjusted as necessary
 Market monitoring, once the product is finally launched onto the national market place sales
figures will be monitored carefully to provide regular feedback so the product can be refined and
the manufacturer can continually rethink and readapt the marketing approach
Quality assurance and quality control
The word quality means that a product is of a particular level of excellence or standard. For
manufacturers to be successful and meet legal requirements they must aim to promote, improve and
maintain quality in all of their products
For consumers, a product’s consistently high quality will give them confidence in the manufacturer, will
encourage them to continue buying that product and to try others from the same range.
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Quality Assurance
Quality assurance (QA) is the term used to describe the promise or guarantee that the manufacturer
makes to the consumer, that products are of a particular standard, and are safe, reliable, well designed
and honestly described
Quality assurance occurs throughout the process of design and manufacture and ensures products are
manufactured consistently and within design specifications. At key stages in the production of a food
there should be quality control checks and all results of the checks should be recorded. This is called the
Quality Assurance System
Food companies may use a quality management system (QMS) as their method of documenting a quality
assurance system. A QMS is a specialised way to document a quality assurance system to make sure it
has been implemented properly Companies that use a QMS to maintain high QA standards receive a
certificate recognised within the industry, called ISO 9000. The International Organisation for
Standardisation (ISO) created the QMS system in 1987 and these standards are regularly updated. In 2005
the International Organisation for Standardisation released a standard, ISO 22000, meant for the food
industry. The standard covers the values of the ISO 9000 and the HACCP standards. It gives one
integrated standard for the food industry.
These requirements include
 Keeping a manual of the company’s policy to include:
- procedures
- specifications
- work instructions
- quality records
 Keeping record to include:
- contacts with customers
- complaints from customers
- staff training and review
- purchases from suppliers
- maintenance of equipment
- HACCP procedures
Quality Control
Quality control is the method a manufacturer uses to check that quality is maintained throughout all
stages of product development and manufacture to make sure the product does not vary from the standard
expected by consumers or the specification laid down by the manufacturer. It is part of the quality
assurance procedure.
Quality control gives a “snapshot” of various stages of the production process. This means that the
manufacturer has a clear idea of what is happening in the production process at that precise moment and
how the product is comparing against the design specification. Quality control looks at the quality of
design and the quality of manufacture
A range of checks can be carried out eg
 Visual checks – eg raw ingredients checked for quality and colour
 Organoleptic check – samples of final product tested for flavour, texture, aroma
 Chemical check – samples tested to ensure they are contamination free
 pH checks to ensure the food has the correct acidity/ alkalinity
 Microbiological check – samples checked to make sure bacteria are not at harmful levels
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


Weight check – weight tested at packaging stage to make sure the product is the prescribed
weight. Weighing and measuring equipment must also be checked regularly
Temperature check – samples are checked regularly to ensure accurate temperature control
Metal check – metal detectors used at the packaging stage
Use of computer technology in food production
1. Computer Aided Design (CAD) software encompasses all areas of product development, from idea
generation and research, investigating the functionality and interactivity of different ingredients,
producing manufacturing flow-charts to assess food safety issues, knowledge-based systems and
innovative imaging systems for product quality and fault diagnostic purposes. Some examples of
computer applications used in developing new food products include:
- Flowchart models show where safety checks for HACCP need to be included
during food production in a factory
- Spreadsheets which make it easier for designers to project costs for large scale production
- Digital cameras allow instant images of the product which can be manipulated
- Nutritional analysis
- Drawing software makes it easier to produce 2D and 3D drawings which may help with
packaging and advertising decisions. Virtual reality software can be used to make a 3D image
even more realistic by allowing the user to“move around” it in 3 dimensions
Computers will continue to revolutionise the development of food products with ever changing advances
in technology.
2. Computer Aided Manufacture (CAM) is used by the food industry to help in the manufacture of food
products. There has been an increasing demand for machines to take over the more complex operations
previously carried out by hand, eg chopping/peeling of fruit. This would improve product consistency
and quality control, reduce overheads and increase production capacity. Advantages of CAM within the
food industry include: reduced food wastage through efficient manufacture; improved product
consistency; avoidance of downtime; reduction in overheads, eg labour costs; increased production
capacity; no fatigue from repetitive manufacturing demands; improved food safety and hygiene standards.
3. Computer Integrated Manufacture (CIM) means that computers are used as an integral element of the
entire manufacturing process and are monitored by a small number of operators. It involves computerbased process control and automation; operations and information systems for manufacturing and quality
control. The hope that profitability can be increased or maximized with automation has been a driving
force for CIM.
CTIO
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Content
Food Politics
Resource Management
Elaboration
EU Directives
The role of the Food Standards Agency
The role of DEFRA / SEERAD
EUROPEAN DIRECTIVES
Background to the influence of EU Directives on consumer law in the UK
On becoming a member of the EU, the UK was obliged to sign the Treaty of Rome. Amongst other
things this included agreement that the member states would cooperate to produce a common set of
trading laws ostensibly for the benefit of the consumer in these countries. Prior to EU membership the
UK (and other countries) had its own legislation and in some areas it was superior to other EU states.
At present if the member countries can reach agreement regarding what the various laws should include
then these are accepted and implemented throughout the member states. This is the function of the
Council of Ministers and a UK government minister from the appropriate department affected by the
agreed proposals, however)
Certain other EU bodies are consulted, i.e. the European Parliament and the Economic and Social
Committee (ECOSOC). The Consumers’ Consultative Committee and Consumers in the European
Community Group have been set representation on their behalf.
What is a European Directive?



A European Directive is a form of EU regulation designed to ensure a common set of rules and
regulations are followed throughout all EU states.
A Directive is an outline plan only and instructs member countries what should happen to ensure
consistency throughout EU states, but leaves the decision up to individual state governments as to
how to do it. Member states are left with a certain amount of leeway as to how the exact rules are
to be adopted
Directives are only binding on the member states to whom they are addressed, which can be just
one member state or a group of them. In practice however, with the exception of directives related
to the Common Agricultural Policy, directives are addressed to all member states.
The purpose of a European Directive is



To make a common set of trading laws throughout all EC states.
To try to harmonise and create common standards instead of having separate rules or standards.
In certain instances this has meant changing some of our national laws and because of this some
decisions which affect our lives are made within other EU countries. As we want to belong to the
community this means we have to be prepared to compromise. Obviously this makes the lawmaking process very complicated and it often takes a long time.
To give an outline plan for proposed legislation in the member countries of the EU.
The following are some examples of areas where we have been affected by EU policy
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Influence of the EU on food law
A) Weights and measures
 The change from the UK minimum weight and measures uses an average weight system to control
weight markings. It means that a few packages are allowed to contain slightly more or less than
the stated quantity as long as the total number averages out to that amount.
Goods which have been packed using the average weight
system will use this label. It is the EU symbol showing
that the packer is measuring the European way. This symbol
is understood throughout other member countries.
e

Standard packaging where goods are sold in prescribed amounts/sizes – many basic foods can
only be sold in pre-determined constant qualities, for example tea, sugar, coffee, butter and
margarine and this enables the consumer to compare prices of these commodities readily.

Food sold pre-packed should show weights in metric measurements – kilograms and grams rather
than pounds and ounces.
B) Additives
In most EU countries the use of additives is controlled. Additives in the UK have been strictly tested.
The European Directives have:


Set a list of authorised additives for use in the EU – the countries each have a list of substances
which experts consider are safe to use.
Stipulated how additives must be stated on food labelling, i.e. E number with additive category
before usage
C) Food labelling
 All food must now be clearly marked with its name and description and most pre-packaged food
must show a list of ingredients and how long it can be kept.
 In the ingredient listings all additives (except flavouring) must be identified by their E numbers
and the type of additives they are must be indicated, e.g. colouring, preservatives etc.
 In addition, EU restrictions are placed on which additives are permitted in food, i.e. there is an
approved list of additives considered safe for use.
 Sets out details with regard to products which have a low energy/reduced energy claim.
 Food packages must be sold in metric weights.
 Pre-packed food products should carry a date of minimum durability. This would normally be a
‘best before’ date, which is the date up to and including which the food will be in the best
condition.
 A ‘use by’ date should be used on pre-packed foods that are microbiologically highly perishable
land could be a danger to the consumer’s health.
 Where the use by date is indicated, it must be followed by a description of good storage
conditions.
 Standardised format for inclusion of the optional nutritional labelling of food items.
 The EU is keen to harmonise standards for processed foods and a number of these proposals have
been very contentious because different EU members and consumers have their own ideas about
what they are used to.
 Directives now apply on the regulation of novel foods and foods for particular nutritional uses
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
An EU Directive 2003 which came into force in 2004 has clarified some aspects of food labelling
and ingredients. Food manufacturers are required to list 12 potentially allergic ingredients. The
allergens include cereals containing gluten, fish, crustaceans, peanuts, soy, milk and dairy
products, nuts, celery, mustard, sesames seed and sulphites. The list of allergenic food ingredients
will be updated as required on the basis of recent scientific knowledge. The Directive underlines
the principle that all ingredients should be listed clearly on labels whenever they are used in prepacked foods. Labels will also need to give clear information about ingredients made from these
foods, for example, a glaze made from eggs.
The aims of this Directive are:



To give a high level of health protection to consumers – many consumers suffer allergy conditions
ranging from very mild to potentially fatal.
To ensure that all consumers are appropriately informed as regards foodstuffs through the listing
of all ingredients.
To provide consumers who have allergies or intolerances with more comprehensive information
on the composition of foodstuffs.
D) Safety/ Hygiene
 Member states have agreed to harmonise food safety regulations on the retailing and catering of
all foodstuffs and in the future may harmonise standards for processed foods.
 Hygiene directives now apply to specific products such as meat, fish and milk
 Directives apply to the use of food contact materials and packaging.
THE ROLE OF THE FOOD STANDARDS AGENCY
The Food Standards Agency (FSA) is an independent food safety watchdog set up by an Act of
Parliament in 2000 to protect the public's health and consumer interests in relation to food.
The Agency regularly consults with consumers by holding meetings in public and seeking and publishing
people’s views.
The Food Standards Agency is concerned with the whole food industry – from farming, food production
and distribution, to retail and catering. It addresses food safety issues at every stage of the chain,
providing information and guidance on best practice and legal requirements.
The Food Standards Agency has the following roles
Food safety







FSA provides independent advice and information to consumers and the Government on food safety
so ensuring safer food for consumers and reducing food related illnesses
FSA protects the consumer through effective enforcement and monitoring of food related regulations
and policies
Controlling genetically modified food for human consumption and animal feedstuffs so ensure
consumers safe food
Monitoring the use of food additives
Licensing and inspection of manufacturers who produce irradiated food
Protecting public health against contaminants in food
The Meat Hygiene Service (MHS) is an Executive Agency of the Food Standard Agency. The FSA is
the central competent authority within the UK responsible for carrying out official controls in
approved fresh meat premises. This includes
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





- monitoring and enforcing food safety standards through the MHS
- Licensing of meat processing companies and for hygiene controls on meat and meat products
In Scotland the FSA will deal with issues relating to food hygiene, fish, shellfish, milk hygiene,
radiological safety and food emergencies.
Looking at and controlling the production of new “novel foods” being developed by manufacturers
Representing the UK on matters of food safety and food standards in the EU and world wide
which helps make sure that all imported food meets the necessary regulations and is safe to eat
FSA helped in the development of food labelling to give more accurate and easy to understand
information to help with the safe storage of food and therefore help prevent outbreaks of food
poisoning
FSA commission research into food related matters so the industry and public are kept up to date
with food safety issues
Link with industry to keep up with technological developments to ensure best methods of ensuring
high standards of quality and safety consumers deserve
Monitoring the composition of food and food labelling and additives
 FSA supports consumer choice through promoting accurate and clear food labelling so helping
consumers understand labelling and so make informed choices eg the traffic light labelling system
 protects the interests of the consumer because it helps consumer by making sure that all food labelling
complies with the appropriate legislation
Advice about the nutrient content of foods and dietary issues
 FSA gives advice to the public on food safety and nutritional matters, therefore raises awareness and
helps to educate the public through leaflets, posters and a web site which has on line experts on
nutrition and health to answer queries
 FSA commissions research into food matters eg on diet habits and labelling to the public are kept up
to date
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DEPARTMENT FOR ENVIRONMENT, FOOD AND RURAL AFFAIRS (DEFRA) and THE
SCOTTISH EXECUTIVE ENVIRONMENT and RURAL AFFAIRS DEPARTMENT (SEERAD)
What does DEFRA do?
The Department for Environment, Food and Rural Affairs deals with a wide
range of issues from climate change and biodiversity to Foot and Mouth and
Common Agricultural Policy. It works for the essentials of life - food, air,
land, water, people, animals and plants.
This department oversees the regulation of the food industries in the UK ,including animal welfare,
safety standards and environmental issues.
DEFRA has roles in both European Union and global policy making, so that its work has a strong
international dimension
The Scottish Executive Environment and Rural Affairs Department (SEERAD)
is the Scottish version of DEFRA.
The aims of DEFRA are as follows:
Sustainable development, which means a better quality of life for everyone, now and for generations to
come including:
 A better environment at home and internationally, and sustainable use of natural resources
 Economic prosperity through sustainable farming, fishing, food, water and other industries that meets
consumers’ requirements
 Thriving economies and communities in rural areas and a countryside for all to enjoy
DEFRA is responsible for :

Protecting and improving the environment eg

improving air quality
promoting an effective and competitive water industry which provides high quality
drinking water
preserving a healthy marine environment
protecting health with controls over the release into the environment of chemicals, GMOs
and radioactive substances
reducing pollution, especially from gases like carbon dioxide emissions that affect the
atmosphere and climate
Development of the economy in rural areas eg
-
making an attempt to reduce rural poverty through the development of the economy
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-

ensuring agriculture contributes to the development of the rural economy
addressing the needs of people living in rural areas. They want to help people in rural
areas to have jobs and money, a sense of community and fair access to transport, housing,
health services, schools and technology such as the internet
Promoting a sustainable, competitive and safe food supply chain which meets consumers’
requirements eg
-
safeguarding the continuing availability to the consumer of adequate supplies of
wholesome, varied and reasonably priced food and drink
- looking at the way food is produced and how it reaches consumers. DEFRA want to
make sure that the people who produce food can make a profit , without damaging the
environment and are therefore encouraging farming processes that do this.
- encouraging the development of local, speciality and other value
products and new product processes

Promoting modern and adaptable farming methods at home and throughout the EU eg
- Contribute to reforming of the Common Agricultural Policy , for example, by finding
ways to prevent future animal, plant and fish disease outbreaks and to help affected areas
to recover
- modernising agriculture to increase competitiveness

Promoting better management and use of natural resources eg
-

cutting down on the amount of waste that is produced.
DEFRA also want to meet tough targets for recycling by encouraging positive
environmental practices such as increasing household waste recycling and
compositing.
Protecting public health in relation to diseases which can be transmitted through food, water
and animals and to ensure high standards of animal health and welfare eg

reducing the risks of future outbreaks of all animal diseases like BSE and Foot and
Mouth
if these diseases do occur, DEFRA ensure that they can control them and are responsible
for putting in place procedures to allow this to happen (both prevention and control)
ensuring that farmed animals and fish are protected by high welfare standards and do not
suffer unnecessary pain or distress
ensuring that as wide a range as possible of high quality, safe medicines are made
available to animals
Within the food industry DEFRA is responsible for giving guidance on a range of foods eg
-
providing guidance and information for egg and poultry producers
providing guidance and information for the new EU beef labelling system
providing guidance and information on EU regulations for the protection of food names
on a geographical or traditional basis eg Scottish shortbread.
providing information on the speciality food and drink sector eg hand made chocolates,
small scale cheese production
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The Scottish Executive Environment and Rural Affairs Department (SEERAD)
SEERAD is responsible for advising the Scottish Government on policy relating to agriculture, rural
development, food, the environment and fisheries, and for ensuring the implementation of those policies
in Scotland
The main aims are:


to help improve the economic performance of Scotland’s agriculture, fishing and food industries
within the wider context of sustainable exploitation of Scottish land, sea and freshwater resources
and rural development, whilst at the same time protecting the interests of the consumers,
protecting and enhancing the environment, and ensuring a fair deal for taxpayers.
To support government ministers in helping the people of Scotland secure a high quality of life
through ensuring there is sustainable development of the natural resources: in particular by
securing a clean, healthy and safe environment, ensuring a safe and effective water industry, and
improving people’s enjoyment of the environment.
SEERAD aims to promote rural development and ensure that the needs and interests of rural Scotland
are reflected in all of the Government’s policies and priorities.
SEERAD ensures that there is effective implementation of the EU Common Agricultural Policy and
Common Fisheries Policy in Scotland. It is also responsible for assisting the development of
agriculture, regulating fish stocks and promoting fisheries conservation measures, for taking action
against plant , animal and fish diseases within the controls of EU single market requirements.
SEERAD also encourages high animal welfare standards on farms and in transport.
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Resource Management
Content
Food Politics
Elaboration
Food/ nutrition and health issues
Implications for health of a poor diet
The benefits to health of a balanced diet is greatly publicised. Scotland has a poor record of health and
much is attributed to our diet (and of course lifestyle). However the Scottish Dietary targets still remain a
guide to improving health through diet
So what are the health benefits of following the dietary target?
Target – Fruit and vegetables
Average intake to double to more than 400grams per day
Implications for health
 Many ways of consuming fruit and vegetables do not involve any or very little quantities of fat in
either preparation or cooking
 Changing diet to include more fruit and vegetables may in turn change ones palate and as a result may
result in a reduction of fatty, sugary foods
 Fruit and vegetables are high in NSP which will be filling and so prevent us snacking on high fat and
sugar foods between meals – this will lesson the risk of tooth decay, overweight, HPB which may
result in CHD or strokes.
 Fruit and veg are low in fat or contain no fat so will assist the overall reduction in fat in the diet and
does not greatly increase calorie intake
 Fruit and veg are low in sugar or so are useful as they do not greatly increase calorie intake which
could lead to overweight
 Fruit and vegetables are a good source of NSP and will help prevent bowel disorders such as
constipation, diverticulitis and possible bowel cancer in later life
 NSP in fruit and vegetables combines with cholesterol and bile salts and reduces the build up of
cholesterol in the blood and helps prevent the cholesterol sticking to the walls of the arteries
 Fruit and vegetables are good sources of anti oxidant vitamins and these have an important role to
play in preventing CHD and cancers. See Antioxidants section for more detail
 Vitamin C will help the absorption of iron especially vegetable sources and so help to prevent
anaemia
 Vitamin A is important for the formation of visual purple which is required to see in dim light
 Potassium in fruit and vegetables will help prevent HBP
 Folic acid – helps prevent megaloblastic anaemia and spina bifida
 Pulse vegetables will supply protein, iron and NSP in the diet
Target- Bread
Intake to increase by 45% from present daily intake of 106g using mainly wholemeal and brown breads
Implications for health
 Bread, especially those high in NSP, will be more filling and so reduce the need to snack on high fat
and sugar foods with the possible risk of obesity, HBP and CHD.
 Bread could contribute to a reduction in obesity, due to the fact that it is a filling food, but this would
depend on the spread or filling used
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Bread is a good source of NSP and will help prevent bowel disorders such as constipation,
diverticulosis and possible bowel cancer in later life
NSP combines with cholesterol and bile salts, so preventing the cholesterol from being absorbed –
reducing the risk of CHD
Bread is a good source of calcium(fortified) – important to work alongside phosphorous to form
calcium phosphate – provides the strong structure to bones and teeth
Bread is a good source of Vitamin B complex – required for release of energy from food
Bread can be fortified with iron, folic acid and Omega 3
Target - Fats
Average intake of total fat to reduce from 40.7% to no more than 35% of food energy
Average intake of saturated fatty acids to reduce from 16.6% to no more than 11% of food energy
Implications for health
 Concentrated source of calories which, if not used up through activities, will contribute to overweight
with a possible link to HBP which then may lead to CHD
 Excess weight may also lead to HBP which could lead to strokes
 Diets high in saturated fats will raise the level of cholesterol in the blood – this cholesterol then
deposits on the walls of the arteries and so narrows the arteries. This restricts the blood flow which
can lead to HBP which may lead to CHD and heart attacks
 Trans fatty acids are as harmful as saturated fats. These type of fats are found in processed foods eg
margarine, biscuits and they cause an increase in cholesterol in the blood and increased risk of heart
disease
 Excess weight gained through eating too many fats can cause complications during operations eg
blood pressure can rise and so increasing risk of a heart attack
 Excess weight also adds to problems during pregnancy eg HBP and increased risks during child birth
 Choice of foods lower in fat such as fat reduced products and choice of cookery methods would help
lower fat content of the diet.
Target – Sugar
Average intake of NME sugars in adults not to increase
Average intake of NME sugars in children to reduce by half ie to less than 10% of total energy
Implications for health
 Sugar provides calories which if not used up through activities may contribute to obesity and this in
turn may result in HBP and CHD
 Sugar is known as “empty calories” as it contains no other valuable nutrients. If sugar is eaten a lot
then other nutrients may become deficient eg vitamins from fruit and veg etc
 A “sweet tooth” may develop especially in childhood which may be difficult to break in later life –
cravings for sugar may develop and become addictive in nature therefore difficult to break down
 Bacteria may feed on the sugar deposits on teeth and so produce acid which will destroy the enamel
on teeth
 High intakes of sugar may result in the development of type 2 diabetes – diabetics are at more risk of
CHD
 Overweight children often become overweight adults
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Target- Salt
Average sodium intake to reduce from 163mmol per day to 100mmol per day
Implications for health
 High salt intakes are linked to HBP with increased risk of CHD
 High intake of salt can lead to loss of calcium from the bones so increased risk of osteoporosis
 Thought to be linked to increased risk of stomach cancers
 Some research has linked high salt consumption to the development of Altzheimers disease
Target- Total Complex carbohydrates
Increase average non-sugar carbohydrates intake by 25% from 124 grams per day, through increased
consumption of fruit and vegetables, bread, breakfast cereals, rice and pasta and through an increase of
25% potato consumption
Implications for health
 Complex carbohydrates, especially those high in NSP, will provide bulk in the diet and prevent
snacking on high fat and sugar foods with the possible risk of obesity, HBP and CHD
 Complex carbohydrates are a good source of NSP and will help prevent bowel disorders such as
constipation, diverticulitis and possible bowel cancer in later life
 Provides a steady supply of energy helping blood sugar levels to remain stable thus preventing
snacking on high fat foods
 Increasing the proportion of starchy carbohydrates eaten with meals will reduce the need to serve high
fat foods to make meals more filling
Target- Breakfast cereals
Average intake to double from the present intake of 17grams per day to 34g
Implications for health
 Consumption of breakfast cereals reduces the need to snack on high fat or sugar foods during the
morning. Breakfast ensures energy is provided during the morning and, for children, helps
concentration in school
 Breakfast cereals are fortified with many vitamins and minerals each with a specific function in the
body
 Milk is usually consumed with breakfast cereals and so gives a good source of calcium, needed
especially by children for bone formation
 Breakfast cereals are low in fat and some are good sources of NSP which will help prevent bowel
disorders such as constipation, diverticulitis and possible bowel cancer in later life.
Target – Fish
White fish consumption to be maintained at current levels
Oil rich fish to be doubled from 44g per week to 88g per week
Implications for health
 Oily and white fish are a sources of protein – needed by children for growth of new cells and tissues
and repair of damages cells by children and adults alike.
 Oily fish are a source of essential fatty acids – omega 3 – which plays a role in keeping cholesterol
levels down
 Omega 3 can also help the blood flow more easily around the body making it less “sticky” and less
likely to clot
 Fish oils can reduce inflammation and provide relief for sufferers of rheumatoid arthritis
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Fish oils can help some skin conditions eg psoriasis
The intake of oily fish during the last 3 months of pregnancy is believed to assist the development of
the child’s brain and retina
Fish (when the bones are eaten) are a good source of calcium – important to work alongside
phosphorous to form calcium phosphate – provides the strong structure to bones and teeth
White fish contains only a little oil, therefore is helpful to weight control. Careful choice of cooking
method eg grilling, steaming will also reduce fat content
Oily fish are a good source of Vitamin A - an anti oxidant vitamin and needed for the development
of visual purple (vision in dim light)
Oily fish are a good source of Vitamin D – to assist the absorption of calcium
All fish are good sources of the B group of vitamin- release of energy and proper functioning of the
nervous system
Target – Breast feeding
The proportion of mothers breastfeeding their babies for the first 5 weeks of life should increase to more
than 50% from the present level of around 30%
Implications for health
 Will help the mother loose weight after childbirth and so help prevent diseases associated with
overweight eg HBP, varicose veins, diabetes, CHD etc
 Ensures the child receives a good balance of nutrients – breast fed babies are less likely to be
overweight
 Gives immunity to disease to babies through the anti bodies from mother. Breast fed babies are less
likely to develop asthma.
 Research has indicated that breast fed babies are less likely to become obese in later life, and give
protection against diabetes and asthma.
 Protects the mother against breast cancer
 Reduces risk of baby developing gastrointestinal and respiratory illnesses in infancy
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Resource Management
Content
Elaboration
Food Politics
Food, nutrition and health policies in Scotland
The Scottish Diet Action Plan was implemented in 1996 at a time when Scotland had a poor record of
diet related health. The aim of the dietary targets was to reduce diet related mortality and morbidity in
Scotland, particularly related to diseases such as heart disease, cancer , diabetes and obesity.
The Scottish Dietary targets
The dietary targets form a framework for tackling the long standing deficiencies in the Scottish diet
Fruit and
vegetables
Bread
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Breakfast cereals
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Fat
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Salt
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Sugar
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Total Complex
Carbohydrates
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Fish
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Breast feeding
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Dietary Targets
Average intake to double to more than 400grams per day
Intake to increase by 45% from present daily intake of
106g using mainly wholemeal and brown breads
Average intake to double from the present intake of
17grams per day to 34g
Average intake of total fat to reduce from 40.7% to no
more than 35% of food energy
Average intake of saturated fatty acids to reduce from
16.6% to no more than 11% of food energy
Average sodium intake to reduce from 163mmol per day to
100mmol per day
Average intake of NME sugars in adults not to increase
Average intake of NME sugars in children to reduce by
half ie to less than 10% of total energy
Increase average non-sugar carbohydrates intake by 25%
from 124 grams per day, through increased consumption of
fruit and vegetables, bread, breakfast cereals, rice and pasta
and through an increase of 25% potato consumption
White fish consumption to be maintained at current levels
Oil rich fish to be doubled from 44g per week to 88g per
week
The proportion of mothers breastfeeding their babies for
the first 5 weeks of life should increase to more than 50%
from the present level of around 30%
The report - “Review of the Scottish Diet Action Plan 1996 – 2005” produced in 2006 evaluated
progress with implementing the Scottish Diet Action Plan (SDAP). Four areas of the SDAP have been
identified as achieving some success
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Improved breast feeding rates
Improved food and diet in schools
Community food initiatives
Health education resources and marketing campaigns
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Despite these successes in delivering the SDAP, Scotland is still failing to meet its dietary targets. The
dietary trends identified in the report show:
 An increase in the amount of fruit and fruit juice consumed but a reduction in the amount of
vegetables eaten
 No improvement in intakes of bread, breakfast cereals and both white and oily fish
 Consumption of bread (total and brown / wholemeal bread) fell over the past 10 years instead of
increasing by 45% and the consumption of potatoes fell by 25% instead of increasing by 25%
 The impact of changes in food intakes on nutrient intake targets was also small, with a slight
reduction in fat consumption as a percentage of food energy ( but still in excess of the 35%
recommended by the dietary targets)
 An increase in the amount of energy provided by NME sugars instead of a decrease.
 The consumption levels of the “healthy” foods targeted to increase are significantly lower in the
most deprived groups of the population
Reasons why the dietary targets are not being met in Scotland
Access to Shops
 Availability of fresh food eg fruit/veg/fish/healthier products in local shops at a suitable price is
often a problem – the more expensive local corner shop may often still be the main supplier of
basic food items for the elderly, lower income groups and those living in areas of high deprivation
 Fresh food e.g. fruit and vegetables in local shops can often be poorly displayed and of poor
quality so people are less likely to purchase
 Poor storage facilities in such shops means fresh fruit and vegetables deteriorate more quickly
meaning both loss on nutrients and less availability of ‘quality’ foods. Also as they may be
considered expensive, money will not be spent on them as they go off quickly
 Local shops tend to sell a higher proportion of lower cost, longer lasting convenience foods which
can be higher in fat, sugar and salt. Access to fresh produce such as fruit and vegetables may be a
problem so consumption is lower
 Often poorer selection in local shops, especially of lower fat/sugar varieties, fruit and vegetables
so less motivation to buy these products
 Large supermarkets may have a wide range of high fat/sugar foods which are tempting and
encourage consumption
 Person doing the shopping will dictate quantity and type of food purchased fruit and vegetables –
choice may be limited by their purchase. High fat foods may be purchased depending on the
shopper’s priorities
Poor Housing and Poverty
 Financial situation of the family will heavily influence the eating experience at home
 Poor housing and limited finances often equate with poor cooking facilities so convenience foods
are used more often and fruit and vegetables are avoided
 Less incentive to prepare fresh foods when facilities are poor so more reliance on prepared
convenience foods which may higher in fat, salt and sugar
 Healthy options and fruit and vegetables which can be more expensive, or perceived to be , do not
sell well in deprived communities Healthier options can often be more expensive especially for
low income groups
 Cost or perceived cost of fruit and vegetables will affect the range eaten. Prepared packs of fruit
and vegetables may be expensive even though they are useful for those who lack food preparation
skills
 Unable to produce homemade foods if food preparation and cooking facilities poor
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Varying priorities within families – TV’s, videos may all take precedence over a healthy diet
Fear of wasting food if healthier options, fresh fruit and vegetables are tried and not liked
especially if income is limited
Fresh foods have a limited shelf life therefore are more prone to waste
Limited family income may mean cheaper less healthy options are chosen. Fatty foods are filling,
cheap – important if budget is limited
Education/Knowledge
 Wording of dietary targets are confusing, making it difficult for general public to know what
they are supposed to be eating, and how much to meet each target
 Lack of appropriate education/practical skills means people do not know what or how to change,
nor do they have the confidence to try new foods and cooking methods eg preparation and
cooking of some fruit and vegetables
 Lack of skills/knowledge may result in a reluctance to prepare fresh foods such as fruit and
vegetables. If skills are limited and both parents working, less time and ability to pass on practical
skills from one generation to another, thus exacerbating the issue of poor diet
 Poorer educational standards may in turn mean less access/understanding of potential health
problems which could occur due to poor diet ,for example, in relation to fat or fruit and vegetable
consumption
 May have good knowledge but not the financial resources to change
 Sense of ‘it’ll not happen to me’ with regard to illness and disease especially with teenagers who
do think about the effect that poor diet will have on them in later life.
 Labelling is still confusing to many consumers so many find it difficult to make an informed
choice – unaware of “hidden” fats and sugars.
 Promotion of many foods as healthy – only 10% fat - leads to confusion and lack of
understanding and so increase consumption of less healthy foods
 Many people distance themselves from healthy eating messages as they think they eat healthily
already. The link between knowledge and practice is poor. For example, people know to eat 5
portions of fruit and vegetables per day but many are not doing this
 Effectiveness of the healthy eating message/publicity campaign re fruit and vegetables is poor .
There is a lack of awareness that frozen vegetables, particularly bulk buying, is cheaper and just as
nutritious as fresh.
Media/advertising
 Promotion of convenience foods appeal to those with limited finances as waste is minimal
 Promotion of foods eg buy one get one free, which are often high in fat, sugar and salt far exceeds
that of ‘healthier’ options so consumers persuaded to follow a poor diet
 Lack of fruit and vegetable advertising – strong advertising for less healthy choices and snacks
 Many adverts for foods high in fat, sugar and salt are directed at children so poor eating habits are
encouraged from an early age and therefore difficult to change in later life.
 Mixed and ever changing messages from the media make it difficult to know what to eat and
what not to eat.
Climate
 Scotland’s colder climate encourages consumption of high energy comfort foods.
 Many fruit and vegetables cannot be grown in Scotland due to the climate. This restricts the range
and if fruit and vegetables are transported or imported, this adds to the cost.
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Time/lifestyle
 Increased use of convenience foods high in fat, sugar, salt due to lack of time for food preparation
 Many people work longer hours so do not have the time nor inclination to prepare own ‘healthy’
foods or fresh fruit and vegetables. (vegetables are often seen as difficult or time consuming to
prepare)
 The shift from eating 3 ‘good’ meals a day to ‘grazing’ making it easy to consume snack foods
which may be of poor nutritional quality rather than cook from “scratch” using fresh foods.
 Few families sit down and eat meals together so several convenience foods may be used at
different times to suit the needs of individual family members
 Changing role of women is a contributory factor in the reduction of practical food preparation
skills which were previously passed from one generation to another. This may have a knock on
effect – increased use of convenience foods and decreased use of fresh foods like fruit and
vegetables
 Increased disposable income where 2 parents working may increase consumption of take away
foods or other foods eaten outwith the home which may be high in fat and salt and low in
vegetables.
 Increased range of fast foods, takeaways and eating out more may be available to those who
have financial resources and so fat, sugar and salt consumption may rise as consumers have no
control over the type or quantity of ingredients used.
Food industry /Manufacturers
 Basic training in nutrition for those working in the food and hospitality industry could improve
 Slow progress at adapting products to make them “healthier” and those products available are
often more expensive and the change in taste may make them less acceptable to consumers
 The food supply chain has not been fully engaged with the need to change to produce more foods
containing fruit and vegetables, lower fat content etc and health messages are often undermined by
powerful marketing and advertising of less healthy food and drinks
 Large chains of supermarkets control much of what is eaten by British families by promoting and
stocking particular types of foods, often large quantities of convenience foods which can be higher
in fat, sugar and salt and this can sometimes mean a more limited stock of fruit and vegetables
 The target for fruit and vegetables has not been embedded in any of the policies or into any of the
Scottish executives policies on agriculture and farming (apart from the Berry project) so consumer
demand for fruit and vegetables has not been stimulated
Cultural conventions
 Poor diet in Scotland is now a historical fact with many high fat foods consumed and consumption
of fruit and vegetables low – difficult to change eating habits and many are unwilling to try
different fruit and vegetables
 Pressure on people in rural areas to change to a diet high in convenience foods –and to move away
from growing their own produce such as vegetables
 Eating habits are passed down through generation so individuals learn to like the food that had
been prepared by their parents. Watching what their parents eat can set patterns of food
consumption for children which are detrimental to health and difficult to change in later life
 Difficult to encourage children to eat foods such as fish, fruit and vegetables – parents do not
always persevere and as a result food dislikes can be formed at an early age
 Sweet consumption is often encouraged and given as a reward by parents, grandparents etc
Consumer attitudes
 Motivation and willingness to change food eating habits may be lacking
 Some consumer’s have a dislike of government intervention – people don’t like being told what
to eat
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Some consumers value other priorities before healthy eating
Some men do not see fruit and vegetables as filling and will prefer more energy dense foods.
Foods in school
 Although school meal, tuck shops and vending machines in schools offer healthy products, these
may be ignored by pupils in favour of less healthy products from local shops
 All pupils may not take advantage of free fruit available in primary schools but it may encourage
increased consumption if pupils have fruit available in the home
Personal Factors
 Personal likes and dislikes – many children are unwilling to try different vegetables
 Fat, sugar and salt are important in the flavour of foods – these foods are desirable so contribute
to health problems
 Appearance of foods – attractively presented foods are more likely to be appealing
 Peer influences, especially teenagers, often discourage eating fruit and vegetables.
CHANGING FOOD HABITS
People who eat a poor diet are more likely to suffer from serious health problems which in turn is placing
the National Health Service under increasing strain. A healthier attitude towards food is an important
factor to develop starting in early childhood.
Despite increasing publicity given to the increasing rates of obesity, cancers, diabetes and premature
death causes by poor diet, many young children and teenagers continue with little regard to the high fat,
sugar and salt diets that are popular with these age groups
There is little doubt that children, parents and schools need to be educated and work together to change
habits to eating patterns.
So why are children resistant to changing their food choices?
The following factors may particularly influence children’s food choices.
Peer pressure
 Peers – children are very conscious of being part of a gang so copy cat behaviour is very common,
similarly being seen to be different i.e. making healthy choices may cause ridicule. However peer
pressure could also have a positive influence on food selection
Parents
 Their eating habits are passed on to their children and children learn to like foods made by
parents. Parents should set a good example themselves
 Mother or the person doing the shopping is usually most involved with the provision of food and
so is the main influence on food choice.
 Parents may want their children to be healthy so may buy products lower fat, sugar, salt and high
in vitamins to help develop a taste for these versions
 Financial situation of the family may mean that foods consumed at home are limited, these limited
choices may be a reason for similar unhealthy choices at school. The financial situation of the
family will heavily influence the eating experience at home.
 Children may be unwilling to try new healthy options of they have not seen and tried them at
home
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Buy a range of fruit and vegetables to have at home so the choice is there. By putting the fruit
bowl at children’s height, they could access it easily and so increase consumption
Introduce new foods gradually to increase the range of flavours and foods eaten
Change cooking methods to provide healthier foods, these will soon become more familiar and
hopefully preferred
Breast feeding babies introduces their palate to a broader range of foods at an earlier age and has
been shown to increase fruit and vegetable consumption in later life
Provide ‘healthy ‘ lunch boxes Make fruit/veg a daily addition to lunch boxes
Encourage children to eat a good breakfast every day
Make meals at home filling to reduce snacking between meals
Encourage children to get involved in cooking and understanding food at home
Reward healthy food choices e.g. sticker scheme. Avoid the use of rewards which focus on
unhealthy foods eg trips to fast food outlets, sweets
Do not have fatty /sugary snacks readily available at home. Start providing healthy options when
children are very young, it can even be too late once they are toddlers to change some eating
habits
Encourage children to choose the fruit and vegetables when shopping
Mix variety of fruit and vegetables into dishes such as pizza, macaroni/pasta
Teenagers may be left to make their own meals and as skills and knowledge may be limited, poor
choices may be made.
Media/promotion
 Advertisers target young people in their adverts for fatty, sugary products, this is a very powerful
medium and hard for children to resist
 Some foods are promoted as if they are healthy - such promotion aimed at children is difficult for
them to decode, so they may actually think they are making a healthy choice
 Media – advertisers target young children by using TV characters to sell foods
 Promotions – children easily attracted to free gifts/toys very often offered by fast food chains
 Supermarkets – where foods are places – shelf height, end of aisle promotions – children notice
foods and pester parents to buy them
 Introduction of ‘healthy eating ranges’ specifically for children, may encourage healthier choices
 Promotional characters or films are used to encourage children to buy the food products
 Music/film/sports stars are all used to promote foods to children – this is a very powerful medium
 Image created round a food to make it appear “cool” to eat the product
 Images in magazines and films portray specific body types which may influence eating habits,
possible adversely
See also Section : Psychology of food : Role /influence of the media
School
 No one encourages children to make healthy choices at lunchtime. At this age, if wise decisions
are to be made, guidance is needed
 Choice available in school may be limited so children use the local shops to buy high fat/ sugar
foods. If the school is near chip shops and cafes, temptation to buy foods from these may prove
irresistible
 Pupils may prefer to ‘escape’ from the school environment to eat elsewhere, choosing to eat
unhealthy foods. Local shops and cafes provide quick, cheap alternative lunches in surroundings
which appeal to pupils but which may not always provide healthy choices
 Vending machines in schools provide healthy options but children may bring in their own snacks
from home or bought on he way to school – these may not always be healthy
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School can teach children positively about food, nutrition and health. Practical skills taught in
school may encourage children to have an interest in preparing fresh foods
School meals may introduce children to new foods not offered at home
Home economics lessons may introduce children to new foods and teach them skills to enable
them to prepare their own foods
Breakfast clubs may promote a healthier start to the day and help reduce snacking
Free fruit in primary may help encourage a greater consumption of fruit
Personal Factors
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Personal likes and dislikes or perceived personal likes and dislikes
Personal like/dislikes – high fat foods such as chips, sausages roll appeal to children’s taste
buds/provide a quick, satisfying fix
Many children prefer the taste of sweet snacks such as cakes and biscuits to fruit and so make that
choice instead of choosing fruit which can be more awkward to eat
Children like the familiar and may be unwilling to experiment with new foods, particularly if
money is limited as they may not then be able to afford an alternative
Habits form easily, children often choose the same thing every day and are unwilling to change
Many of the unhealthy snack foods are easy to eat and can be eaten on the go
Allergies to specific foods
Appearance of the food itself, e.g. attractively presented foods are more likely to be appealing
Amount of money available – both personally and in the home will influence the foods the
child/family can buy. If teenagers work then they will have their own money to spend as they wish
Boredom leading to snacking leading to poor eating habits
Health
 Difficult for children to relate their health as an adult with what they eat as a child, the time scales
are to great
 Some may make very positive food choices due to sporting interests or the desire to look good.
Culture
 Association of foods with events e.g. Christmas
 Types of foods offered outwith the home e.g. friends homes may influence the range of foods they
are willing to eat
 Experiences of foreign holidays may make children confident to try new foods at home
 Ethnic background may influence foods prepared at home
 Religion may prohibit the consumption of specific foods
SCHOOLS
Schools can make a valuable contribution to improving the nutritional quality of children’s diets and
promoting consistent messages about healthy eating within a health promoting schools environment.
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HUNGRY FOR SUCCESS
(A Whole School Approach to School Meals in Scotland )
This was a document in which the Scottish Executive set out to revitalise school meal services in
Scotland – linking school meal services with the curriculum, health education and health promotion. For
the first time in the UK, national nutrient- based standards for school lunches were stated.
The Hungry for Success document was intended to improve the diet of Scottish school children which
causes concern due to high intakes of fat, sugar and salt.
The reasons for implementing this initiative was to include :
 The very best of health, education and social justice for all Scottish school children
 To provide attractive and nutritionally balanced meals for all school children
 To provide an eating environment for school children that is welcoming, comfortable and fun
The recommendations of the publication were linked to the Scottish diet action plan and dietary reference
values.
The Schools (Health Promotion and Nutrition) (Scotland) Act 2007
The Nutritional Requirements for Food and Drink in Schools (Scotland) Regulations 2008
The Schools (Health Promotion and Nutrition) (Scotland) Act 2007 and the Nutritional Requirements for
Food and Drink in Schools (Scotland) Regulations 2008 build on Hungry for Success and requires local
authorities to ensure that food and drink provided in schools comply with the nutritional requirements
specified by Scottish Ministers by regulations
The Act makes health promotion a central purpose of schooling. A school is health promoting if it
provides activities and an environment which promote the physical, social, mental and emotional health
and well being of pupils.
The Act gives Scottish Ministers the power to set nutritional requirements for food and drink in schools
by Regulations. The Nutritional Requirements for Food and Drink in Schools (Scotland) Regulations
2008 explains the nutritional requirements and provides guidance on how to comply with them.
The Regulations are broken down into two parts:
1. Two sets of standards for school lunches:
 Nutrient standards which set out the proportion of nutrients that pupils should receive from an
average day’s school lunch
The statutory nutrient standards for school lunches have been calculated to ensure that the school
lunch provides a third of the daily nutritional requirements of primary and secondary school
pupils. The nutrient standards represent the amount of energy(calories) and key nutrients
required to be provided by an average day’s school lunch
For some nutrients a minimum levels have been set. This includes- protein, total carbohydrate,
fibre, iron, calcium, vitamin A, vitamin C, folate and zinc.
For other nutrients a maximum level has been set. This includes total fat, saturated fat, non milk
extrinsic sugars and sodium
 Food standards and drink standards, which define the types of food and drinks that pupils
should be offered in a school lunch and their frequency as well as setting nutritional requirements
for specific types of food and drinks which may be provided.
Food Standards – main points
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Fruit and vegetables
Oily fish
Variety of extra bread
Oils and spreads
Deep fried foods
Table salt and other
condiments
Confectionery
Savoury snacks
A choice of at least two types of vegetables and two
types of fruit (not including fruit juice) must be provided
every day as aprt of the school lunch
Must be provided at least once every three weeks
Additional bread must be provided every day as a meal
accompaniment, with a variety of bread, which must
include brown or wholemeal, being provided over the
week
Only oils and spreads high in polyunsaturated and/or
monounsaturated fats can be used in food preparation
Menus must not contain more than three deep fried items
in a single week(including chips). Chips, if served, must
be part of a meal
Additional salt cannot be provided
Condiments (if provided) must be dispensed in no more
than 10ml portions
No confectionery can be provided
No savoury snacks can be provided except savoury
crackers, oatcakes or bread sticks
Drink standards
The only permitted ar plain water, skimmed/ semi skimmed milk and other lower fat milks, milk
drinks and drinking yoghurts, soya, rice or oat drinks enriched with calcium, tea and coffee, fruit
juices and vegetable juices, blended drinks or fruit, vegetables, fruit juice or vegetable juice, water
and fruit/ vegetable juice combination drinks. Several of these drinks have also to meet specific
criteria with regard to sugar and/ or fat content
2. Food and drink standards for school food and drinks served outwith the school lunch eg breakfast
clubs, tuckshops, vending machines, mid morning services, community cafes and after school clubs.
These food outlets must follow the drink standards which apply to school lunches. A variety of fruits and
/ or vegetables, savoury snacks with reduced amounts of fat, saturated fats, sodium and sugar in packs of
no more than 25g may be sold. No confectionery is allowed.
To further improve the eating habits of children, a “whole school approach” should be used in the
following ways
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Essential that healthy eating messages taught in the classroom are backed by foods on offer in
school otherwise messages become confusing
Eating well needs to be part of everyone’s life – if children eat differently at school this could
affect food choices out of school and the food choices of entire families
Breakfast clubs, if available, must back up messages taught in the classroom
After school clubs must provide children with nutritious, filling snacks to reinforce messages
The introduction of promotional schemes to facilitate healthy choices
Caterers must back agreed healthy eating messages and not overtly promote unhealthy choices
over healthy.
Senior managers/dining hall supervisors,dinner ladies/men should be aware of healthy eating
messages and encourage healthy choices
Pupils and staff must be allowed to comment on school meals in a meaningful and constructive
way
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Incentive schemes could be used, e.g. pricing, competitions, to encourage healthy choices
Links between biology and nutrition could be used to promote the value of foods
Links between PE and foods could be linked via sports nutrition
Home economics departments have a vital role to play in providing pupils with the skills and
knowledge to prepare healthy, nutritious foods
Home Economics departments can link with school meals supervisors to promote good choices at
lunchtime by using the curriculum, competitions, food tasting etc.
Involvement of parents vital to the improvement, they must be on board, educated and well
informed
School board/PTA could help organise educational activities and leaflets for parents regarding
healthy choices
Community dieticians could be used to bridge the gap between home and school
Joint projects between health centres and schools could help reinforce messages
Reduction in the use of sweets as prizes at school activities
Have a clear whole school policy regarding nutrition at school to include:
Development and education of all school staff to promote the healthy eating initiative
Consultation and involvement of pupils at all stages of policy development and implementation to
ensure their views are heard
Use of School Nutrition Action Groups or Food Focus groups to promote whole school health
and nutrition
Health weeks and health promoting events will encourage interest as would use of local
‘celebrities’ to promote healthy eating
Local authority involved in training food providers about healthy eating
Positive incentive to encourage pupils to stay and eat in school to try and discourage those who
eat out of school
School trips organised with thought given to food eaten to ensure they meet schools nutrition
policy
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Resource Management
Content
Food Politics
Elaboration
Food, nutrition and health policies in
Scotland
To help individuals improve their diet, different sectors of society have a role to play.
Primary Producers
 Stimulate demand for fruit and vegetables by means of innovative, developmental initiatives and
imaginative marketing campaigns
 Encourage the breeding of leaner livestock for human consumption to reduce fat
 Consumer demand for oil rich fish should be promoted
 Promote the consumption of local grown fresh fruit eg raspberries through farm shops, pick your
own, farmers markets.
 Organic farming now producing an increasing range of fruit and vegetables so encouraging fruit/
vegetable target. Many local farmers deliver boxes of organic vegetables to households
Manufacturers and Processors
 Weaning and infant food manufacturers should work towards producing products free of, or low
in, non-milk extrinsic sugars.
 Nutritional training should be available for the food manufacturing, processing and bakery
industries.
 Information on the composition and nutritional values of food products (labelling) should be
presented in such a way as to facilitate consumer understanding of them and to allow informed
choices to be made.
 Manufacturers also use celebrities to promote some times unhealthy products to encourage
purchase
 Small but progressive reductions of fat, salt and sugar content of products should be undertaken
by manufacturers to encourage a change in consumers palates.
 Manufacturers have made attempts to meet the demands of health conscious consumers and the
dietary targets through a number of developments. They are trying to:
Reduce fat
- In response to consumer demands for “slimming” products, manufacturers have developed
products(fat replacers) which act as substitutes for the fat content to reduce the energy value of
ready meals
- Manufacturers can reduce the saturated fat content of ready meals to suit consumers wishing to
lower blood cholesterol levels or to reduce concerns about coronary heart disease
- Manufacturers have increased the range of products using quorn, tofu and soya which supply
consumers with a low fat source of protein
- Use of oils/fats which have a lower quantity/percentage of saturated fats and a proportionately
higher amount of unsaturated fats
- Reduction in the amounts of fats/oils found in ready made foods e.g. reduced fat meals.
- Use of lower fat ingredients in products and reduced fat versions such as low fat dairy products
Reduce sugar
- Breakfast cereals, biscuits and desserts have reduced sugar claims
- Reduced sugar products ef fruit can be tinned in natural juice or in apple juice, reduced sugar jam
- Sugar substitutes or artificial sweeteners are being used by manufacturers in ready meals in
response to consumer demand for low sugar / energy products particularly for those consumers on
weight reduction diet or concerned about dental decay.
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Natural sweeteners, such as dried fruit, can be added to some baked products to increase
acceptability and assist in reducing NME sugars
Reduce salt
- Manufacturers are reducing salt, by the use of spices and herbs in ready meals in
response to consumer concerns about the link between hypertension and salt
intake
Increase total complex carbohydrates
- Manufacturers are incorporating more wholegrain ingredients into ready meals to satisfy
consumer demand for products high in NSP.
- Manufacturers have increased the amount of NSP in foods, e.g. white bread with added NSP, used
both white and wholemeal flours together and adding oatflakes to bread, in an effort to encourage
consumers to eat more bread.
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A range of prepared rice and pasta products with vegetables is on offer not only for vegetarians
but for those who wish to go part way to meeting this dietary target. These products are a
convenient and easy way for consumers to increase their consumption, especially if they are
unsure of how to cook these foods from scratch.
Fruit and vegetables
Manufacturers are incorporating more fruit and vegetables into ready meals to satisfy consumer
demand to increase fruit and vegetables intake
Prepared vegetables, mixed salads available in chilled conditions on supermarket shelves,
therefore saving the consumer time and effort for peeling and preparation
Bread
Manufacturers now produce a wide range of speciality bread that encourage consumers to eat
more bread
Bread has been produced with added grains and NSP. These will still appeal to children because
they are white and therefore encourage consumption
Manufacturers produce part baked breads which can be baked and served hot in the home. This
may encourage consumption
Breakfast cereals
There is an increasing range of breakfast cereal and products such as breakfast bars, cereal bars,
yoghurts with breakfast cereals and individual servings in packets Breakfast cereals have added
NSP and reduced-sugar claims in order to increase consumption.
Fish
White fish, which contains very little fat is often used in “low fat” ranges of prepared dishes
Oily fish , such as tuna, is made into ready meals such as tuna and pasta bake, tuna pate, tuna
canned in brine or tinned in savoury sauces for snacks
Because fish is easily and quickly cooked many manufacturers include fish dishes in their
microwaveable, “steam cuisine” and chilled ranges. These require little additional preparation
therefore making it easier for the consumer
The Retail Sector
 Supermarkets should further develop innovative way, including in-store initiatives, of marketing
healthy products to consumers eg tasting of new products and price reductions
 Ensure that “own brand” products sold in stores provides easily understood information on
product composition and nutritional value to enable consumers to make healthy choices.
 Put in place measures, such as free, low cost, transport, to facilitate access to their stores by low
income consumers within the community.
 In store cafes should encourage healthy choices / ranges
 Health promotion campaigns in stores
 Improvement in presentation of the fresh fish counter to encourage purchase
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Mother and baby rooms to encourage breast feeding
Loyalty card schemes could encourage healthy purchases through coupons
Community Action
 Health Boards should have designated, nutritionally trained staff with specific responsibility for
action to improve the diet of low income communities in their areas..
 Consideration of the dietary needs of local populations should undertaken by local authorities
when developing strategies for regenerating their deprived areas eg placemen of supermarkets .
 Community initiatives such as community cafes , cookery classes to teach basic skills
NHS
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Health Boards should ensure that their health promotion activity includes regular campaigns to
alert potential parents of the need for good nutrition prior to, as well as during pregnancy
GPs, obstetricians, midwives and health visitors should provide dietary information to expectant
mothers about their own nutritional needs as well as those of their babies. Health Boards should
monitor the quality of the information so provided.
Health boards should continue to encourage the achievement of local breast-feeding targets.
Anti and pre natal classes could influence on diet of mother and child and also encourage the
target of breast feeding
Should ensure that the catering service in all NHS establishments meets guidelines.
Sufficient public health nutritionists or suitably experienced state registered dieticians should be
appointed by health boards.
Education
 Education sector should examine the potential to include material on the benefits of breastfeeding
in order to inform pupils.
 Health professionals, residential and day care staff with care responsibilities for children under
five should have a working knowledge of the dietary and nutritional needs of young children.
 Special initiatives to encourage children under five to eat healthily should be explored by local
authorities, including the possibility of employing dieticians to provide advice and support to
families with young children.
 HMIe nutrition advisers inspect all aspects of food provision in schools.
Caterers
 Should work progressively towards providing a variety of vegetables and/or side salad as part of
the main course of every meal. The cost should be included in the price of the meal. Caterers to
look at the portion size – may need to increase the quantity of vegetables and complex
carbohydrates
 Nutrition and dietary education should be a strong focus in the curriculum of all hotel and catering
management courses.
 Fast food sector should broaden range of nutritionally beneficial foods on offer and reduce the fat
content of standard products as much as possible.
 Nutritional guidelines should be issued to all catering staff and all catering staff should have a
basic level of training in nutrition and diet.
 In 2009 a pilot scheme will operate where fast food and café chains will start displaying calorie
counts on menus. However the menus will not give information on fat, sugar and salt content of
meals
 The Scottish Office should ensure that public service catering sector should reflect balanced
nutritional guidelines.
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Awards such as the National Healthy Eating Award Scheme / Healthy Choices should be
encouraged
Fast food outlets which are popular with teenagers should introduce healthy options otherwise fat
intake will increase
The Scottish Tourist Board should consider ways of incorporating nutritional advice within its
campaign to raise catering standards throughout Scotland.
Local Authorities
 The potential for local authorities to maximise the promotion of healthy eating should be explored
eg by issuing the contract to catering companies who supply school meals.
 Many local authorities have initiatives to improve eating habits eg food co-operatives, cookery
classes
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Resource Management
Content
Food Politics
Elaboration
The impact of nutritional/health, cultural,
social, economic and environmental factors
(eg Fair Trade) on food availability,
selection and consumption patterns
Food Availability, selection and consumption patterns
Information about food and its effect on health is plentiful and yet some people continue to ignore
health information and continue to eat foods that may lead to health problems. Conversely others will
take the same information and commit to a healthier diet. Factors such as nutritional/health, cultural,
social, economic and environmental factors affect food availability, selection and consumption
patterns and in many cases these factors overlap.
1. NUTRITIONAL and HEALTH FACTORS affecting availability, selection and consumption
pattern
Nutritional Knowledge
 Food selection will be influenced by knowledge of the nutritional content of
foods and the effect on health . If people believe that changes to diet will lead to
positive health results they are more likely to heed information about the link
between food choices and the risks for diseases such as heart disease and cancer.
 Nutritional labeling on food may not be easily understood by some consumers so may not assist
them to make healthy choices. However manufacturers are trying to, through simplified food
labeling such as traffic lights and Guideline Daily Amounts, give consumers clearer information
on the nutritional content of food.
 There is an increased interest and awareness in the health benefits of foods and of “healthy eating”
. Availability of a number of prepared products has considerable increased in the supermarket
such as :
- Low or reduced fat options available because of the number of people who want to lose or who
are concerned about the type of fat they are eating
- Low sugar foods for people who are interested in reducing sugar intake
- Low salt foods who are interested in reducing intake of salt
 Healthy eating trends have led to the production of a range of functional foods, for example some
with cholesterol lowering claims
Health influences
 Health factors which affect the choice of food can be linked to dietary related diseases and food
allergies or intolerances.
 An unbalanced diet can result in a variety of dietary related diseases such as heart disease,
obesity, diabetes etc
 Increased risk to health in adults life – eating habits are established in childhood, research has
indicated a strong link between diet in childhood and diet related diseases in later life.
 The health of individuals at different stages of their lives will affect selection of foods.
Convalescents, pregnant women and elderly may all have special nutritional requirements which
will affect food choice at particular times in their life
 Allergies to food may restrict food choice. Certain people are allergic to peanuts and may have an
anaphylactic reaction. Manufacturers now print a warning on food product labels
 Allergies to additives may also be common, particularly in children and may encourage
hyperactivity
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Food intolerances to lactose will restrict the intake of milk products and milk products. It is
possible to buy lactose free foods
Coeliac disease, where the lining of the intestine is damaged, is caused by a sensitivity to the
protein, gluten. Gluten is found in wheat, barley, rye and oats so these foods cannot be eaten. As
wheat protein is often added to many manufactured foods it is important to check food labels.
Many foods are labeled “gluten free” and so more choice is made available to the consumer who
suffers from celiac disease
2. CULTURAL FACTORS affecting availability, selection and consumption pattern
A strong influence on food preferences is tradition or cultural background. People around us influence
food choice and very often we prefer the foods that we consumed during our childhood years grew.
Many eating and food preparation habits tend to reflect what was learned from parents. For example
we tend to eat three meals an day and may often have the same type of food daily eg breakfast cereals
in the morning. Establishing a routine makes life more convenient in that we know when and what
we are going to eat.
Peer pressure
 The need for social acceptance and the imitation of one's peer group influences food
choice, particularly during adolescence. Adolescents like to fit in with their friends
 Adolescence is a time when changes in attitudes to food is likely to happen. As children get
older, they generally have access to a wider range of foods so individual likes and dislikes will
emerge. Peer group approval is very important at this stage.
 Influences from peer groups may affect a person's choice of diet. They may be unconsciously
pressured into trying special diets, food fads or develop the same likes and dislikes as those of
another person.
 These decisions are made so that the individual feels part of a group.
Climatic conditions
 Climate will also influence the type of foods that can be grown in the country
 Technological developments in agriculture and the fact that many foods can be imported
can mean that climate may have less influence on food choice
 In cold weather there is a need for energy giving and filling foods that will provide warmth
to the body. In hot climates refreshing foods such as salad and fruit are popular
 Custom also determines that certain foods are eaten in winter and not in summer eg
Christmas pudding
Religious influences
Food is an important part of religious rites, symbols and customs. Some religious rules apply to everyday
eating, whereas others are concerned with special celebrations.
Hinduism
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The Cow is sacred as are its products, such as milk and ghee (clarified butter). Hindus also
consider coconut sacred. These products are not eaten because they are sacred.
The pig, i.e. pork, and shellfish are considered unclean and are therefore not eaten.
Most Hindus are vegetarians and do not eat eggs
Islam
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Moslems do not eat pork and flesh of clawed animals. Other animals have to be ritually
slaughtered by process known as Halal.
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In the UK, this type of meat is more expensive, which would be a consideration when
choosing food.
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Jewish dietary laws specify that foods are “fit and proper” or kosher to eat. These are
meats from clean animals that chew their cud and have cloven feet.The animals are
slaughtered in a ritual ceremony.
Fish must have fins and scales
Foods that are forbidden include pork, bacon, ham, shellfish, eels, eggs with blood spots
and gelatine.
Milk and meat should not be eaten in the same meal.
Judaism
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Religious rules may also influence eating frequency and periodicity:
 Food and drink are almost universally associated with hospitality. Different cultures tend
to have celebrations at various periods of the year at which foods and drinks may be
offered and received according to the occasion. Some examples are:
- The Feast of the Passover
This is celebrated by Jewish people. Matzo (the special unleavened
bread) is broken by the father and a piece is passed to everyone. Wine is
drunk four times and each person reaches out and takes a small selection
of green vegetables, usually parsley or lettuce, dips it in salt water and
eats it.
- Ramadan
Religious rules may also influence eating frequency For example during
the month of Ramadan, Muslims fast from dawn to sunset. They consume
two meals per day, one before sunrise and one after sunset
 In the UK, Christmas and Easter have set traditions regarding food, such as Christmas cake
and hot-cross buns.
 Foods are also used to celebrate particular events in an individual's life, such as birth,
coming of age and marriage.
Cultural cuisine
A culture and the foods its people choose are linked closely. Scotland is a multi cultural society with
many variations of cuisine. This has influenced the choice, availability and consumption of foods for
Scottish people ,bringing with it a broadening of food experiences. As people from other cultures come
to Scotland, their food habits may change to include Scottish foods.
Personal taste
 If food looks attractive, smells appetizing and tastes good then consumers are more likely to
want these foods
 The food industry produces a huge choice of food products to suit a wide variety of tastes so
individuals and families have more variety in their diet
 Individual likes and dislikes within families can also be accommodated as many products are
available in single portions – this is useful if one family member is a vegetarian
 The food that people choose to eat depends not only on taste preferences but on individual
moral and ethical considerations. For example, vegetarians or vegans may object to the killing
of animals and may not like the taste or texture of animal flesh
 Despite the huge range of ready meals available, many consumers find that the flavour and
texture of these become very repetitive and boring. Some ready meals do not taste quite as
good as the similar home cooked variety, depending on the skill of the cook.,
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Access to shops
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In some areas there is limited access to shops. There may not be any shops local to people’s
homes or they might have trouble reaching them due to disability or lack of public transport.
In recent years, increasing numbers of stores have been closed down, leaving some areas
without shops.
Without adequate transport, many people’s diet will be affected by which shops they can reach
and how often. If they cannot get to the shops regularly then they may avoid buying items
such as fruit which will not last as long as other products. This could make achieving the
government’s recommended 5 a day dietary target difficult
Even if people can get to the shop, not all local shops stock ranges that can be found in most
major supermarkets. Sometimes the limited stock is the least healthy food. Shopkeepers may
not stock fresh fruit and because of their limited shelf life which may make them seem
unprofitable.
Geographical location affects the purchasing of foods. Choice of foods will
be either be vast (as in the city) or very limited (as in small village or town).
Geographical location may also affect the range and frequency of delivery of fresh foods
Transport systems are now so well developed that it is possible for us in the UK to get fruits,
vegetables and other foods flown in from all parts of the world.
Markets, which provide a range of products at reasonable prices (because of low overheads),
are often available to the small community. These are a good way to buy fresh fruit and
vegetables. Farms may even offer 'pick your own' facilities, which will give the consumer
very fresh, cheap produce
Some people are confined to their local area when shopping for food because they have no
private transport - this can limit their choice of foods especially if they have to carry home
heavy loads
The Internet is fast becoming popular as a means of shopping by those people who have
difficulty getting to the shops. Goods can be ordered through a website, which can then be
delivered at extra cost to the customer.
Corner shops are a useful part of the smaller community. They frequently keep hours which
suit local lifestyles but there are higher costs and less choice of products.
In rural areas people may have access to foods eg wild game, fishing, wild berries whereas
city dwellers would not
3. SOCIAL FACTORS affecting availability, selection and consumption pattern
Advertising/ marketing and Promotional Techniques
The media especially television, has a major influence on food choice.
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It is not surprising that some of the most popular products sold are high fat or sugar foods. These
are aggressively advertised and can influence people to buy foods of poor nutritional quality.
However advertising of “healthier” food products are could lead to an improvement in diet.
Reports and interviews on various topics, especially health, make us choose food differently.
Articles in newspapers and magazines may persuade us not to buy certain products; they may
almost 'frighten' people because of exaggerated publicity.
Advertising may persuade a person into buying a food product but if it fails to meet the consumers
expectation’s , then it is doubtful that a second purchase will follow.
Studies suggest that taste, texture, appearances and social acceptability generally receive greater
priority than the nutritional quality of a sample product. Advertising companies use research to
assess how a product may be effective.
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The advertisers main aim is to influence 'brand choice', so it may be brand loyalty sought after by
all companies, hence the individuals choice is again assumed.
Target groups are identified when advertising. Adverts on television are shown at times when the
target group will be watching televisions so increasing sales
A variety of promotional techniques are chosen with the target group in mind eg free toys are
often given with children’s food products
Advertising, particularly on the television, may influence consumers, particularly children, to eat
too many high sugar and fat foods.
Lifestyle
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More women are employed outwith the home and have less time for meal preparation Quickly
and easily prepared or reheated eg convenience ready meals may be used a lot.
Increase in family income when both adults work – this means that they can afford the higher cost
of ready made meals
More people live alone and want a choice of single portion meals which are easy to prepare as
they may not have the time or inclination to cook from scratch
People want and enjoy more leisure time so do not want to spend time preparing meals
“Eating our” has increased and many restaurants have developed play areas for children which
encourages families to eat our at a reasonable cost.
People travel greater distances to work so less time and energy for meal preparation
Snacking and grazing are common throughout the day as opposed to sitting down and having a
meal. Consumers want food that is easily consumed on the move eg breakfast bars, ready made
sandwiches
More homes have microwaves for quick cooking of meals
More homes have freezers which can store food for long periods of time and cut down on
shopping trips
People may not have the required food preparation skills so buy “take-away” or cook chill foods
The growth of “take away” and fast food outlets which produce a large selection of ready to eat
foods have given consumers a greater choice of quick foods with no effort involved. Many have a
home delivery service or a drive through facility
Time available for preparation/cooking and eating
 Ready prepared meals require no effort and are especially useful if tired or in a hurry
 Many new appliances can be programmed and so can save time in food and meal preparation
 Many foods can be cooked in one container eg slow cookers, steamers and so will save time in
cooking and cleaning up
 Different lifestyles mean fewer families have the time to sit down for a meal together so opt
for quick convenience meals and snacks which can be prepared when needed
 As people are working longer hours, the demand for take away food or eating out has grown,
saving time and effort in food preparation and cooking
 Many people take very little time to eat meals while at work. There is now a large variety of
convenience products eg dried soups, pot noodles, prepared sandwiches and snacks which are
handy to eat in the place of work
 As fewer families sit down to eat a balanced meal together and prefer to snack or graze when
they feel hungry. This habit can lead to having too much fat and sugar in the diet
 People are now less willing to spend time on preparing food when working. They want to
spend time on more leisure activities.
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Preparation and cooking skills
 Loss of practical skills or limited practical skills in food preparation may mean that more
ready meals and take away meals are used as an alternative to cooking.
 Reliance on convenience foods may mean that traditional food preparation and cooking skills
are lost
 If the cook’s skills are limited, a variety in the diet can still be achieved because of the
increased range of food products , food preparation and cooking equipment available
 Many manufacturers make exotic , luxury type foods which the consumer may not have the
skills or confidence to prepare themselves
Preparation and cooking equipment available
 There is a huge variety of food preparation equipment available to make food preparation
easier and less time consuming for consumers with busy lifestyles
 Advances in technology has meant that food processors, mixers, blenders, juicers have led to
quicker and easier food preparation, which could encourage consumers to use more fresh food
produce
 There are many types of cooking equipment which can help speed up the cooking process, or
save time and money when deciding on choice of food products
 The ownership of microwave ovens has increased and encouraged the use of ready prepared
frozen and chilled meals. Single portion meals are specifically intended for use in the
microwave.
 Freezer ownership has resulted in consumers being able to take ready prepared food straight
from the freezer and microwave them in a matter of minutes
 Many new cooking appliances do the monitoring and timing of the cooking process eg bread
makers, ice cream makers . This may encourage consumers to try these at hope and produce a
more “home made “ product
Range of retail outlets selling food









There is a wide choice of places from which to purchase food. These include local shops,
markets, discount stores, supermarkets / superstores, manufacturers selling by post and home
delivery food services eg pizzas
Local shops may be specialist shops eg butchers and may sell also local produce such as fruit
and vegetables. Higher prices may be charged which may restrict food choice
Markets are a good way to buy local produce and this may often be cheaper.
Farmers markets, which appear in many Scottish town, offer consumers a range of good
quality foods. These markets support Scotland’s farmers and producers by selling beef,
cheeses, fish, venison, organic foods etc
Some farms offer “pick your own” facilities which will give the consumer very fresh cheap
produce eg strawberries
Discount food stores stock fewer types of products than most supermarkets but at lower prices
which means that consumers on a limited budget will still have a choice of foods.
Supermarkets and superstores offer a range of foods and food products and often have “special
offers” available to the consumer so increasing food choice
Many supermarkets offer fresh bakery products, fishmonger, butcher, delicatessen facilities
within the store
Longer opening hours and 24 hour opening in supermarkets means that consumers will
always have access to a range of foods
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
Many supermarkets offer the availability of on-line shopping to consumers who own
computers
Foreign Travel





More people travel abroad, therefore they have developed different tastes and want to eat
similar foods at home
The food industry new produces a range of ready meals with a combination of ethnic
ingredients
There are now many ethnic groups in the UK who have greatly influenced our choice of foods
and who have greatly influenced our choice of foods and who provide a relatively cheap and
popular “take away” service
Television cookery programmes with celebrity chefs have given consumers a taste for more
exotic foods
Consumption of rice and pasta dishes has increased and this may be due to more foreign travel
Shift pattern and working hours




Longer opening hours in all sections of industry and services mean that people have less
time and inclination to prepare food, so there is a big market for ready meals that are quick
and easy to prepare
A variety of frozen or cook-chill meals are available which can be microwaved in a short
space of time and provide variety in the diet
As many people have long working hours, they may need to take single portion ready
meals with them to heat at work
The increase in shift working has meant irregular eating patterns with people in a
household eating at different times of the day. Workers can quickly heat ready meals
when they come home.
Technological Innovations

Shopping has changed considerably in the last 20 years, partly due to changing and busier
lifestyles. This change has led to less time for shopping. One stop shopping, perhaps only
once a week, is the normal pattern for consumers.

Technological innovations include scanners used in the 'Shop & Go' method. Loyalty
cards, which allow a record of all our purchases to be kept on computer, may affect our
choice of where we shop.
On Line Shopping




A wide range of goods can now be purchased over the internet so it is possible to access goods
from all over the world regardless of where you live.
Consumers can easily shop at any time of the day or night and from the comfort of home, there are
no crowds or queues to contend with , delivery times can be selected which are convenient to the
shopper.
Many consumers now use this facility to do food shopping which saves the consumer time during
a busy week. It is a very useful method of shopping for people who are housebound or disabled
A less stressful way of shopping as it save time traveling to and from the shops / loading and
unloading the shopping at the checkout and at home
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


Some consumers are however reluctant to purchase food on the internet because in some
instances delivery charges substantially increase the cost of the goods
They do not like not being able to actually see or touch the goods with the computer screen
perhaps not showing the quality and size exactly
Hassle involved in returning goods if unsuitable can be off putting eg poor quality vegetables,
shelf life too short
Fast Foods


For some families frequent fast food consumption is a way of life.
Frequent consumption as opposed to an occasional treat can affect health.
See Biochemistry, preservation and processing: Fast Foods
4. ECONOMIC FACTORS affecting availability, selection and consumption pattern
Available income
 There is evidence to show that people with a poor diet – mostly those on a low income –
are more likely to die younger than those who have a balanced healthy diet.
 Increased risk to health in adults life – eating habits are established in childhood, research
has indicated a strong link between diet in childhood and diet related diseases in later life.
 The amount of money available restricts both the quantity, quality and variety of food
which can be purchased
 Unfortunately, food may sometimes be the last thing to be considered in household
budgets. For someone on a low income, essential bills are usually paid first and the food is
bought with whatever is left, so cheap brands and economy foods (which may be high in
fat and sugar) often feature largely in the family diet
 Unfortunately many bad dietary habits are associated with poverty. Manufactured foods
are a cheaper option because they use less energy to prepare, saving on gas or electric bills.
 Manufactured foods are standard in quality and so less wastage. This encourages parents
living on a limited income, to stay with predictable, familiar foods and avoiding any
innovation with regard to food choice.
 Fruit and vegetable may not be purchased due to fear of waste
 In 2009 statistics from the Save the Children website, stated that one in four children in
Scotland was officially living in poverty so it is likely that for many of them their diet is
also poor which briings implications for their future health
 Sometimes ready meals can cost less than the total cost of ingredients if each is purchased
separately. This could apply to people living on their own, as it can be more expensive to
cook from scratch for one person.
 Untried foods may not be chosen for fear of waste if money is limited and so range of
foods eaten may encourage diet related disease in later life.
 If two people work in a household, then the increased income could mean that their diet
could be very healthy and varied if a section of “healthy” foods are chosen
 Two wages could also mean that more money may be available to buy more ready meals
and convenience foods and these could be higher in fat and sugar
 High disposable income may result in more money being available for ready meals,
convenience foods, luxury brand foods, functional foods or organic foods
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5. ENVIRONMENTAL FACTORS affecting availability, selection and consumption pattern
Environmental issues
 Environmental awareness is a concept which affects the decisions people make when purchasing
food
 Increased interest in environmental issues has led to more additive free food being produced
because consumers believe too many chemicals are being used in food production
 Consumers are buying more natural, unprocessed food because of the fear of chemicals in food
could be carcinogenic/ cancer causing
 The trend for vegetarianism is growing because of fear of animal related diseases
a. Organically produced foods
 Organic food is purchased because, during growth, only animal and vegetable waste materials are
used instead of man made chemicals and fertilizers. Consumers may have concerns that man
made chemicals could have cancer causing properties
See Biochemistry, preservation and processing – Organic food
b. Fair Trade Products
 The purpose of the Fair Trade movement is to improve the wages and working conditions of
workers in third world countries producing goods. Workers are paid a living wage which enables
them to cover basic needs, including food, shelter, education and health care for their families.


By requiring companies to pay above market prices, Fairtrade addresses the injustices of
conventional trade, which traditionally discriminates against the poorest, weakest producers. It
enables them to improve their lot and have more control over their lives.
Since Fair Trade organisations work directly with producers, they are able to return a greater
percentage of the selling price to the producer. The producer has the advantage that they use
environmentally friendly practices which manage and use local resources. This gives the local
community an incentive to preserve their natural environments for future generations

The Fair Trade label is marked on food products. Therefore consumers who are concerned with
the environment and working conditions, for example child labour, in the Third world will
purchase these

An increasing range of food products at present for consumers to choose from – bananas, coffee,
chocolate, tea, honey, snacks, biscuits, sugar, fruit juice, fresh fruit.

The Fair Trade products tend to be expensive and therefore may not available to low income
groups
c. Energy saving
 Consumers who use a microwave will save the world’s resources as well as saving themselves
money.
d. Cruelty free
 Many consumers feel concern about animals are breed and treated within the food chain
 Examples where animal care is considered are free range chicken and eggs along with “dolphin
friendly” tuna
e. Packaging to reduce pollution
 Manufacturers are being encouraged to face up to their responsibilities in
protecting the environment by cutting down on the amount of packaging used and
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trying to produce:
- goods packaged in biodegradable materials (ie they rot away)
- goods packaged in paper which has been recycled
- refillable containers
- environmentally friendly products
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Resource Management
Content
Elaboration
Food Science

The properties of food and their uses –
Carbohydrates Solubility, Inversion and crystallisation,
Caramelisation, Gelatinisation,
Retrogradation of starch and Pectin gel
formation
PROPERTIES of CARBOHYDRATES
Starches and sugars are of plant origin and serve a variety of roles in food production due to their
properties
1.
Solubility

Starches are not readily soluble in cold water.

Starches are soluble in hot water and form pastes and gels

Manufacturers use the solubility of starches to improve the texture and viscosity of foods.

When a suspension of starch in water is heated, the water penetrates the outer layers of the starch
granules and the granules begin to swell. The starch granules break up and the contents disperse
throughout the water.

The starch/water mixture becomes more viscous i.e. it thickens and forms a paste which, on
cooling, forms a gel. This property is used by manufacturers to make sauces.

Because of their viscosity , starch pastes are used to thicken foods, and starch gels, which can be
modified by sugar or acid, are used in puddings.

In recent years, natural starches have been modified by physical and chemical means and as a
result the range of uses of starch as a food ingredient by a manufacturer has increased. Food items
which require the minimum of heating to achieve the desired viscosity are now available e.g.
instant puddings which do not require cooking. Pre gelatinised starches are used in some
manufactured foods. These are cooked in water i.e. gelatinised and then dried. These are used in
instant desserts.
2.
Inversion and crystallisation

Invert sugar is related to sucrose. Sucrose is a disaccharide which goes through a process of
hydrolysis to form monosaccharides. Hydrolysis is the chemical breakdown of a molecule, by
combination with water, producing smaller molecules. The hydrolysis of sucrose is also known as
the inversion of sucrose and the product, a mixture of glucose and fructose is called invert sugar.
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
Inversion may be brought about either by heating sucrose with an acid or by adding the enzyme
invertase.

Invert sugar is used in the production of jam, boiled sweets and some other sugar confections. A
small quantity of invert sugar, added to a hot sucrose solution will help reduce the likelihood of
crystallisation when the mixture is cooled.

Invert sugar can prevent or help control the degree of sucrose crystallisation.

Glucose and fructose crystallise more slowly than sucrose, so when some invert sugar is added to
the mixture, the amount of sucrose which could rapidly crystallise is reduced. This is important
during the cooling of syrups, when most of the crystals are formed and during later storage where
crystals precipitate and grow in size.

Manufacturers substitute some invert sugar to slow down the crystallisation process during storage
to ensure the product is acceptable to the consumer.

A mixture of sucrose and invert sugar has greater solubility in water than sucrose on its own –
increased solubility means less crystallisation.

Invert sugar also encourages the formation of small crystals which are essential in some products –the finished product will be smoother e.g. fudge making, fondant making and soft mints.

Invert sugar will also prevent more chewy candies drying out and becoming too brittle.
3.
Caramelisation

When sugars are heated they caramelise. Although caramelisation occurs most readily in the
absence of water, sugar solutions (syrups) will caramelise if heated strongly enough.

Caramelisation occurs when sugar is heated to a temperature above its melting point. It turns
brown and has a toffee flavour. When sprinkled over the top of a crème caramel the sugar gives a
toffee flavour and adds crunch.

If heated too long it becomes black in appearance and has a bitter flavour

Sugar toppings on cakes and pastries can be caramelised to give an attractive appearance and good
flavour.

Caramel can be added to ice creams and mousses.
4.
Gelatinisation

Gelatinisation results when a suspension of starch in water is heated, the water penetrates the outer
layer of the starch granules and the granules begin to swell. This occurs as the temperature rises
from 60C to 80C. The granules may swell to five times their original size. As the size of the
granules increase the mixture becomes viscous. At about 80C the starch granules break up and
the contents are dispersed throughout the water and as a result the mixture becomes more viscous
i.e. thickens and forms a sol. On cooling, if the proportion of starch to water is sufficiently great,
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the starch molecules form a network with the water enclosed in its meshes so producing a gel.
The entire process is known as gelatinisation of starch and it very important in food production.
The texture of the food will be a gel rather than a fluid, which means it is easier to transport and
eat.

Starches take up water and produce viscous pastes and gels and give the desired texture to
foodstuffs e.g. macaroni and cheese.

In food production, gelatinisation is responsible for the thickening of sauces, soups and gravies by
the addition of flour or cornflour.

Gelatinisation is also important in baked goods e.g. bread and other flour goods where it
contributes to the desired crumb structure and texture of the product. Storage behaviour and the
rate of digestion are also affected by the gelatinisation of starch.

Starch is a mixture of 2 different polysaccharides.

a)
Amylose – this molecule consists of between 50-500 glucose units joined in a straight
chain. Amylose containing starches gel best but are less stable than high amylopectin
starches.
b)
Amylopectin – this molecule consists of up to 100,000 glucose units joined in a branchedchain structure.
The strength of a starch gel depends on a number of factors including:
a)
The proportion of starch and water present – the more starch the stronger the gel.
b)
The proportion of amylose in the starch. Amylose aids gelling because the molecules form
a network in which water is trapped. High amylose starches are used where a rigid gel is
needed. Amylopectin molecules are larger but are more compact and therefore do not hold
water as well. High amylopectin starches (i.e. waxy starches) gel only at high
concentrations.
c)
The presence of sugar. Sugar competes with the starch for water and therefore reduces gel
strength.
d)
The presence of acid. Acid hydrolyses starch and reduces gel strength forming a viscous
paste. This happens in lemon meringue pie filling.

The extent of starch gelatination in baked goods strongly affects product properties, including
storage behaviour and the rate of digestion.

In some baked products, many starch granules remain ungelatinised due to the high proportion of
fat and the low proportion of water.

In other products, like white bread, which has a high moisture content, about 96% of the wheat
granules are gelatinised.
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
Waxy maize starch will produce a clear cohesive paste which may be desired by manufacturers
depending on the use.

Potato starch is used in extruded cereals and snack food products and in dry mixes for soups and
cakes.

Rice starch produces opaque gels useful for baby food.

Potato and tapioca starches have weak intermolecular bonding and swell greatly to give high
viscosity pastes. But because the highly swollen granules break easily, the viscosity quickly
decreases with only moderate shear (shaking or whipping).
5.
Retrogradation of starch

Both pastes and gels can revert or retrograde back to the insoluble form on freezing or ageing,
causing changes in food texture which would be unacceptable to the consumer.

Although amylose containing starches gel best they are less stable than amylopectin starches.
Because the amylose molecules tend to unwind and the gel becomes opaque and like a pulpy
sponge. This change is called retrogradation and occurs particularly when foods are frozen and
then thawed.

High amylopectin starches e.g. waxy corn starch should be used by manufacturers when
preparing foods for a freeze/thaw process.

Chemically modified starches are widely used in frozen manufactured foods as they do not
retrograde easily and so the texture of a product does not change.
6.
Pectin gel formation.

Pectin is a complex mixture of polysaccharides found in many fruits and in some vegetables –
apples and the peel of citrus fruits are particularly rich in pectin.

Pectin is important as a gelling agent especially in jam making. During jam making, its molecules
form a three dimensional network (which is the framework of the gel) with the water, sugar and
solid matter from the fruit. Pectin forms a gel when sugar and acid are added and this is the basis
of jelly manufacture.

The correct proportion of sugar is needed in jam to assist gel formation, usually about 65%.

Pectin will not form a satisfactory gel until the pH of the mixture is 3-3.5 (acidic). In jams made
from fruit with a low pectin content, such as strawberries, the addition of an acid, e.g. lemon juice,
lowers pH and aids setting. Unripe fruit contains more acid and pectin, whilst over-ripe fruit
contains pectin which has been converted into a form which is unable to form a gel.

Pectin in colloidal solutions contribute viscosity to tomato paste and stabilise the fine particles in
orange juice from settling out.

Pectin is also added to foods as thickeners and stabilisers.
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Resource Management
Content
Elaboration
Food Science.

The properties of food and their uses –
Fats and Oils –
Melting characteristics
Plasticity related to creaming and
shortening properties
Hydrogenation of oils
Smoke point related to uses as a cooking
medium
Colloidal systems
Emulsifying agent and stabilisers
Hydrolytic and oxidative rancidity
PROPERTIES of FATS AND OILS
Fats and oils are composed of two basic parts: Glyceride and fatty acids. A fat is termed a lipid which is
solid at room temperature, while an oil is a liquid.
7.
Melting characteristics

Fats melt when heated. Since fats are a mixture of triglycerides they do not have a distinct
melting point but melt over a range of temperatures. Most fats melt at a temperature of between
30-40C.

The more saturated the fat, the higher the melting point.

The more unsaturated the fat, the lower the melting point
2.
Plasticity related to creaming and shortening properties

Substances which have the property of plasticity will change their shape when pressure is applied
to them, but will remain in their final shape when the pressure is removed. They do not return to
their original shape

Fats do not melt immediately but over a range of temperatures – this property is called plasticity.

Fats are plastic at certain temperatures i.e. they are soft and can be spread.

Plasticity is due to the mix of tri-glycerides each of which has its own melting point. This means
that at a given temperature some of the fat will be liquid and some will be in the form of a solid
with very fine crystals.

Fats containing smaller crystals, which are produced by rapid cooling of the fat during
manufacture, will be more plastic.
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
Some fats have been formulated to have low melting points so that the product can be spread
straight from the fridge e.g. soft margarines.

The range of temperatures over which a fat shows plastic behaviour is known as the plastic range
of the fat. A mixture of triglycerides with a large range of melting points will form a fat with a
wide plastic range. This type of fat is better for certain purposes e.g. creaming and spreading.

Most animal fats have a narrow plastic range and are hard and difficult to spread e.g. butter
straight from the fridge.

Shortenings used in bakery production should have a wide range of plasticity as possible which
means that the melting behaviour should remain constant over a specified temperature range so
that the fat can be easily manipulated without melting at room temperature (24-42C). Plastic fats
will coat the flour particles readily.

Shortenings (semi solid fats) give a “short” or tender quality to baked products as well as
enhancing the aeration of leavened (raised) products such as cakes and give a good flavour and
texture to the product.

Shortenings will prevent toughness in products such as pastry, by surrounding the starch granules
and protein molecules and thus break up the structure.

Fat also prevents contact between the protein in the flour and water in the dough and so restricts
the formation of gluten so that the gluten formed is in short lengths and not long elastic strands
e.g. bread..

Shortenings in products such as doughnuts will change or modify the gluten protein of flour.

When making rich cakes, fat and sugar are beaten or creamed together. This process incorporates
small air bubbles into the mixture, forming a foam and so lightening the product.

In icings and fillings, fats help to form very small air bubbles when creamed or beaten and thus
creates a light, fluffy structure.
3.
Hydrogenation

This involves the addition of hydrogen to unsaturated fatty acids which changes oil to fat. Partial
hydrogenation of fats and oils are used in the manufacture of margarine and shortenings. The
addition of hydrogen is only partial as not all the possible hydrogens are added
During processing, the most unsaturated fatty acid chains are selected for hydrogenation. This
means that not all partially hydrogenated oils will be that same


Food manufacturers use fats and oils that have been altered by hydrogenation by adding hydrogen
atoms to the double bonds in monounsaturated and polyunsaturated fatty acids in order to
increase the degree of saturation of the fatty acids in the oil and as a result increase the melting
point of the fat.

A polyunsaturated oil, which is liquid can be changed to a fat that is solid at room temperature
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
Hydrogenation of oils is used by manufacturers to produce a fat consistency and texture
appropriate to the food product being produced

Hydrogenation creates stability to fats and oils which would otherwise be unstable and so
manufacturers can use fats and oils that they otherwise could not.

The process of hydrogenation creates trans fatty acids which behaves biologically like saturated
fats and as a result is a major contributor to heart disease. Many manufacturers are removing
trans fats from their products – making it a good health selling point for consumers
4.
Smoke point related to uses as a cooking medium.

As a cooking medium, flavour and texture are added to food items when cooked by frying.

For manufacturers a cooking oil must be stable under high temperatures and provide moisture
during cooking.

When a fat or oil is heated to a certain temperature it starts to decompose (break down into fatty
acids and glycerol) producing a blue haze or smoke. Most fats and oils start to smoke at around
200C. The smoke point for lard is 185C and for corn oil is 232C. In general vegetable oils
have a higher smoke point than animal fats.

Decomposition of the triglycerides produces small amounts of glycerol and fatty acids. The
glycerol further decomposes producing a compound called acrolein. As this is irreversible so it is
advisable when using a fat for deep fat frying that the frying temperature should be kept below the
smoke point so preventing this decomposition

Smoke point is a useful measure when assessing the suitability of a fat or oil for frying purposes.
Fats with a high smoke point are best for frying.

Repeated heating of a fat or oil or the presence of burnt food particles will reduce the smoke point.

Repeated heating will also produce oxidative and hydrolytic changes in the fat and give
undesirable flavours to the foods cooked in the fat.

Temperature of oil should be maintained at 180C during frying – important for manufacturers to
maintain correct temperature to produce an acceptable product.

Too low a temperature will result in a greasy product as a result of absorbing a considerable
amount of fat.

Water in food will contribute to the breakdown of fatty acids which occur on heating. Hydrolysis
results in an oil of poor quality which has a lower smoking point, darker colour and changed
flavour.

When oil is heated it will polymerise, which results in the production of a viscous oil that is
readily absorbed by foods. This results in a greasy product.

The more saturated the oil (solid) the more stable it is to breakdown by oxidation and hydrolysis.
In addition, less likely to polymerise.
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
Partial hydrogenation makes soya oil more stable.

Sunflower and safflower have been genetically developed to be used as frying oils.

Snacks which are fried and stored prior to eating require a stable oil.

If oil is used continually, as in a chip shop, a frying fat must be used which can withstand heavy
use. Solid fats used to preferable due to their stability through many hours of frying but generally
oils are used due to consumers health concerns

Stability of fats and oils are an important consideration in catering where they may be used for
long periods of time.
5.
Colloidal systems

A colloid is a suspension of particles in a solution – oil and water do not mix i.e. they separate out
even after shaken together vigorously.

An emulsifying agent is required to prevent this separation e.g. in mayonnaise, egg yolk is used
as the emulsifying agent holding the oil and vinegar together in suspension i.e. forming a colloidal
solution and improving the appearance of the mayonnaise.
6.
Emulsifying agents and stabilisers

The main purposes of each are as follows
emulsifiers are used to make stable emulsions or creamy suspensions from oils and fats and water.
Stabilisers are used to improve the stability of emulsions and prevent separation of their
components.
The lecithin in egg yolk is used as an emulsifying agent in mayonnaise.


Food manufacturers have to ensure that the choice of fats and oils used in food production can
remain stable for the maximum length of time.

In low fat products where a quantity of fat or oil is removed, it must be replaced if the product is
to be comparable with the traditional product. Water is often added to replace the fat which has
been removed along with a commercial additive stabiliser to ensure the texture is acceptable and
that the oil/fat and water do not separate.
7.
Hydrolytic and oxidative rancidity

Rancidity is the term used to describe the spoilage of fats and oils – off flavours develop.

Oxidative rancidity occurs as a result of the reaction between unsaturated fats and oxygen from
the air, giving rise to an unpleasant rancid taste. The more unsaturated the fat, the more likely the
rancidity is to occur

The rate of oxidative rancidity is accelerated by:
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




Heat/temperature
Exposure to light
Amount of oxygen present
Traces of metal such as copper and iron
Oxidative rancidity can be reduced by:



The presence of anti oxidants – e.g. citric acid, vegetable oils contain natural anti oxidants
such as Vitamin E.
Packaging materials – keeping well wrapped and in a cool, dark place.
Anti oxidants may be added to foods which contain fats. They work by reacting with “free
radicals” which are produced in the first stages of oxidative rancidity – this reaction stops
the onset of rancidity. Manufacturers must ensure that the correct amount of anti oxidant
is used as too high a concentration can actually speed up rancidity. Manufacturers have to
make sure that the choice of fats and oils used in production of a food item can remain
stable for a long time – anti oxidants may help.

Hydrolytic rancidity is caused by enzymes called lipases – these enzymes hydrolyse fats, breaking
them down into fatty acids and glycerol. Lipases may occur naturally in fats and oils but they can
be inactivated by heat treatment. They may also be produced by micro organisms present in fatty
foods. The free fatty acids which are produced by this reaction can give fats an unpleasant taste
and smell e.g. when butter goes rancid.

Hydrolytic rancidity has to be considered in the dairy and meat industry.
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Resource Management
Content
Elaboration
Food Science.

The properties of food and their uses –
Protein.Colloidal systems
Denaturation
Gels and gelatin
Maillard reaction
PROPERTIES of PROTEIN
1.
Colloidal systems

A colloid is a suspension of particles in a solution. If a substance such as albumin, the protein in
egg white, is mixed with water, it does not dissolve but forms a colloidal dispersion. The
molecules of protein do not dissolve and are dispersed throughout the water.

Gelatine consist of very large molecules which have a thread like shape.

This shape allows the molecules to trap and hold relatively large amounts of water – this forms a
jelly like solid known as a gel.

During gel formation the long molecules link together loosely to form a mesh.

This makes the gel stable i.e. it sets and forms a colloidal system as the particles are held in
suspension in the gel.

Manufacturers use gelatine in cold desserts e.g. mousse, jellies and in savoury pies e.g. pork pies.

Types of colloidal systems are:





Foam – beaten egg white
Solid Foam – meringue, cake
Emulsion – milk, cream, mayonnaise
Gel – jelly, baked egg custard
Sol – egg white
2.
Coagulation and denaturation

Proteins undergo a process called denaturation. Denaturation involves breaking of the cross
linkages which maintains the shape of the protein molecule.
Denaturation of protein is usually irreversible as it is impossible to regain the original structure of
the protein molecule.
As a result of denaturation the properties of protein change – it becomes less soluble and becomes
hard and sets. This is known as coagulation.


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
Many proteins are denatured by heat i.e. they coagulate.

Coagulation results in loss of solubility or change from a fluid (Sol) to a more solid state to a
formation of a gel e.g. egg white begins to coagulate at 60ºC; egg yolk begins coagulation at
65/66ºC. This coagulation is used extensively in the preparation of many dishes e.g. egg custard
and sponge cake.

The muscle fibre proteins in meat coagulate when heated resulting in the shrinkage of meat during
cooking.

As temperature rises, coagulation continues until whole mass is solid – different proteins
coagulate at different rates.

If cooking temperature is kept below 100ºC coagulation is slow and coagulated protein is not too
firm i.e. it is more digestible, important when cooking meat and products containing eggs.
Manufacturers would have to take account of this when formulating cooking instructions which
would give consumers good results.

If cooking temperature is above 100ºC coagulation is rapid and denatured protein would form a
hard solid mass – this is particularly important when stewing/casseroling meat which will become
tough if cooked at too high a temperature and/or for too long.

Coagulation is brought about by the following:
a. Action of heat

Coagulation of protein is responsible for the thickening effect eggs have in products e.g.
egg custard, quiche, lemon curd.

Coagulation of egg custard produces a gel.

The property of coagulation is used by manufacturers when coating Scotch eggs, fish,
rissoles, etc., in breadcrumbs. The egg cooks/sets and holds the breadcrumbs in place.

Overheating would result in protein becoming hard and separates from the liquid in the
product which will then produce a holey, open textured product.

The firmness of the final product or custard will depend on the proportion of ingredients
e.g. eggs to milk, and the addition of other ingredients e.g. addition of sugar raises the
temperature for coagulation and produces a softer texture.
b. Presence of acid

When milk sours, the bacteria in the milk ferment lactose, producing lactic acid. The pH
of the milk is lowered and this causes the milk protein – caseinogen – to coagulate.

The starter culture, used in the manufacture of some milk products, such as yoghurt and
cheese, consists of lactose-fermenting bacteria. The lactic acid, produced by the bacteria,
is responsible for the coagulation or “setting” of the milk and the formation of a curd.
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c. Addition of salt

During cheesemaking, salt is often added to the curd to increase firmness and also to
suppress the growth of micro-organisms.

Salts are necessary for the gelatine of egg custard mixtures – present in milk of by the
addition of salt.
d. Mechanical action

Mechanical action during the whisking of egg white causes a partial coagulation of the
protein. The protein molecules unfold and form a network round the air bubbles and so
stabilise the foam. This property is used by manufacturers when whisking egg white for
meringues and souffles, whole eggs and/or yolks for sponge cakes.

Heating results in further coagulation and the formation of a rigid structure due to the
denaturation of the protein e.g. sponge cakes.

When whisking e.g. egg white, foaming may be promoted by the addition of acid
substances (vinegar, cream of tartar) which lowers the pH value – used in pavlova to make
the foam more stable.

Overbeating – too much air incorporated; protein is denatured too much; the protein film
around bubbles or air becomes too thin and less elastic; the foam then “collapses” resulting
in loss of volume.

Addition of salt reduces stability of foam – decreases volume.

Addition of sugar retards denaturation of egg white foam; better to add sugar after egg
whites are beaten.

Addition of sugar produces a softer foam e.g. sponge cakes.

High pressure mechanical shear is generated by vigorous shaking, kneading or whipping.
Protein is denatured because very small air bubbles are incorporated within the mechanical
action. In the food industry, there are many processes which include high pressure shear in
their operation. For example, extrusion, high speed blending and homogenisation. The
greater the rate of shear, the greater the rate of denaturisation.
e. Enzymic coagulation

Enzymic coagulation or clotting of milk is used in the production of cheese.

The protein, casein, is coagulated bv the addition of rennin (or other enzyme) – forms a
continuous mass initially; breaks into curds when agitated i.e. gel structure is broken
down.
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3.
Gels and gelatin

Gelatin is relatively soluble in cold water, but hydrates readily in warm water. When gelatin is
added to cold water the granules swell into particles which can absorb 5 – 10 times their weight in
water. When the temperature is raised above 40C the swollen particles form a solution which gels
on cooling to its setting point

Proteins can be used to produce gels in cold desserts e.g. mousse, table jellies and in savoury
pies/aspic jelly. Used as a gelling agent.

Gelatin is produced from the protein collagen – commercial product gelatine – used as a
stabilising agent for emulsions e.g. ice cream.

On cooling gelatin sol (i.e. protein in water) will set to form a gel – this is semi-rigid but is not
coagulated by heat.

Unlike egg custard, this type of gel is reversible i.e. on heating it will liquify.

If gelatin sol is cooled until viscous but not set it can be beaten into a foam to incorporate air –
gelatine would have a degree of elasticity at this stage, and would be able to stretch and surround
air bubbles and is used in whipped cream and gelatine desserts.

The viscosity of gelatine plays a role in the production of starch molded confectionery where the
working speeds demanded during processing require gelatine with a low viscosity

Used by manufacturer as gelatine, it gives a melt in the mouth characteristic. It is a useful
nutritive component because it is a protein and is free from cholesterol.
4.
Maillard reaction (or non-enzymic browing)

This reaction is very important in the food manufacturing industry.

Occurs when protein and carbohydrates exist together. The amino acid called lysine reacts well to
browning. In combination with carbohydrates, the protein reacts causing non enzymic browning.
Reducing sugars e.g. glucose are the most reactive in Maillard reaction.

This produces desirable changes in flavour, colour and aroma during dry cooking methods e.g.
roasting, baking and grilling, e.g. consumers expect cold cooked chicken to be a good brown
colour.

Important for baked goods such as bread, biscuits and cakes: nuts and coffee beans (roasting):
flavour in biscuits, breakfast cereals and meat extracts: roasted or grilled meat/poultry.

Maillard browning occurs at high temperatures and at pH values of 7 or above.

Sometimes non enzymic browning is not desired by a manufacturer as it is not suitable for the
food product. It can be prevented by controlling:


moisture content
temperature
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


pH
adding an inhibitor such as sulphur dioxide
Although the reaction is generally considered desirable during cooking, there are 2 undesirable
effects. Firstly there is some loss of nutritional value of proteins. Amino acids containing an
extra amino group e.g. the essential amino acid lysine, are most likely to be involved. Secondly,
the reaction can cause discoloration of foods during storage, for example the gradual browning of
dried milk powder – undesirable from a manufacturer’s point of view as it would indicate
deterioration.
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Resource Management
Content
Food Science. The chemical structure
of the main nutrients
Elaboration
The chemical structure of :
 Carbohydrates (sugar, starch and non starch
polysaccharides) – monosaccharide, disaccharides
and polysaccharides
 Fats and oils – fatty acids and glycerol;
unsaturated, saturated, poly unsaturated; essential
fatty acids; trans and cis fatty acids
 Proteins – amino acids
CARBOHYDRATES
Carbohydrates are found in all plants, produced during the process of photosynthesis.
Carbohydrates are compounds of carbon, hydrogen and oxygen in the ratio of Cn:H2n:On. They can be
divided into 3 main categories according to the size of the molecule, namely:
 monosaccharide
 disaccharides
 polysaccharides
Monosaccharides
These are the simplest carbohydrate molecule with the general formula of C6H12O6
Its structure can be shown as:
Glucose, fructose and galactose are the basic monosaccharides. They have the same chemical formula but
differ in the way they are arranged. The chemical names of all sugars have the ending “ose”. Glucose is
found in grapes, sweet fruits and honey. Fructose is found in sweet fruits and honey. Galactose is not
found in food but is produced when lactose, a disaccharide, is broken down during digestion.
Monosaccharides are white crystalline solids which dissolve in water to give clear colourless solutions.
Disaccharides- double sugars
These sugars are formed when two monosaccharide molecules join together with the elimination of one
molecule of water eg sucrose is built from one molecule of glucose and fructose. Disaccharides have the
general formula of C12H22O11.
Disaccharides like monosaccharides are white crystalline solids which dissolve in water to give colourless
solutions. The following table shows the monosaccharides that make up each disaccharide.
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Disaccharide
Sucrose
Lactose
Maltose
=
=
=
Monosaccharides
glucose
+
fructose
glucose
+
galactose
glucose
+
glucose
Polysaccharides ( Complex Carbohydrates)
Polysaccharides are enormous molecules made up of one or several types of monosaccharide units
(usually glucose) which are joined together, with the elimination of one water molecule at each link. They
have the general formula (C6H10O5)n where n represents a large number and can be over 1000
monosaccharide units.
Polysaccharides can be further divided into two groups:
 starch which the body can use. Acids in the stomach break down starch into monosaccharides
and use them as a source of energy.
 non starch polysaccharides which the body cannot digest
Starch
Starch is made up of glucose units, joined together. It is a white solid, not sweet and will not dissolve in
water. Starch molecules are formed in roughly spherical granules. Starch actually consists of two
different polymers of a glucose unit - amylose and amylopectin. Amylose starches are very long straight
chains of glucose units while amylopectin is very large, highly branches polymer. Some waxy starches,
like rice and maize, contain largely amylopectin
Non starch polysaccharides (NSP)
Non starch polysaccharides are the most complex of all the carbohydrates. They are so complicated that
humans are unable to digest them as the acids in our stomach cannot break the links between the glucose
units. They can be further divided into :
 cellulose
 pectin
Cellulose
Cellulose is one of the most common non starch polysaccharides and is always very large with several
thousand glucose units joined together in chain like molecules. Bundles of these chains lying side by side
are then linked together to give cellulose fibres.
Pectin
Pectin is the name given to a mixture of non starch polysaccharides found in fruits and some roots. It is
responsible for the formation of gels in jam manufacture. Pectins have a flexible back bone made up of a
chain of monosaccharide units. This is then divided into sections classified as either smooth ( no
monosaccharide units attached) or hairy (other monosaccharide units attached). The smooth sections of
pectin’s can join together which forms gels.
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FATS and OILS
Like carbohydrates, fats and oils are compounds of carbon, hydrogen and oxygen.
Fatty acids and glycerol
Fats and oils are similar chemically, both belonging to the chemical group of tryglycerides. Triglyceride
molecules consist of one molecule of glycerol with three molecules of fatty acids as shown below
G
L
Y
C
E
R
O
L
Fatty acid
Fatty acid
Fatty acid
Glycerol (also known as glycerin) is depicted as follows, with three carbon atoms and their associated
hydroxyl groups(OH):
H2 COH
H2 COH
H2 COH
Fatty acids differ in many ways, a main difference being the chain length.
Fatty acids can also be categorized as follows:
 saturated where the carbon atoms have all the hydrogen atoms that will combine with them
 unsaturated where some of the hydrogen atoms are missing from some of the carbon atoms.
Degrees of unsaturation differ depending on the number of missing hydrogens.
The ratio of saturated and unsaturated fatty acids has a major impact on whether a substance is a fat or an
oil as shown below
Fat
Solid at room temperature
Longer fatty acid chain
Chains are more saturated
Higher melting point
Oil
Liquid at room temperature
Shorter fatty acid chain
Chains are less saturated
Lower melting point
Saturated, monounsaturated and polyunsaturated fatty acids
Each fatty acid is made up of a chain of carbon atoms with a methyl group at one end and an acid group
at the other. Each carbon atom in between has either one hydrogen atom attached (monounsaturated) or
two hydrogen atoms attached (saturated) as shown below
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Monounsaturated
Saturated fatty acid
H
H
C
H
Methyl
group
O
C
C
C
H
H
Carbon
group
H
H
OH
H
C
H
Acid
group
H
H
O
C
C
C
H
H
Methyl
group
OH
H
Carbon
group
Acid
group
If there is more than one double bond in a fatty acid it is known as a polyunsaturated fatty acid. These
fatty acids will have a longer carbon chain. They easily combine with oxygen in the air to become rancid.
It is the acid group from each fatty acid which is able to combine with the glycerol to form a triglyceride.
All tryglycerides (fats and oils) contain a mixture of both saturated and unsaturated fatty acids.
Fats and oils can be described as saturated or unsaturated according to their proportion of fatty acids
present eg butter is described as a saturated fat because it has more saturated fatty acids than unsaturated
fatty acids. Most vegetable oils are described as unsaturated fats because they have more mono or
polyunsaturated fatty acids.
Saturated fats are solid at room temperature and tend to be from animal sources whilst most unsaturated
fats are liquid at room temperature and are usually from vegetable sources.
Essential fatty acids
The body can make the fatty acids it needs except for the following two:
 alpha-linolenic (n–3) Also called omega 3
 linoleic acid (n–6) Also called omega 6
These are known as the essential fatty acids as they must be supplied by the diet. They are easily
identified due to the unique positioning of the double bond. Linoleic acid has a double bond three carbon
atoms from the methyl end of the carbon chain. Alpha linolenic has a double bond six carbon atoms from
the methyl end of the carbon chain.
Cis and trans fatty acids
These terms refer to the arrangement of the hydrogen atoms in unsaturated fatty acid molecules. One
arrangement is called the “cis” (where the hydrogen atoms are on the same sides of the double carbon
bond) as shown below:
Cis form
H
C
H
H
C
H
C
Trans form
H
H
H
C
C
C
H
H
H
C
C
H
H
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During the processing of oils to make margarine, trans fatty acids are formed. This means that instead of
being on the same side of the molecule, the hydrogen atoms next to the double bond are on the opposite
sides. The cis and trans arrangement is important as trans fatty acids appear to behave in the body in the
same way as saturated fatty acids.
PROTEINS
Chemically, proteins differ from carbohydrates and fats as they always contain nitrogen. They are
composed of carbon, hydrogen, oxygen, nitrogen and sometimes sulphur and phosphorous. As a result
proteins are much more complex substances than carbohydrates and fats.
Proteins are made up of simple substances known as amino acids. Amino acids are chemical compounds
with an amino acid (NH2) and a carboxyl (acid) group (COOH) attached to the same carbon atom as
illustrated below
Different for each
amino acid
R
H
O
C
C
H
OH
Acid
group
H
Amino group
The rest of the amino acid is represented by R. R is different for every amino acid. There are about twenty
different amino acids commonly found in plant and animal proteins. This gives each amino acid its
individuality as seen in the chart below
Name
Abbrev
Symbol
R Structure
Alanine
Ala
CH3
Aspartic acid
Asp
CH2
Glutamic acid
Glu
CH2
Glycine
Gly
H
**
Isoleucine
Ile
CH(CH3)
**
Leucine
Leu
**
Lysine
Lys
CH2
CH2
Iso
electric
Ph
6.1.1
2.98
COOH
3.08
COOH
6.07
C2H5
6.04
CH(CH3)2
6.04
CH2
CH2
CH2
9.74
NH2
**
Phenylalanine
5.91
Phe
CH2
(benzene
ring)
**
Serine
Ser
CH2
**
Valine
Val
CH (CH3)2
OH
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6.00
78
** indicates an essential amino acid
The amino group of one amino acid can link with the acid group of another amino acid to form a chain of
amino acids. The link is called a peptide bond.
When two amino acids are joined together a dipeptide is formed.
When many amino acids join together a poly peptide is formed as detailed below.
The primary structure of proteins is determined by the peptide bonding. Each protein has its own specific
number and sequence of amino acids. The chains of amino acids making up protein are also held together
by further levels of structural organization (bonding) secondary, tertiary and quaternary. The final shape
of the molecule is important as it often determines the function of the protein. Any errors in the primary
structure can result in faulty proteins being formed.
Each species, including humans has its own characteristic proteins. The proteins of human muscle are
very different from those of beef muscle.
Indispensable (essential) and dispensable (non essential) amino acids
Plants can build their own protein from the carbon dioxide they obtain from the air and from water and
mineral substances containing nitrogen from the soil.
Animals, including humans, are unable to make proteins and therefore depend entirely on proteins already
made up in plants or animals.
When we digest protein foods our digestive juices break up the protein back into different amino acids.
These amino acids are then circulated in the blood. Each cell of the body chooses the amino acid it
requires for growth and repair, with any surplus being used for energy.
The human body, however, is able to make some amino acids for itself by transferring the amino group
of an amino acid to another molecule. This is known as transamination. Due to this fact, many of the
amino acids are known as dispensable (non essential) amino acids as the human body can make them
from other amino acids that the body gets eg glycine can become alanine. Examples of dispensable
amino acids are:
Alanine
Arginine
Glutamic
acid
Tryosine
Clutamine
Aspartic
acid
Glycine
Asparagine
Cysteine
Cystine
Hydroxyproline
Proline
Serine
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It is not possible for every amino acid to do this, so a certain amount must be supplied by the diet. These
are known as indispensable (essential) amino acids.
Examples of indispensable amino acids are:
Isoleucine
Phenylalanine
Leucine
Threonine
Lysine
Trytophan
Methionine
Valine
Histidine and arganine are essential for infants since their requirement for these is greater than their
ability to synthesis their amino acids during their period of rapid growth.
Resource Management
Content
Nutrients and their effect on the health and
development of individuals
Elaboration
An in depth study of nutrients, their
function and the effect on the health and
development of individuals at different life
stages / special circumstances
Pregnancy and lactation
Infants and young children
Teenagers
Adults
Elderly
Vegetarians
Weight reduction
Sports performance
Reference should also be made to sections on Main nutrients,Micronutrients, Anti
oxidants and Dietary diseases
PREGNANCY and LACTATION
A varied diet containing adequate amounts of energy and nutrients is essential both before a woman
becomes pregnant (conceives), during pregnancy and if she breast-feeds (lactation). The mother’s diet
influences the health of the baby in the short-term and perhaps even in the long-term.
PRECONCEPTION
Being a healthy body weight is important before pregnancy. Being underweight can affect fertility,
making it more difficult to conceive. It can also increase the chance of the baby having a low birth
weight, which can increase the risk of ill health in early and later life. Being very overweight can also
affect fertility and increases the risk of complications such as high blood pressure, infections and diabetes
during pregnancy.
Folate/folic acid
The vitamin folate is particularly important before conception and during the first twelve weeks of
pregnancy. Extra folate at this time reduces the risk of having a baby with a neural tube defect, such as
spina bifida.
All women of child bearing age who may become pregnant are advised to take daily supplements (400
micrograms) of folic acid (the manufactured form of folate), as it is difficult to achieve the extra folate
needed through diet alone. This is because the vitamin is important at a time when many women do not
realise that they are pregnant. A woman who has already had a baby with a neural tube defect may be
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advised by her doctor to take a larger supplement (for example 5 mg/day). It is also important to consume
foods that are naturally good sources of folate e.g. green vegetables, oranges, and foods that have been
fortified with folic acid e.g. some breads and breakfast cereals.
DURING PREGNANCY
Contrary to the popular phrase ‘eating for two’, most pregnant women do not need to double their food
intake. In fact, it is only during the latter part of pregnancy that some additional energy is needed; an
increase of 0.8 MJ or 200 kcals a day in the last 3 months of pregnancy is recommended, although the
needs of individual women will vary, depending on how active they are (see below). However, an
expectant mother requires a healthy and varied diet to provide her and her growing baby with the full
range of nutrients.
Weight gain
A weight gain of 12.5 kg in women of normal pre-pregnant weight is associated with the lowest risk of
complications during pregnancy and labour. In practice, however, there is a wide range of weight gains in
individual women who have normal and healthy pregnancies, with average weight gains of between 1116 kg.
During pregnancy a woman’s nutritional needs increase because the diet must provide sufficient energy
and nutrients:



to meet both the mother’s usual needs and provide extra for the growth of the breasts, uterus and
placenta
to meet the needs of the growing fetus
for the mother to lay down stores of nutrients to help the growth of the fetus, and for lactation
Nutrients and oxygen pass from the mother’s blood to the fetus from the placenta, via the umbilical cord.
In the last 3 months of pregnancy, the body has a slightly greater requirement for energy. This is a time
of rapid growth and movement for the growing baby
The estimated average requirement for energy (EAR) increases during the last three months of pregnancy
by an average of 0.8 MJ (200 kcal) per day. At this time a woman’s energy expenditure from physical
activity is usually reduced. If a mother’s food intake is very low at this stage and if her fat stores are low,
the fetus grows more slowly and the baby may have a low birth weight. This may increase the risk of
heart disease, diabetes and raised blood pressure many years later, in adult life.
It is important at this stage not to eat too many energy foods as weight gain may occur because of reduced
activity at this stage in pregnancy.
A diet high in fat and or sugar may result in the mother gaining weight during pregnancy which may be
difficult to loose after the birth and so she may have long term weight and associated health problems
such as varicose veins, diabetes, arthritis etc
Gaining too much weight may increase her risk of high blood pressure which in turn increases the risk of
pre eclampsia.
Poor diet during pregnancy may lead to obesity problems for the baby in later life. Children are more
likely to become overweight adults if their parents are obese
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Carbohydrates and fats
The source of energy should mainly be supplied by carbohydrates. Constipation can be a problem in
pregnancy. If it is, more NSP should be taken along with increased fluid intake and gentle exercise such
as walking or swimming.
A diet rich in saturated fats during pregnancy has been linked with later development of breast cancer in
children
Omega 3 fatty acids are required for the development of the fetal nervous system and are higher in the
last three months of pregnancy.
Iron
The mother must have enough iron during pregnancy to supply her own body and to provide the growing
baby with a store of iron for the first four months after birth. Breast milk and cow’s milk are both poor
sources of iron, so a store of iron is essential. A mother’s haemoglobin count is checked regularly during
pregnancy.
Iron needs are increased during pregnancy for the growth of the placenta and fetus. Consequently it is
recommended that pregnant women consume plenty of foods containing iron such as red meat, fortified
breakfast cereals, pulses, breads and green vegetables eaten as part of a normal diet. However, there is
also an iron saving because of the absence of menstruation (periods) and an increase in iron absorption
during pregnancy, so most pregnant women do not need extra iron during pregnancy. But some groups of
women (e.g. young women aged 15-18 years) typically have low intakes of iron before becoming
pregnant, and are at risk of developing anaemia. Iron deficiency anaemia during pregnancy can increase
the risk of the baby having a low birth weight and developing iron deficiency anaemia during the first
year or two of life. These women will be prescribed iron supplements and may also be given dietary
advice to ensure that their diets contain adequate amounts of all nutrients.
Protein
A little additional protein may be required for the development of the foetus’s body cells. Amino acids
are actively transported across the placenta to the fetus
Too much, however, could contribute to weight gain.
Folic acid
Women have been advised to ensure that their diet contains adequate supplies of folic acid before
becoming pregnant and during pregnancy, especially the first 3 months of pregnancy. Folic acid reduces
the risk of babies being born with neural tube defects such as spina bifida. It is required for the
development of the brain and nervous system in the baby
Calcium, phosphorous and Vitamin D
The baby’s bones are supplied with calcium provided by the mother’s diet. A diet low in calcium may
result in the formation and calcification of the baby’s bone being affected
It is important that calcium intake is maintained to ensure that calcium deposits from the mother’s bones
and teeth are not used for this purpose.
A diet low in vitamin D may result in poor calcium absorption and as a result the formation and
calcification of the baby’s bones may be affected
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A diet low in vitamin D can lead to low birth weight and tetany in the baby and osteomalacia in the
mother
Vitamin C
To enable iron to be absorbed, foods rich in iron and Vitamin C are required. Vitamin C is also required
for the baby’s tissue formation.
Vitamin A
Vitamin A is essential for good health. However, large intakes during early pregnancy have been linked
to birth defects. Women who are pregnant, or who might become pregnant, should not take vitamin A
supplements unless they are advised to do so by a health professional. Liver and liver products (e.g. paté)
may contain large amounts of vitamin A, so these should also be avoided.
Other factors to be considered during pregnancy
Alcohol
Drinking alcohol during pregnancy can damage the unborn child, so pregnant women are advised to avoid
alcohol
Drinking alcohol during pregnancy, especially in large quantities(alcoholism) may in some cases result in
foetal alcohol syndrome, this may affect growth, brain development, mental retardation and organ defects
in the unborn child.
Caffeine

The Food Standards Agency (FSA) advises pregnant women to limit the amount of caffeine they
consume to no more than 300 mg a day (around 4 cups of coffee). High levels of caffeine can
result in babies having a low birth weight, or even lead to pregnant mothers miscarrying. Caffeine
is added to some soft drinks and energy drinks, as well as occurring naturally in foods
Smoking
Pregnant women should not smoke. One effect of smoking may be to reduce the flow of blood to the
placenta and so reduce or slow down the supply of nutrients to the fetus and so affect fetal growth. This
may result in a low birth weight
Fish
The population guideline recommendation for fish consumption is at least two portions of fish per week,
one of which should be oily fish. This recommendation also applies to pregnant and breast-feeding
women, but they should limit oily fish to up to 2 servings per week). Also these groups of women should
avoid the fish marlin, swordfish and shark because of potential exposure to methylmercury exposure. The
FSA also advises pregnant women that the amount of tuna eaten should be limited to no more than 2 tuna
steaks per week or 4 medium-sized cans a week. This is again because tuna may contain mercury, which
at high levels can harm a baby’s developing nervous system.
The basis of these recommendations is that the consumption of fish, particularly oily fish, confers
significant health benefits in terms of protection against heart disease. This is attributed to the long chain
n-3 (omega-3) polyunsaturated fats of which oily fish is a rich source. These types of fatty acid are also
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required for the development of the central nervous system in the fetus and young infant, so are important
for both pregnant and breastfeeding women. However, the FSA has set a maximum limit on oily fish
consumption due to the risk of exposure to pollutants such as dioxins and polychlorinated biphenyls
(PCBs) which have been found in oily fish.
AA (arachidonic acid) and DHA (docosahexaenoic acid) are long chain polyunsaturated fatty acids that
are important for fetal development of the brain, nervous system and retina and so an adequate supply is
essential during pregnancy. Whereas AA can be synthesised from another fatty acid, linoleic acid, DHA
can only be synthesised to a limited extent. Therefore dietary DHA is particularly important and the best
source is oily fish, in which DHA is available pre-formed, although it can also be obtained from foods
fortified or enriched with DHA.
Physical activity
Staying physically active during pregnancy is important to promote general health and help to alleviate
common complaints during pregnancy such as backache and constipation. Useful activities include
swimming, some forms of yoga, toning and stretching, which can be done at any stage of pregnancy.
Harmful bacteria
Listeriosis is a rare flu-like illness caused by bacteria called Listeria monocytogenes. Listeriosis in
pregnancy may cause miscarriage, still-birth or severe illness in the newborn baby. Although it is rare in
this country, pregnant women are advised to avoid those foods where high levels of the bacteria have
occasionally been found, for example paté and blue-veined and soft cheeses such as Brie and Camembert.
For similar reasons, it is emphasised that pregnant women re-heat ready-cooked meals (particularly those
containing poultry) until they are piping hot and that they wash fruit and vegetables well, especially if
they are to be eaten raw (which is also the advice given to the general population).
Toxoplasmosis is an illness caused by a parasite which can be found in cat faeces. The parasite can also
be present in raw meat and occasionally goat’s milk. The illness can in rare cases, be passed to the unborn
baby via its mother, resulting in a range of problems, some of them serious. As a safeguard, pregnant
women should not eat raw or undercooked meat, unpasteurised goat’s milk or goat’s cheese, or unwashed
raw fruit and vegetables. Good food hygiene practices should be followed in the kitchen and contact with
cat litter trays or soil that may have been fouled by cats should be avoided by wearing gloves.
Salmonella poisoning is particularly undesirable during pregnancy, although it is not likely to have a
direct adverse effect on the baby. As a precaution, pregnant women should avoid eating raw eggs or food
that contains eggs that are raw or partially cooked. Eggs should be cooked until both the white and yolk
are solid. Raw meat and chicken can also be a source of salmonella bacteria. All meat, especially poultry,
should be thoroughly cooked and it is important to avoid contamination of other foods by washing hands
after touching raw meat and by preventing raw meat and poultry from touching or dripping onto other
food (e.g. in the fridge), especially that which is already cooked or will be eaten raw.
LACTATION
Advice states that breast-feeding is the best method of feeding for babies. A varied diet is important
whilst breast-feeding to ensure a sufficient intake of all nutrients needed by both the mother and the
baby.
The production of milk requires a supply of nutrients. Some, such as energy, will be partly met from the
mother’s stores.
Breast-feeding mums may also advised to take supplements containing 10 mcg of vitamin D each day.
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Advantages of breast feeding
1. Pyschological benefits
 Mother bonds with child and establishes a close emotional attachment to the child
2. Health benefits
 Breast milk contains anti bodies and other protective substances which provide specific
protection for the child and encourages growth and development of infant tissues and
organs
 Baby is less likely to become overweight because baby decides when full and stops
feeding.
 No likelihood of allergies to breast milk
 Greater resistance to infection especially gastro – intestinal infection and diarrhoea
 Medical evidence suggests that babies who are breast feed have a lower risk of developing
asthma
 Breast feeding may help the mother to loose excess fat stores gained during pregnancy
 Medical evidence suggests that women who breast feed and breast fed babies have a lower
risk of developing breast cancer
 Breast milk contains essential fatty acids ie omega 3 and 6 which assist in brain
development of the baby
3. Hygiene benefits
 Human milk is germ free
 Less chance of stomach upsets through unhygienic preparation of feeds
4. More convenient and labour saving
 No preparation time is needed and there is less hassle
 No equipment to sterilise
 Possible to feed baby on demand and quickly if necessary
 Cannot be prepared incorrectly
5. Easier to digest and suitable for all babies
 Easier to digest therefore less chance of nappy rash and stomach upsets
 Milk contains all the energy and essential nutrients needed by babies and in the correct
proportion
6. More economical
 No extra equipment is needed, no milk formulae to buy - breast feeding is free
 Always at the correct temperature so no heating is needed
INFANTS / YOUNG CHILDREN
Key points
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Encouraging pre-school children to eat a healthy, varied diet will provide all the nutrients they
need for healthy growth and development and help to establish good eating habits for life. Poor
eating habits may be difficult to change in later life
Poor diet in childhood can lead to health problems in later life
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Young children who are growing and are usually very active have high energy and nutrient
requirements in relation to their size.
Young children have small stomachs and may not be able to obtain all the energy and nutrients
they need if their diet contains too much fibre. Such diets can sometimes reduce the amount of
minerals they can absorb, such as calcium and iron.
By the time they are 5 years old, children should be eating family food and consuming a varied
diet
A healthy diet will help children avoid becoming overweight or obese
Regular meals, consisting of small attractive servings and a pleasant atmosphere are important in
encouraging young children to eat
Include the use of naturally brightly coloured foods in meals and snacks
Introduce new tastes and textures gradually.
Use food products which are additive free
Dietary guidelines
Energy
A variety of foods should be introduced so that a range of nutrients are obtained.
 Children’s energy requirements increase rapidly because they are growing quickly and becoming
more active. They have a high energy requirement for their size. To achieve this energy intake,
foods which are high in energy (and also rich in nutrients) and eaten as part of small and frequent
meals may be necessary for younger children, who do not have large enough stomachs to cope
with big meals.
 Some complex carbohydrate foods such as wholemeal bread, potatoes should be included to
supply energy
 Do not include too much NSP rich foods as this will be very filling and children would be unable
to eat enough food to supply all the other nutrients they need
 Avoid giving children too many foods high in fat and fried foods – as children approach school
age their fat intakes should be in line with the Scottish dietary recommendations
 Choose lower fat versions of some dairy produce eg yoghurts
 Whole milk is recommended for children over the age of 12 months as a main drink as it is a rich
source of a number of nutrients. Semi-skimmed milk can be introduced after the child is two, as
long as the rest of the diet provides enough energy. Skimmed milk is not suitable for children
under five years of age, as it does not provide enough energy and vitamin A for the growing child.
 Avoid too many sugary foods as this will contribute to obesity and tooth decay. Avoid giving
sweets as a reward and avoid sugar coated breakfast cereals
Protein

Protein is required for growth of new body cells and tissues as well as repair of damaged tissues
through play, falls etc. Children will be going through a growth spurt at this age.
Calcium, phosphorus and Vitamin D
 Calcium, phosphorous and Vitamin D are required to form and maintain strong bones and teeth.
 Young children need plenty of calcium in their diets for healthy bones and teeth. Dairy products
such as milk, cheese and yogurt are good sources of calcium. Other foods such as white bread,
dark green leafy vegetables, pulses (e.g. baked beans) and fortified cereals can also contribute to
calcium intake.
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Iron
 Supply iron rich foods to prevent anaemia eg add dried fruits to breakfast cereals. Red meat is the
best source of easily absorbable iron and can be offered to children from 6 months of age. Iron
rich foods, such as liver and red meat, may not be popular with young children, so other ways of
providing this nutrient must be found, Children who are vegetarian must have alternative sources
of iron, such as green vegetables and pulses. Other useful sources include bread and some
breakfast cereals. Iron from plant sources is less well absorbed than iron from animal sources but
can be improved by consuming vitamin C rich foods or drinks (such as orange juice) with a meal.
Vitamin C
 Vitamin C is required to assist the absorption of iron and prevent anaemia, particularly since the
volume of blood increases during the early years.
 Necessary for healing wound/sores – children may be active and be more at risk of injury
 Encourage the eating of fruit and vegetables as a low fat and sugar snack. Serve vegetable sticks
as snacks and give fresh and dried fruits as snacks in order to supply Vitamin C
Sodium
 Avoid salty foods as this encourages a liking for salt in the diet. Avoid salty snacks and a lot of
processed foods in the diet
TEENAGERS
General points
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Adolescence is a period of rapid growth, body development and a high level of activity and as a
result nutrient requirements increase at this stage
Not all teenager have high activity levels and his must be reflected in the energy intake if obesity
is to be avoided.
Many teenagers have a tendency to “graze” on snack or fast foods so it is essential to encourage a
healthy diet.
Food habits during teenage years will affect health in later life
Smoking is extremely detrimental to bone health and alcohol should only be drunk in moderation,
as it is a toxin to bone cells. Teenagers should establish a regular exercise programme as exercise
can increase and stimulate bone density
Dietary guidelines
In addition to the normal functioning f nutrients, teenagers have increased requirements for:
 Energy- especially if participating in games and sports
Males need more energy than females because:
(a) they tend to have a larger body size than females and so require more energy
(b) they may be more active than females and so will need a greater amount of energy to supply the
cells
(c) males tend to be more muscular than females and so will have a greater need for energy sources to
the muscles.
Energy should be supplied in the form of complex carbohydrates. Vitamin B complex is required to
release energy from carbohydrate foods.
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Protein
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Teenagers require protein for their rapid growth spurt and to repair damaged tissues especially if a lot
of sports are played
 Calcium
About 45% of the adult sized skeleton forms during adolescence, so plenty calcium and phosphorous
foods should be eaten to ensure the proper formation of bones and teeth. Vitamin D will promote the
absorption of calcium.
 Iron
For both males and females, iron requirements increase as blood volume expands throughout growth.
Iron is particularly important, especially in early adolescence for girls, to prevent anaemia developing
when menstruation starts.
Teenagers may be susceptible to anaemia if diet is poor.
 Sodium
Low intake may result in muscle cramps e.g. if the teenager get dehydrated
Excess can cause high blood pressure as the result of the expansion of extra cellular fluid volume –
particularly dangerous in later life, important not to start bad habits at this age
 Phosphorus
An essential component of all bones along with calcium to ensure strong bones and teeth are
developed and maintained during teenage years. It is also vital in the repair of bones e.g. after an
injury
 Vitamin C
Vitamin C is required to assist the absorption of iron and prevent anaemia, particularly since the volume
of blood increases during the teenage years. Plenty of fruit and vegetables should be eaten to provide this
anti oxidant vitamin.
Necessary for healing wound/sores – teenagers with active lifestyles may be more at risk of injury
Antioxidant properties are beneficial to teenagers to help prevent cancers/heart disease in the future
 Vitamin A
Has anti-oxidant properties – important for teenagers to reduce the risk of cancers/disease in the future
Required to keep the mucous membranes in the throat, digestive and bronchial and excretory systems
moist and free from infection
Also needed for the maintenance and health of the skin – important for people of this age to look good
 Vitamin B complex
Allows the chemical reaction to occur which releases energy from CHO – important for teenagers
especially those who are very active
Teenagers must ensure adequate supplies to obtain energy from their food otherwise they will be
lethargic, which may be common behaviour at this age anyway and lack of B vitamins could make it
worse
 Folic Acid
Essential for the formation of red blood cells and the prevention of megaloblastic anaemia – vital for
teenagers who require increased iron at this stage of development as it can act as a ‘back up’ if iron is
lacking
Required for the release of energy from food
Required for normal growth in children, particularly important during the teenage ‘growth spurt’
Maintains muscle tone – important for active, sporty teenagers
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Vitamin B12
Important for the production of red blood cells to help prevent pernicious anaemia. Teenagers may be
susceptible to anaemia due to muscle development (boys) and menstruation (girls)
Vitamin D
Required to promote the absorption of calcium and phosphorus to build strong bones and teeth – vital for
developing teenage bones and teeth
Promotes quicker healing of fractures which active teenagers may be more prone to
Vitamin E
Antioxidant properties – it protects polyunsaturated fatty acids from damage by free radicals, especially
cell membranes in the body - beneficial to teenagers to help prevent cancers/heart disease in the future
Vitamin K
Assists in the production of coagulation factors in the blood to enable it to clot properly after an accident
– vital at all stages of life.
ADULTS
General points
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The nutritional requirements of an adult will vary greatly depending on age, gender, lifestyle and
occupation
Body growth declines in adulthood
Adults require a good diet to maintain and repair the body and to keep it healthy
Activity levels along with body size will determine the energy and nutrient requirements
Women will need less food than men but will need more iron because of menstruation
For women their nutrient requirement will change during pregnancy and after the birth of a baby
Dietary guidelines
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Adults who are not very active need to pay careful attention to their energy intake, because if
energy intake exceeds energy output then the result will be weight gain. Meals and portion sizes
should be varied according to energy needs
In comparison to adolescents, energy requirements are lower for both men and women, as are
requirements for protein, calcium and phosphorous
Reducing the intake of saturated fats, while increasing the totals complex carbohydrates (TCC)
foods will provide sufficient energy for active adults.
ELDERLY
Factors affecting dietary intake in order people.
Physical changes which may affect diet are:
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Decline in the senses of taste and smell
Dentition and the state of the mouth play an important part in the food intake Deteriorating teeth
can cause difficulty with chewing and may result in the eating of a more restricted range of foods
eg avoiding foods tha need a lot of chewing such as raw carrots, apples, toast
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Decreased salivary secretion
Medication may result in loss of taste and dry mouth
Reduced secretion of hydrochloric acid in the stomach affecting absorption of calcium, iron and
vitamin B12
Insensitivity to thirst. Dehydration is common in the elderly and it causes confusion and
constipation
Decline in renal function (kidney), affecting drug excretion and maintenance of water balance
The effect of medication, often long term, on nutrient requirements and appetite
Mental illness and depression are also likely to affect food intake. There may be a complete
disregard for eating with a loss of time sense so that mealtimes are ignored
Lack of mobility eg people with arthritis, may cause difficulty in shopping, preparing and
cooking food
Possible reduction in the efficiency of the immune system, making infections more likely
Social factors affecting diet are :
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Availability of money – many retired people live on a fixed income. A limited budget may
influence food choice.
Lack of education about the importance of nutrition
Social isolation may be the result of retirement, rehousing, death of friends and relatives.
Where an effort is made to share food and eat in company, food intake is better.
An elderly person living alone may lack the motivation to prepare a balanced diet and may
snack on prepared high fat and sugar foods.
Dietary requirements
In general, as people get older their dietary needs approach those of the very young: that is , they need a
diet which is nutrient dense, since energy requirements fall but nutrient requirements do not. Elderly use
the nutrients for general functions but some may have more importance than others
Energy
Elderly have a wide range of energy requirements. A fit active retired person may be more active than
when they were at work, whilst others, because of infirmity, may be chair or bed bound. Generally as
people grow older, they need less energy as usually they are less active
The gradual loss of lean body tissue with age reduces the basal metabolic requirements
More elderly people are overweight than underweight due to lack of exercise
Obesity can be a problem – increased risk of heart disease, high blood pressure, extra weight puts undue
strain on joints
Non Starch Polysaccharides (NSP)
Constipation is common in the elderly. To alleviate this, an increased intake of foods high in NSP is
recommended. Sufficient liquid should be drunk and exercise will also help prevent constipation. The
elderly often may not have sufficient fruit and vegetables in the diet due to cost or difficulty in
preparation.
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Protein
A reduce income may mean that it is not possible to buy much meat or other protein foods. Elderly people
may avoid protein foods like meat because of their cost and texture. Protein intake must be used for
wound healing and tissue repair rather than for energy needs
Micro nutrients
There is a lack of specific recommendations for older people for many of the vitamins and minerals,
although it is known that the ability to digest, absorb, metabolise and excrete nutrients changes with age
(e.g. vitamin B12 absorption is decreased because the intrinsic factor needed for its absorption is thought
to decrease with age).
Some older people, especially those living in institutions, may have low intakes or low blood levels of a
range of micronutrients.
Minerals
Iron
 Elderly should be encouraged to eat foods rich in iron to prevent anaemia eg meat, eggs, breakfast
cereals, bread, beans. They may be susceptible to anaemia as the desire to cook wanes
 The elderly may have poor absorption of iron.
Calcium
 Eating several sources of calcium will keep bones healthy and prevent osteoporosis eg milk,
cheese, bread, breakfast cereals
 Calcium is also required for blood clotting, which could be important as the elderly may be at
more risk of falling
 An essential component of all bones so is required to help prevent osteoporosis and will help with
bone repair if the elderly person falls
Sodium
 An excess of sodium is particularly dangerous in the elderly as it will cause high blood pressure
as a result of the expansion of extra cellular fluid volume
Potassium
 A deficiency may result in muscular weakness and potassium is also linked with a reduced risk of
hypertension
Vitamins
Vitamin D
 If elderly are housebound then they may lack exposure to sunlight and be at risk from a
deficiency of Vitamin D. This will lead to poor absorption of calcium and may cause
osteomalacia
 Vitamin D is the only vitamin where there is an increased recommendation for the elderly as
there may be an inadequate exposure to the sun in summer
 Kidney function declines with age and this results in less efficient production of the active
substance from Vitamin D.
 People aged 65 years and over may have to take a vitamin D supplement as well as regularly
eating food sources (e.g. oily fish, cod liver oil and margarine).
Vitamin A
 A good intake of this anti oxidant vitamins is important as the elderly are more at risk from
cancers and CHD
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Necessary for good night vision – the elderly often have failing eyesight
Elderly who have difficulty in chewing would benefit from fruit and vegetables being pureed to
meet dietary needs for fruit and vegetables
Vitamin C
 A good intake of this anti oxidant vitamins is important as the elderly are more at risk from
cancers and CHD
 Assists with the absorption of iron to prevent anaemia – elderly sometimes do not have a balanced
diet and cannot be bothered to prepare fruit and vegetables.
 Elderly who have difficulty in chewing would benefit from fruit and vegetables being pureed to
meet dietary needs for fruit and vegetables
As well as attention to diet, elderly people should take part in some exercise which would improve
fitness, muscle strength and flexibility. This would help them continue the everyday activities that are
essential to independent living.
VEGETARIANS
Types of vegetarians
People follow a vegetarian diet for a variety of personal, philosophical, ecological and economical
reasons. Variations in strictness of vegetarianism are largely dependent on the person’s beliefs and
reasons for adopting vegetarianism. This may be for a variety of personal, philosophical, ecological and
economical reasons.
Lacto-ovo-vegetarian
Lacto- ovo vegetarians do not eat meat, meat products or fish. They will eat animal products such as
eggs, milk, cheese and dairy products
Lacto-vegetarian
Exclusion of all meat, fish and poultry and eggs; milk and milk products are still consumed
Vegan
Exclusion of all foods of animal origin; diets comprise grains, vegetables, vegetable oils, cereals, pulses
such as beans and lentils, nuts, fruit and seeds. Non-food animal products, such as leather, may also be
avoided.
‘Semi’ or ‘demi’ vegetatarian
Exclusion of red meat or all meat, but fish and other animal products are still consumed; some people also
include poultry
Pesco-vegetarian
Exclusion of all red meat and poultry, but fish and other animal products are still consumed
.
Fruitarian
Exclusion of all foods of animal origin as well as pulses and cereals. Diets mainly comprise raw and dried
fruits, nuts, honey and olive oil. People following this type of eating pattern are at great risk of nutritional
deficiency; their diets require vitamin and mineral supplementation
Macrobiotic
The diet progresses through a series of levels, gradually eliminating all animal produce, fruit and
vegetables and, at the highest level, leading to a restricted diet of cereal (brown rice) only. Fluids may
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also be severely restricted. Children are particularly at risk of nutritional deficiency and studies have
shown that growth patterns are disrupted by the most restricted macrobiotic diets.
Nutrition for vegetarians
Provided a vegetarian diet is well balanced, it should provide all of the nutrients needed by the body
throughout life
Protein
Protein from animal-derived food contains all of the amino-acids (protein ‘building-blocks) that the body
needs, and so a vegetarian diet that includes animal products is likely to contain enough high quality
protein.
Most plant food proteins (with the exception of soya) have a low content of one or more of the amino
acids needed by the body (essential amino acids). Furthermore, different ones are missing in different
plant foods. Therefore, plant foods can be combined to provide high quality protein. Complementary
combinations include:
 Pulses/rice – bean casserole and rice, dhal and rice
 Pulses/cereal - baked beans on toast
 Nuts/cereal – peanut butter sandwich, nut roast
If the proteins from different plant sources are eaten together (or at least over a day), the amino acid
profiles of the plant proteins will complement each other. Deficits in amino acids in any one plant protein
will be compensated for by the amino acids in another. Thus if vegetarians and vegans eat a variety of
vegetable proteins there is no reason why their intake of protein cannot be as good as that of a person who
eats meat or other foods that contain animal protein.
Carbohydrates
Vegetarians need to use complex carbohydrate as a source of energy
The high intake of NSP in vegetarian will have a positive effect on health, as more pulses, nuts, fruits
and vegetables are consumed
Fats
Lacto – ovo vegetarians should limit their consumption of dairy foods such as cheese, butter, whole milk
to avoid a large intake of saturated fats. Reduced fat versions of these foods should be used
With vegans the saturated fat content of the diet will be lower as more polyunsaturated fats are consumed
Minerals
Calcium
Vegetarians who consume milk and milk products are likely to have adequate intakes of calcium.
Vegans can obtain adequate calcium from plant foods. Good sources include tofu, green leafy vegetables,
watercress, dried fruit, seeds and nuts. White bread is fortified with calcium, as are soya milks. The
presence of phytic acid in wholegrain cereals and NSP may make calcium unavailable to the body
Where requirements for calcium are high,supplements containing calcium and calcium-fortified foods
(such as fortified soya products) may be useful.
Iodine
Lacto-ovo-vegetarian diets usually contain adequate amounts of iodine, but vegans are at risk of low
intakes. On the other hand, those who consume a lot of seaweed may have excessive intakes of iodine.
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Consumption of small amounts of iodised salt or seaweed is therefore advisable for those following a
vegan diet to ensure sufficient intake.
Iron
Much of the easily-absorbed iron (haem iron) in non vegetarian diets comes from red meat and offal.
Plant foods contain no haem iron at all. Iron from non-haem sources such as eggs, cereal products, green
vegetables, nuts and pulses is less well absorbed, but the presence of vitamin C from fruit, fruit juices and
vegetables will enhance the absorption of non-haem iron; for example, having beans on toast and a glass
of orange juice at the same meal. However, tea (because of tannins) and the plant substances phytate and
NSP may reduce iron absorption. Iron may be unavailable to the body from certain plant foods due to the
presence of phytic acid.
Provided sufficient iron is included in the diet, iron deficiency anaemia is not common amongst
vegetarians and vegans, but iron deficiency anaemia has been reported in macrobiotic vegetarians who
followed a very restrictive diet and consume brown rice, which is rich in phytates, as their staple food.
Zinc
Foods considered to be the best sources of this mineral include meat, poultry, dairy products, bread and
other cereal products, and seafood. If many of these foods are excluded, dietary intake may be low but it
is thought that adaptation to the diet might occur with time, resulting in an increase in the proportion of
zinc absorbed from the intestine.
Good plant sources of zinc include bread and cereal products, pulses, nuts and seeds, but many of these
are also high in phytate, which inhibits of zinc absorption. Although unrefined foods (e.g. wholemeal
bread and brown rice) do contain more phytate, they are still preferable to refined sources, which contain
less zinc and other micronutrients.
Vitamins
Most vitamins can be provided by foods of plant origin. However, vitamin B12 is found only in foods of
animal origin, and there are few plant sources of vitamin D.
Vitamin B12
Although the body’s requirement for vitamin B12 is only a few micrograms per day, it is essential that
vegans, and other people who avoid all animal foods, include a source of vitamin B12 in their diet, either
as a supplement (usually in tablet form) or as fortified foods (such as yeast extract, fortified soya milk or
fortified breakfast cereal).
Vegans may be at risk of developing megaloblastic anaemia.
Vitamin D
Low vitamin D intake has been found among the Asian population, particularly among children,
adolescents women and the elderly, many of whom are vegetarian. Prolonged deficiency of vitamin D
results in rickets in children and osteomalacia in adults. A combination of factors may be associated with
low vitamin D status including:
 low exposure to sunlight: this may be due to seclusion or strict dress codes limiting vitamin D
synthesis in the skin.
 type of vegetarian diet: vitamin D is found naturally in only a few foods, all of which are of
animal origin, for example meat, oily fish such as mackerel and sardines, eggs, whole milk and its
products.
 fortified foods further ensure adequate amounts eg vegetable margarines, soya milks. Some
breakfast cereals, yoghurts and all margarines (required by law in the UK to contain vitamin D)
and reduced fat spreads are fortified with vitamin D.
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WEIGHT REDUCTION DIETS
See also notes on “Obesity”
Many people in the UK are overweight although average energy intakes of the population have decreased
over the past few years, activity levels have also dropped. People are taking less exercise, there is now
more labour saving devices and these factors may contribute to the increase in the number of people who
are overweight or obese.
Why do people put on weight?
If we eat food which provides more energy than we need for our normal activities and lifestyle, this extra
energy is stored as body fat. For body weight to remain constant, energy intake must equal energy output.
Dietary guidelines
The most effective and healthy way to reduce weight is to take in slightly less energy from food than the
body needs each day. The body then makes up the difference by releasing energy it has stored as fat.
Gradually the stores of fat are reduced. Usually a diet promoting 1000 – 1500 Kcals per day is
recommended depending on the individual. In particular –
 Cut down on total intake of food eaten each day
 Cut down on sugary and fatty foods.
 Eat more total complex carbohydrate, NSP rich foods and fruit and vegetables which are low in
calories and are good sources of NSP , vitamins and minerals. These foods are filling and will help
prevent snacking on sugary , fatty foods.
 Use cooking methods which do not involve adding fat.
Very low calorie diets, “crash” diets and meal replacement drinks are advertised as a quick and easy way
to lose weight. These types of diet can cause problems because –
1.
2.
3.
4.
5.
They do not encourage the dieter to change their eating habits in the long term.
Once normal eating resumes, weight may be put back on quickly.
They often lead to loss of muscle instead of fat.
They may not be nutritionally balanced.
They can be expensive.
SPORTS PERFORMANCE
Good nutrition will not guarantee athletic success but without it, an athletes full potential will not be
realised. The increased need for specific nutrients depends not only on the amount of exercise
undertaken but also the type, intensity and duration of the physical activity.
Carbohydrates
High levels of physical activity, for example in intensive training for competitions, will require an
increase in energy intake. Carbohydrate is the most important fuel for an active person and is stored in the
muscles as glycogen. This store of glycogen needs to be topped up each day
Many sports include very high exercise intensity which may be of short duration such as sprinting or
energy over a longer time in endurance sports such as cycling races. During endurance sports the body
uses energy from its own energy stores – fat from adipose tissue and carbohydrates stored as glycogen in
the liver and muscles.
The energy used will have to be replaced by a nutritionally balanced diet which meets the extra energy
needs. Care must be taken to ensure that the diet does not become unbalanced if athletes consume too
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many high energy density snacks which are too high in fat and too low in carbohydrate and micro
nutrients.
A low fat, high carbohydrate snack or light meal should be eaten about 2 – 3hours before exercise – this
allows time for the stomach to empty before the sports event. Athletes should then start refuelling energy
stores after exercise with low fat, high carbohydrate food. After strenuous exercise, approximately 1g of
carbohydrate per kg body weight should be consumed. If the exercise was light then 50g of carbohydrate
should be enough.
An insufficient supply of carbohydrates to muscles can lead to fatigue during prolonged physical activity.
Consumption of glucose or other carbohydrates before or during exercise has shown to postpone fatigue,
conserve muscle glycogen and improve performance. A sufficient supply of the B complex vitamins
should be eaten in order to ensure the release of energy from food.
The type of carbohydrates which should be consumed include plenty of starch rich foods such as bread,
pasta, rice and cereals. High fibre varieties should be chosen.
Sweet sugary foods should only be consumed in small amounts. They can be useful sources of
carbohydrates if energy requirements are high
Fluid
Fluid needs also need to be increased in response to training, with additional fluid losses from sweating
being influenced by the intensity and duration of exercise and climatic conditions.
Large sweat losses may cause severe dehydration, impaired blood circulation and heat transfer, leading to
heat exhaustion and collapse. As well as looking after total fluid requirements over the day, the athlete
should also take to drink before, during and after each workout.
Water is an excellent sports drink but if the exercise is strenuous or if it lasts longer than an hour then
dilute fruit juices or a suitable sports drink should be consumed as these will supply some carbohydrate as
well as fluid
Protein
Strength and endurance athletes do have a higher requirement than the average person for protein.
However this requirement can usually be met by having a healthy balanced diet so no additional sources
of protein require to be eaten.
Protein is needed to support muscle gain and repair damaged body tissues. If insufficient carbohydrate is
eaten to fuel muscles, then protein will be used instead.
Studies have shown that the large protein supplements taken by many athletes are not effective either in
increasing muscle mass or boosting performance
Vitamins and minerals
There is no convincing evidence as yet that any particular vitamin or mineral supplements boost
performance in athletes who eat a nutritionally balanced diet.
There may be small increases in requirements for some water soluble vitamins, such as vitamin C,
thiamine, niacin and riboflavin, in those athletes who take part in very vigorous activities. However a well
balanced diet should provide these.
Vitamin and mineral supplements may be required by athletes who restrict their energy intake, use severe
weight loss practices or eat a high carbohydrate diet with a low micronutrient content.
Some athletes are at risk of becoming iron deficient. Iron requirements may need to be increased due to
growth needs.
Anaemia in athletes is usually due to low dietary intake. This is more likely in athletes, often female
athletes, who restrict their energy intake to keep their body weight low.
Exercise may increase iron losses and it may impair the increase in iron absorption that normally happens
when iron stores are low.
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Inadequate iron intake can reduce exercise performance. Athletes with low iron stores often complain of
tiredness and an inability to recover after heavy training.
Many female athletes have such low body weight that they stop menstruating. A serious outcome of
menstrual disturbance is either the high risk of direct loss of bone density or failure to gain peak bone
mass that should occur usually 10 – 15 years after the onset of puberty. This may affect their bone health
and make them more prone to developing osteoporosis in later life.
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UNIT : Resource Management
Elaboration
Content
Nutrients and their effect on the health
and development of individuals
Protein
Fats – saturated, unsaturated, trans fatty
acids
Carbohydrates
Reference should also be made to sections on Health of Individuals,
Micronutrients, Anti oxidants and Dietary diseases
It is important for good health to eat a balanced diet. A balanced diet provides all the necessary nutrients
in the correct proportions and quantities to meet our needs. One way to follow a balanced diet is to make
sure we eat a variety of foods which supply a range of nutrients.
PROTEIN
Our bodies are composed of millions of cells which are constantly being replaced and repaired. As the
body grows, new cells are added. Each cell contains a substance called protoplasm which contains
protein.
There are many different proteins and they are all complex molecules which contain oxygen, carbon,
hydrogen and nitrogen.. The protein molecules are made up of small units joined together like links in a
chain. These units are called amino acids.
At least 22 amino acids are known to occur naturally. Different proteins are made when different numbers
and types of amino acids combine. Of the 22 amino acids
some are called essential amino acids. These must be supplied by the protein in the diet.
Sources
 Proteins are made up of amino acids.
High Biological Value proteins (HBV)



Proteins that contain all the essential amino acids are called High Biological Value proteins (HBV)
These are found mainly in animal sources such as meat, cheese, fish, milk, eggs.
The plant food soya beans contain HBV protein
Low Biological Value proteins (LBV)


Proteins that lack one or more of the essential amino acids are called Low Biological Value proteins
(LBV)

These are found mainly in plant food such as
- cereals eg wheat, rice, oats
- pulses eg peas, beans, lentils
- some nuts, quorn
LBV protein foods are not inferior to HBV protein foods. If a combination of LBV foods are eaten
together eg beans on toast then the essential amino acids which are limited in one are provided by the
other. In this way, proteins complement each other to provide a sufficient supply of essential amino
acids
Functions
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Proteins are essential to life, all living cells are built and replaced by protein molecules
The main purposes of protein are:
 Growth and maintenance of cells
The number of cells in the body increase during periods of growth so in childhood and adolescence
protein requirements increase.
Protein is also used to form enzymes and anti bodies and some hormones. These substances are
produced within cells.
 Repair of cells. Protein in the tissues is constantly being broken down and must be replaced by
amino acids from the diet. This happens at all stages of life
The secondary purpose of protein is to provide energy
Excess protein will provide the body with energy, once it has been used for its main purpose of growth,
repair and maintenance.
However if there is dietary deficiency of energy, protein will be used first as an energy source rather
than for growth and repair. Adding carbohydrate to such a diet will “spare” the protein for its main
purpose.
Protein requirements
Everyone needs some protein in their daily diet, even when they have stopped growing, but at certain
times there are increased needs
Babies and children require a lot of protein as they are growing rapidly
Adolescents require protein for their rapid growth spurt
Pregnant women require a little more than usual to cater for the growing baby
Lactating mothers require more than usual for milk production during breast feeding
FATS
 The term “fat” includes both fats (solid at room temperature) and oils (liquid at room temperature
 Fat is present in food either as “visible” or “invisible” fat
- Visible fat is easy to detect in food eg fat on meat, butter, margarine, lard, cooking oil
- Invisible fat is a constituent part of food and is difficult to detect eg pastry, cakes, biscuits
FUNCTIONS OF FATS







Provide a concentrated source of energy
Provide essential fatty acids It contains the essential fatty acids (EFAs), linoleic acid (n-6 – omega
6) and alpha linolenic acid (n-3- omega 3). These and fatty acids synthesised from them are important
in the formation of cell membranes particularly in nerve tissue. At least 1.2% of energy intake should
come from EFAs
Provides a source of fat soluble vitamins A,D,E and K
Surrounds and protects certain vital organs such as the kidneys
Forms an insulating layer underneath the skin and so helps maintain body temperature
Foods containing fat provide a feeling of fullness (satiety) through consumption of foods containing
fat
Required for the structure of all body cells
Fats can be classified into:
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SATURATED FATS
UNSATURATED FATS
1. SATURATED FATS




Important points
Fats which are solid at room
temperature are mostly made of
saturated fatty acids
A diet high in saturated fats tend to
raise blood cholesterol levels
(particularly the low density
lipoprotein – LDL, the “bad”
cholesterol) in some people so
increasing the risk of heart disease
The LDL tends to stick to artery
walls, increasing the risk of blood
clots and blockage of the artery.
Certain cancers such as bowel and
breast cancer have been linked with
high intakes of saturated fats.
Sources
Mainly of animal origin
 Meat and its products eg pies,
sausages, lard, suet
 Fats eg butter, hard margarine, some
blended cooking oils
 Milk and dairy products eg butter,
whole milk, cheese, cream, eggs
But also
 Coconut oil and palm oil which are
used to make biscuits, pastry, cakes
2 UNSATURATED FATS
Important points
A. Monounsaturated fats
 Monounsaturated remain liquid at room temperature, but
start to solidify when chilled
 Monounsaturated fats reduce the bad LDL cholesterol but
also maintains or slightly increases the good High Density
Lipoprotein (HDL) cholesterol
 HDL cholesterol helps to ferry the cholesterol away from the
arteries to the liver where it is broken down into bile
B Polyunsaturated fats
 Polyunsaturated fats usually remain liquid at both room
temperature and cold temperatures.
 Polyunsaturates help to bring down blood cholesterol levels
 There are specific polyunsaturates which are vital for health
and cannot be made in the body. These are called Essential
Fatty Acids (EFA’s) and must be obtained from food.
Essential Fatty Acids
The two main EFA’s are
i ) Omega 3 (or Alpha Linolenic acid)
Omega 3 reduces the tendency of blood to clot so reducing
Sources




olive oil
rape seed oil
avocados
nuts

oily fish eg mackerel and
sardines
pure vegetable oils eg
sunflower, soya
nuts and seeds


Omega 3
 Oily fish – mackerel,
pilchards, sardines,
herrings, trout
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the risk of a heart attack.
It may also reduce the incidence of inflammatory diseases
such as rheumatoid arthritis.
ii) Omega 6 (or Linoleic acid)
These tend to decrease bad cholesterol but too much may also
decrease good cholesterol
Both Omega 3 and 6 are needed for brain development of
babies. Humans make special linolenic and linoleic acids in
breast milk. This is one of the reasons why human breast
milk is best for babies.

Another type of polyunsaturated fat is called Trans Fatty
Acids
Trans Fatty Acids
These fats are polyunsaturated fats artificially hardened by
adding extra hydrogen.
They cause an increased risk of heart disease and rheumatoid
arthritis
Trans fatty acids increase blood levels of bad cholesterol and
may reduce levels of good cholesterol.
Trans fatty acids are not listed on food ingredients but
hydrogenated or partially hydrogenated oils are listed
Omega 6
 Polyunsaturated
margarine
 Corn, sunflower and soya
bean oils





Hard margarine
Biscuits and cakes
Commercially fried foods
eg French fries from fast
food chains
Packaged snacks
Any food label that
indicates hydrogenated or
partially hydrogenated
fats / oils
3. CARBOHYDRATES
FUNCTIONS OF CARBOHYDRATES
 Supply energy for all activities
 Supply energy to maintain normal body temperature
 Supply indigestible fibrous material (NSP: Non Starch Polysaccharides)) to aid digestion
 Are important in the structure of cells
Carbohydrates can be subdivided into three main groups
1 Monosaccharides (sugars)
2 Disaccharides (sugars)
3 Polysaccharides (starches)
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Important points
Sources
1. Monosaccharides
Monosaccharides or simple sugars are single unit
carbohydrates.
There are three main monosaccharides
 Glucose found in
Fruit, vegetables eg onions, beetroot,
available in powder, liquid or tablet
form honey
Fruit and vegetables, honey

Fructose (often called “fruit sugar”) found in
Milk

Gelactose found in
2. Disaccharides
These are double sugars made up of 2
monosaccharides joined together.
These are three main disaccharides
 Sucrose
Used in cookery and is obtained by refining
sugar cane or beet.
Sucrose is formed from one unit of glucose and
one unit of fructose
 Lactose
Is found in the milk of mammals to supply the
infant with a source of energy. It is not as
sweet as sucrose.
Lactose is formed from one unit of glucose and
one unit of gelactose
 Maltose
Is sometimes called “malt sugar” and is found
in cereals where it is formed during germination
Maltose is formed from two units of glucose
Important points
Polysaccharides
These are called starches or complex
carbohydrates
They consist of chains of monosaccharides. The
main polysaccharides are
 Starch
This is formed from many glucose units joined
together like links in a chain
 Non starch Polysaccharides (NSP)
Refined sugar cane or beet. Some
fruit and vegetables.
Milk
Germinating cereals eg barley
Sources
Bread, flour, potatoes, cakes
Wholegrain cereals – oats,
wheat, rice, wholemeal bread
Skins of fruit and vegetables
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SUGARS
These can also be classified as
 Intrinsic Sugars – are those that form part of the cell structure of plants for example, fruit
 Extrinsic Sugars – are not part of the cell structure of plants. They include non-milk extrinsic sugars
(NME sugars) for example, refined sugar, sugar added to foods, extracted sugars in honey and fruit
juice.
STARCHES
It is recommended that we should get most of our energy from starch or complex carbohydrate foods
rather than sugar. There are a number of reasons for this.




Starch foods are good sources of other nutrients. Examples could be potatoes which are also a source
of Vitamin C, bread is also a source of protein , calcium and iron. Sugar is often described as “empty
calories” since it provides energy but no other nutrients.
Starch foods provide bulk with few calories. Most of these foods provide substantial amounts of
water and NSP. This means that they are filling without being a concentrated source of energy.
They do not encourage tooth decay, as bacteria in the mouth do not like starches. Sugar provides food
for acid producing bacteria on the surface of the teeth and this acid damages teeth.
They are generally inexpensive foods. For example bread and breakfast cereals are inexpensive and
are fortified with vitamins and minerals.
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UNIT : Resource Management
Content
Elaboration
Nutrients and their effect on the health
Micro nutrients
and development of individuals
Reference should also be made to sections on Health of Individuals, Main
nutrients, Anti oxidants and Dietary diseases
MICRO NUTRIENTS
Micro-nutrients are vitamins, minerals and trace elements found in the food we eat. Vitamins are organic
substances which are needed by the body in very small quantities. They cannot be synthesized in
sufficient amounts in the body and therefore must be augmented by the diet. They are usually part of the
enzymes system and often involve in the metabolism of the major nutrients of fat, carbohydrates and
protein. The most common vitamins required by the body:

vitamins A

vitamins B complex

vitamins C

vitamins D

vitamins E

vitamins K
Minerals elements found in our food are not always available to the body and therefore their
bioavailability is often limited. The mineral elements required in the diet are:

calcium

phosphorus

sodium

potassium

magnesium

iron
Trace elements are required by the body in smaller quantities than mineral elements. The most commonly
considered trace elements are:

iodine

copper

selenium

zinc

fluorine
Bioavailability is described as the proportion of the nutrient from the diet which is used in the body.
Differing nutrients have differing bioavailabilities, e.g. calcium, iron, zinc and copper have limited
bioavailability. The differences occur for varying reasons, e.g.

The presence of phytate, oxalate and other substances in food may bind the mineral elements, hence
making them unavailable.

physiological factors, e.g. age, state of health, nutritional status can alter the bioavailability of some
nutrients
Therefore a varied diet is essential to ensure an adequate intake of all the required nutrients for each
individuals needs.
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MICRO NUTRIENTS – MINERALS
CALCIUM
Calcium is the most abundant mineral in the human body. Of the body's total calcium, about 99% is in the
bones and teeth where it plays a structural role. The remaining 1% is present in body tissues and fluids
where it is essential for cell metabolism, muscle contraction and nerve impulse transmission.
SOURCES
Milk, milk products, cheese, bread (added to white flour by law), bones of canned fish, hard water.
FUNCTIONS
1. With phosphorus, it combines to make calcium phosphate, which is the chief material that gives
hardness and strength to bones and teeth. The skeleton is made up of many bones joined together
to make a rigid framework to keep us upright, to enable us to move and to make a protective
casing for the delicate parts of the body. The teeth need to be built strongly, too, so that we can
chew and eat a variety of tougher hard food.
Before birth, the bones and teeth begin their formation as an elastic substance known as cartilage.
In a child, the cartilage that is to become bone becomes harder and more rigid as the minerals
calcium and phosphorus becomes enmeshed in the cartilage. This process is called calcification.
Ninety-nine per cent of the calcium in the body is in the bones and teeth. One per cent is in plasma
and soft tissue. Over 90 % of bone tissue is laid down during the childhood years of growth. Bone
mass reaches a peak at about the age of 30 to 35 years and therefore declines progressively. In
women at about the time of the menopause, the rate of bone loss increases markedly. There is little
evidence that increasing dietary calcium at any age would help to reduce bone loss.
2. Required for maintenance of bones and teeth once formed.
3. Calcium is also needed for correct functioning of the muscles and the nerves. Without calcium, the
muscles cannot continue to contract and impulses cannot be transmitted efficiently along the
nerves.
4. Required for part of the complex mechanism which causes blood to clot after an injury
5. Required for the normal action of some hormones.
ABSORPTION OF CALCIUM
Although on chemical analysis a food may appear to be very rich in calcium, we cannot always make use
of the calcium it contains.
Green leafy vegetables often contain fairly large quantities of calcium, but they have also a great deal of
fibre. Fibre cannot be digested in the human digestive system, and as the fibre and the calcium may be
closely linked, much of the calcium may be made unavailable to the body. For this reason, we can absorb
the calcium in milk much better than the calcium in cabbage. Lactose present in milk also increases the
absorption of calcium.
A substance called phytic acid is found in whole grain cereal foods such as wholemeal bead and in
oatmeal, peas, beans and nuts. Phytic acid combines with calcium in a form that prevents us absorbing the
calcium from the food following digestion.
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To overcome any possible shortage of calcium that might result from this association with phytic acid, it
was recommended by the Medical Research Council that white flour be enriched with calcium. White
flour itself is practically free from phytic acid (unlike wholemeal flour) but it was thought wise to enrich
of our staple foods that would be eaten every day by the vast majority of the population.
The amount of calcium and phosphorus that can be extracted from the digested foods is absorbed through
the wall of the small intestine into the blood to be carried to the bone – and tooth – building areas of the
body.
Factors affecting the absorption of calcium
1 Assists
Vitamin D
 Vitamin D controls absorption of calcium so there must be a good supply in the diet
 Without vitamin D we cannot make use of the calcium in food.
Lactose
 This is a sugar present in milk and increases calcium absorption on hydrolysis
Protein
 The amino acids formed from protein as a result of digestion combine with calcium to form soluble
salts and these salts are very readily absorbed
2 Limits
Lack of vitamin D
 Without vitamin D less calcium will be absorbed and this deficit may adversely affect the strength of
bones and teeth.
Phytic acid
 Phytic acid is found in wholegrain cereal foods and combines with calcium in a form that prevents
calcium being absorbed
NSP
 NSP cannot be digested in the human digestive system as the NSP and calcium bind together. Much
of the calcium in fibrous foods is made unavailable to the body.
Fats
 Fats, particularly saturated fatty acids, form insoluble soaps with calcium which cannot be absorbed
Oxalic acid
 Oxalic acid, which is particularly high in rhubarb and spinach, also interferes with calcium absorption
CONTROL OF CALCIFICATION
The actual absorption of calcium and the mineralization of bones and teeth are controlled by vitamin D.
Without this vitamin, we cannot make use of the calcium in the food we eat. In the body the deposition of
calcium phosphate is also governed by a hormone produced by the small glands in the neck called the
parathyroid glands. The work of the parathyroid hormone is to regulate the amount of calcium and
phosphorus carried by the blood.
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After absorption of the minerals into the blood stream, the parathyroid hormone cause calcium phosphate
to be deposited in the bones and teeth until blood is left with only its small normal quota of calcium and
phosphorus carried by the blood.
CALCIUM REQUIRMENTS
Determining calcium requirements is difficult for several reasons. Adaptation to both high and low
intakes occurs, but it occurs slowly. At dietary calcium intakes of about 800 mg/d absorption is about
20%. If intakes are low as 250mg/d, about 70% is absorbed.
Our bodies do appear to adapt to low intakes of calcium by increasing the amount the body absorbs from
the food we eat. Many different studies have shown that populations with very low calcium intakes, by
our standards, have normal amounts of calcium in their bones and tissues, and this evidence is used to
argue that we do not need to increase our calcium intakes.
Effects on Health and Development
Humans have a constant need for calcium throughout their life. While new bone is made, existing
bone is taken away, so that in young children the whole skeleton is replaced over 2 years. In adults, this
takes between 7 – 10 Years. Research shows that regular exercise stimulates new bone production. The
formation of bones and skull in the form of calcium phosphate needed at all stages of life.
a)
Babies

b)
Children




c)
Calcium plays a part in the formation of the enzyme trypsin and the activation of rennin which
is important in the digestion of milk – necessary to digest milk and extract nutrients for well
being.
Rapid period of growth – calcium is required for developing skeleton and building bone mass
for adulthood.
If children suffer a shortage of calcium when there are growing, bones and teeth cannot be
properly mineralised. The skeleton is not made strong enough to support the body, and the
legs which carry its main weight become badly formed. This condition is known as rickets.
The long bones of the legs bend under the weight of the body; knock knees and bow legs are
typical symptoms of rickets. Rickets are no longer a major problem in this country, partly due
to the fortification of margarine and vitamin D. Because bone formation is closely linked with
vitamin D, rickets may also be caused by a shortage of vitamins.
Another sign of calcium deficiency in children is tooth decay and loss of teeth.
Some of the Asian population still have rickets as some traditional Asian diets are low in
vitamin D and Asian cultures do not encourage exposure to sunlight – the best source of
vitamin D
Teenagers


Teenagers who have a poor diet low in calcium and an inactive lifestyle do not reach
maximum bone density during the period of growth in teenage years. This can lead to
osteoporosis in later life.
Required for blood clotting – teenagers with an active lifestyle may be more prone to
accidents
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d)
Adults

e)
In adults a shortage of calcium from food results in calcium being removed from the bones
and teeth, but not being replaced. Gradually the bones lose their strength and may finally
become soft and weak that they become deformed and painful. A shortage of calcium in
adults can lead in this way to the disease of osteomalacia (adult rickets).
Pregnancy


During pregnancy, calcium absorption increases and no additional calcium is generally
needed. An exception is the pregnant whose needs for dietary calcium both for herself and
for the foetus – used for developing foetus are particularly high.
Necessary for the foetus – used for developing skeletal structure.
f) Older People

Osteoporosis occurs in older people, particularly in women after the menopause. Calcium
is gradually lost from the bones which become more porous and fracture more easily. Peak
bones mass (PMB) when the bones are at their most dense, occurs between the ages of 35
and 40 years. From this age, loss of bone occurs at the rate of 3% of PMB per year. In
women during the 5 years following the menopause the loss is greater due to the
deficiency of the hormone oestrogen. HRT has been shown to reduce this loss.
Osteoporosis is not thought to be caused by a lack of calcium or Vitamin D, but plenty of
dietary calcium together with regular exercise are recommended as preventative measure.
 Poor density leads to osteomalacia/osteporosis.
Bone loss can be affected by wide variety of factors e.g.
 Immobility
 Early menopause as there is an increased risk of osteoporosis
 Family history (genetics)
 Low calcium intake
 Underweight
 High alcohol intake
 Smoking
2. IRON
Iron is a mineral found in every cell of the body. It is vital for good health and for mental and physical
well being.
FUNCTIONS


Iron is a component of haemoglobin, the substance which gives red blood cells their
colour. Haemoglobin is required to transport oxygen around the body to every cell for the
production of energy and the maintenance of all cell functions. Haemoglobin is made of
complex protein molecules which contain iron.
One of the important functions of the blood is to serve as a transport system, the blood
carrying nutrients from where they are derived to where they are needed. For example,
digested foods from the intestine pass into the blood for transport to all cells. Similarly,
oxygen is absorbed into the blood in the lungs and carried to all parts of the body by the
blood stream. An adequate supply of oxygen is essential for the body cells to carry out
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

their functions. A shortage of oxygen can damage the cells; if they are deprived of oxygen
the cells will die.
Making Energy. Iron is essential in the chemical reactions that produce energy from food.
So if your iron levels are low then you body may not be able to use all the energy available
to it.
Ensuring a healthy immune system. The cells which fight infection and defend the body
against foreign organisms depend on adequate stores of iron. So if your iron stores are low
your body is prone to more frequent infections.
FOODS THAT SUPPLY IRON
Good sources – liver, Kidney, corned beef, cocoa, plain chocolate, red meat.
Reasonable sources – white bread (added by law), curry powder, treacle, dried fruit, pulses such as beans
and lentils, fortified breakfast cereals.
Wholemeal grains: these contain iron, but it may be unavailable to the body due to the presence of phytic
acid.
Green leafy vegetables e.g. broccoli and spinach, these contain some iron, but it may be unavailable to the
body due to the fibre content
ABSORPTION OF IRON
It has been estimated that only between 5 – 20% of the iron in the diet is normally absorbed.
To prevent an excess of iron entering the body from food normally eaten, the intestine has a safeguard
that allows only the absorption of the quantity of iron needed at that time. This safeguard is called the
mucosal block. Requirements within the body may vary from day to day – but iron must always be
included in the diet.
The amount of iron which is absorbed appears to be influenced by the need of the body for iron.
Someone who is deficient in iron will be able to absorb more than a person who has adequate stores of
iron
Absorption is also affected by the type of the iron. Iron obtained from meat is more easily absorbed than
iron from plant foods. The iron in meat is found in the form of haem iron which is easily absorbed.
Iron in cereals and vegetables is non haem iron which is less easily absorbed. This iron is present as ferric
iron but is more easily absorbed in the form of ferrous iron. Vitamin C helps in the conversion of iron
from its ferric state to the easily absorbed ferrous state and helps absorption of the ferrous iron from the
intestine. Vitamin C significantly increases iron absorption especially from plant food.
Too much fibre in leafy vegetables and fresh fruit, or phytic acid in whole grain cereal foods prevents the
absorption of iron from foods which purely by chemical analysis may appear to be sources of the mineral.
Large carbohydrate molecules may also surround the iron molecules and so prevent their uptake by the
mucosal cells. A poor diet which is rich in low carbohydrates but low in protein is likely to be low in iron
content, and the actual composition of this kind of diet slows down the absorption of what iron there is.
Tannin, found in tea and coffee is also thought to make iron more difficult to absorb.
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Effects on Health and Development
General symptoms of low iron intake for all ages.
If for any reason the body is short of iron, if, for example, the daily food does not contain enough or if it
is unable to be properly absorbed from the intestine, red blood cells are made with less than their full
quota of haemoglobin. This is the cause of the condition known as iron deficiency anaemia.
Because there is less haemoglobin in the cells, less oxygen can be carried by the blood, and because they
are short of oxygen the body calls work less efficiently. The muscles become more easily fatigued and the
characteristics signs of anaemia are tiredness, breathlessness and listlessness (lack of energy). When the
blood is anaemic the heart has to beat more quickly to carry the blood’s smaller load of oxygen to the
muscles, and this causes palpitations during exercise.
Iron stores in the body become depleted and haemoglobin synthesis is inhibited. Symptoms of anaemia
include tiredness, lack of stamina, breathlessness, headaches, insomnia, loss of appetite and pallor. All
these symptoms are associated with decreased oxygen supply to tissues and organs.
Iron also plays an important role in the immune system, people with low iron levels having lowered
resistance to infection.
Research has also shown iron deficiency to be associated with impaired brain function, and iron
deficiency in infants can result in impaired learning ability and behavioural problems.
A Babies and Children
a. Foetus builds store of iron in its liver from the mother’s blood for use during its
early stages of life.
b. Babies are born with enough iron to last 4 months, as milk contains no iron. After
this, they require iron from food. During body growth, when the actual volume of
blood is increasing and, therefore, the number of red blood cells needs to be
increased also, good supplies of iron are necessary. As new blood is being
produced, new red blood cells continue to replace existing but worn cells. Children,
therefore, need iron from both building and repair of the blood.
B Teenagers




Teenagers require iron during the rapid growth spurt to cope with the increased
volume of blood.
Teenage girls may require more iron due to the blood losses during menstruation.
An increasing number of teenagers are following vegetarian diets, cutting out meat
as a source of iron. Snacking or grazing during the day could also potentially
reduce iron intake.
Teenagers may be more susceptible to anaemia if diet is poor
C Pregnancy

The increased needs of pregnancy should be met without a further increase in iron
intake because of cessation of menstrual losses and the mobilisation of some of
the mother’s stores. Dietary supplementation may be needed by mothers with low
iron stores or teenage mothers. After the birth of the baby, iron supplies must be
replaced.
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D Adults



Adults need iron only for the normal replacement of old cells with new ones,
though children and adults alike need extra iron to replace any blood that may be
lost through bleeding/accidents/operations.
Women with a high menstrual loss may require increased iron to prevent anaemia.
Individuals with a high intake of dietary inhibitors e.g. tannin in tea.
E Old people


Some elderly may have poor absorption of iron and so may become anaemic.
Elderly often do not get an adequate diet and this can cause a shortage of iron
resulting in them feeling tired and listless
3 PHOSPHORUS
FUNCTIONS

Phosphorus works in conjunction with calcium and therefore has the same functions. It
combines with calcium to make calcium phosphate, which is the chief material that gives
hardness and strength to bones to teeth.

It is also present in all living cells where it is involved in the release of energy in the
body.
SOURCES
Phosphorus is present as phosphate in all plant and animal cells, and is therefore present in all
natural foods. It forms part of many proteins, and is often used as an additive in manufactured
foods.
Phosphorus is found in so many of the foods we eat that we are unlikely to be short of phosphorus
provided we eat a fairly varied diet. Of all foods, cheese, meat, eggs and flour and bread (except
wholemeal) supply the majority of our phosphorus intake.
Effects on Health and Development

There appears to be known deficiency, due to sufficient phosphorus
available in the diet.

Plays an essential part in the basic biomechanical mechanism by which energy is obtained
for the processes of life – necessary for all age groups.

Required in conjunction with calcium for bone formation essential that adequate supplies
are available at times of bone growth e.g. young children/teenagers.

Elderly must also have adequate supply to ensure strong bones offset osteoporosis/
osteomalacia.
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Speeds up the healing process and puts a stop to calcium loss from injury.

Keeps muscles, including the heart, contracting regularly and smoothly.

Assures transmission of impulses from one nerve to another.
Those at Risk for Low Phosphorus:



Those on weight-loss diets of 1,000 calories a day or less
Pregnant and nursing women
Those who drink heavily
4. SODIUM
Sodium is a vital component of the fluid bathing all cells. It is closely involved with control of body fluid
content. It has long been known that the amount of dietary sodium needed to perform its vital function is
only a fraction of the amount most people in the UK take. The mature healthy kidney is capable of
regulating body sodium very accurately.
SOURCES
Sodium is usually eaten as common salt, added as salt to food e.g. cheese, bacon, fish, processed foods
and found naturally in fish, meat and in many other foods. On food labels both sodium and the salt
equivalent are usually stated (salt = 2.5 times the sodium)
FUNCTIONS
1. Body fluids – all body fluids contain salt but especially those fluids
outside the cells
such as blood. Sodium allows nutrients to flow into
body cells and waste products to flow
out.
2. Water balance – maintaining the water balance in the body. Salt intake
may have to be
severely restricted in certain kidney diseases or where water is retained in the body.
3. Blood pressure – continual high sodium intakes can be associated with
pressure/helps control blood pressure and blood volume.
high
blood
4. Muscle activity – during strenuous work or exercise, large amounts of salt may be lost
through sweating. This will cause a lowering of the salt concentration of the tissue fluids
resulting in weariness and muscular cramps.
5. Essential for the transmission of nerve and muscle impulses.
Effects on Health and Development
a)
Babies
Too much salty foods for babies may result in kidney damage.
b)
Children/Teenagers
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A taste for salty foods should not be encouraged in childhood as it may carry on into
adulthood and result in hypertension.
c)
Adults
Evidence suggests that sodium plays a part in the development of high blood pressure
(hypertension). It seems that some people’s kidneys may have problems getting rid of
sodium. This causes fluid to be retained in the body to dilute the blood. Over a period
of time the retained fluids also make the blood vessels contract. The increased
amount
blood the heart has to pump through the blood vessels, and the resistance to
flow, make the heart work harder. This may cause the blood pressure to rise.
of
Some people are more likely to develop high blood pressure than others if their
sodium intake is high.
It is sometimes necessary to place a person on a salt-restricted diet, for certain medical
conditions. e.g.heart, kidney or liver disease, high blood pressure
There is a relationship between sodium intake and a rise in blood pressure with age.
Possible ways of reducing sodium intake






reducing the amount of salt used when cooking eg steaming foods with no added
salt
using herb and spices to season foods.
tasting food before adding any salt
eating more home prepared meals where you are in control of the amount of salt
used.
choosing processed foods which have been manufactured with a reduced amount of
salt included
eating yeast-raised cakes, e.g. doughnuts, Chelsea buns instead of cakes raised with
backing powder, which contains sodium compounds.
5 POTASSIUM
FUNCTION
Potassium is an essential mineral needed to regulate water balance, levels of acidity, blood pressure, and
neuromuscular function. This mineral also plays a critical role in the transmission of electrical impulses in
the heart.
Potassium and sodium work together in the body to maintain muscle tone, blood pressure, water balance,
and other functions. Many researchers believe that part of the blood pressure problem caused by too much
salt (which contains sodium) is made worse by too little dietary potassium.
FUNCTION
Potassium is found inside body cells. It is involved in the regulation of the fluid content of cells and the
function of muscles and nerves.
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Deficiency is rare, but may occur if potassium is not absorbed e.g. as a result of excessive use of laxatives
or vomiting – symptoms of deficiency include depression, mental confusion and muscular weakness. The
effect on the heart can lead to heart failure.
It is thought that taking fairly high intakes of potassium may counteract the effects of a high sodium
intake and reduce the likelihood of developing high blood pressure.
SOURCES
Found in a wide variety of food, particularly fruit (especially bananas) and vegetables, meat and milk.
Effects on Health and Development


Potassium regulates the balance of the body acids and plays a role in nerve and muscle function.
Together with sodium, potassium works to regulate blood pressure and water balance and to keep the
heart muscle beating in a steady, normal rhythm
Potassium helps sharp, clear thinking by assuring adequate oxygen transport to the brain.

potassium levels are though to be linked with sodium levels in the prevention of hypertension –
important factor for middle aged and elderly

prolonged diarrhoea may lead to potassium depletion which may result in heart failure

very old people whose muscles waste away may become short of potassium.
6 MAGNESIUM
Magnesium in the Body
Research studies have shown that magnesium plays an even greater role in health than was previously
thought. Second only to potassium in terms of concentration within the individual cells in the body, the
function of magnesium revolves primarily around its ability to activate many enzymes including those in
DNA and protein synthesis.
FUNCTION

Magnesium is found together with calcium and phosphorus in bones and teeth. It is necessary for
the normal skeletal development so important in children and teenagers

It is also needed in the body for the functioning of enzymes. Magnesium participates in more than
300 enzymatic reactions in the body and these include those responsible for energy metabolism,
fatty acid metabolism, protein synthesis, neuromuscular contractions/relaxations, bone integrity and
prostaglandin synthesis to name but a few.

It has a significant role to pay in the production of energy and in maintaining and optimising muscle
health.. Having a good supply of magnesium can facilitate oxygen and energy being delivered to
working muscle tissue.

the muscles themselves actually contain about 26% of all magnesium found in the body, with 50 60% in the bone and the rest in muscles and other soft tissue. The magnesium in bone provides a
reservoir in case deficiencies occur in soft tissue magnesium. The tissues with the highest
concentration of magnesium are those that are metabolically active, which again links to
magnesium's critical role in energy production.
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Sources of magnesium - plant foods such as wholegrains, vegetables (such as spinach, potatoes) and
legumes (such as black beans), tofu and some types of seafood (such as halibut, oysters, crab)
Deficiency of magnesium is rare but may occur as a result of:

excessive loss during bouts of diarrhoea or vomiting

unsuitable slimming habits

chronically poor diets

alcoholism- alcohol increases urinary excretion of magnesium but alcoholics are also often
malnourished

malabsorption syndrome. We generally absorb about 50% of dietary magnesium. Diets high in fibre
or high phosphorus or high calcium(usually in the form of supplements) can result in decreased
absorption.
Symptoms include:

loss of appetite, nausea and muscular weakness

muscle cramps, irritability and confusion

heart rhythm is disturbed and quickens

anxiety and insomnia
Effects on Health and Development

Magnesium is needed by all groups of people for the functions above.

Magnesium is particularly important for children’s skeletal development.
MICRO NUTRIENTS – TRACE ELEMENTS
1. IODINE
FUNCTIONS
Iodine is required to make the hormone thyroxine, which is produced by the thyroid gland in the neck.
Thyroxine, along with other hormones, is required for

Normal body growth and development of the central nervous system

Helps to regulate body temperature

Energy production and oxygen consumption in cells, thereby maintaining the body’s metabolic
rate.

If the thyroid hormone in insufficient, the basal metabolic rate is reduced as is body activity.
Normal growth and development is also impaired.
SOURCES
Iodine is widely distributed in foods, but is found in good supply:






sea foods
milk
egg
green vegetables, especially spinach
fresh water (depending on area)
iodized salt (added commercially)
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DEFICIENCY
A deficiency of iodine leads to a reduction in the amount of thyroxine produced by the thyroid gland. As
a result the metabolism slows down and the gland swells up caused by severe enlargement of the thyroid
gland – called goitre.
In fetal and infant development, thyroid hormones and therefore iodine, are essential for the normal
development of the brain. Insufficient levels can result in permanent brain retardation of the fetus or new
born child.
In severe cases in children this can lead to cretinism which, in addition to mental retardation, can cause
stunted growth, hearing and speech defects.
2. ZINC
The mineral zinc is present in every part of the body and has a wide range of functions. It helps with the
healing of wounds and is a vital component of many enzyme reactions. Zinc is vital for the healthy
working of many of the body's systems. It is particularly important for healthy skin and is essential for a
healthy immune system and resistance to infection.
FUNCTIONS









Zinc has a range of functions. It plays a crucial role in growth and cell division where it is required for
protein and DNA synthesis, in insulin activity, in the metabolism of the ovaries and testes, and in liver
function.
As a component of many enzymes, zinc is involved in the metabolism of proteins, carbohydrates,
lipids and energy.
Zinc and copper are key components of superoxide dismutase, an enzyme that speeds up anti oxidant
reactions and helps protect cells from free radical damage
Zinc is vital for a quick reacting immune system and is essential to the proper development and
maintenance of the immune system. Without zinc the body could not fight off viruses, bacteria and
fungi. A mild deficiency of zinc may increase the risk of infection
Zinc is a key component of the enzyme that activates vitamin A in the retina. Zinc deficient people
may show signs of night blindness.
In severe zinc deficiency, cells fail to replicate. This may be why zinc is so important for normal
growth and development of children and sexual maturation of adolescents. Deficiency cause stunted
growth and delayed sexual maturing.
Some evidence that zinc is concerned with some of the processes involved with foetal development.
Zinc interacts with a number of hormones including insulin
Some studies show that zinc plays a role in taste perception and appetite regulation
Effects on Health and Development
Zinc deficiency may exist in some groups e.g.

rapidly growing children

pregnant women

sufferers of anorexia nervosa

vegans
Some other groups may also be at risk of a mild deficiency due to diet related problems, namely:



pre-school children of low income families
constant dieters
the elderly who may make poor food choices
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Our body contains about 2-3g of zinc. There are no specific storage sites known for zinc and so a regular
supply in the diet is required. Zinc is found in all parts of our body, 60% is found in muscle, 30% in bone
and about 5% in our skin.
Particularly high concentrations are in the prostate gland and semen. Men need more zinc than women
because male semen contains 100 times more zinc than is found in the blood. The more sexually active a
man the more zinc he will require. The recommended amounts of zinc for adult men are 1/3 higher than
those for women.
The first signs of zinc deficiency are impairment of taste, a poor immune response and skin problems.
Other symptoms of zinc deficiency can include hair loss, diarrhoea, fatigue, delayed wound healing, and
decreased growth rate and mental development in infants. It is thought that zinc supplementation can help
skin conditions such as acne and eczema, prostate problems, anorexia nervosa, alcoholics and those
suffering from trauma or post-surgery. It is always better to seek the advice of an expert before using
supplements.
SOURCES
Zinc is present in a wide variety of foods, particularly in association with protein foods. Present in a wide
variety of foods but the main sources are meat, milk sardines, chicken, lentils, nuts, bread and other
cereals A vegetarian diet often contains less zinc than a meat based diet and so it is important for
vegetarians to eat plenty of foods that are rich in this vital mineral.
Good sources for vegetarians include dairy products, beans and lentils, yeast, nuts, seeds and wholegrain
cereals. Pumpkin seeds provide one of the most concentrated vegetarian food sources of zinc.
Only 20% of the zinc present in the diet is actually absorbed by the body. Dietary fibre and phytic acid,
found in bran, wholegrain cereals, pulses and nuts, inhibit zinc absorption. Phytic acid forms a highly
insoluble complex with zinc which the body cannot absorb. Cooking processes can reduce the adverse
effects of both phytic acid and dietary fibre on zinc absorption.
3. SELENIUM
Selenium is an important mineral and antioxidant and has several functions in the human body.
FUNCTION






Forms part of an enzyme system in the red blood cells.
As an antioxidant, selenium is thought to be important in protecting healthy cells against the
damaging effects of metabolism, which may contribute to cancer or other chronic conditions.
Research in this area in on going.
Selenium is best known as a component of glutathione peroxidases, a family of anti oxidant
enzymes which reduce peroxides before they can attack intracellular membranes. Selenium is an
essential building-block for these anti-oxidant enzymes.
Both selenium and vitamin E play a role in preventing lipid peroxidation and membrane damage.
Glutathione peroxidases reduce the number of peroxides available to form free radicals so
eliminating highly reactive free radicals. As vitamin E quenches free radicals, and so fewer free
radicals spares Vitamin E for further anti oxidant activity. So it could be said that selenium works in
combination with vitamins E as an anti-oxidant
Selenium interacts with iodine in thyroid hormone metabolism.
It is also important in the immune system and its response to infection.
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
Valuable to the health and development of all ages. Deficiency of this trace element is unknown in
the UK.
SOURCES
Selenium is found in all foods in very low concentrations. Main sources includefish, meats, eggs,
shellfish, nuts and cereal products.
4. FLUORIDE
FUNCTIONS

Fluoride may be an important factor in the strengthening of teeth against decay by combining with
calcium phosphate. It is thought that it combines with the protective enamel coating of the teeth,
thus making them more resistant to attack by the acid produced by bacteria in the mouth.

It is involved in bone mineralization.
SOURCES
Fluoride is found naturally in tea, sea water fish, and in some parts to the country in water supplies.
Fluoride is also added to tooth paste.
Effects on Health Development
The strengthening affect that fluoride has on the teeth is only of value when the teeth are developing in
children. Only minute quantities are required for this.
An excess intake of fluoride can be harmful, as it causes the teeth to become “mottled” with dark brown
spots.
5. COPPER
FUNCTIONS




Components part of several enzymes – one of the most important one being the enzyme that
catalyses the oxidation of ferrous to ferric iron so copper helps the absorption of iron.
Copper is an important component of superoxide dismutase, enzymes involved in anti oxidant
reactions.
Copper participates in immune system function, red and white blood cell maturation, blood clotting,
bone strength, brain development and cholesterol and glucose metabolism
Copper is part of an enzyme that forms cross links in collagen and elastin- connective tissue
proteins
SOURCES
Shellfish, Liver, Kidney, Lean meat, cereals, nuts, bread, dried fruit.
Effects on Health and Development
Several groups may also be at risk of a deficiency, namely:
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

infants fed on a milk diet too long
chronic malabsorption syndrome
kidney dialysis patients
Menke’s syndrome ( a rare hereditary disorder which is associated with reduced copper uptake) and
Wilson’s disease (an inherited disease where excess copper accumulates in the brain and causes
neurological damage) show low blood cooper levels in spite of an adequate daily intake.
MICRO NUTRIENTS – VITAMINS
a)
FAT SOLUBLE VITAMINS
VITAMIN A
Found as Vitamin A (retinol) in butter, milk, cheese, eggs and oily fish and Vitamin A (beta- carotene) in
yellow, green and orange coloured fruit and vegetables.
Effect on Health and Development
a)
b)
General Use

Vitamin A has oxidant properties which acts in body cells removing free radicals –
important for middle aged/elderly who may be more at risk from cancer/disease.
Important to teenagers to reduce the risk of cancers/ CHD in the future

Necessary for formation of visual purple – a pigment found in the retina and is necessary
for vision reduced light.

Vitamin A is also essential for the maintenance of healthy skin and surface tissues,
particularly the most mucous membranes such as the cornea at the front of the eye and
lining of the respiratory and digestive tract.
Children

c)
Lack of Vitamin A in the diet of children reduces the rate of growth. Retinol is
essential for the growth and metabolism of all body cells.
Pregnant Women

Vitamin A can be toxic in high quantities for the foetus. A relationship has been
suggested between high intakes of vitamin A during pregnancy and defects of the
baby. Pregnant women should avoid foods high in Vitamin A especially Liver.
There is little evidence of a deficiency in the UK, although some groups can be at risk due to a reduced
absorption, namely:



suffers of cystic fibrosis
people with chronic liver disease
people with celiac disease
A deficiency can cause:

night blindness
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
xerophthalmia

the formation of plugs of keratin in the skin’s hair follicles.
See also notes on Anti oxidants.
VITAMIN D
SOURCES
Main sources are margarine, oily fish, eggs, fortified breakfast cereals and sunlight.
Effects on Health and Development
a)
b)
General Use

Necessary for the growth and maintenance of bones and teeth- teenagers and children

Required for the absorption of calcium from the intestines.

Acts to maintain a constant level of calcium from the intestine..

Needed for the uptake of calcium and phosphorous by the bones and teeth.
Children

Young babies and children, who are protected from the sun, most have adequate dietary
supplies to allow skeletal development.

Children receiving an inadequate supply of Vitamin D may develop rickets (see calcium
notes).
c)
Teenagers/ Adults
Promotes quicker healing of fractures which active teenager may be more prone to.
Bone density formed during teenage years – Vit D helps absorption of calcium and so
prevents osteoporosis in later years
Elderly who may be less mobile or house bound must also ensure adequate dietary
supplies to keep bones strong and prevent osteoporosis/osteomalacia.
An excess of Vitamin D is toxic as it results in an excess absorption of calcium into the blood. the extra
calcium is deposited in the lungs and kidneys and can cause death.
VITAMIN E
SOURCES
Found in wheatgerm, vegetable oils, nuts, margarine and egg yolk.
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Effects on Health and Development
General Use
Vitamin E has an important role as an anti oxidant. Free radicals, produces as a result of normal
chemical reactions in the body, can damage the lipids (fatty compounds) found in cell membranes.
The free radicals oxidize the lipids, forming peroxides. This lipid peroxidation can cause damage to
the cell membrane and leaking of the cell contents which in turn is though to increase the risk of
inflammatory diseases such as rheumatoid arthritis. Peroxides may also play a part in the information
of ‘plaque’ in artery walls which can lead to CHD. Vitamin E lipids, especially polyunsaturated fatty
acids (PUFA) against free radical damage.
Free radicals may also damage molecules inside the cell such as DNA and proteins. Cells will damage
DNA are more prone to cancer. Vitamin E is therefore thought to give some protection against some
forms of cancer.
Deficiency of Vitamin E does not normally occur in humans though it has occurred in premature
babies fed on an infant formula deficient in Vitamin E.
It has also occurred in some people unable to absorb and utilise Vitamin E adequately – these people
developed nervous system problems.
High doses may decrease the symptoms of neurological disorders, slow the progress of Parkinson’s
and improve mobility for arthritis sufferers.
VITAMIN K
SOURCES
Found in green vegetables, cereals.
Effects on Health and Development
General Use

Essential for the formation of clotting agents.

Essential for the normal clotting of blood. Insufficient results in defective clotting of
blood – important after an accident

Production of coagulation inhibitors.

Babies, particularly if they are born premature, have low levels of Vitamin K and as a
result, Vitamin K is now given routinely to newborn babies in the UK to prevent the
haemorrhagic disease of the newborn.
A deficiency of Vitamin K is rarely seen because the vitamin is synthesized by bacteria in the
digestive tract.
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WATER SOLUBLE VITAMINS
VITAMIN B1 (Thiamin)
SOURCES
Cereals, added to white flour by law in Britain, meat, breakfast cereals, potatoes, beans, nuts and
milk.
Effects on Health and development
a)
General Use



Involved in the oxidation of nutrients and the release of energy in the body.
During the release of energy, each reaction requires a specific enzyme – thiamine acts as a
co-enzyme for 2 of the reactions.
If thiamine is deficient in the diet, glucose is only partially oxidised. The breakdown stops
at a substance called pyruvic acid. A build up of pyruvic acid in the blood causes muscular
weakness, palpitations of the heart and degeneration of the nerves. This disease is called
beri-beri which is rare in the UK but common in parts of Asia
Beri-Beri has been found in anorexics and alcoholics. A high intake of alcohol increases
the requirements for thiamine as thiamine is needed to break down alcohol in the body.
b)
Teenagers/ active people

c)
An adequate supply of B1 is especially important for very active people e.g. teenagers to
ensure release of energy from food otherwise they will be lethargic/ tired
Elderly

Although they may be less active, they must have adequate supplies to obtain energy from
food otherwise they will be lethargic.
VITAMIN B2 (riboflavine)
SOURCES
Cheese, liver, kidney and eggs, milk, meat, potatoes and green vegetables.
Effects on Health and Development
a)
General Use


Forms part of the enzyme system concerned in the oxidation of glucose and the release
of energy in body cells.
Deficiency affects the eyes, lips and tongue. Cracks appear at the corners of the mouth,
the tongue becomes red and swollen and in severe cases, blood vessels invade the
cornea of the eye.
Active people/ teenagers must have a good intake to ensure release of energy from food.
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VITAMIN B3 (niacin)
SOURCES
Yeast, meat, fish, cheese, pulse vegetables and cereals.
Effects on Health and Development
a)
General Use

Forms part of an enzyme system concerned in the oxidation of glucose and the release
of energy in the body cells.
Although unknown in the UK, the deficiency disease is pellagra. Its symptoms



are:
dermatitis
diarrhoea
dementia
Active people/ teenagers must have a good intake to ensure release of energy from
food.
VITAMIN B6
SOURCES
Meat, potatoes and vegetables
Effects on Health and Development
a)
General Use
 It is a co-enzyme involved in the conversion of one amino acid to another
 Involved with the metabolism of glycogen in muscle (for energy production)
 Deficiencies of B6 may result in increased nuclear uptake of steroid hormones and
enhanced sensitivity of the target organs to hormone activity. This may be related to the
cause and treatment of the hormone dependent cancers of breast, uterus and prostrate
VITAMIN B12
SOURCES
Offal, meat, liver, milk, yeast extract
Effects on Health and Development
b)
General Use

Works with folic acid , for red blood cell information.

Needed for the metabolism of amino acids as well as other enzyme systems throughout the
body.
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
Involved in more than one enzyme system in the body.

Helps with the normal transmission of nerve impulses

A deficiency of Vitamin B12 causes pernicious anaemia. This is when the normal
division of red blood cells is disrupted so that they enter the blood stream at an early stage,
when they are bigger and fewer than normal. Prolonged deficiency in pregnancy is a risk
factor for neural tube defects in the new born.
Vegans who eat no animal produce of any kind are the only people in whom a
dietary
deficiency of Vitamin B12 has been observed. For absorption of this vitamin a
substance secreted by the cells of the stomach, called the intrinsic factor, must be
present. Lack of the intrinsic factor is the common cause of pernicious anaemia, which
occurs in the elderly and in Crohn’s disease
FOLIC ACID
SOURCES
Liver, green leafy vegetables, potatoes, kidney, nuts, pulse vegetables, breakfast cereals, flour and cereal
foods.
Effects on Health and Development
a)
General Use



b)
Teenagers


c)
d)
A dietary deficiency causes a type of anaemia – megaloblastic anaemia where the red
blood cells become enlarged and cannot give up their oxygen properly to the cells. It
is closely linked with the action of Vitamin B 12
Folic acid acts as a back up if iron is lacking so prevents anaemia
Required for the release of energy from food, particularly amino acids
Required for normal growth in children- important during teenage growth spurt
Maintains muscle tone – important for active, sporty teenagers
Women / pregnancy

All women likely to become pregnant should increase folic acid intake – from the start
of trying to conceive until at least the 12th week of pregnancy.

Increased folic acid during pregnancy may prevent neural tube defects (spina bifida) in
babies.
Children
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
A deficiency may result in slow growth – needed for normal growth in babies and
young children
Normal cooking destroys 80% of the folate in vegetables and with longer cooking and keeping hot there
may be complete destruction. The increase in takeaway food may mean that many people have low
intakes.
VITAMIN C
SOURCES
Fruit, vegetables
Effects on health and Development
a)
General Use

Necessary for the formation of collagen – the main protein of connective tissue which
binds body cells together.
 Involved in healing of wound/sores, prevents scurvy.
 Vitamin C has anti oxidant properties – assists Vitamin E in its role as an anti oxidant
 Shown to reduce cancers of the digestive tract.
 Aids the absorption of non-haem iron from the intestine and so prevents anaemia.
Converts ferric iron to ferrous to assist absorption.
Less severe or mild deficiency symptoms may include:
 Fatigue, irritability, general weakness
 greater susceptibility to infection
 walls of blood vessels weaken and break in places. Blod escapes and appears as small red
spots (haemorrhages) under the skin
b)
Babies

c)
Babies being weaned at 4 months must have adequate amounts of Vitamin C to assist with
absorption of iron from food
Teenagers





d)
Essential that teenagers, especially girls, have adequate Vitamin C to keep iron absorption
and to prevent anaemia.
Blood volume is expanding due to the rapid growth spurt in teenagers
Necessary for healing cuts and wounds – teenagers with active lifestyles may be more at
risk from injury
Anti oxidant properties are beneficial to teenagers to help prevent cancers/ CHD in later
life
Required to make connective tissue which binds body cells together
Adults


Anti oxidant properties beneficial to middle aged/ elderly at risk from CHD/cancer
Mild scurvy, delayed wound healing may occur in some long-stay geriatric patients due to
eating institutional food in which there is little Vitamin C left after cooking.
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UNIT : RESOURCE MANAGEMENT
Content
Elaboration
Food Science: the nature of food
In-depth study of nutrients, their function
constituents in relation to their properties and the effect on the health and
in food manufacture.
development of individuals.
 Anti-oxidants – role in health
The damage which can be caused to the body by free radicals and the importance of vitamins and
minerals in protecting against such damage has recently aroused interest.
A daily diet high in anti-oxidants is good insurance. It is a way you can help protect yourself against the
two main killer diseases of Western countries – cancer and coronary heart disease – as well as protecting
eyes from macular degeneration and claims to holding back the ageing process.
Studies consistently show that people who have high intakes of phyto-chemical rich fruit and vegetables
have lower levels of cancer and heart disease.
What are anti-oxidants?
Anti-oxidants are substances which act as the body’s first line of defence against unwanted damage. They
are produced either in the body or obtained from the food we eat. The three best known anti-oxidants are:
 Vitamin C

Vitamin E
 Carotenoids (vegetable source of Vitamin A)
Other very important anti-oxidants include:

Minerals – selenium, zinc, copper, manganese (often key components of enzymes)

Enzymes – superoxide dimutase (containing copper or manganese), catalase, glutathione
peroxides (containing selenium)

Flavaniods and a large amount of natural plant compounds(phyto-chemicals)
Compound(s)
Found in
Flavonoids *
Tea, wine, grapes, apples, onions, berries
Isoflavones
Soy beans, tofu, soy drink, other beans
Lignans
Flaxseed, oilseeds, brans, beans, vegetables, fruit
Carotenoids *
Orange and red fruit, yellow, orange and green vegetables
Indoles & Iso-thiocyanates
Cruciferous vegetables, such as broccoli
Sulphides
Cabbage, cauliflower and turnip
Phyates *
* most common
Garlic, onion, leeks, cruciferous vegetables
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What do anti-oxidants do?

Anti-oxidants neutralise or scavenge (‘gobble up’) substances called free radicals which would
otherwise damage cells, membranes and DNA.
What are free radicals?
Free radicals are electronically unstable molecules that can easily react with and damage other molecules.
They are formed both inside and outside the body.

In the body, they are formed as a by-product of metabolism whenever oxygen is involved.
The more oxygen we use, the higher the level of free radicals produced in the body.
 During normal metabolism a small proportion of free radicals are formed but they are
immediately rendered harmless or ‘quenched’ by vitamins, minerals and enzymes.
 Externally they are left behind in a variety of situations e.g. by smog, cigarette smoke,
pollution, ozone, solvents, pesticides and the sun’s ionising radiation.
What do free radicals do?
Free radicals can damage cells, membranes, DNA genetic material and other body structures in much the
same way that air turns a cut apple brown or rusts a nail or makes butter go rancid.
Current nutrition thinking is that when the balance between free radicals and anti –oxidants is skewed
high, they ‘damage’ proteins, fatty acids and DNA and so set the scene for tissue injury that eventually
leads to chronic diseases like cancer, heart disease, macular degeneration of the eye and cataracts. They
may also contribute to the ageing process and early senility.
Free radicals can damage cell membranes. Cell membranes contain lipids, some of which are unsaturated
and these lipids react with free oxygen radicals to become lipid peroxides, the same reaction as rancidity
in fat. The effect on the cell is to damage the barrier between its content and tissue fluid – this results in
mixing compounds which are usually separate and so normal function is disturbed.
If free radicals are not quenched then a chain reaction can start which produces extensive damage to
tissue.
In some situations the production of free radicals increases and the protective mechanism fails. Examples
are smoking, ageing, inflammation (e.g. rheumatoid arthritis), tissue injury following heart attacks and
certain types of chemical poisoning.
Nutritionists believe that free radicals cause LDL – cholesterol to become oxidised, causing them to be
deposited in the walls of blood vessels starting the process of atherosclerosis. LDL- cholesterol only
becomes harmful when it is oxidised.
Researchers at the University of Edinburgh have found wide differences in the incidences of heart disease
in Britain which have been closely liked to differences in the intake of the anti-oxidant nutrients.
Scotland, for example, has the world’s highest level of heart disease, and the Scottish diet traditionally
lacks fresh fruit and vegetables which are the best sources of many anti-oxidants.
What about anti-oxidant supplements?
It is not enough to simply swallow a pill. Food is a complex mix of dozens of phytochemicals many of
which exhibit anti-oxidant activity, like the flavonoids in tea. This is why it is better to eat a healthy diet
including lots of fruit and vegetables, rather than a supplement.
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However, some people, professional athletes, smokers and those living in polluted areas, may benefit
from a modest supplement programme. Because anti-oxidants work best as a team, it is wise to choose
one that offers a broad range including vitamin C, vitamin E, zinc, selenium and carotenoids.
ANTI-OXIDANTS-VITAMINS
Carotenoids (vegetable source of Vitamin A)
Carotenoids or carotenes which are coloured compounds found in yellow, green and orange vegetables.
Some carotenes, notably beta-carotenes, are converted into Vitamin A in the intestine. Carotenoids are
important in their own right as protective anti-oxidants.
Carotenoids
The carotenoids are a group of 500 to 600 compounds responsible for the yellow and orange colours in
fresh produce. Many have anti-oxidant properties due to their highly-conjugated double bound structures.
Epidemiological evidence repeatedly links high intakes of fruit and vegetables (the major source of
carotenoids) with lower risk of cancers. One study found that people who ate vegetables rich in
carotenoids had a 43% lower risk of macular degeneration of the eye than those who only ate small
amounts.
1. Beta-carotene is converted to Vitamin A in the body and is the best known and most abundant
carotenoids. Its function are:



To inactivate free radicals
Improve the immune capacity of the body
Inhibits the early stages of tumour development
2. Alpha-carotene acts as an anti-oxidant and like beta-carotene, is converted to Vitamin A in the
body. High intakes are associated are associated with decreased risk of lung cancer. Best sources
are carrots and pumpkin.
3. Beta-cryptoxanthan acts as an anti-oxidant and like beta-carotene, is converted to Vitamin A in
the body. High intakes are associated with decreased risk of cancer of the cervix .Best sources are
oranges, orange juice, paw-paw, peaches and other orange coloured fruit.
4. Lutein and Zeaxanthin protect the macula of the eye from deterioration which can be a leading
cause of vision loss among older adults. Best sources are broccoli and dark green lettuce.
5. Lycopene is the most powerful anti-oxidant of all the carotenoids. Scientists have found that
tomatoes are rich in a substance call lycopene, one of several hundred carotenoids that are
responsible for many of the red, orange and yellow colours of vegetables and fruit.
Lycopene is responsible for the tomato’s rich red colour and functions as a powerful anti-oxidant,
even more potent than the much-publicised beta-carotene.
Lycopene works to quench a highly-reactive free radical known as ‘singlet oxygen’. In fact, it has
the greatest quenching ability and highest anti-oxidant activity of all the activity of all the
carotenoids. This quenching protects cells and preserves genetic material from attack by harmful
free radicals generated by UV light, pollution and smoking.
Absorbing Lycopene
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Lycopene is better absorbed by the body when cooked. This is because cooking and processing
softens and disrupts the sturdy cell walls of the tomato, so releasing the lycopene.
In a recent German study volunteers were asked to consume meals containing the same amount of
lycopene from either 400g of ripe tomatoes or 40g of tomato paste (heat-treated during
manufacture), both served with bread and a little oil. The scientists reported that lycopene was
absorbed from both sources, but significantly more from the tomato paste.
Health benefits of Lycopene
Tomatoes and prostrate cancer
High intakes of Lycopene have been linked to a lower risk of prostrate
cancer in men. Best
sources are tomato-based products including tomato sauce and canned tomatoes.
A study from Harvard Medical School which looked at the diets of some
48,000 men found that those with high intakes of lycopene from a high
consumption of
tomato-based foods had a much lower risk of prostate cancer.
Tomatoes, tomato sauce and pizza
accounted for 82% of the lycopene in the
diets of the men surveyed.
The survey found that:


Eating more than 10 servings a week of tomato-based foods was associated with a 35% reduction
in prostate cancer risk.
Eating 7 to 9 servings a week of tomato-based foods was associated with a 22% reduction in
prostrate cancer risk.
Lycopene and heart disease
Lycopene is fat-soluble and is carried in the bloodstream attached to the ‘dangerous’ LDL-cholesterol
where its seems to work in conjunction with vitamin E protecting LDL from oxidation and so may
have a positive effect on heart disease prevention. This fits with numerous epidemiological studies
over the past 10 years showing high intakes of fruit and vegetables exert a protective effect against
heart disease, as does vitamin E. Lycopene’s role in fighting cancer of the lungs, cervix and digestive
tract is also being investigated.
Lycopene and sun protection
Lycopene protects the tomato from burning as it ripens in the sun, and it appears humans can benefit
in the same way. One of the early clues was that UV rays leave beta-carotene unaffected, but
significantly deplete lycopene levels.
Some of the sun’s damaging effects are thought to be mediated through reactive oxygen species.
Because lycopene is so good as quenching these, nutritionists hope that lycopene may help to protect
the skin against UV light in the short term (sunburn) as well as over the long term (cumulative effects
of the sun exposure and skin cancer).
Vitamin C

Vitamin C scavenges oxygen free radicals.

Inhibits nitrosamine formation.
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
It is important anti-oxidant, especially in the regeneration of oxidised vitamin E in membranes in
the body. In this way it is important in maintaining membrane structure.

Has been shown to reduce cancers of the digestive tract (oesophagus, stomach and pancreas).

Aids the absorption of iron especially vegetable sources (that is, non-haem iron).
Vitamin E

Vitamin E is present in the cell membranes where it acts as an anti-oxidant and quenches free
oxygen radicals, so protecting the lipids of cell membranes from damage. In doing so it is
rendered inactive but is restored by reacting with Vitamin C.
 Vitamin E protects LDL cholesterol from oxidation and so helps prevent coronary heart disease
and certain forms of cancer.
 Vitamin E is the major anti-oxidant in all cell membranes where it maintains the stability of fatty
acids in the phospholipids layer. Vitamin E protects bonds from polyunsaturated fat from breaking
down
Best Sources
Vegetable oils (e.g. sunflower), nuts, wheat germ, margarines, whole grains and green vegetables.
ANTI-OXIDANTS – MINERALS
Selenium

Selenium works in combination with vitamins C and E. It is a component of the anti-oxidant
enzymes glutathione peroxidase which reduces peroxides before they can attack intracellular
membranes (glutathione peroxidase is involved in the quenching of free radicals).

It also enhances immune response.

Best sources are seafood, liver, kidney, lean meat and whole grains, although their content
depends on the soils where they are grown
Copper

Copper is a component of several enzymes and as such, it has an important role in many
reactions, including the quenching of free radicals.

It is also involved in forming blood cells.

Best sources are seafood, liver, kidney, lean meat, wheat bran, nuts, yeast, cocoa powder and dried
fruit.
Zinc

Zinc is part of the enzyme superoxide dismutase which prevents free radicals from forming
peroxides.

Best sources are seafood (especially oysters), lean meat, chicken, milk, whole grains, wholemeal,
dried beans, lentils and nuts.
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ANTI-OXIDANTS – ENZYMES
Superoxide dismutase containing copper and manganese prevents free radicals from forming peroxides
that can harm tissues.
Glutathione peroxidase containing selenium reduces peroxides therefore preventing them from attacking
cellular membranes.
ANTI-OXIDANTS-FLAVONOIDS
The flavonoids found in tea are powerful anti-oxidants and free radical scavengers. Flavonoids consist of
a number of compounds including catechins. Catechins have been shown to be powerful anti-oxidants –
anywhere from 2 to 6 times more powerful than vitamin C and E. Diets rich in fruit and vegetables, in tea
and red wine are associated with good cardiovascular health. Several studies have suggested that
flavonoids-rich foods are particularly cardio protective. Tea and wine are of particular interest being rich
in flavonoids – particularly catechins
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Resource Management
ELABORATION
CONTENT
Nutrients and their effect on the health
and development of individuals
Inter relationship of nutrients
Factors affecting absorption of nutrients
CALCUIM, PHOSPHOROUS and VITAMIN D




Calcium and phosphorous are both needed together for the formation and maintenance of strong
bones and teeth. Together they form calcium phosphate which gives bones and teeth their hardness.
Absorption of calcium is controlled by Vitamin D. A diet lacking in Vitamin D results in poor
calcium absorption and adversely affects the formation and maintenance of strong bones and teeth
Without Vitamin D we cannot make use of the calcium in food
If blood levels of calcium and phosphorous fall too low then the hormone produced by the parathyroid
gland removes these nutrients from the bones and teeth and back into the blood
Calcium absorption is also affected by






Lactose- This is a sugar present in milk and increases calcium absorption on hydrolysis
Protein - The amino acids formed from protein as a result of digestion combine with calcium to form
soluble salts and these salts are very readily absorbed
Phytic acid - Phytic acid is found in wholegrain cereal foods and combines with calcium in a form
that prevents calcium being absorbed
NSP cannot be digested in the human digestive system as the NSP and calcium bind together. Much
of the calcium in fibrous foods is made unavailable to the body.
Fats, particularly saturated fatty acids, form insoluble soaps with calcium which cannot be absorbed
Oxalic acid, which is particularly high in rhubarb and spinach, also interferes with calcium absorption
ACE VITAMINS




The best known anti oxidants, which help to neutralise potentially damaging free radicals in the body,
are Vitamins A, C and E
A diet high in ACE Vitamins is thought to reduce the risk of coronary heart disease.
Vitamin E improves the activity of Vitamin A in the body
Vitamin C helps the action of Vitamin E in the body eg after Vitamin E has been used by the body
and is finished, vitamin C then works on this Vitamin E to recycle it.
IRON, VITAMIN C and FOLIC ACID




Depending on the food source of iron, not all of the iron which is eaten is actually absorbed by the
body. Iron in our food is ferric iron and cannot be absorbed until it is changed to ferrous iron
Vitamin C is required to change iron into its more easily absorbed form – ferrous iron and also to
ensure an adequate supply of red blood cells. If vitamin C is lacking in the diet then the iron will not
be changed into ferrous iron.
Folic acid also improves the red blood cell count – if iron is lacking then folic acid can supplement the
supply
Folic acid can also help prevent megaloblastic anaemia if the iron absorption is poo
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VITAMIN B COMPLEX and CARBOHYDRATE





Vitamin B Complex acts as a link in a complex chain of chemical reactions which release energy
from carbohydrates so adequate supplies of B Complex vitamins must be present in the diet
The B Complex vitamins have a role in the release of energy from food so that it can be used by the
body
The more energy is needed by the body eg a sports person, then the more Vitamin B complex is
required to release the energy
Vitamin B1 (Thiamine) helps release energy from glucose
Vitamin B2 (riboflavin) and Vitamin B3 (niacin) help release energy from food
IRON, NSP and PHYTIC ACID




Too much indigestible NSP in leafy vegetables and fresh fruit can bind with iron and therefore not
allow it to be absorbed into the blood stream.
Phytates found in food containing NSP will remove iron from the body in waste materials
Phytates form insoluble complexes with iron in the small intestine which then inhibits iron absorption
Phytic acid in wholegrain cereals binds with iron to prevent absorption
Iron absorption is also affected by tannin found in tea
WATER and NSP
 NSP absorbs water in the gut. The bulk and softness of the waste matter is affected by this absorption
of the water
 If there is no NSP in the waste matter, no water is absorbed into it and the waste matter is then
difficult to get rid of from the body (constipation)
 If there is plenty of NSP and the waste matter absorbs water, it becomes bulkier, softer and much
easier to pass out of the body
 NSP is of great importance in the diet as it absorbs a lot of water, and binds the other food residues to
itself. This ensures that the faeces are soft and bulky and so can pass easily out of the body easily and
quickly.
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Resource Management
Content
Elaboration
Nutrients and their effect on the health and Health and dietary diseases
development of individuals
Coronary Heart disease
Obesity and Weight reduction
Hypertension
Cancer
Diabetes
Iron deficiency anaemia
Bowel disorders
Osteomalacia, osteoporosis
Dental decay
Reference should also be made to sections on Health of Individuals, Main
nutrients, Micronutrients and Anti oxidants
CORONARY HEART DISEASE (CHD)
Coronary heart disease is the term used to describe the gradual narrowing of the coronary arteries. These
arteries supply blood and oxygen to the heart muscle
The arteries usually narrow because of a build up of a fatty type substance (cholesterol) within the inner
lining of the coronary artery and this slows down blood circulation and the amount of oxygen that reaches
the heart. This build up is usually caused by an increased concentration of cholesterol in the blood.
There are two degrees of coronary artery disease:
 in one the blood flow is reduced to the point where the increased demand of hard work cannot be
met and this results in angina,
 in the other the coronary artery becomes completely blocked usually by a clot, and this is
coronary thrombosis.
Angina
The pain is usually linked to exertion and forces the patient to stop, subsequently it passes away within a
few minutes. The pain is a result of not enough oxygen and nutrients being supplied to the heart muscle
and so the muscle becomes starved.
Coronary thrombosis (heart attack)
Deposits of cholesterol are found in the lining of the arteries. These deposits may be quite thick, roughen
the interior of the arteries, and makes the risk of blood clots more likely. If the clot formation blocks the
coronary artery then part of the heart muscle is deprived of blood and oxygen. This may lead to heart
failure and the patient dies. Some heart attacks only cause a small amount of damage to the heart muscle
and people can recover quite quickly.. A heart attack is usually accompanied by severe pain. Obstruction
of an artery to the brain is one of the causes of a stroke, i.e. cerebral thrombosis.
RISK FACTORS which may contribute to coronary heart disease include:
1 DIETARY FACTORS
a. Obesity caused by over eating


Too much food – this may lead to obesity. Being obese can make it more difficult for blood to
pump through the heart increasing the risk of HBP and CHD
Being overweight is a major risk factor and leads to problems such as high blood pressure or
diabetes, both of which are a risk factor which can lead to heart disease
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b. Too much total fat intake
 Eating too much fat in total can cause obesity which is a contributory factor in heart disease
c. Too much saturated fat intake
 Mainly from animal origin – increases the level of cholesterol in the blood. Cholesterol is made in
the liver in our bodies using the fat we eat, especially saturated fats. High blood cholesterol is
thought to be one of the risk factors in the development of heart disease
 Cholesterol is ferried around the bloodstream by proteins called lipoproteins. LDL stands for low
density lipoprotein. It is often branded bad cholesterol, because high levels of LDL increase the
risk of heart disease. LDL carries approximately 70% of the blood cholesterol.
 A high level of LDL cholesterol in the blood (especially if it is oxidised) can lead to fatty deposits
in the arteries known as plaque which cause the artery to narrow, increasing the risk of blood clots
and blockage of the artery.
 Too many saturated fats may also make the blood more sticky and likely to clot
d. Too much trans fatty acids
 These increase blood levels of LDL cholesterol and may reduce levels of good cholesterol and so
increase the risk of heart disease
e. Too few polyunsaturated fats
 Omega 3 a polyunsaturated fatty acid is found mainly in oily fish such as mackerel,
sardines and pilchards. Omega 3 reduces the risk of blood clots forming, so reducing
the risk of a heart attack
f Too few monounsaturated fats
 They reduce low density lipo proteins (high levels increase risk of CHD) which tend to form fatty
deposits on artery walls and increase risk of bloods clotting and increase high density lipo proteins
(high levels reduce risk of CHD) which help remove fats cholesterol to the liver where it is broken
down into bile
g. Too much salt
 Eating too much salt may cause high blood pressure. If blood pressure is too high for too long,
the arteries can be damaged. This can make them brittle and liable to clog with cholesterol. If this
happens in one of the arteries that supplies the heart with blood, the result could be a heart attack
h Too much sugar
 If too much sugar is eaten then this can result in obesity, high blood pressure and heart disease.
 Dietary sucrose can also cause disturbances in the body which are characteristics of type- 2
diabetes. CHD is a common cause of death in people with diabetes
i. Too little NSP
 Soluble NSP found in oats, fruit, lentils and peas have been shown to reduce blood cholesterol
levels
 Soluble fibre lowers the levels of cholesterol in the blood by binding with bile salts which are
made from cholesterol thus preventing re absorption
 High intake of starchy carbohydrate foods promotes a feeling of fullness, provides a steady supply
of energy helping blood sugar levels thus reducing the risk of snacking on high fat foods thus
increasing fat intake and risk of obesity
j. Too little fruit and vegetables/ anti oxidants
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


Fruit and vegetables are good sources of anti oxidant vitamins – the ACE vitamins. The anti
oxidant vitamins neutralise the “free radicals” which may damage cells and tissues within the
body and this gives us some protection against heart disease.
ACE vitamins slow down the rate at which LDL cholesterol is deposited on the artery walls, so
helping to prevent heart disease
Low consumption of ACE vitamins – ACE vitamins reduce the number of damaging free radicals
in the body. It is thought that free radicals cause some cholesterols to become oxidised, causing
them to be deposited on the walls of blood cells staring the process of atherosclerosis
LIFESTYLE FACTORS
Cigarette Smoking
 Cigarette smoking this is the largest known contributory factor to CHD and increases the chance
of blood clots forming
 Smoking causes the blood to thicken, so increasing the tendency to clot
 Constricts (narrows) the arteries, so reducing the blood flow to the heart
 The nicotine in tobacco smoke increases the pulse rate and raises the blood pressure. The carbon
monoxide content of cigarette smoke cuts down the oxygen in the blood so the heart has to work
harder
 Smokers need a high intake of ACE vitamins as smoking increases the number of free radicals in
the body. Free radicals damage cells and tissues and so increase the risk of heart disease
 Smoking introduces harmful free radicals into the body and destroys anti oxidant vitamins which
could then lead to a build up of cholesterol in the arteries
3. Heredity
 Some families may inherit high risk factors such as a liking for fatty foods and so will increase the
risk of heart disease. Poor eating habits developed in childhood often develop habits which are
carried onto adulthood
 Genetic conditions may produce high blood cholesterol levels
4. High alcohol intake
 This can cause high blood pressure which can contribute to heart disease
5. Lack of physical exercise
 Regular exercise benefits the heart from increased stamina and strengthens the heart muscle and
makes it more efficient
 Regular exercise reduces stress and lowers blood cholesterol levels – both of which can contribute
to heart disease
 Exercise helps weight loss and maintenance
 Lack of physical exercise - exercise strengthens the vessels leading to heart muscle and so less
likely to develop to develop CHD
 Lack of physical exercise – may cause energy intake to exceed energy output thus increasing the
risk of obesity and CHD
 Regular exercise has a beneficial effect on blood cholesterol levels
6. Emotional stress
 People who are tense, impatient and anxious may be more likely to suffer from heart disease
 Emotional stress – stress can increase blood pressure which increases the risk of CHD
 Blood pressure also tends to rise under stress and this could damage the artery walls, particularly
if they are clogged with cholesterol. The heart then has to pump harder to force blood round the
body.
7. Gender
 More men than women tend to have heart disease but it is affecting an increasing number of
women
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Women under 40 years may be protected from heart disease by their hormone oestrogen. After
the menopause when oestrogen levels are reduced, cholesterol levels rise and the risk of heart
disease increases.
Lifestyle factors
 Less food eaten within household environment therefore less control and responsibility for its
nutritional content
 Traditional cooking methods such as frying – difficulty in changing to more “healthy” methods
 Sedentary lifestyle from an early age contributes to overweight
 High consumption of convenience foods, take ways due to inability or unwillingness to cook.
Many of these foods contain high fat content contributing to CHD
 Children have much more choice in relation to food and often make inappropriate choices which
have led to obesity and increased risk of CHD in later life
OBESITY
A major dietary problem in this country today is obesity. Overweight caused by excess body fat is a
hazard to health. There are no exact figures to tell us what an individual of a given height, with a certain
bone structure, should weigh. Tables which have recommended weights give a good guide, and it is
always clear when a person is so grossly overweight that they become obese. Usually overweight is
caused by long term overeating. Your energy requirement dictates what you can eat and this varies from
person to person, and becomes less as you grow older.
A way of measuring body fatness is to use the Body Mass Index (BMI) which is a measure of a person’s
body weight in kg divided by the square of their height in metres. The BMI classification is used
internationally and the World Heath Organisation (WHO) defines obesity as being a BMI of over 30. A
BMI of 25 – 30 is classed as overweight.
Reasons for the rise in obesity
1. Dietary reasons
High sugar and/or fat diet
 Sweets contain high quantities of fat/sugar which can contribute to weight gain especially if eaten
daily between meals or instead of meals
 Drinks with added sugar eg sweetened fruit drinks/ fizzy drinks can contribute to weight gain
 Fast foods and snack consumption are both high These are popular especially with teenagers and
have a high fat and energy content
 If energy intake from food is more than energy output over a period of time then this leads to obesity.
Reluctance to eat fresh fruit and vegetables
 Prefer to snack on high fat and sugar foods rather than fruit and vegetables
 There may be limited availability in the home due to cost or lack of knowledge about how to prepare
these foods.
Increased consumption of pre – prepared convenience meals in the home
 Increasing tendency for these meals to be used in the home as an alternative to home made meals –
these foods can be high in fat and sugar.
Huge increase in range of convenience food and fast food eating outlets
 More take away meals are eaten by families especially teenagers – these can have a high energy
value.
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Diet low in NSP and total complex carbohydrates
 Both these foods are filling therefore less likely to snack on high fat and sugar foods which may lead
to obesity
Lack of sensible eating habits
 Eating habits, food fads are developed in childhood and are difficult to change. Overweight parents
often have overweight children and although it could be argued that body type could be hereditary,
the cause is probably due to family eating habits.
 High fat/sugar diet in childhood leads to problems like obesity in later life.
 People tend to adopt eating habits when young and as they get older they continue to eat the same
amount, but their physical and energy output are reduced
 Erosion of family mealtimes means ‘grazing’ more common, often on high fat/sugar snacks
2. Consumer attitudes
 Poor diet in Scotland is now a historical fact, fried and high fat foods are traditional. In the past they
were required for warmth but much less so now so they contribute to obesity.
 Some consumers anxious about adaptations made to food products to make them healthier e.g. fat
replacers, sugar substitutes, so they continue to but higher fat/sugar varities.
 Some consumers just do not want to change
3 Lack of exercise and physical activity
 Increased use of cars by all members of the family eg teenagers do not walk to school. Make more
journeys on foot or by bicycle
 Lack of sports facilities locally or the cost may be too high
 Sedentary lifestyle, particularly of young people - increasing number of teenagers just watch TV or
play computer games.
 Obesity is less likely to found in people that have jobs involving hard physical work and who lead
active lives
 Parents may be inactive and do not encourage teenagers to take part in sports outside school
 Parents may be concerned about the safety of children outdoors so physical activity such as playing
in the park or street is not allowed
 Poor weather in Scotland is not always conducive to outdoor excercise to population generally may be
less active. Poor weather also encourages use of cars.
4Advertising and media
 Majority of advertising of food products is for those which can contribute to obesity, very little for
healthier options
 Special offers – buy one get one free – can encourage over purchasing of foods which if unhealthy
can promote overeating
 Use of cartoon/TV characters on foods can encourage pester power to prevail and foods may well be
high in fat/sugar which appeal to children
5. Access to shops
 Larger supermarkets which have a better range of lower fat/sugar, higher NSP foods usually out of
town,not all people have access to transport
 Rural nature of Scotland means that access to larger supermarkets which have a better range of lower
fat/sugar, higher NSP not always easy, therefore availability of products which may help reduce
obesity are limited.
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6. Manufacturers
 Some manufacturers are making slow progress at adapting foods to make them lower in fat/sugar.
 New labelling schemes not always understood fully by consumers so may be ignored.
7.Family income
 Where income is limited, cheaper, poorer quality foods may be bought in quantity – often high fat,
sugar foods- in preference to more expensive protein foods or fruit and vegetables
 Lack of money discourages experimentation with new foods which could be wasted so poor diet
continues.
 Lower fat/sugar foods often more expensive.
 Fresh foods have a limited shelf life and are more prone to waste.
 Fresh fruit and vegetables are expensive.
 Higher income may mean more disposable income being given to teenagers providing more
opportunity for them to buy snacks and fizzy drink
 Higher income - more convenience type foods may be bought to accommodate a busy lifestyle. These
foods can be high fat/sugar
8. Skills/Knowledge
 Lack of preparation and cooking skills means a reluctance to prepare fresh foods such as fruit and
vegetables, so convenience/take away foods which can be higher in calories are consumed.
 Children learn poor eating habits from parents so problem continues down the generations.
 Messages often confusing and contradictory – as a result people stick to what is familiar – which
leads to obesity.
 General lack of nutrition aducation may means people don’t actually know what to do to reduce
their risk of obesity
9. Cooking Facilities
 Poor housing and limitied finances often equal poor cooking facilities. Improving them to facilitate
‘home cooking’ not always seen as a priority so higher fat convenince foods and takeaways may be
consumed more regularly.
 Poor facilities reduces the ability and willingniess to prepare fresh foods which exascerbates obesity
problem
10 Lifestyle
 Lack of time for shopping and food preparation – look for quick to prepare meals which require little
food preparation and cooking. Convenience foods are often high in fat and sugar
 Increased ownership of microwaves and freezers make convenience type foods very useful for busy
families
 The huge increase of convenience foods and eating outlets available can lead to people eating too
many convenience or take-away foods, which again often have a high energy value.
11 Psychological factors
 If a person is anxious, depressed, bored or lonely, then she/he may find eating a great comfort and
overeat.
12 Taste
 Both fat and sugar add flavour to food so by reducing them foods become less appealing so
consumers revert to varieties which are higher in fat and sugar.
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Childhood obesity
Over weight and obesity in children is rising rapidly and is a major concern. Figures show that:
 About one in 10 children aged under 10 is obese
 One in four 11-15 year olds is obese
 Some estimates say that by 2050 half of the UK’s young boys and one in five young girls will be
very overweight
Children are now less active and are more likely to spend their spare time watching television and
playing computer games. A healthy diet and lifestyle would help towards reducing obesity level in
children.
Parents must play a role in preventing overweight at an early age by ensuring that sensible eating habits
are encouraged
How can parents help?
1. Helping the development of sensible eating habits
 Parent’s eating habits are passed on to their children and children learn to like foods made by
parents, there is an opportunity to make the foods eaten lower in fat.
 Lifelong eating habits are established in childhood so it is vital good habits are established in
childhood
 Encouraging the eating of a variety of foods at an early age is likely to promote good eating habits
throughout life
 Eating the correct balance of foods/nutrients contributes to the maintenance of a healthy
weight/reduces risk of obesity
 Eating proper meals will reduce the need to snack on fatty sugary foods which are high in calories
 Children may be unwilling to try new healthy options of they have not seen and tried them at
home, so offer a wide range of foods to children
 Lack of food preparation skills lead to a reliance on convenience foods which may be high in fat
or sugar and low in fruit, vegetables or NSP
 Financial situation of the family may mean that foods consumed at home are limited, these limited
choices may be a cause for similar unhealthy choices at school
 Sensible eating habits during pregnancy reduce the risk of childhood obesity
 Educating children by encouraging them to work with food and help cook their own meals can
lead to an informed attitude towards food and its function in the body
 Education from parents - teaching children about nutrition and teaching about foods and food
choices
2. Promoting positive attitudes towards food
 If food is used as a comfort or as a treat, it can lead to eating for the wrong reasons and may lead
to obesity
 Encouraging meals to be a social occasion more time is spent eating so a greater feeling of
fullness which lead to less snacking/grazing
 If meals seen as a social occasion then there is less eating on ones own which is often when
overeating takes place
 Family meals encourage children to try new foods so this could reinforce good eating habits
3. Ensuring regular exercise patterns
 Parents can encourage children to exercise more by setting a good example and exercising
themselves
 Parents can walk children to school instead of taking the car
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Parents can take children to the park, swimming lessons etc and make exercise part of their life
Health problems associated with obesity
Heart and circulatory systems
 Overweight people are more likely to develop high blood pressure.
 High blood pressure can lead to coronary heart disease as the heart has to work harder to supply
extra oxygen and nutrients needed by tissues.
 Strokes
 Angina
 More likely to suffer from varicose veins, haemorrhoids, swollen ankles
 A tendency towards high blood cholesterol levels
Joint
 Problems with hip, knee and back joints and arthritis as extra weight is placed on muscles and
skeleton if overweight.
 More likely to develop osteoarthritis in knee joint
Metabolic
 Type 2 diabetes
 Stones in the gall bladder
 More chance of digestive glands being overworked or ceasing to function.
Cancer
 In women, increased risk of cancer of the ovaries, cervix and breast cancer
 In men increased risk of prostrate and bowel cancers
Other
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Breathless during exertion as heart and lungs have to work harder to maintain oxygen supply.
Likely to tire more easily
Reduced mobility and agility
Psychological problems, such as low self esteem, lack of confidence can result from obesity.
Unwilling to take part in exercise due to body size which then makes the problem of obesity
worse
Overweight people often suffer from psychological disorders such as depression and anxiety.
Obese people may be laughed at by their peer group
Dental caries if obesity is caused by eating a high sugar diet
Complications can occur during surgery with obesity.
People who are overweight can experience difficulties during pregnancy and child birth.
Reduced fertility
Menstrual irregularities
Weight reduction
The only way to reduce weight is to use up excess fat. This means that daily food intake must be reduced
so that the excess body fat must be used to meet the body’s needs for energy. While on a reducing diet
meals still must be “well balanced”, though the energy intake is reduced the essential nutrients must be
provided.
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To reduce weight:
 Decrease kilojoule intake without decreasing bodily activity.
 Cut down on fat and sugar intake
 Use complex carbohydrates as a filling energy source. They contain fewer calories, gram for
gram, than foods with a high fat content, and give a feeling of fullness and satiety
 Do not cut down on essential body building foods such as protein but watch that excess protein is
not eaten, as this will contribute to weight gain if not used up as energy
 Eat plenty of fresh fruit and vegetable to provide bulk in diet without providing excessively high
Kj intake.
 Establish a good eating pattern of three meals per day.
 Try not to miss a meal as hunger may increase the likelihood of unhealthy snacking
 Avoid eating between meals - if hungry have fruit
 Avoid frying as a method of cooking - choose to grill foods instead of frying.
 Do not go on a crash diet as a steady weight loss is much healthier.
 Avoid “gimmick” diets – these do not establish good eating habits.
 Adopt a new pattern of sensible eating and keep to this after weight loss, rather than reverting to
bad eating habits.
 Establish a regular pattern of exercise.
HYPERTENSION (High blood pressure)
Everyone has blood pressure. The pressure is created by the heart’s constant pumping of blood around
the body.
Exercise, excitement, anger or anxiety all make the heart beat faster and increases blood pressure
temporarily
High blood pressure is often called hypertension.
High blood pressure is usually caused by narrowed or damaged blood arteries – this means that the heart
has to work harder to pump blood around the body. When blood is forced through arteries at high
pressure, it is more likely to damage artery walls.
There are many factors which contribute to high blood pressure:
 Being overweight
Excess body fat increases the risk of high blood pressure. Maintaining a healthy body weight (for adults
this means a BMI of 20-25) by eating a balanced diet and being physically active can protect against
hypertension. For those who are overweight, losing as little as 5 to 10 percent of body weight may lower
blood pressure. Weight-reducing diets may also reduce the dose of anti-hypertensive medications required
to control blood pressure levels.
 Poor diet
A diet that is low in fat and includes low fat dairy foods and fruit and vegetables has been shown to lower
blood pressure in people with or without high blood pressure. This diet reduced the amount of fat,
saturates and cholesterol and increased the amount of potassium, magnesium and calcium. Reducing the
amount of salt in the diet also had a beneficial effect. The best effect was achieved when both approaches
were combined. This highlights the importance of improving the overall diet rather than focusing on
single nutrients. Eating a healthy balanced diet will also help to maintain a healthy body weight.
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Salt
Reports conclude that sodium intake is an important determinant of blood pressure, in part influencing the
rise of blood pressure with age. As the main source of sodium in the diet is salt (sodium chloride), it has
been recommended that people in the UK try to reduce their salt intake to 6g per day. For most people
this will mean reducing their current intake by one third.
Potassium, calcium and magnesium
An inadequate dietary intake of potassium may increase blood pressure. A high potassium intake may,
therefore, protect against developing hypertension and improve blood pressure control in patients with
hypertension. There is also evidence to suggest that the effect of sodium on blood pressure may be
related to the amount of potassium in the diet and that the ratio of sodium to potassium in the diet might
be more important than the absolute amount of either. Potassium is found in meat, milk, vegetables,
potatoes, fruit (especially bananas) and juices, bread, fish, nuts and seeds.
Studies have also suggested that ensuring an adequate amount of calcium and magnesium in the diet is
important to protect against high blood pressure, as well as for general health. Sources of calcium include
milk and dairy products, soft bones in canned fish, bread, pulses, green vegetables, dried fruit, nuts and
seeds. Foods containing magnesium include cereals and cereal products, meat, green vegetables, milk,
potatoes, nuts and seeds.
The amount and type of fat in the diet
The amount and type of fat in the diet affects blood cholesterol levels. A high blood cholesterol level
increases the risk of heart disease and stroke and is, therefore, an important consideration in people with
high blood pressure.
Omega 3 fatty acids appear to have beneficial effects on heart health, Studies, which have given very
high doses of fish oil supplements to people with high blood pressure, have found reductions in blood
pressure. However, these levels of intake would not be obtained from a normal diet. More research is
needed in this area but current advice is to eat at least one portion of oil-rich fish per week.

Lack of exercise
Regular physical activity can help to lower blood pressure and enhance weight loss. It can also reduce the
risk of heart disease; people who exercise regularly have a 50% lower risk of dying of a heart attack. The
‘feel good factor’ that regular physical activity brings is also beneficial and many people use exercise as a
way to reduce stress.
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Excessive alcohol
Drinking too much alcohol not only directly puts up blood pressure, it can also lead to weight gain.
Excess alcohol consumption can cause resistance to anti-hypertensive therapy and is a risk factor for
several diseases, including stroke, heart disease, liver disease.
 Stress
Although the evidence is fairly limited, stress is often cited as a contributor to high blood pressure.
 Smoking
The avoidance of tobacco in any form is particularly important for people with high blood pressure.
Smoking damages the heart and circulation and increases the risk of heart disease and stroke.
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Age – as people get older blood pressure rises a little as the artery walls become less elastic
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Family history – high blood pressure is more likely if it is common within families
High blood pressure does not usually have any symptoms, but it is important – especially if it goes
unnoticed over a long period of time. It is one of several risk factors which increase the chance of having
a stroke, heart attack or kidney failure.
To reduce the risk of high blood pressure:
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Avoid obesity – keeping weight down helps keep blood pressure down
Reduce alcohol intake, if necessary, to no more than 21 units per week for a man, or no more than 14
units for a woman (one unit equals a half pint of ordinary beer, a small glass of wine or a single
measure of spirits). Alcohol is high in calories and can increase blood pressure.
Add less salt to food, and cut down on salty foods. This will not help everyone with hypertension but
those who take a lot of salt may well benefit from cutting down. Research has shown that there is a
link between sodium intake and high blood pressure.
Regular physical exercise helps control stress, helps keep blood pressure normal
Stop smoking. Smoking temporarily raises blood pressure. It also adds to the damage that high blood
pressure may cause to the heart and blood vessels.
People who suffer from hypertension should avoid stressful situations which are likely to raise the
blood pressure because this condition may lead to a heart attack or a stroke.
It should also be noted that reducing fat intake, particularly saturated fat, is recommended because
cholesterol found in saturated fats can narrow arteries and so restrict blood flow.
Potassium tends to reduce blood pressure, so a diet which is high in, for example, cereals, fruit and
vegetables, i.e. is high in potassium, will have a beneficial effect on blood pressure.
CANCER
Research figures have stated that more than 1 in 3 people in the UK will develop cancer at some point
during their lifetime. As result of rising rates of obesity, it has been estimated that there could be 12,000
cases of weight related cancer every year by 2010
To reduce the risk of cancer it is advisable to avoid smoking, keep body weight within the healthy range
for height, maintain regular physical activity, keep alcohol consumption to a moderate level, and eat a
balanced diet with plenty of fruit and vegetables and moderate amounts of red and processed meats.
What Is Cancer?
The body is made up of small units called cells. New cells are constantly produced to replace cells that
have become worn out or damaged. New cells are also made during growth, e.g. during infancy and
childhood. Normally, the body regulates the growth of new cells but occasionally abnormal cells are
produced. These abnormal cells do not function properly and if they are not destroyed by the body’s
surveillance system, they may develop (mutate) and also rapidly increase in number, causing cancer. The
abnormal cells may also spread to other parts of the body and multiply there.
Cancer can occur in different parts of the body. In the UK, the most common cancers in men are lung
cancer, prostate cancer and colon cancer. The most common cancers in women are breast cancer, lung
cancer and colon cancer.
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Factors Involved in cancer
The risk of cancer is affected by:
Genetic factors: People who have a family history of a particular cancer are more likely to develop it
themselves.
Hormonal Factors: The risk of some cancers e.g. some breast cancers is linked to levels of certain
hormones in the body.
Environmental factors: A range of environmental factors affect the development of a large proportion of
cancers, to varying degrees. Examples are tobacco smoke, diet, alcohol, some chemicals, and many other
aspects of lifestyle e.g. physical activity and body weight
Diet and cancer
Health experts agree that diet plays an important part in cancer risk. Approximately 30% of cancers could
be prevented by dietary means in Western countries. Despite this, consumers continue to eat a diet high in
fats, sugars, salt , processed foods and red meats. Research has linked all these foods with an increased
risk of cancer.
Diet has a greater influence on some types of cancer than others. The strongest links are with some
cancers of the gastrointestinal tract e.g. of the mouth, throat, stomach and large bowel (colon) and some
hormone-related cancers e.g. breast.
Large intakes of salt have been linked to stomach cancer. Research carried out in the UK has indicated
that a high intake of salt and preserved foods increase the risk of stomach cancer. Some foods are obvious
sources of salt such as crisps, bacon, processed meats and junk/ snack foods but it the salt content of
supposedly “healthy” food eg cereals, yoghurts that causes concern as these are less obvious sources to
consumers.
Experts agree that the main cause of stomach cancer is infection with helicobacter pylori. High salt
intake appears to interact with this to influence the risk of stomach cancer. Stomach cancer rates are
highest in where there are high salt intakes such as Japan and China.
Several studies have suggested that a high consumption of red and/or processed meat is associated with
increased risk of colon cancer in both men and women
High intakes of saturated fats may be linked to breast cancer
A number of studies suggest that fruit and vegetables reduce the risk of certain cancers including mouth,
throat, stomach and bowel cancers. In developing countries, cancers of the mouth, throat and oesophagus
are thought to be related to a diet low in fruit and vegetables. Some studies suggest a reduced risk of
stomach cancer with higher intakes of fruit and vegetables..
One of the mechanisms proposed to explain the beneficial effect of fruit and vegetables is via the
antioxidants they contain, such as vitamin C, carotenoids and other plant phytochemicals
Although dietary intakes and blood levels of antioxidant nutrients such as vitamin E and beta-carotene
have generally been associated with a lower risk of cancer (e.g. lung cancer), some studies have not
generally supported a beneficial effect. Fruit and vegetables also contain other components that might be
of benefit in cancer prevention. For example, there is thought to be a beneficial effect of dietary fibre on
bowel cancer risk.
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Body weight
Researchers have estimated that excess weight causes 3.8% of cancer. According to a Cancer Research
UK survey , only 29% of overweight or obese people were aware that being overweight increases the risk
of developing cancer despite the fact that it is now well established that being obese increases the risk of
developing several types of cancer.
Overweight and obesity are established risk factors for cancers of the oesophagus, bowel and kidney .
Overweight women also have an increased risk of womb cancer.
Obesity increases the risk of breast cancer in post-menopausal women by 50%, probably due to
associated increases in hormones. There is also evidence to suggest that obesity and overweight increase
the risk of gallbladder and pancreatic cancers.
The risk of colon cancer increases by approximately 60% in men and 30% in women with a Body Mass
Index (BMI) greater than 28.5, compared with a BMI under 22.3 (a healthy BMI is between 20 and 25).
Obese men have a 90% increased risk of dying from colon cancer.
Weight is also a factor in cancer survival. Obese or overweight people are less likely to survive than those
of a healthy weight. This may be due to the increased difficulty in being able to diagnose cancer in
overweight people and so the cancer may be more advanced before it can be treated.
Physical activity
Being physically active is important for weight control and may have other benefits (e.g. increase bowel
movement, enhance immune function, raise levels of various hormones and signaling molecules in the
body that can result in a sense of well-being). Research consistently shows that physical activity reduces
the risk of colon cancer, and there is some suggestion that physical activity can reduce the risk of breast
cancer.
Alcohol
In addition to smoking, alcohol is one of the main risk factors for cancers of the mouth, throat and
oesophagus. Alcohol is also the main diet-related risk factor for liver cancer and this is thought to be
through its effects on liver cirrhosis. There is also a large amount of research to show that breast cancer
risk increases with increasing amounts of alcohol consumption: there is a 7% increase in risk for one
alcoholic drink every day (compared to none). The effects of alcohol on breast cancer risk may involve
increasing oestrogen levels. Some recent studies also show that alcohol might increase the risk of colon
cancer.
DIABETES
What is diabetes?
Diabetes (or diabetes mellitus) is a condition in which the amount of glucose in the blood is not
controlled. The process of moving glucose from the blood into the body’s cells relies on a hormone called
insulin. When insulin levels are too low or are not effective, blood glucose levels can rise and this may
result in diabetes.
Diabetes develops when the body cannot use glucose properly. Around 1.4 million people in the UK
have diagnosed diabetes, of whom around 1 million have type 2 diabetes. In addition, there are a
large number of people who may have unrecognised diabetes.
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Insulin
The hormone insulin is made by the pancreas, a gland lying just behind the stomach. Insulin is one of the
hormones that help to control the level of blood sugar, glucose, which is a vital fuel for cells. Insulin
clears glucose from the blood and helps it to enter the cells, such as in muscles, liver and adipose (fat)
tissue. It is important that insulin works properly because both low and high levels of blood sugar are
harmful to the body. A low level of blood glucose is called hypoglycaemia while a high level is called
hyperglycaemia.
The symptoms
The main symptoms of untreated diabetes are:
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increased thirst
need to pass urine much more often, especially at night
weight loss
tiredness
blurred vision
TYPE 1 DIABETES
What is type 1 diabetes?
Type 1 diabetes is also known as insulin-dependent diabetes. It is an auto-immune condition in which the
immune system of the body (that protects the body against infection and disease) turns against itself. As a
result most, or all, of the insulin-producing cells of the pancreas are destroyed and the pancreas is not able
to produce enough insulin. How the insulin-producing cells are damaged is not very well understood but
it may be due to a viral or other infection, coupled with a genetic predisposition. Without insulin, the
body is neither able to use glucose as a fuel for the cells (causing rapid weight loss) nor control the level
of blood glucose. As a result, the level of blood glucose can become too high.
Treatment
It is important to maintain the body’s blood glucose level in order to eliminate the symptoms and prevent
long term consequences of high blood glucose levels, particularly circulation problems, and damage to
nerves, kidneys and eyes. Type 1 diabetes is managed by injections of insulin coupled with a healthy diet.
People with diabetes are given individual advice on how to inject themselves with insulin, what type of
diet to eat and how to check the level of glucose in their blood and urine.
Insulin injections
Insulin injections are vital for survival. Insulin cannot be taken by mouth because it would be destroyed in
the stomach. There are different kinds of insulin treatments available. Insulin is usually injected 1-4 times
per day depending on the type of insulin (quick-acting or slow-acting) and the daily routine of the person.
The amount and timing of insulin injections are adjusted depending on the timing, amount and type of
food eaten (mostly the amount of carbohydrates, i.e. starches and sugars) and the frequency, timing and
quantity of exercise taken. The aim is to avoid wide swings in the blood sugar level after and between
meals, as these are associated with a greater risk of complications later in life.
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TYPE 2 DIABETES
What is type 2 diabetes?
Type 2 diabetes (also sometimes referred to as non-insulin dependent diabetes) occurs when the body
does not produce enough insulin or the insulin produced does not work properly (this is known as insulin
resistance). Type 2 diabetes usually develops in middle-aged people (over the age of 40) and later life but
also recently amongst teenagers in the UK. It can be managed by diet and exercise alone or in
combination with tablets or insulin injections
If type 2 diabetes is treated properly from the early stages of the disease, the risk of any long-term
complications is reduced. These complications include heart disease, stroke, high blood pressure,
circulation problems, and damage to the nerves, kidneys and eyes. Regular medical check-ups are very
important for people with diabetes and also for those who are at high risk of diabetes.
Eating a healthy balanced diet, taking regular physical exercise, and maintaining a healthy body weight
can help to prevent or delay the onset of type 2 diabetes.
Prevalence of type 2 diabetes
Type 2 diabetes is increasing rapidly both in the UK and in the world in general. This is thought to be
linked with the fact that obesity is increasing There are currently around 1.4 million people with
diagnosed diabetes in the UK, of which around 1 million have type 2 diabetes. In addition, there are a
large number of people who may have unrecognised diabetes.
Who is at risk of type 2 diabetes?
There are several risk factors for type 2 diabetes of which inherited predisposition, obesity and physical
inactivity are the most important.
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Hereditary factors are more significant when diabetes is diagnosed at younger age. But when
diabetes is diagnosed at older age, life-style factors are more relevant.
The rise in obesity rates in the UK is a main contributor to the rapid increase in the prevalence of
diabetes. Most people with newly diagnosed type 2 diabetes are overweight or obese (Body Mass
Index of 30 or over)
Dietary factors can contribute to the development of type 2 diabetes. The most significant factors are a
diet high in energy, fat (especially saturates) and low in dietary fibre. This kind of diet is harmful because
it causes weight gain and also impairs insulin action.
Lack of exercise is harmful because it can promote weight gain and it also impairs insulin action. Regular
exercise has many benefits. Apart from improving the ability of insulin to act, it also helps overweight
people to lose weight. Everyday activities, like cycling or walking to work, or walking up the stairs
instead of taking the lift, can be helpful.
Treatment
Changes to diet and physical activity are the two main approaches in the treatment of type 2 diabetes. The
aim of the treatment is to help the people to control blood glucose level and also to help weight loss.
Usually it is possible to control diabetes by diet and activity but, still, some people may need tablets or
insulin injection, about 30% of cases are managed by diet and insulin injections. The recommended diet
for patients with type 2 diabetes is the same the healthy diet recommended for all people.
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The dietary advice for people with diabetes has changed considerably over the last century. People with
diabetes were told to eliminate all sugar and sugary foods from their diet. This resulted in people with
diabetes buying special diabetic foods to replace everyday sugar-containing foods. Today, however, the
most important message for people with diabetes is to eat healthily, in exactly the same way that is
recommended for the whole population – that is a balanced diet based on starchy foods and plenty of fruit
and vegetables, and is low in fat, salt and sugar. This means that a small amount of sugar and sugarcontaining foods can be eaten, preferably as part of a healthy meal. Special diabetic cakes, biscuits or
pastries are of no particular benefit and as well as them being more expensive, they may contain a lot of
fat.
People with diabetes should try to maintain a healthy weight and eat a diet that is low in fat (particularly
saturates) and salt but contains plenty of fruit and vegetables (at least five portions a day) and starchy
carbohydrate foods such as bread, rice and pasta (particularly whole-grain versions).
People with type 2 diabetes are at greater risk of cardiovascular disease than the general population.
Dietary advice should therefore focus on reducing cardiovascular disease risk.
Alcoholic Drinks
Advice on alcoholic drinks is the same as for the general population (up to 3 units a day for women and
up to 4 for men). Alcohol can have both hypo- and hyperglycaemic effects, depending on the amount
consumed, the type of drink and whether it is consumed with a meal. In studies in people with diabetes,
alcohol had no acute effect on blood glucose or insulin levels, indicating that such beverages should be
regarded as additional items rather than substitutions for foods.
IRON DEFICIENCY ANAEMIA
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The human body contains about 4g or iron.
Iron is a vital part of haemoglobin, the pigment in red blood cells that is responsible for
transporting oxygen from the lungs to the cells of all body tissues.
Oxygen is needed by all body cells to break down nutrients and obtain energy..
If you become too short of iron you start making red blood cells containing less haemoglobin.
That means your body has to work harder to supply you with enough oxygen. This extra work can
leave you feeling weak, constantly tired and short of breath – all of these things are symptoms of
iron deficiency anaemia. Resistance to infection is reduced and there may be poor regulation of
body heat.
Extra iron which is not needed for haemoglobin is stored in the liver, spleen or bone marrow,
ready to be used if there is a shortage in the diet
Prevention of iron deficiency anaemia
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the daily food intake must include sufficient iron to maintain the normal level of haemoglobin in
the blood. Eggs, red meat especially liver and kidney, fortified bread and breakfast cereals, dried
fruit, beans, lentils and leafy green vegetables all contain iron.
Eat foods rich in Vitamin C alongside these iron rich foods to help absorption
Iron from food sources not linked with NSP or phytates ( eg meat) is more easily absorbed by the
body.
A course of iron tablets may also be taken to make up a shortage of iron.
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Reasons why iron may be lacking in the diet
 Snacking and grazing throughout the day rather than traditional meals could reduce iron intake
 If people are not aware of nutrition or are lacking in the skills to prepare iron rich foods then
sufficient iron may not be included in their diet
 Less red meat may be eaten for health reasons – to reduce saturated fats or for moral or religious
reasons
 Dark green vegetables can be unpopular particularly with the younger age groups
 If a good supply of fruit and vegetables, supplying Vitamin C, are not eaten then absorption of
iron will be affected
How much iron is needed?
Most people lose about 1 or 2mg of iron a day from their bodies. But to replace that you need to eat foods
containing a greater amount – about 8 to 15mg – because only a small proportion of the iron in food is
absorbed by our bodies
Certain groups of people may be more likely to suffer from iron deficiency anaemia:
1.Adolescent girls and women who are menstruating, as it is estimated that 30mg of iron is lost during
menstruation and this will be more if periods are heavy and prolonged.
2. Pregnant women. During pregnancy, a total of about 400 mg of iron is supplied to the unborn child
and the actual birth causes the loss of a further 250 mg . However the increased needs of pregnancy for
iron should be met without a further increase in iron as menstruation has stopped and the mother’s store
of iron can be used. Dietary supplements may be needed by mothers with low iron stores eg teenage
mothers.
3. Babies are born with an iron store which is needed because milk has a low iron content. This store will
only last about four months so it is important to introduce iron-rich foods quite soon (about four months)
to prevent anaemia. This can be done by giving enriched cereals, pureed vegetables, minced meat, etc.
It is particularly important to ensure that babies and young children get enough iron. There seems to be a
critical period – between six months and five years – when a shortage of iron in the diet can cause a small
but permanent reduction in a child’s learning ability.
4. Teenage boys require plenty of iron because during growth the volume of blood increases. There has
been quite an increase in the number of teenage boys suffering from anaemia particularly during the
‘growth spurt’ period. As their bodies grow so does the volume of blood required. They may also require
extra iron for muscle growth and also to supply oxygen to the muscles during sporting activities.
5. Elderly The main reasons for anaemia in the elderly are either that they cannot afford iron-rich foods
or because they are often living alone and cannot be bothered or do not have the strength to prepare
adequate meals. Also the high consumption of tea can be factor, as the tannin in tea prevents absorption
of iron
6. Vegetarians may have difficulty in obtaining enough iron as the main food sources are those not
consumed by them, e.g. red meat, liver, kidney, eggs. The other good sources are perhaps those that are
slightly less popular, e.g. green leafy vegetables, dried fruits, etc, and more of these are required to give
the same quantity of iron and this can make diets bulky.
Vegans may absorb less iron due to the high phytic acid content of NSP foods such as cereals.
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7. People living on low incomes. Low income may mean that this group of people cannot afford iron
rich food, they may not be sufficiently motivated to prepare adequate iron rich meals and they may have
poor facilities for storage, preparation and cooking of foods.
8. Athletes. They may have a higher loss of iron from the body due to muscular activity.
TOO MUCH IRON
Too much iron can be more harmful than too little. Our bodies regulate the amount of iron so for the great
majority of people there is no risk of poisoning from even the largest amounts of iron that you are ever
likely to get from food. But the larger amounts concentrated in iron tablets are not so safe.
Iron tablets are a common cause of poisoning in young children. The tablets can often look like sweets,
and the amount of iron in just a few can be harmful for children. If you are taking an iron supplement it
would be wise to treat it as a medicine and lock it away safely.
BOWEL DISORDERS
NSP is of great importance to health as it:
 Aids the removal of waste products, which could be harmful or toxic, from the body
 Absorbs a lot of water ensuring that the faeces are soft and bulky, enabling them to pass along the
intestine by means of peristalsis
 Helps prevent various bowel disorders including constipation, diverticular disease, bowel cancer, and
haemorrhoids (piles)
There are two types of NSP
i )Soluble NSP
This type of NSP is thought to slow down the digestion and absorption ofcarbohydrates and so help to
control blood sugar levels – is useful for diabetics
ii)Insoluble NSP
Insoluble NSP absorbs water and increases in bulk, so helping the gut keep in good
working order
Constipation
Many people suffer from constipation. The faeces become very hard and move slowly through the
intestine, and a lot of effort is required to remove them. Abdominal discomfort and a general feeling of ill
health accompany this condition
Diverticulitis
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If extra stain is put on the muscular walls of the small intestine because of constipation, then
diverticular disease may develop
 If the faeces are small and hard due to a lack of NSP and water, then the muscular walls of the intestine
have to work harder to move the faeces along
 This results in increased pressure in the intestine. Pouches of the bowel lining are forced through
weak spots in the intestinal walls to form small pockets, called diverticula, and where they occur the
subject is said to be affected by diverticulitis.
 Diverticula usually occur in the lower part of the large intestine. They may start to harbour bacteria
which are usually excreted.
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Symptoms are acute abdominal pain, flatulence and diarrhoea.
Diverticulitis usually only appears in people who have a diet low in NSP and are less active.
An increase in consumption of refined and convenience foods also contributes to this condition.
Irritable bowel syndrome
Irritable bowel syndrome (IBS) is a poorly understood disorder. It has been estimated that IBS affects
about 20% of adults in the UK and the condition affects three times as many women as men. The
symptoms are abdominal pain and discomfort, and a change in bowel habit, which may be either
constipation or diarrhoea. The pain is usually related either to eating or going to the toilet. These
symptoms can also be features of other bowel disorders and so IBS is often diagnosed by a process of
elimination.
• People with constipation-dominant IBS may benefit from an increase in dietary fibre
• People with diarrhoea-dominant IBS may benefit from a decrease in insoluble fibre
Some sufferers associate their symptoms with eating particular types of food but there is not enough
scientific evidence to suggest that specific exclusion diets are routinely beneficial.
Some evidence suggests a number of IBS sufferers may be sensitive to excessive amounts of caffeine and
to sorbitol (a sugar alcohol which is found naturally in fruits such as plums, apricots, cherries and apples
and is also used in some products in place of sugar) and should try limiting intakes of foods and
beverages containing these compounds.
There is some research into the effect probiotics may have on IBS. As the evidence is currently limited,
no clear guidance can be given although, anecdotal evidence suggests some individuals may find they are
of benefit.
Haemorrhoids (Piles)
These may be caused by the increased effort required to remove hard faeces in constipation sufferers
Bowel cancer
It is suggested that people today do not eat enough NSP and this is the cause of many bowel disorders and
bowel cancer
Many foods eaten today are refined. This means that they have much of their NSP content removed eg
white flour, white rice. It is important to ensure the bowel regularly gets rid of poisonous waste as this
will help prevent bowel cancer.
OSTEOMALACIA
If absorption of calcium and phosphorus from the small intestine is reduced due to a lack of Vitamin D,
too much phytic acid or too much NSP, there will be insufficient to maintain the strength of bones. Bones
become weak, fragile and may break easily. Strength of teeth is also not maintained.
This is an adult form of rickets more common in the elderly which can result in serious fractures, after
even a minor fall
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The reasons for osteomalacia in the elderly are not exercising enough, not getting out in the sunshine
particularly in winter, not being able to get out or afford some of the required foods and often being on
drugs for a medical condition.
OSTEOPOROSIS
Osteoporosis – brittle bone disease – is on the increase, affecting men as well as women
Osteoporosis develops gradually and unnoticeably over many years; diet and lifestyle now can affect the
chances of getting it later on.
What is osteoporosis ?
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Osteoporosis means porous bones.
Bones are made up of collagen for flexibility, and calcium for strength. In osteoporosis bones lose
some of their internal collagen and calcium making them weak and liable to break. –hence the
name of brittle bone disease
Osteoporosis is not a problem of too little calcium but of the way we use and keep that calcium in
our bones.
Most people do not know they have osteoporosis until they have a minor fall or make an awkward
movement and end up fracturing a bone.
Some people with osteoporosis experience chronic backache or notice they are getting shorter and
developing a stoop as the bones of their spine become weakened and compacted. Losing 5 – 10
cm in height is common, and the spinal curve may develop into a “Dowager’s Hump”.
This shortening of the body means there is less room for internal organs – the stomach can be
forced up into the chest and the abdomen pushed forward. This can cause chest pain and a feeling
that food is stuck behind the breast bone
The bone cycle
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Bone tissue is constantly turning over, being broken down and rebuilt.
Bones stop growing in length around late teens and early twenties or early thirties.
At this age bones reach their ‘peak bone mass’ (PMB)– their maximum size and density Potential
peak bone mass is determined by heredity, but whether this potential is achieved depends on diet
and lifestyle factors. After the mid 30’s bone density declines – loss of bone occurs at the rate of
0.3% of PMB per year
Teenagers with low calcium intakes may not reach their potential peak bone mass. At risk are those
who avoid dairy foods, are slimming or rely heavily on ‘junk food’ containing little calcium
In women during the five years following the menopause the loss is greater due to the lack of the
hormone oestrogen. Hormone replacement treatment(HRT) assists in the prevention of loss of
calcium from bones , stimulates the production of new bone therefore helping to ensure that bones
do not become brittle and so helps prevent osteoporosis
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Factors which may help to reduce the risk of osteoporosis
Factor
Explanation
Calcium rich diet
A high intake of calcium in childhood and teenage years
which are the main stage of bone development helps to raise
peak bone mass and so prevent osteoporosis in later life
Calcium is necessary for the formation and maintenance of
bones
Vitamin D rich diet
Vitamin D helps the absorption of calcium in the body which
helps achieve peak bone mass, helping to prevent osteoporosis
Phosphorous rich
diet
Phosphorus combines with calcium to produce calcium
phosphate which is the main substance necessary for bone
hardness/ strength so helping to prevent osteoporosis
Exposure to
sunlight/ultra violet
light
Exposure is essential for the syntheses of Vitamin D. Vitamin
D is essential for calcium absorption in the intestine so
helping bone formation and preventing osteoporosis
Low fat/ saturated
fat intake
A high intake of fat/ saturated fat may lead to poor calcium
absorption which could contribute to osteoporosis
Low salt/sodium
intake
This will slow down the loss of calcium from the bones and
help prevent osteoporosis.
Factor
Explanation
Regular exercise
Regular exercise will increase bone density/ stimulate bone
formation and reduce the risk the risk of osteoporosis. In
young people, exercise may raise peak bone mass reducing the
onset of the osteoporosis in later life
In adults, exercise protects against bone loss reducing the risk
of /delaying the onset of osteoporosis
Not smoking
The nicotine in cigarette can cause actual bone loss so
stopping smoking can reduce bone loss so can help prevent
osteoporosis
Low alcohol intake
As alcohol is a toxin to bone cells and increased alcohol
consumption may start to decrease bone mass which may lead
to osteoporosis
A balanced diet
An unbalanced diet may result in a diet low in calcium/
vitamin D/ phosphorus and bone density may be affected
therefore increasing the risk of osteoporosis
Low intake of junk
foods
Junk foods tend to be lacking in calcium and so would not
allow peak bone mass to develop. This increases the risk of
osteoporosis
As junk foods tends to be high in fat/ saturated fat which may
hinder calcium absorption leading to increased risk of
osteoporosis
A healthy body
weight
As obesity could put an extra strain on the bones and indicates
an unbalanced diet which may be short in calcium therefore
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an increased risk of osteoporosis
Low NSP intake
High intake of NSP in the diet could hinder the absorption of
calcium and contribute to osteoporosis
Low phytic acid
intake
High intake of phytic acid in the diet could hinder the
absorption of calcium and contribute to osteoporosis
Include lactose in the Lactose in the diet could assist the absorption of calcium and
diet
help achieve peak bone mass and so help reduce the risk of
osteoporosis
Include protein in
the diet
Protein in the diet could assist the absorption of calcium and
help achieve peak bone mass and so help reduce the risk of
osteoporosis
DENTAL DECAY
Foods that contain a high proportion of sugar are reduced to a very sticky mixture when they are chewed
and mixed with saliva. Even after swallowing, sugary particles are left sticking to the teeth. If the teeth
are not thoroughly cleaned afterwards, traces of very sticky foods, such as toffees, may be detected,
clinging to the teeth as long as twenty-four hours later. Bacteria which are normally present in the mouth,
attack the sugary residues, and change them to acids. The acids gradually dissolve small areas of the
teeth’s protective covering, the enamel. This is the way tooth decay begins.
Theoretically, sugar in any form will cause tooth decay, but in practice, sugars contained naturally in
foods, e.g. fruit, have less effect. Sucrose is the sugar that contributes most to dental decay. It is the
frequency and amount of NMES – mainly confectionary, soft drinks and table sugar – that are the main
causes.
Other carbohydrates, especially cooked starch (e.g. present in crisps), which can be broken down by
enzymes in saliva to component sugars, may also damage teeth, although to a much lesser degree. This is
because starch has to be broken down before fermentation can occur
Fresh fruit is not strongly associated with caries. This is thought to be due to the fact that the sugars in
fruit are held in the cells of the fruit, and are not released until chewing breaks down the cells. However,
the acidity of some fruits and fruit juices (e.g. oranges, lemons, limes) can cause dental erosion – the
progressive loss of enamel from the tooth (link) – in certain circumstances, e.g. if the juice is swished
around the mouth or fed in a baby’s bottle.
In a fruit juice the sugars are no longer held in the cells of the fruit. Consumption of fruit juice is therefore
potentially associated with caries development especially if the juice is in contact with the teeth for a long
period of time.
Another factor which affects the risk of developing caries is the retentiveness (stickiness) of the
carbohydrate. Foods such as dried fruit or toffees may stick to the teeth and so reduce the pH in the mouth
for a longer time than would occur than less sticky food. It is important that teeth are brushed regularly
each day, preferably with a fluoride toothpaste, to remove any food sticking to the teeth or trapped
between the teeth. Regular tooth brushing and the use of dental floss also removes the dental plaque
coating the tooth surface and gum margins, which constrains the bacteria responsible for dental decay.
Regular visits to the dentist are important to ensure that dental health is maintained.
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The most effective means of reducing dental caries that is available to the individual, is to control the
sugar intake. The most important factor is not the total amount of sugar that is consumed but the number
of times that sugar enters the mouth. Sugar eaten at meals is not as damaging as sugar eaten between
meals as snacks. The main aim in sugar control for the prevention of decay is to persuade people to limit
their consumption of food and drinks containing sugar to meal times.
Prevention of Dental Caries
Diet
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Foods rich in calcium, phosphorous and Vitamin D must be eaten to give teeth their hardness
Vitamin C must be included in the diet to keep the gums healthy
Crunchy foods, like apples and carrots, should be eaten regularly to exercise the gums and prevent
infection
Eating too much salt/ sodium in the diet could lead to extraction of calcium from the bone, thereby
weakening the teeth
Saliva plays an important part in that the flow of it over the teeth not only helps cleaning but helps to
neutralise the acid. This is why foods that require a lot of chewing and are not sticky are better
because they increase saliva production.
“Diet” drinks lower the intake of sugar but are a major cause of tooth erosion (tooth wear) due to the
acidity of the drinks . Water should be the preferred drink.
Reduce NME sugars intake by :
- limiting consumption of sugar, sugary foods and drinks which cause a build up of plaque
which attacks the enamel
- avoiding sugary and sticky snacks between meals as this prolongs exposure to the acid
which causes a build up of plaque
- becoming aware of the foods with ‘hidden’ sugar – read the labels on food products
- increasing use of fresh or dried fruit as sweetening agents on breakfast cereals, in baking
and also as a snack food. These are intrinsic sugars which do not produce the same
amount of acid in the mouth
- avoiding grazing on biscuits and juice – continual contact with sugar
- avoiding sweet foods last thing at night
- not missing breakfast – more sweets may be eaten as snacks
- sensible choice from the tuckshop and vending machine
- eating fresh fruit and vegetables as snacks
- not being influenced by adverts for sweet foods
- not giving children sweets when they have been upset or hurt themselves or as a reward.
This will encourage a sweet tooth in later life
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Content
Food commodities
Unit: Resource Management
Elaboration
Composition and properties of the following goods in a
Raw and cooked state:
1. Fruit and vegetables
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structure and texture
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changes during ripening and cooking
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plant pigments and enzymic browning

sensory qualities

relationship to health
2.
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Meat and Fish
structure and texture
post-mortem changes
changes during cooking
meat and fish colour
meat tenderness
sensory qualities
relationship to health
3.
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Dairy foods, milk and milk products and eggs
constituents
uses in food preparation
changes during cooking
sensory qualities
relationship to health
4.
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Cereals and baked goods
types
function and uses of rice & pasta; flour: fats and
shortening: sugar : raising agents
changes during cooking
sensory qualities
relationship to health
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Vegetables
Vegetable structure:
Vegetables have no common biological structure. They are obtained from different parts of many plants.
They can be categorised as follows:
Leaves e.g. cabbage, lettuce
Roots
e.g. carrots, radishes, turnip
Fruits
e.g. tomatoes, cucumber
Stem, stalk
e.g. celery
Flower e.g. cauliflower
Seeds
e.g. peas, beans, lentils
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Key facts
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vegetables usually have high water content.
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their content of indigestible carbohydrate (mostly cellulose) makes them important in the diet due to
the production on non starch polysaccharides.(NSP)

many vegetables are good sources of vitamin C, beta-carotene and mineral elements, particularly
iron.
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vegetables contain varying amounts of carbohydrate, e.g. beans, corn, peas and potatoes. In nature
they contain sugar which is replaced by starch on maturity.
Texture of vegetables
The crunchy texture of vegetables adds variety to the diet. The texture of vegetables (and fruits) is often
an indication of quality and it depends on the turgor of the cells and the presence of supporting tissues
and the cohesiveness of the cells. Plant tissues assume a characteristic water content and at this level the
cells is described as a turgid cell or in a complete state of turgor. A plant cell is like a balloon blown up
with water- this internal pressure is called turgor pressure. When the water is cut off to the cell, water is
gradually lost from the plant. This means that the turgor pressure cannot be maintained and the cell walls
start to collapse. This spreads throughout the plant which “wilts”. Leafy vegetables such as lettuce remain
turgid for short time only before becoming limp.
Key facts
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the wall of cells in plant tissue serves as the structure of the plant. They are distributed to provide
support for the plant.
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crunchiness in vegetables is caused by the pressure that turgid cells exert on one another

cementing material (pectin substances and hemi-cellulose) between cells make them stick together.
This makes raw vegetables resist the pressure of the teeth chewing.
Changes during cooking
Some vegetables are almost inedible until they are cooked and for this reason, many are cooked before
they are eaten. Those vegetables which are acceptable raw are termed “salad vegetables”
Key facts

cooking will soften vegetables as the pectins and hemi-cellulose dissolve and the starch gelatinises.

uncooked starchy vegetables are difficult to digest because the starch granules resist the action of
enzymes produced during digestion.

cooking destroys a number of micro- organisms which are present on the surface of vegetables.

vegetables should be cooked in boiling water (usually small quantities). When crisp vegetables are
immersed in boiling water, heat denatures the cytoplasm and cell membranes. The result is that the
cells no longer retain water. Water is lost by diffusion through the cell walls which become
permeable at this point. It is this loss of water which makes boiled cooked vegetables become limp.
(very often overcooked)

Vitamin C may be destroyed by an enzyme called oxidase which is found naturally in vegetables
and fruit. This enzyme destroys Vitamin C by oxidation when the cell walls become weakened as
the plant wilts or when cut or bruised during preparation. Oxidase can be destroyed by plunging the
vegetable into boiling water so conserving Vitamin C

ideally, cooking should stop when vegetables are still slightly crisp (al dente) with the exception of
starchy vegetables, e.g. potatoes.

cooking dulls the bright colour of vegetables, particularly that if green vegetables. When a green
vegetable is immersed in boiling water it becomes brighter green. However, as cooking continues,
the colour changes to a more olive green. This result is due to acids in plants which affect the
chlorophyll. (gives plants green colour)
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to preserve the bright green of vegetables when cooking, it is necessary to cook in minimum
amount of water for a short time with the lid on.
carotenoids are yellow, orange and red coloured fat soluble pigments found in vegetables, e.g.
carrots, peppers. Colour loss is not as noticeable in these vegetables, e.g. carrots, peppers. Colour
loss will occur only after lengthy cooking at high temperatures.
anthocyannins belong to a group of compounds known as flavanoids which give the red, blue and
purple colours to a range of vegetables and fruit. They are soluble in water and leach out easily into
cooking water. In other methods of cooking they are relatively stable.
Yellow and red vegetables
The pigment responsible for the colour of these vegetables is a precursor to vitamin A which they contain.
These pigments are known as carotenoids and they are responsible for impairing the colour to most
yellow, orange or red foods. Important carotenoids include:
 The orange carotenes of carrots, apricots and peaches
 The red lycopene of tomatoes, watermelon and apricots
 The yellow –orange xanthophylls of corn, peaches and paprika
 The yellow crocetin of the spice saffron
Seeds
Peas, beans and lentils grow as seeds inside pods and are referred to collectively as legumes. A legume is
any member of the pea family, including chickpea, runner beans, soya beans and lentils. The seeds of
these plants are known as pulses.
They have a high protein content but are low in one essential amino acids, methionine, but have a
plentiful supply of lysine. Apart from being a good source of cheap protein, especially when eaten in
combination to provide all essential amino acids, pulses are particularly useful addition to our diet for two
main reasons:
1. They have the lowest fat content of any protein foods
2. Their dietary fibre content is extremely high
Beans have over 200 different types but the most popular in the U.K. is baked beans. The oil in soya
beans are very often used in the manufacture of margarine and proportions similar to animal tissue and
contain a significant amount of unsaturated fat.
Pulses are a good source of protein and NSP. Care must be taken when cooking as the addition of salt,
vinegar, lemon juice or tomatoes can cause the outside of the beans to toughen, preventing them from
cooking properly.
Fruits
Structure and texture
The structure and texture of fruits is very similar to vegetables. Most fruits consist of the pulpy, edible
material which develops around and adheres to the seeds of the plant after it has flowered. The taste of
fruit is a blend of the sweetness and acidity presents, complemented by the flavour of that particular fruit.
Some fruits, for example, tomatoes, peppers and cucumbers are eaten as vegetables. However, they are
the fruits of the plant.
Changes during ripening
Unripe fruit is practically inedible. It is often green in colour, but during ripening, the green colour may
be replaced by a yellow or reddish colour. Harvested fruit is kept in cool storage until sold to the
consumer. At these temperatures they should have an extended storage life because the organic acids of
the fruits tend to decrease during storage and ripening at lower temperatures. Acids disappear during
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ripening and this affects both the colour and taste of the fruit. The flesh softens and becomes sweeter and
juicier and a characteristic ‘ripe’ flavour and odour develops.
The changes which occur during ripening are caused partly by enzymes conversion of complex
substances to simpler substances.
 hard starch – packed cells are softened by conversion of starch to sugar which dissolve and
enhance the sweetness and juiciness of the fruit.
 Insoluble protopectin, which cements plant cells closely together, is converted to soluble
pectin. In this soluble pectin. In this soluble state, the pectin connects the cells more
flexibly.
 fruit is cut off from its supply of nutrients when it is harvested. The results in the halt of
growth. However, ripening may continue and sometimes the fruit ripens more rapidly than
if it had been allowed to continue growing.
 citrus fruits and other fruits which do not store starch, obtain their sugar from the leaves of
the plant on which they grow. They do not therefore become sweeter after picking.
 some fruits produce minute amounts of ethylene during their growing period. Larger
amounts are produced when the fruit is passing through the critical ripening period. At this
time, cell activity is at a maximum. Ethylene activity promotes ripening and is used in
commercial fruit production to accelerate ripening of fruit.
Ripening
Ripeness marks the end of the fruit’s growth and the beginning of its death. Fruits which have soft flesh
and thin skin pass rapidly from ripeness to rottenness. Harder fruits and those protected by a hard skin can
remain in good condition for a lot longer. Undamaged fruit may remain edible for some time but
eventually will decay as a result of the continued activity of its own enzymes and attack by microorganisms.
Sensory qualities of fruit and vegetables
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fruit is refreshing to eat and adds colour and flavour to diet. The taste of fruit is a subtle
blend of sweetness and acidity. The relative amounts of sugar and acids present determines
whether a particular fruit is sweet or sour.
Vegetables do not have such pleasant tastes, smells and flavours as fruit in general.
However, vegetables do have distinctive flavours, tastes and smells. Many vegetables are
less attractive to some people, especially children, because of the smell given off by
sulphur compounds.
Relationship of fruit and vegetables to health.
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both groups constitute such diversity that it is difficult to generalise about their
relationship to health. In general, green leafy vegetables, potatoes and fruits are good
sources of vitamin C.
Legumes are fairly high in protein, good sources of calcium and iron and contain some of
the B group of vitamins. Soya beans are a particularly good source of protein
Dietary fibre(NSP) in fruit and vegetables combines with cholesterol and bile salts
preventing cholesterol from being absorbed - lack of fruit and vegetables may increase the
risk of CHD. NSP can bind with the bile salts to lower cholesterol levels
fruit and vegetables are important sources of non-starch polysaccharides and so reduces
the risk of constipation and bowel disorders.
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fruits and vegetables are high in NSP and promote a feeling of fullness so reducing the
risk of snacking on high fat/sugar snacks between meals which can contribute to a higher
risk of obesity, Type 2 Diabetes, CHD, tooth decay and certain cancers.
A diet lacking in fruit and vegetables increases the risk of cancer; in particular mouth,
pharynx, larynx, oesophagus, lung, stomach and pancreas
Vegetables and fruit contain phytochemicals which are known to help prevent certain
human cancers. Citrus fruits are particularly high in class of phytochemicals known as
limonoids which can have a protective effect against variety of human cancers/ cruciferous
vegetables (cauliflower, Brussels sprouts, cabbage and broccoli) contain indoles a type of
phytochemical which may offer some protection against cancer. A diet lacking in fruits
and vegetables prevent this benefit.
A diet lacking in fruit and vegetables may not contain enough phytochemicals which are
not considered as nutrients but can reduce the risk of cardiovascular disease, cancers and
problems associated with ageing
fruit and vegetables will also supply flavonoids which are cardio protective and are
powerful antioxidants and scavenge free radicals.
depending on the vegetable, they contain some iron, folate and vitamin A
there is growing awareness that vegetables and fruit provide materials besides vitamins
and minerals that are important for long term health. Cruciferous vegetables consist of
cauliflower, brussels sprouts, cabbage and broccoli. They contain a number of beneficial
phytochemicals including indoles, which are nitrogen compounds, which may offer some
protection against cancer because they help to prevent carcinogens from damaging DNA.
Phytochemicals are not considered essential nutrients, yet their consumption can have long
term effects on reducing the risk of cardiovascular disease, cancers and problems
associated with the ageing process.
Brussels sprouts may help to protect against some types of breast cancer which are linked
to high levels of the hormone oestrogen. The indoles contained in brussels sprouts
stimulate the liver and break down the hormone.
Carotenoids function as an anti-oxidant and can be converted into retinol (vitamin A) in
the small intestines.
Red and yellow vegetables and fruit are a good source of beta-carotene.
Plants, including vegetables, produce flavanoids. These are a broad family of substances
that can function as anti-oxidants to block oxidative damage to cells due to free radicals.
Vegetables produce flavonoids which act as anti-oxidants to block damage to cells by free
radicals– lack of vegetables can lead to a deficiency of flavonoids
A diet lacking in fruit and vegetables may result in a deficiency in antioxidants which
counteract free radicals reducing senility and early ageing. Antioxidants are vital to health
as they are substances which act in the body’s first line of defence against unwanted
damage to cells
If there is an imbalance between antioxidants and free radicals, high levels of free radicals
can attack proteins, fatty acids, DNA, which can result in chronic illness e.g. CHD, cancer,
degeneration of the eyes so it is vital to have a good supply of anti-oxidants in the diet.
Studies consistently show that people who have high intakes of fruit and vegetables (and
antioxidant vitamins) have lower levels of cancer and CHD.
Citrus fruits, e.g. oranges, lemons and grapefruit are high in NSP and vitamin C, provide
an acceptable amount of folic acid and thiamine, although are low in protein and fat.
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Meat
Structure and texture of meat
Meat is the flesh or muscle of the animal. It is composed of muscle fibres, each of which is an elongated
cell. The fibres are held together by connective tissue. Fatty deposits known as ‘marbling’ and blood
vessels are found between bundles of fibres. The fibrous nature of the muscles gives rise to what is
known as the ‘grain’ of the meat. It is easier to cut or chew meat with the grain, i.e. in the direction of the
fibres rather than across the fibres.
Structure of meat-muscle bundles
Composition
The composition of meat is very variable. The fat content varies from 10% - 50% depending on the
animal and the part from which it comes. Meat with a high fat content has a low water content and vice
versa.
Protein
The cells of the muscle fibres contain two soluble proteins- myosin- which are thicker filaments - and
actin- which are thinner. These proteins are responsible for the contraction of muscle and for rigor mortis.
Connective tissue surrounds the muscle fibres is mainly collagen, whilst the walls of the muscle fibre are
mainly elastin. Collagen is gradually converted into gelatine during cooking. Elastin is a tough, insoluble
protein and is not affected by cooking. It is very tough and is commonly known as “gristle”.
Fat
In addition to the deposits of fat called marbling, fat is also stored under the skin of animals and around
some of the internal organs such as suet around the kidney. Meat requires some fat to prevent it drying up
during cooking but consumers today favour meat with reduced fat content.
Post-mortem changes
When an animal is slaughtered, various changes take place. After death ATP (adenosine triphoshate) is
broken down. Myosin and actin combine to form rigid chains of actomysin, otherwise known as rigor
mortis. At this time the meat becomes rigid and tough and requires time, known as conditioning, when the
stiffness diminishes and the tenderness and flavour improve. Conditioning is also called hanging, ageing
and maturation.
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Conditioning is a complex process and can be affected by 3 main factors, namely:
1.
temperature
2.
pH
3.
length of storage
After an animal’s death the glycogen present in the muscular tissues is broken down by stages into lactic
acids, the pH falling. During conditioning proteins of the muscular tissue are denatured, i.e. an unfolding
of the protein molecule which is usually irreversible, through the proteins of the connective tissue are not.
Denaturation results in an increase in tenderness as does the effects of ensymes such as calpains and
cathepsins which are naturally present in the muscle.
Changes during cooking
There are 4 main reasons why we cook meat, namely:
 to make it easier to chew
 to make it easier to digest
 to make it safe to eat
 to make it more flavoursome
It is important to choose a cooking method appropriate to the cut of meat.
The changes which take place are:
 A change in colour from red to brown. This is due mainly to changes in the pigment myoglobin
which occurs at 63oC
 Muscle fibre proteins coagulate. The texture becomes firmer as the proteins myosin and actin, in
the muscle fibres, coagulate above 50oC
 Meat juices are squeezed out as the collagen and elastin contract at 60oC. This causes the meat to
shrink and reduce in weight. In the moist methods of cooking these juices will pass into the
cooking liquid and be eaten as gravy.
 Collagen in the connective tissue is converted into gelatine which makes the meat more tender.
Tougher cuts of meat which contain more connective tissue are best cooked by moist methods of
cooking such as stewing where there is a greater breakdown of the connective tissue will result
due to the added moisture and the longer length of cooking time.
 Fat melts which helps to keep the lean part of the meat moist by reducing water loss. Some of the
fat runs out to form dripping.
 If cooked properly, meat becomes more tender as the collagen is softened at 80oC to 100oC which
dissolves in the presence of water to form gelatine.
Meat colour
Consumers recognise fresh meat as having a bright red colour and hence colour has a major influence on
the visual appearance of meat.
The colour of meat is primarily dependent upon the concentration and chemical state of the major meat
pigments in the muscle and cell tissue, namely myoglobin and haemoglobin which are collectively known
as “haem” pigments. When an animal is bled after slaughter, the blood is drained from the body, thus
leaving myoglobin as the primary pigment responsible for the meat colour. When meat is exposed to the
oxygen in the air, the purple-red myoglobin absorbs oxygen and is converted to bright pink
oxymyoglobin. After prolonged exposure, oxymyoglobin is chemically oxidised to brown metmyoglobin.
Metmyoglobin is the major pigment noticed on discoloured meat and results from the oxidation of the
iron within myoglobin. It is at this stage that the consumer finds the product unacceptable.
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Meat tenderness
The following factors determine the tenderness of meat:
 Size of muscle fibre – meat composed of small, narrow fibres is more tender than meat composed
of larger fibres
 Amount of connective tissue – tough meat contains more connective tissue than tender meat. The
older the animal and the greater its activity during life, the greater the amount of connective tissue
 The activity of the animal before death – the animal must be rested before slaughter. If it is not,
the supply of glycogen in the muscle tissue are reduced and less lactic acid is produced during
hanging.
 length of hanging after slaughter. Meat is hung for several days to make it more tender. During
hanging, glycogen, which is present in muscle tissue, is converted to lactic acid. The pH of the
meat falls from about 7.4 to 5.5. The reduction of the pH brings about partial denaturation of the
fibre proteins which increases tenderness.
 Meat may be further tenderised before cooking by physical and chemical means. Physical means
may be pounding with a meat hammer, cutting or mincing. Chemical means by using acid
marinades, e.g. lemon juice, vinegar or wine. These products help to coagulate proteins.
Sensory qualities
The flavour and the smell of meat are the main attraction of it. The presence of a variety of substances
known as meat extractives which are soluble in water contribute to the flavour. Fat will also contribute to
the flavour of meat.
Relationship to health
 Meat is a valuable protein in food of high biological value and important sources of vitamins,
particularly thiamin, riboflavin, niacin, B6 and B12
 Meat is one of the best sources of “haem” iron, with liver being a particularly rich source
 Meat can enhance the absorption of “non-haem” iron from plant sources when both are eaten
together
 A useful source of zinc, in a bioavailable form, and of the trace elements copper, manganese and
selenium
 Relatively low in fat if the fat is trimmed off the meat before cooking
 Liver and kidney contain vitamins A and D
Fish
There are many species of fish, both sea and fresh water varieties which are used for human consumption
There are three main categories of fish:
1. Oily fish – for example, herring, salmon, sardines, tuna., sometimes called “pelagic” as they are
found in the middle and surface waters
2. White fish – for example, haddock, halibut, cod, sometimes called “demersal” fish as they are
found at the bottom of the sea.
3. Shellfish – for example, prawns, lobster, mussels, crab, sometimes called “invertebrates” as they
do not possess an internal skeleton.
Like meat, fish is the flesh or muscle of the animal. One of the main differences between fish and meat is
that fish deteriorates rapidly and should be eaten as soon as possible after being caught. Other variables
affect the quality and freshness of fish, namely:
 difference in tissue composition of species
 influences of the season
 difference between salt and freshwater fish
 difference in procurement and holding practices on board fishing vessels
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Structure and texture
 the flaky texture of fish is due to fish muscle which consists of blocks of short fibres called
myotomes. The structure makes the texture very different from meat. The myotomes are separated
by thin sheets of connective tissue.
 Fish has lees connective tissue than meat and no elastin. As a result, fish is more tender than meat.
Post-mortem changes
There are several reasons for the rapid spoilage of fresh fish:
 Microbiological
 Physiological
 Chemical
Microbiogical. Bacteria exists on the surface of the fish and in its intestinal tract. When the fish is killed,
these bacteria then attack the fish tissue. These bacteria are resistant to low temperatures and therefore
continue to grow even when fish are kept in refrigerated conditions.
Physiological. Glycogen in the muscle of fish is used up as the fish struggles when caught. This means
that there is little glycogen left to be converted to lactic acid after death. Lactic acid acts as a preservative
by slowing bacteria growth.
Chemical. As fish spoils rapidly a number of methods of preserving it have developed, e.g. smoking,
salting, and drying. Freezing and canning are the most common methods used nowadays to preserve fish.
Changes during cooking
When fish is cooked, the muscle fibres (collagen) alter their structure and coagulate to form the
characteristic firm flakes of fish. The small amount of connective tissue is easily denatured and converted
to gelatine, at a lower temperature than meat, and dissolves therefore it cooks quickly and is easily
digested.
It is important not to overcook fish as this will result in a tough, dry texture due to the hardening of the
muscle fibres.
Fish colour
Fresh white fish should have a white translucent colour and a firm texture to the fillet of the fish. Oily fish
will have a pinkish tinge to the flesh and a firm texture to the fillet of the fish.
Relationship to health
 all fish is a good source of high biological value protein so assisting growth/ repair/maintenance
of body tissues
 oily fish is a good source of polyunsaturated fats . This type of fat can assist in the prevention of
heart disease, cholesterol reduction and reduce the risk of strokes
 oily fish contain between 10% - 20% unsaturated oil; n – 3(omega 3)
 fish is a rich source of omega 3 (a long chain polyunsaturated fatty acid – PUFA) which has an
important role in the diet to help lower the effects on blood fats, decreasing the chances of the
blood vessels being clogged up with cholesterol. Omega 3 can also help the blood flow more
easily around the body by making it less “sticky” allowing it to flow around the body easier so
reducing the risk of heart disease
 omega 3 can help reduce inflammation and may help ease the pain of sufferers of rheumatoid
arthritis
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omega 3 has also been linked to improved brain function and may improve concentration and the
ability for children to learn
white fish contains les than 2% oil
all fish are a good source of some of the B vitamins - thiamine, riboflavin, niacin and vitamin B6.
These vitamins are essential for the conversion of food to energy (preventing tiredness) and for
healthy nerve tissue (preventing impaired nerve function)
oily fish are an important source of vitamin A which is required for vision in dim light, normal
growth in children and protection for surface tissues
oily fish is a good source of vitamin D which aids the absorption of calcium so helping the
development and maintenance of strong bones and teeth and preventing osteoporosis
oily fish tends to be high in iron which is required for the formation of red blood cells therefore
helping to prevent anaemia
fish is a good source of calcium, particularly when the bones are eaten, e.g. tinned sardines. This
assists the development and maintenance of strong bones and teeth and preventing osteoporosis
fish is an important source of phosphorus and magnesium and of the trace elements iodine,
fluorine and zinc
fish oils may possibly help prevent cancer cells progressing to the stage where the person
develops a tumour
fish oils can help some skin conditions, e.g. psoriasis
a good intake of oily fish during the last 3 months of pregnancy is believed to assist in the
development of the child’s brain and retina.
Sodium content of oily fish can be high which may lead to hypertension, strokes of heart disease
Milk and milk products
The milk which is usually consumed in the UK is cow’s milk. However, other types are available. For
example, goat milk and ewes milk.
Composition
Milk is composed of a variety of nutrients either dissolved in water or dispersed in a colloid. The
colloidal system is complex but in simple terms is a fat-in-water emulsion. The composition of milk
varies depending on the age and breed of cow, the animal feed given and the time of year.
Protein
The most important proteins in milk are caseinogen, and the whey proteins called lactalbumin and
lactoglobulin.
Fat
The fat in milk is easy to digest as it is very finely emulsified
Carbohydrate
The type of carbohydrate in milk is called lactose which is a disaccharide. In sour milk the lactose has
been changed by the action of certain bacteria to lactic acid.
Uses in food preparation
Increasingly milk is consumed in semi-skimmed and skimmed forms, each is manufactured by
centrifuging whole milk to remove the butterfat as cream. By law, semi-skimmed milk must contain 1.5%
to 1.8% fat and skimmed milk 0.3% fat.
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As milk is a rich source of nutrients it provides an ideal medium for the growth of micro-organisms.
Therefore, it is important that milk is heat treated, for example, pasteurised or UHT (Ultra High
Temperature ) to ensure that harmful organisms are destroyed before consumption.
Various types of milk are available such as pasteurised, sterilized, spray dried, evaporated and condensed.
The greater the severity of heat treatment then the greater the loss of vitamins . Dried skimmed milk
contains just a trace of fat and so lacks vitamins A and D . As a result it should not be used to feed babies
but it does provide a good source of protein, calcium and riboflavin.
The following substances are produced from milk and are used in a wide variety of food production, both
domestically and commercially.
Cream
 Cream is separated from milk by centrifugal force. This is a process which involves spinning milk
in a centrifuge so that heavier particles are forced to the outside and the lighter particles which
make the cream, remain towards the centre. The fat content of cream is regulated by law.
 Single cream must contain a minimum fat content of 18%
 Double cream must contain a minimum fat content of 48%
 Only cream with a fat content of more than 35% - 40% fat. Clotted cream can have a fat content of
up to 70%
 Cream contains all the fat and a proportion of the protein and lactose in milk.
 Double cream has a higher energy value that single cream since it has a higher fat content
 All types of cream contain some Vitamins A and D
Butter
 Butter is made by churning cream
 Butter is a source of vitamins A and D. However the vitamin content will vary as in the winter
months cows are fed differently so the vitamin content is lower.
 Butter has a high fat content
Crème fraiche
 This made from pasteurised cows milk to which a lactic acid bacteria culture has been added.
 This thickens the cream and gives it a distinctive sharp flavour
 A half fat version is available
 It has a longer shelf life than double cream so it can be stored in the fridge for a couple of weeks.
Yogurt
 This is made by souring milk by using a pure culture of bacteria
 They convert the lactose in milk into lactic acid
 The acid brings about the coagulation of the milk proteins and helps preserve the yoghurt
 Since it is made from milk, the nutritional value of yoghurt is similar to milk
Cheese.
 There is a vast range of cheeses available to the consumer. Regardless of type, they are
manufactured by milk being coagulated by a lactic acid starter culture and then the solid is cut into
small pieces to allow the whey to drain off. The solid curd is then dried off, salt added and the
cheese pressed or moulded or ripened.
 Cheese is a more concentrated source of nutrients than milk due to the lower water content
 Cheese does not contain carbohydrate as milk does. The lactose is partly converted into lactic
acid and the remainder is lost in the whey
Fromage frais
 This is a fresh, low fat curd cheese (similar to cottage cheese but processed until the texture is
smooth and free from lumps) made from pasteurised cow’s milk.
 Fromage frais has very little fat but there are ones that have cream added which makes them better
for cooking
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Changes to milk during cooking
 Boiling milk spoils the flavour and slightly reduces the food value of milk
 when milk is heated, the whey proteins coagulate and a skin forms on the surface. The skin holds
steam and is responsible for the ease at which milk boils over.
 during prolonged cooking, caramelisation of the milk sugar, lactose, may occur this contributes to
the flavour of sterilised milk.
 cooking will destroy some of the thiamine and vitamin C which are present
 heat sensitive vitamins (thiamine and vitamin C) are lost in processing
Relationship to health
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milk makes a contribution in the diet to a range of nutrients especially protein and calcium
it contains a moderate amount of Vitamin A and Vitamins B1, B2 and nicotinic acid
milk is however, deficient in iron, vitamins C and D
semi-skimmed and skimmed milk is not suitable for babies or infants under the age of 5
cheese is a good source of calcium, phosphorus, protein and vitamin A
cheese also contains the B group of vitamins and vitamin D
cheese is high in fat due to its concentrated nature.
A reduction in fat intake can be achieved by selecting reduced fat versions of all dairy products
Eggs
The new egg of a hen weighs approximately 60grams and comprises three major parts; the shell, the
white and the yoke.
The porous shell is composed mainly of calcium carbonate. The colour does not indicate the quality of the
egg. Inside the shell there are two thin membranes which separate the shell from the white. The white is
divided into regions of thick and thin white and is held in position by a string of protein called the
chalzae. The air space in the egg determines the age and quality of the egg. The air space becomes larger
as air enters through the porous shell and collects in the air space and the moisture evaporated through the
porous shell. Bacteria as well as air and odours can pass through the shell and therefore eggs deteriorate
on storage.
Diagram of an egg
Composition
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The white of an egg is a colloidal solution of protein (mainly albumen) in water together with
small quantities of vitamins and minerals.
The yolk is a fat in water emulsion and is approximately one third fat, one third water and one
third protein.
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Uses of eggs in food preparation
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eggs increase the nutritional value of dishes.
eggs are an inexpensive ingredient with many properties so are an invaluable component of many
products
thickening agent – egg protein coagulates thus enabling mixtures to thicken. For example, egg
custard
binding agent – coagulation of protein enables mixtures to hold together on cooking. For example,
rissoles
emulsifying agent – egg yolk contains lecithin which is an emulsifying agent used in the
production of mayonnaise.
foaming – when egg whites are beaten, air is incorporated and the protein partially coagulates and
forms a foam. Meringues are prepared in this way.
aeration - eggs are used in creamed mixtures to produce lightness to products
flavour and colour – eggs provide a rich colour to some products and also add flavour to otherwise
insipid end products.
coating – eggs can be used in conjunction with breadcrumbs to coat food to protect it whilst
cooking, e.g. fish and scotch eggs
Changes during cooking
The following changes take place when eggs are cooked:
 when eggs are heated the protein in the white and the yoke coagulate
 egg white proteins coagulate first at about 60 degrees C. The white becomes opaque and forms a
gel
 yolk protein coagulate at 66oC and the yolks thicken
 the rate of coagulation is increased by the presence of salts and acid. Salt and vinegar can be
added to the water used for poaching eggs to bring about rapid coagulation of the white
 iron sulphate is formed in eggs during cooking and causes a black discolouration around the yolk
of the egg which have been hard boiled. The reaction occurs more readily in stale eggs.
Discolouration can be reduced by placing eggs in cold water immediately after cooking.
 there is a slight loss of vitamins, especially the Vitamin B group, as a result of cooking eggs
Relationship to health
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eggs are an inexpensive food. Factory farming methods have reduced costs. Free range eggs and
organic eggs are more expensive but due to animal welfare concerns sales of these are increasing
the yolk contains two proteins – vitellin and livetin, containing all the essential amino acids. This
makes eggs a very valuable protein food.
the fat is very finely emulsified and easily digested form.
contain valuable amounts of iron, vitamin A and D
eggs contain small amounts of vitamin D, riboflavin and thiamine
Eggs also provide vitamin B2. A smaller amount of the other B group vitamins are also provided
See also Food Science: Properties of food and their uses – Protein
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Cereals and baked goods
Structure of cereal
Cereals are cultivated grasses, the seeds of which are used as a food source. The most commonly used
cereals or grasses are:
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Wheat
Rye
Oats
Barley
Rice
Miaze
The structure of all cereal grains is similar, with each type differing in detail only. The structure of the
grain can be divided into 3 main parts, namely:
1. The endosperm
2. The bran
3. The germ
Diagram of a wheat grain
The endosperm is the food reserves on which the young plant lives until it has developed a root system.
It consists of tightly packed cells containing mainly starch with some protein and vitamin B complex.
The bran is a tough skin which protects the inner seed from soil organisms which may attack it. It is an
excellent source of non starch polysaccharides, vitamin B complex and minerals such as calcium, iron
and phosphorus.
The germ is an embryo plant with a radical which can grow into the root system and a plumule which
can subsequently develop into stems, leaves and ears. Therefore, a new plant would grow from the germ
under ideal conditions. It is a very good source of vitamins B complex, especially thiamine and vitamin E
but this can be readily lost by oxidation.
Types of cereals
In Britain, the most commonly used cereal is wheat. There are two main growing seasons for which
different types of wheat are used:
1 Winter wheat (soft wheat) is grown in Britain and is sown in autumn and harvested
the following August. It contains less than 10% protein and therefore is low in gluten and gives a “weak”
flour which produces a close texture. Therefore, it is best used for cakes and biscuits.
2 Spring wheat (hard wheat) is sown and harvested in the same year in countries like Canada which have
a very severe winter. This wheat contains 12-24% protein and is therefore higher in gluten. It produces a
“strong” flour which forms a strong elastic dough more suitable for bread making.
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Semolina means semi-milled. It is the grains which have not been ground to a fine flour. Semolina is
used for traditional pasta making when it is made from hard, durum wheat. The semolina is mixed with
water and dried. It is produced in variety of shapes by the extrusion process. Pasta provides starch,
protein, B vitamins and minerals. Wholemeal pasta will provide a good source of dietary fibre.
Semolina from softer wheat is used in the U.K. for puddings and cakes.
Self-raising flour is made adding an acidic raising agent and sodium bicarbonate to soft flour to allow
carbon dioxide to be formed during the cooking process, which aerates the dough.
Milling of flour
Milling is the process of converting grains into flour. In wholemeal flour all parts of the grain are used,
whilst in white flour only the endosperm is used.
When grain arrives at the flourmill it will be dirty and may contain other particles, e.g. dust, mud and
insects etc. All of this material must be removed before milling can take place. This process id called
“cleaning”. Many methods and combinations of methods of cleaning are employed, e.g. sieves, magnets
or air currents, to ensure that the wheat is free from other particles.
The grain is the “conditioned” which ensures that all the grains have the same moisture content and
distribution of moisture within each grain. Conditioning assists in toughening the bran so that it can be
easily separated from the endosperm at the next stage.
Wheat grains are almost always milled into flour before being eaten. Some flours are still produced using
the traditional milling method where the wheat is ground between
two circular grooved stones, the upper of which moves whilst the lower remains stationary. In this
process, all the wheat grain can be ground, producing “wholemeal” flour as the flour contains all the
components of the grain. This flour is described as “stone ground” flour.
However, the modern method of producing flour is “roller grinding”. it can be divided into two distinct
stages, namely:
1. Breaking. The wheat grains pass between grooved rollers which operate in pairs, the top one
rolling faster that the lower. These rollers are set to shear open the wheat grain to expose and
remove the white endosperm.
2. Reduction. This stage reduces the endosperm from the bran in the breaking operation, to a fine
flour. The endosperm passes through a set of smooth reduction rollers which each pair being set
more finely than the previous pair. After passing through each set of rollers the product is sieved
and coarse particles are passed to the next set of rollers to continue the reduction process until the
flour granules are of the necessary size.
Changes during bread making
 When the flour is kneaded with water, the two proteins present in flour, namely gliadin and
glutenin, become hydrated and form an elastic complex called “gluten”. The manufacture of bread
is possible due to this protein complex.
 The gas produced stretches the gluten in the dough producing little bubbles which become trapped
forming the characteristic framework of the loaf.
 When the dough is baked the increase in temperature causes the carbon dioxide bubbles to expand
within the dough, thereby causing a further rise in the volume of the bread.
 The heating also causes the protein to “set” turning the dough into bread.
 During baking the expansion of the carbon dioxide causes the bread to rise rapidly and the alcohol
is driven off.
 At a temperature of approximately 54oC the yeast is inactivated.
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The action of heat and steam on the outside of the bread forms dextrin which converts to caramel
which gives the crust its brown colour.
Sensory qualities
The character of a dough depends on the type if flour used. Strong flour contains more gluten and are
therefore used to make bread as the dough must be able to expand to a greater degree and yield baked
products of especially light density. Weaker flours contain less gluten and are therefore used to make
cakes and biscuits.
Relationship to health
All varieties of bread make a valuable contribution to a healthy diet, providing:
 Starchy carbohydrates
The Scottish diet action plan has recommended that the intake of complex carbohydrates should increase,
thereby replacing some of the more fatty and sugary foods in our diet. Eating a diet rich in complex
carbohydrates such as bread, pasta, rice and potatoes is an easy and convenient way to fulfil this aim.
 Non starch polysaccharides
All breads are a good source of non starch polysaccharides but wholemeal bread is an especially good
source because it contains a larger amount of non starch polysaccharides due to the inclusion of the bran
of the wheat grain in the flour.
 Protein
Protein in bread comes mainly from gliatin and glutenin present in flour. When a liquid is added to the
flour, they combine to form gluten. Bread is a protein of low biological value as it contains little of the
essential amino acids required by the body.
 Vitamins
Wholemeal bread is an especially good source of thiamine and nicotinic acid as both the bran and the
germ sections of the wheat grain are rich sources and are included in this type of bread. However, it is a
legal requirement that white flour is fortified with thiamine and niacin.
Folate is also located in the bran and the germ sections of the wheat grain and therefore wholemeal bread
is a good source. Some white bread is also an excellent source of folate due to fortification.
 Minerals
Iron and calcium are found in the germ and bran sections of the wheat grain and therefore wholemeal
bread is a good source of each. However, white bread is fortified with both minerals. Studies have shown
that iron can be poorly absorbed from bread as it can pass through the body unabsorbed. Therefore iron in
bread may have a low bioavailability.
Coeliac disease arises in people who are sensitive to gluten. It is thought to occur in 1 in 2000 people in
the U.K. although in Western Ireland the incidence is much greater, 1 in 300. The celiac condition can
develop at any age in any person. In infants the symptoms usually develop shortly after the introduction
of solid foods, containing gluten, to the diet. The symptoms usually are:
 loss of appetite
 weight remains stable or decreases instead of increasing
 irritability
 listlessness
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abdominal swelling
diarrhoea
Adult coeliacs are usually diagnosed from the symptoms of the effects of gluten on small intestines,
namely:
 diarrhoea
 abdominal swelling
 discomfort
 pain
 vomiting
Although in many cases diagnosis is difficult due to the many similarities to other diseases.
The damage which occurs prevents the small intestines from fully absorbing nutrients from digested
foods. This can lead to serve illness similar to malnutrition
The only effective treatment is the exclusion of gluten from the diet. A gluten- free diet always excludes
wheat, rye and barley. Oats may also have to be excluded if the sufferer has an intolerance to them also.
This diet needs to be strictly adhered to for life to reduce the risk of further symptoms and associated
conditions.
Bakery products
Wheat flours find their principle applications in the production of bakery products. Most bakery products
are leavened, i.e. they are raised by some means to yield baked goods of low density. Baking strictly
refers to heating dough products in an oven but there are many steps that must take place before that if the
product is to be successful.
A general classification for baked goods is as follows:
 yeast raised goods. These include breads and sweet doughs leavened by carbon dioxide from yeast
fermentation.
 chemically leavened goods. These include cakes and biscuits raised by carbon dioxide from
chemical agents, e.g. baking powders. Baking powders used in cake making contain particles of
sodium bicarbonate as a source of carbon dioxide when water and heat are supplied.
 air-leavened goods. This includes sponges whisked to include air which is then used to raise the
product.
 partially leavened goods. These include pie crusts, certain crackers and other items where no
intentional leavened agents are used yet a slight leavening occurs due to the expanding steam and
other gases during the baking process.
Other ingredients which play a role in baked products include:
Sugar
 Sugar provides sweetness to baked goods
 Sugar helps to colour baked goods. When it is heated in a liquid it begins to caramelise at 154ºC.
 When sugar and amino acids interact together in baked products then non enzymic browning takes
place (also called Maillard reaction)
 Sugar also helps to aerate mixtures and so makes them light and risen. When fat and caster sugar
are creamed together, the air is sticks to the sugar crystal. The fat surrounds the air bubbles and
“traps” them in the mixture and so the mixture rises when cooked .
 Sugar increases the coagulation temperature of eggs and gluten in a mixture. The air bubbles in a
mixture have more time to expand before the mixture sets so making the product lighter and well
risen
 Sugar helps foams such as meringues to remain stable and so the air which has been whisked in is
not easily lost. The foam is strengthened by the sugar allowing the meringue to be piped or spread
without bursting the air bubbles
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Sugar is attracted to water. This property helps products to remain moist and helps to maintain the
texture and mouth feel of the product.
The water attracting property of sugar also helps to make baked products tender. Sugar takes up
some of the water that would be taken up by the protein (gluten) in the flour. Gluten development
is reduced and so a more soft and tender crumb is produced
See also Food Science: Properties of food and their uses – Carbohydrates
Fats and shortenings
 Fats such as soft margarine will trap air bubbles when creamed with sugar. For this to be
successful, the fats should have a mouldable, pliable property called plasticity.
 Fats have a “shortening effect in pastry and biscuits. The fat coats the particles of flour and
reduces the amount of water that can be absorbed by the flour due to the waterproof coating of fat.
The plasticity of the fat allows it to surround and coat the flour poarticles.
 The shortening effect results in a crumbly short texture. When only a little water is absorbed by
the flour, less gluten is developed which would make the mixture elastic and stretchy, so the
mixture is “shortened”
See also Food Science: Properties of food and their uses – Fats and Oils
Other types of cereals
Rice
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Oats
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Rye
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A grain of rice has the same structure as a grain of wheat
Milling then “polishing” the rice removes the bran and germ and so also removes most of the B
complex vitamins. Where rice is a staple food , thiamine deficiency is common and a disease
called beri beri is caused.
Par boiling of rice prior to milling means that the majority of thiamine, instead of being lost in the
bran, migrates into the grain so it is not lost during milling.
Brown rice is not polished but contains the whole grain. It is higher in dietary fibre as well as
thiamine.
Oats are fairly rich in protein but does not contain gluten.
It contains more fat than other cereals (about 7%) so care has to be taken during storage to prevent
rancidity.
Oats can contribute to health as they have been shown to lower blood cholesterol levels.
Oats contain phytic acid but only in extreme cases would this affect the absorption of calcium
The rye protein contains some gluten but it lacks elasticity so rye bread lacks volume and is heavy
in texture.
Doughs made from rye are sometimes soured with starter cultures which gives acidity and a
characteristic flavour to the bread
Maize
 Maize contains some protein but it is poor quality, a fair proportion of fat but as it contains no
gluten it cannot be used for bread
 Most maize is eaten as sweetcorn or corn on the cob.
 Cornflour is made from maize and is almost pure starch. It is used for thickening sauces and soups
Barley
 This is a very hardy cereal and is used in the brewing industry
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It contains less protein and less fat than wheat and because of its low gluten content is not used in
baking
“pearl” barley has had most of the bran and germ removed and is used in broths and barley water
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Unit: Resource Management
Content
Elaboration
Biochemistry, preservation and processing
1. Role of micro-organisms in the
development of flavours and textures.
(Part 1)
2. beneficial effects of micro-organisms
related to specific foodstuffs:
 cheese
 yoghurt
 alcoholic drinks
 bread
Role of micro-organisms in the development of flavours and textures.
The importance of enzymes to the food industry can be appreciated by considering the wide range of uses
and applications for example:
 enzymes in cheese and milk production
 enzymes in the meat industry
 enzymes in the baking industry
 enzymes in the production of beverages and fruit juices
Beneficial effects of micro-organisms in cheese production
Cheese manufacture is an ancient activity which has been modified and refined over the centuries. Cheese
making remained an essentially small-scale activity until the application of scientific principles,
commencing around the early 20th century, permitted large-scale manufacture. Today manufacture of the
more popular varieties is on a very large-scale and cheese is an important export commodity in the
economies of the major producing countries such as Eire, France, Australia and New Zealand. Cheese is
made from milk by coagulating the protein to form a curd and then maturing this with a starter culture of
lactic acid bacteria to produce a large number of differing cheeses. Varieties may be classified according
to moisture content and according to the means by which ripening is achieved.
The varying classes of cheese are:
1. Hard (26-50% moisture) and can be further subdivided into:
 Internally ripened, no added ripening micro-organisms, e.g. Parmesan, cheddar, double
Gloucester
 Internally ripened, added ripening bacteria, e.g. Emmental
 Internally ripened, secondary surface ripening by mould, e.g. Blue Cheshire
2. Semi-hard (42-52% moisture) and can be further subdivided into:
 Internally ripened, no added ripening micro-organisms e.g. Lancashire, Edam
 Internally ripened, ripening mould added, e.g. Stilton, Roquefort
3. Semi-soft (45-55% moisture) and can be further subdivided into:
 Surface ripened, ripening bacteria added, e.g. Limburger, Port du Salut.
4. Soft (48-80% moisture) and can be further subdivided into:
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surface ripened, ripening mould added, e.g. Brie, Camembert
unripened, e.g. Cottage, Coulommier
5. Others, e.g. brined varieties, Whey cheese
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Technology
The basic technology for the manufacture of all types of cheese is similar with relatively small changes in
procedures during manufacture resulting in perceived differences in the final cheese. The technology is
well established but has been subject to a considerable degree of refinement and automation.
The role of starter micro-organisms (enzymes) in the manufacture of cheese
In modern practice bacteria of the group commonly referred to as lactic acid bacteria (LAB) are added to
milk to as starter-cultures, their key role being the production of lactic acid by fermentation of lactose.
Lactic acid is responsible for the fresh acidic flavour of unripened cheese and is of importance in the
formation and texturing of the cheese In addition, starters cultures play other essential roles e.g.
 The production of volatile flavour compounds such as dracetyl and aldhydes
 the synthesis of proteoytic and lipolytic enzymes involved in the ripening of cheese and the
control of pathogenic organisms.
Starter cultures
The starter culture used in cheese-making can be prepared in a number of ways. Traditionally a liquid
culture, termed the bulk starter, was used in cheese-making. Direct vat innoculation cultures, which are
concentrated cultures in freeze dried or frozen form, are now widely used. The choice of starter culture
used in cheese- making will to some extent determine the flavour and texture properties of the curd.
Micro-organisms and enzymes in cheese manufacture
Micro-organisms are used in cheese-making to:
1. promote acid development during curd manufacture
2. confer distinct textural properties to the cheese
3. confer distinct flavour properties to the cheese
1 Acid production
Acid production during cheese-making is essential in the formation of a gel from the milk casein. The
development of acid throughout the cheese-making process encourages the contraction of rennet curds on
heating and the expulsion of moisture from the cheese by syneresis
2 Textural properties
The extent of acid development influences the textural properties of the cheese, and also provides the
correct environmental conditions which allow the formation of flavourful compounds in cheese
manufacture.
Varying types of micro-organisms are used to produce low levels of carbon dioxide, thereby giving the
desired textural characteristics in some mould-ripened cheeses, e.g. moulds are used to assist in the
ripening of Camembert, Brie and Roquefort.
3 Flavour properties
Varying types of micro-organisms are used to produce distinct flavours, e.g. the propionic bacteria used
in the manufacture of Emmental and Gruyere Cheese produce propionic acid and carbon dioxide. The
propionic acid contributes a distinct flavour character to the cheese, while the carbon dioxide is essential
for the development of ‘eyes’. In unripened cheese, the lactic acid produced by the starters contribute to
the sharp flavours of the cheese. In cheese which is ripened, the lowering of the pH of the curd will to
some extent control the rate of enzymic reactions responsible for flavour development, and ensure that
the flavour compounds formed are maintained in a stable condition.
The growth of spoilage and pathogenic bacteria is suppressed by lowering of the pH during cheese
manufacture.
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Beneficial effects of micro-organisms in yoghurt manufacture
1. yoghurt is made from milk which has been fermented by micro-organisms. In the UK it is usually
made from cow’s milk, but goat’s or ewe’s milk can also be used. Yoghurt is eaten all over the
world, and originates from West Asia and Eastern Europe.
Types of yoghurt
Yoghurt is divided into two main categories according to its consistency and method of manufacture:
 set yoghurt
 stirred yoghurt (either thick or pouring consistency).
Composition
Yoghurt can be made from milk in any of the following forms:
 whole milk – minimum fat content 3.5% as recommended by the Food Standards Committee in
1975.
 semi-skimmed milk – minimum fat content 1-2%
 skimmed milk – minimum fat content 0.3% as recommended by the Food Standards Committee
1975
Concentrated skimmed milk is most often used in commercial yoghurt manufacture. The Food Standards
Committee also recommend that yoghurt should contain not less than 8.5% non-fat solids, which consist
of casein and whey proteins. The firmer the yoghurt, the more solids there are and the less likely it is to
separate. The milk used must conform to the same high standards of hygiene and composition as liquid
milk, and it must also be free from the antibiotics that are given to cows to treat udder infections, as these
antibiotics affect the bacteria used in yoghurt production
Bacteria culture.
The taste and texture of yoghurt are brought about by carefully controlled addition of a special harmless
bacteria culture. The bacteria used belong to the lactic acid bacteria group which ferment the disaccharide
sugar lactose in milk. Under the right conditions of temperature, moisture and food they produce lactic
acid.
The two bacteria used are:
1. lactobacillus bulgaricus
2. streptococcus thermophillis
During the fermentation the milk proteins coagulate and the yoghurt sets. A colourless volatile liquid
called acetaldehyde is also produced. It is acetaldehyde which is mainly responsible for the characteristic
flavour of yoghurt.
Commercial manufacture
The process outlined below is a general method used in commercial manufacture of stirred yoghurt but
the method varies between manufacturers to give them the opportunity to create their own distinct
product.
1. The milk is homogenised to give the finished yoghurt a smooth, creamy texture. This also helps to
prevent the final product separating.
2. The milk is then pasteurised at 85-950C for 15 -30 minutes. This helps to stabilise the proteins and
this results in a nearly sterile product.
3. The milk is then cooled to 40-430C, which is suitable for the fermentation process to take place.
4. The two bacteria (the ‘starter’ culture) are added to the milk in equal proportions, usually as 0.52% of the total finished product
5. The culture is then incubated at 37-440C for 4-6 hours, during which time fermentation takes
place, the product becomes acidic, the flavours develop, and the proteins coagulate.
6. Once the level of acid reaches 0.8-1.8% the bacteria growth stops, although the bacteria remain
alive.
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7. The yoghurt is then cooled to 4.50C, and held at this temperature during storage and distribution to
shops
8. Additives may be include in the yoghurt, e.g.
 vitamin A and D
 stabilisers, e.g. gelatine, agar, pectin, to prevent the yoghurt from separating into curds and whey.
 sucrose
 colour
 flavourings, e.g. strawberry and black cherry
 preservatives
although additives are strictly controlled by legislation
Storage of yoghurt
Yoghurt should be stored at 4.50C as at this temperature the bacteria grow very slowly. After about ten
days they begin to affect the finished product as the bacterial growth raises the acid content which makes
the product unpalatable and begins to separate. In fruit yoghurt the yeast cells from the added fruit
ferment the sucrose and produce carbon dioxide gas and alcohol which can be seen when the lid of the
yoghurt container becomes raised, i.e. “blown”.
Yogurt products
It is possible to buy a range of yoghurt based products including:
 bio-yoghurts
 yoghurt drinks
 yoghurt ice cream
 soya yoghurts
Enzymes in the production of beverages and fruit juices
Micro-organisms play a part in the preparation and manufacture in many ways. They range from the
relatively uncontrolled activities in the production of tea and coffee, through to the highly controlled
action of adding commercial enzymes found in the brewing and fruit juice industries.
Alcohol production using micro-organisms/enzymes (wine and beer)
Brewing is the term for hot water extraction of plant materials. Thus, making coffee or tea is brewing.
Brewing is a critical step in beer making and the entire process is termed brewing, but this does not
completely describe the steps involved. Brewing of beer goes back 6000 years, and today’s practices are
similar to those used in earliest times. What has been gained is an understanding of the principles of
biochemistry and microbiology underlying the beer-making process and a high degree of sanitation and
efficiency in the manufacturing practices.
Alcohol using micro-organisms/enzymes
The two most important industrial uses of yeast are in the production of alcohol and in the making of
bread.
The economic importance of yeast lies in its ability to breakdown carbohydrate foods into alcohol and
carbon dioxide. This process is known as “alcoholic fermentation”. Yeast contains a collection of
enzymes, known as zymase, which is responsible for the fermentation of sugars, such as glucose, into
ethanol and carbon dioxide.
Alcohol
Brewing is the general term for the hot water extraction of plant materials. Thus, making coffee or tea is
brewing. Brewing of beer goes back over 6000 years, and today’s practices are similar to those used in
earlier times. However, we have gained a much better understanding of the principles of biochemistry and
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microbiology underlying the beer making process and a high degree of sanitation and efficiency in
manufacturing practices.
Raw Materials and Manufacture
The principle of raw materials of beer manufacture, are water and hops, and malted cereal grains,
principally barley. In many cases, rice, corn, or other unmalted grains are also added as a source of
additional or “adjunct” carbohydrate for the fermentation by Saccharomyces yeast into ethyl alcohol and
carbon dioxide. The hops are used to add the characteristic flavour of most beers, additional carbon
dioxide may be added to the amount naturally produced by fermentation.
Malt
Malt is barley grain that has been germinated to the point where roots and stems just begin to appear. The
green malt is then gently dried to stop the growth yet leave enzyme activity intact. Germination results in
the activation of enzymes which convert starches in the malted barley and in other cereal grains into
sugars, which can be easily fermented by the yeast during the formation step. This is necessary because
yeast cannot utilise the starch in the cereal grains for the conversion to ethanol and carbon dioxide.
Hops
Hops are plants, the flowers of which contain resins and essential oils that contribute to a characteristic
bitter flavour and pleasant odour to beer. Hops also contain tannins, which add to the beer colour. Hops
added during brewing and after the enzymes of the malt have converted the starch to sugar maltose. Hops
also have mild preservative properties and add foam holding capacity to the beer. All of these functions,
however, are secondary to the role of hops in flavour and aroma.
Cereal Adjuncts
Corn, rice, and other cereals are used in beer making to provide supplemental carbohydrates, principally
starch, for conversion to sugar for subsequent fermentation. Without these adjunct cereals, the limiting
nutritional factor for yeast in fermentation would be protein. This means that carbohydrate would remain
after fermentation and produce a heavier type beer. In some cases, this is desirable, but most breweries
prefer lighter-type beers.
Wine
 The making of wine by fermenting grapes has a long tradition and goes back to at least 4000B.C.
Wine Varieties
The varieties and names given to wine are legion and reflect the region of origin, varieties of grape used
in the manufacture, and certain properties such as degree of sweetness, colour, alcohol content, and
effervescence.
Sweetness and Alcohol Content
The sweetness and alcohol content of wines are interrelated because fermentation converts grape sugars
to ethanol. As more alcohol is produced, the sweetness decreases; when virtually all of the sugar is
fermented, the wine is without sweetness and is said to be “dry”. Dry wines contain all the alcohol that
the specific grape is capable of yielding under the conditions of fermentation. This generally is 12-14%
alcohol; by volume.
The relationship between disappearance of sweetness and increase in alcohol content cannot be used to
characterise wines, however, because both alcohol content and sweetness of finished wines can be further
and independently adjusted. The terms “natural” and “fortified” also have been used in relation to
alcohol; content. Depending on the sugar content of the grapes, characteristics of the yeast culture, and
fermentation practices employed, natural fermentation generally yields an alcohol concentration of less
than 16% by volume even if more sugars are added. This is because the amount of alcohol is toxic to the
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yeast and it stops fermentation. The wine must still be pasteurised after bottling to ensure against growth
of unwanted micro-organisms.
The term light wine is used to describe a wine having an alcohol content from about 5% to 10% ( the term
light has nothing to do with colour). Fortified wines are those that have received additional distilled
spirits to bring their alcohol content up to 17-21% by volume. They are less perishable and may be stable
without pasteurisation.
Fermentation
As grapes mature, the wine yeast Saccharomyces euipsoideus naturally accumulates on the skins. When
the crushed grapes of filtered juice is placed at a temperature of about 27 0 C, the juice proceeds to
ferment, yielding essentially equal quantities of ethyl alcohol and carbon dioxide and traces of flavour
compounds.
Wine yeast is relatively resistant to sulphur dioxide and so this agent commonly is added to the grapes or
must to help control undesirable micro-organisms, particularly bacteria. Sulphur dioxide is also effective
in inhibiting browning enzymes of the grapes and providing reducing conditions by reacting with oxygen.
Fermentation causes a rise in temperature, and so cooling is required to prevent yeast inactivation.
Fermentation under conditions of limited exposure to air may continue until the sugar is entirely
consumed, when it stops naturally, or fermentation may be interrupted prior to this point. At around 27 0C,
fermentation may last for some 10 days depending on the type of wine
Bread production using micro-organisms/enzymes
The two most important industrial uses of yeast are in bread making and for the production of alcohol.
Yeast has the ability to break down carbohydrate foods into alcohol and carbon dioxide. This process is
known as “alcoholic fermentation”. Yeast contains a number of enzymes, known as zymase, which is
responsible for the fermentation of sugars, such as glucose, into ethanol and carbon dioxide.
Yeasts are simple, single-celled fungi. There are 2 main forms used in the making of bread, namely:
 Fresh yeast. This is sometimes called “live” or “fresh” yeast which is quick and easy to use but
can be difficult to obtain. It should be stored in a refrigerator to prevent multiplication in advance
of use.
 Dried yeast. This is sometimes called “dried” or “dehydrated” yeast. It is very useful as it has a
shelf life of one year.
Bread making
Several ingredients are required in the fermentation process, namely:
 water
 yeast
 salt
 sugar
 flour
 sugar
The water requires to be warm, i.e. blood temperature, of approximately 320C, to encourage the yeast to
ferment. At a temperature of 430C yeast cell are inactivated and at 540C they are killed. It is therefore
very important that the correct temperature of water is used for optimum results.
The yeast uses a small amount of sugar as a starter to ferment and produce carbon dioxide and alcohol.
Salt is added to the dough to give flavour. The amount of salt used is a delicate balance because too much
salt can inhibit the yeast whilst too little can cause the dough to be sticky and unmanageable.
Fat is used in the dough help improve the breads keeping qualities.
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“Hard” flour is used ie flour contain a high amount of gluten.
When the flour is kneaded with water, the two proteins present in flour, namely gliadin and glutenin,
become hydrated and form an elastic complex called “gluten” The manufacture of bread is possible due
this protein complex.
The gas produced stretches the gluten in the dough producing little bubbles which become trapped
forming the characteristic framework of the loaf.
When the dough is baked the increase in temperature causes the carbon dioxide bubbles to expand within
the dough, thereby causing a further rise in the volume of the bread.
The heating also causes the gluten to “set”, turning the dough into bread. During baking the expansion of
the carbon dioxide causes the bread to rise rapidly and the alcohol is driven off.
At a temperature of approximately 540C the yeast is inactivated.
The action of heat and steam on the outside of the bread forms dextrin which converts to caramel which
gives the crust its brown colour.
Chorleywood bread making process
This is a well known commercial method of making bread used by large and small companies alike. It is
fundamentally the same process as for home made bread but it is much faster as the time consuming
fermentation stage of the process is replaced by high speed mixing.
Other types of bread
There is a huge variety of different breads on the market, but the basic fundamentals apply to all.
Unleavened bread is made without yeast and is basically a mixture of water, flour and flavourings only.
Bread such as ciabatta and foccaccia have olive oil added. Croissants and pastries may have eggs, butter
and other fats added as well as varying quantities of sugar in sweeter breads such as Danish pastries.
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Unit: Resource Management
Content
Elaboration
Biochemistry, preservation and
 Adverse effects of micro-organisms and
processing
enzymes in the development of flavours and
textures in food
 Physical and chemical changes in food
(Part 2)
stuffs after preservation affecting structure,
texture, colour and nutritive value
Adverse effects of micro-organisms and enzymes in the development of flavours and textures in
food.
Food poisoning is an unpleasant illness which can occur after eating contaminated foods which may
appear harmless – the colour, taste and appearance look normal.
If food spoilage occurs the colour, taste and appearance of the food change so the food could not be eaten.
Micro organisms mainly responsible for food spoilage are moulds, bacteria and yeasts
The types of food poisoning are:
 Chemical
 Biological
 Bacterial
Chemical
This type of food should not be significant if all hygiene regulations are adhered to.
Chemical food poisoning takes place if food is contaminated by substances added to food during
agricultural production, storage or manufacture eg
 residues of drugs given to animals
 residues of pesticides or fertilisers
 misuse of a chemical during agricultural production
 cleaning chemicals used for cleaning machinery during food production
 contaminants leeching into food from packaging
Biological
This type is caused by eating foods containing naturally occurring toxins
Few natural toxins are thought to contribute to food poisoning. The main ones being:
1. Scombrotoxin found in fish( eg certain types of oily fish like mackerel and tuna) This type of
poisoning is caused by heat stable toxins which are freed by the action of bacteria on fish protein
during spoilage. The toxin is produced by bacterial action but is not itself a bacterial toxin.
Symptoms include flushing, sweating and sometimes nausea and diarrhoea
2. Raw red kidney beans contain a toxic substance called haemagglutinin which causes the red
blood cells to stick together. Raw kidney beans must be boiled for 10 minutes to kill this toxin.
Tinned kidney beans are safe to eat as they have been heated during processing.
3. Solanine is found in potatoes and has a green appearance. In high enough quantities it will cause
headache, vomiting and diarrhoea and can even be fatal. However levels of solanine in potatoes
are rarely sufficient to cause illness. Green potatoes should not be eaten
4. Paralytic shellfish poisoning. This is rare but can result in serious and sometimes fatal food
poisoning. It is caused by eating raw mussels or oysters which has fed on a certain type of
plankton
5. Some fungi produce toxic chemicals called mycotoxins. The death cap mushroom (the amanita
variety) contain this poisonous toxin and eating this variety will cause liver damage and even
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death. These type of mushrooms are similar to the edible variety and could easily be picked and
eaten by mistake
6. Moulds also grow on many foods that will not support bacterial growth because fungi are more
tolerant of low water and low pH than bacteria. These include nuts, bread, jam and cheese. These
mouldy foods could be potentially dangerous and should always be thrown out.
Bacterial ( bacteria or their spores and toxins)
Bacterial food poisoning is the most common type of food poisoning and takes place when food is
contaminated by pathogenic bacteria.
Spores
 Some bacteria are able to produce spores.
 Spores are bacteria in a resting state and they do not multiply.
 When the spores return to favourable conditions, the spore releases the bacterium which will then
grow and multiply.
 Spores can be very resistant to heat. High temperatures of above 100ºC for long periods of time
are often needed to destroy spores.
 Spores can also resist a high concentration of chemicals.
Toxins
 Some pathogenic bacteria produce a toxin or poison in the food which is difficult to destroy by
normal cooking processes.
Conditions required for the growth of bacteria
1. Warmth
 The best temperature for the growth of bacteria is 37ºC – body temperature.
 The temperature range of 5ºC – 63ºC is often referred to as “the danger zone”. Foods should be
kept below or above these temperatures whenever possible.
 Ensure that food is thoroughly cooked to core temperatures of 75ºC or above.
 Reheat food to 82ºC. Small numbers of bacteria may have survived the original cooking and
continue to multiply. By increasing the temperature, these bacteria will be destroyed
 At room temperatures of 20ºC – 50ºC bacteria will multiply rapidly.
 Most bacteria will multiply very slowly in a refrigerator (1ºC – 4ºC )
 No bacteria will multiply in frozen food ( - 18ºC ) but many will survive and reproduce on
thawing.
2.Food
 Like all living cells bacteria need food to grow
 Some food are high risk foods because:
- bacteria grow easily on these foods – these foods are usually high in protein and moisture
- they can be eaten without further cooking which would normally destroy the bacteria
- they require refrigerated storage
 Examples of high risk foods are:
- all cooked meats and poultry
- cooked meat products eg stew, gravies, sauces, stock and soups
- shellfish and other sea food
- milk cream, artificial cream, custards and dairy produce
- cooked eggs and products made from egg eg raw eggs in mayonnaise,
- cooked rice.
 Other food which do not normally support the growth of bacteria are known as low risk foods
 Examples of low risk foods are those which are high in:
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- salt
- sugar
- acid
 This is why food preservation methods such as salting, jam making, pickling or keeping food
in syrup are successful
3. Moisture
 Like all living cells bacteria need moisture to grow
 Bacteria prefer a high water content but many foods contain sufficient moisture for growth
 Once dried foods such as milk powder, dried egg have water or milk added then any bacteria
present will start to multiply when the food is reconstituted
 It is essential to use this food as soon as possible after adding the water.
4. Time
 Given the correct conditions of food, moisture, and warmth some bacteria can divide into two
every 12 – 20 minutes. This process is called binary fission.
 A few bacteria, given sufficient time, can multiply quickly to produce enough to cause food
poisoning.
 It is essential that high risk foods are not left in the danger zone (5ºC – 63ºC) for as short as
time as possible.
5. Oxygen (aerobes and anaerobes)
 Most bacteria require oxygen to grow. These are called aerobic bacteria.
 Some bacteria do not require oxygen to grow. These are called anaerobic bacteria.
6. pH levels
 Acidity is measured using the pH scale which has 14 points
 pH 7 is neutral, that is neither acid or alkaline.
 Most pathogenic bacteria cannot grow in an acid environment of pH 4.7 or less, for example in
the pickling method of preservation.
Main food poisoning bacteria.
a. Food poisoning caused by bacteria such as:
 salmonella
 staphylococcus aureus
 clostridium perfringens
 bacillus cereus
In this type of food poisoning a large number of bacteria are usually involved and this normally requires
them to multiply within the food.
b. Food poisoning caused by food borne diseases such as :
 campylobacter enteritis
 listeria
 E coli 0157
Food borne diseases are usually food related. Only small numbers of these bacteria are required to cause
the illness and they do not need to multiply within the food. The bacteria responsible are usually found in
the intestines of man or animals
a. Food poisoning caused by bacteria
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1. Salmonella
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Salmonella are aerobic bacteria which do not form spores.
They grow at temperatures between 6°C and 46°C. Best temperature for growth is 37ºC
They are killed rapidly at 75°C.
This bacteria can grow aerobically(with oxygen) or anaerobically(without oxygen)
Symptoms include fever, headache, abdominal pain, diarrhoea and vomiting. Symptoms may last
from 1 to 7 days
Sources of salmonella
Intensive farming methods and slaughtering practices mean that raw meat, poultry and eggs could be
potential sources of salmonella
Chickens reared under battery conditions are likely to be infected with salmonella more than free range
hens. This is due to the fact that the hens are kept close together and cross infection occurs between birds
Eggs and products containing raw eggs (eg mayonnaise) or if only lightly cooked. Eggs may have
salmonella on the shell and inside the egg. It is advised that all eggs should be well cooked.
Rats, mice, domestic pets, birds may carry the bacteria in their intestines, on their fur/feathers and feet
Food handlers carry this bacteria in their intestines so could contaminate the food if they have not washed
their hands after visiting the toilet.
Prevention
Personal hygiene
Wash hands before and after handling food, especially raw meat, poultry and eggs
Kitchen hygiene
Use different surfaces and equipment such as knives, chopping boards for preparing raw and cooked food
to prevent cross-contamination
Clean all surfaces, equipment and tools thoroughly before and after use to prevent cross contamination
Correct storage of foods
Foods likely to should be stored under refrigeration.
Cooked and uncooked meats stored separately
Thawing food
Thaw frozen meat and poultry thoroughly before cooking, preferably thawing in the refrigerator
Cooking/reheating thoroughly
Cook food thoroughly so that the temperature at the centre of the food is high enough to kill bacteria.
Eggs in particular should be thoroughly cooked.
2. Staphylococcus aureus
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Multiplies in food stored between 10 and 40ºC producing a toxin. When food is swallowed this
toxin irritates the stomach lining causing vomiting.
Does not multiply below 5ºC
This bacteria is killed by heat (1 – 2 minutes in boiling water) but the toxin it produces is more
resistant to heat and can withstand up to 30 minutes in boiling water
Therefore lightly cooked food will contain no living bacteria but may contain active toxin, which
will cause food poisoning
Symptoms include vomiting, abdominal pain, diarrhoea, exhaustion and sub normal temperatures.
Symptoms last no more than 24 hours
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Sources of Staphylococcus aureus
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Humans, in the warm, damp conditions of the nose, throat, pores and hair follicles of the skin
In boils, styes, septic cuts and can be transferred to food via the hands
Food which can be contaminated after cooking when eaten cold or only mildly reheated such as sliced
cold meat, cooked poultry, stuffed rolled joints of meat not cooked in the centre, cream dishes,
custards
Can grow in a higher salt concentration than other food poisoning bacteria and so could be found in
ham
Prevention
Personal hygiene
Wash hands before and after handling food
No coughing or sneezing over food
Cover cuts and sores with a waterproof dressing
Handling food as little as possible and using tongs for lifting
Kitchen hygiene
A high standard of kitchen hygiene eg chopping boards, cutting and mincing machines and cloths must be
cleaned thoroughly after use
Thorough Cooking / Reheating
Rapid cooking of high risk foods to prevent spreading of this bacteria produces a toxin in food, which is
difficult to destroy by normal cooking temperature
Reheat foods once only to 82ºC to destroy the bacteria
Correct storage of foods
Store high risk food in a refrigerator at 4°C or below.
3. Clostridium perfringens
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This is an anaerobic bacteria which grows best in the absence of oxygen
Best temperature for growth is between 43 and 47ºC
Spores of this bacteria will pass out with the faeces of animals and humans and into the soil and
sewage systems. Water and vegetation carry the infection back into the animal kingdom and so
into food production systems
Can survive cooking by forming spores
Reheating should be carefully done because of the spores which may be formed
The anaerobic nature of this bacteria allows it to multiply in the internal cavities of meat and
poultry where oxygen has been driven by the heat of cooking so care must be taken when cooking
food in bulk.
Symptoms include: Abdominal pains and diarrhoea. Rarely vomiting. Symptoms last 1 –2 days
Sources of clostridium perfringens
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Present in animal and human intestines so will be present in animal and human excreta
Soil and vegetables covered in soil or dust
Raw meat and poultry
Flies, cockroaches and bluebottles
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Prevention
Personal Hygiene
Wash hands after handling raw meat and unwashed vegetables
Wash hands thoroughly after visiting the toilet
Kitchen hygiene
Using different surfaces, boards and equipment for raw and cooked foods
Removing soil regularly from vegetable stores and preparation areas
Scrub vegetables before peeling
Correct storage of food
Separate raw and high risk foods.
Cooling cooked foods quickly and refrigerating immediately – large volumes of meat should be divided
into smaller portions to cool more quickly
Reheating thoroughly
Reheating quickly and thoroughly and serving immediately
Never reheat meat products more than once
4. Bacillus cereus
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This is an aerobic bacteria which grows best with oxygen
Best temperatures for growth is between 35 – 38ºC
Forms spores when conditions are unfavourable for growth
Spores will survive most cooking processes
If food is left in a warm place or not cooked quickly then spores germinate, producing vegetative
bacteria which in turn multiply and produce a very heat resistant toxin.
If food is then reheated quickly or insufficiently the heat is unlikely to destroy the toxin. When
the food is eaten the toxin irritates the stomach lining which causes vomiting
Symptoms. There are two types of illness.
- Vomiting type
This begins 1 – 6 hours after eating contaminated food and does not last more than 24 hours.
It is thought that an enzyme in saliva starts the digestion of starch in the mouth and so releases
the toxins which are vomited out before reaching the intestines.
- Diarrhoea type
This begins 8 – 16 hours after eating contaminated food. Symptoms include diarrhoea,
abdominal pain but rarely vomiting. This type is less common and lasts less than 24 hours
Sources of Bacillus cereus
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Soil and dust
Spices
Vegetables
Dairy products
Eggs
Cereals particularly rice and cornflour
Rice dishes, cornflour sauces and milk pudding
Cooked rice dishes
Prevention
Kitchen hygiene
High standards of kitchen hygiene must be maintained eg clean surfaces and equipment
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Check cereal dust is removed from storage and preparation areas to avoid contamination
Soil and dust
Ensure vegetables are washed before using
Ensure soil from vegetables left lying around in storage areas does not contaminate surfaces
Pre cooked rice
Avoid preparing rice in advance because if the rice is left in a warm kitchen, bacteria can multiply.
Reheating during flash frying as in fried rice must be thorough or else bacteria will not be destroyed.
Cool rice immediately after cooking then refrigerate
Cook smaller amounts of rice to avoid the need to store it. Ideally left over rice should be thrown out.
Avoid reheating rice but if necessary reheat thoroughly and serve at once
Throw out cooked rice after 24 hours
b. Food poisoning caused by food borne diseases
1.Campylobacter enteritis
 This bacteria grows under partial anaerobic conditions
 Best temperature for growth is 43ºC
 Symptoms include headaches, dizziness, backache, abdominal pain, diarrhoea. The illness can last
2 to 3 days
Sources
 Farm animals such as cows, sheep and chicken
 Domestic animals such as cats and dogs
 Infection can be spread from animal to person and from person to person.
 Raw and undercooked chicken
 Raw, unpasteurised milk
 Untreated natural water
 Cross contamination from raw to cooked foods eg meat and poultry
Prevention
Personal hygiene
Wash hands before and after handling food, especially raw meat and poultry
Kitchen hygiene
Clean all surfaces, equipment and tools thoroughly before and after use to prevent cross contamination
Do not allow domestic pets into areas where food is prepared
Correct storage of food.
High risk foods should be stored in a refrigerator at temperatures below 5ºC as bacteria find it difficult to
multiply
Cooking/ thoroughly
All chicken must be cooked thoroughly as campylobacter is destroyed by heat
Separation of raw and cooked foods
Display, store, prepare raw and cooked foods separately to prevent contamination between raw and
cooked foods eg meat and poultry
2. Listeria
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Vacuum packing and modified atmosphere packing, in which the level of oxygen is decreased and
the level of carbon dioxide is increased, also help to prevent the growth of listeria
Strict temperature control must be enforced during the distribution and storage of ready-to-eat
products
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At risk groups should avoid high risk foods. Pregnant women should avoid pates, soft cheese as
they may contain listeria which can damage the foetus, cause a miscarriage, still birth or illness in
the new born baby. Elderly people and people with reduced immunity due to illness are also at
risk groups.
Symptoms
- Infection with listeria causes listeriosis. Bacteria get into the bloodstream and multiply
- In mild cases the person will feel shivery and feverish
- In high risk groups listeria can cause meningitis, severe aches and pains, fever, confusion,
septicaemia and pneumonia..
Sources
 Soft ripened cheeses such as Brie and Camembert
 Pate, salami and continental sausages
 Cook chill meals
 Raw and cooked meats, ready- to- eat chicken
 Fish and sea food
 Coleslaw and pre-packed salads
Prevention
Personal hygiene
Listeria is found in human excreta and soil therefore food handlers should follow strict personal hygiene
rules when handling and preparing high risk foods
Correct storage of food
Refrigerate below 3ºC. Although listeria still can multiply at this temperature or lower , the growth should
be slower. Listeria may even grow very slowly at 0ºC.
Observe use- by dates. Bacteria need time to multiply therefore high risk foods should be thrown out after
the use by date
Wash salads, fruit and vegetables
Listeria is found in soil therefore traces may occur in plant foods. If these foods are eaten raw listeria will
still be present
Cooking thoroughly
Cook above the core temperature of 75ºC for at least 2 minutes. Most listeria will be destroyed at this
temperature.
Ensure that food cooked in the microwave is not unevenly heated as listeria could survive in cooler parts
of the food.
Reheating thoroughly
Reheat to 82ºC . Small numbers of bacteria may have survived the original cooking and continue to
multiply. By increasing the temperature, these bacteria will be destroyed.
3.E coli 0157
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This bacteria grows aerobically and anaerobically
Best temperature for growth is 37ºC but is readily killed at temperatures above 55ºC
Symptoms
- Illness can last 1 to 5 days or can be life threatening.
- Abdominal pain, fever ,diarrhoea some times vomiting
- In babies the acute diarrhoea and dehydration can be fatal.
- E coli 0157 can cause kidney failure and particularly in children can lead to temporary or
permanent kidney damage and anaemia
- Toxins can be released which destroy gut and kidney cells which can be fatal
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Sources
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Raw foods of animal origin eg meat and poultry.
This bacteria can then be passed to cooked food by cross contamination from hands, surfaces and
equipment
Mincing meat can spread bacteria throughout the meat
Undercooked meats especially hamburgers
 Incorrectly pasteurised milk and milk products
 Water in foreign countries
Prevention
Personal Hygiene
Wash hands before and after handling food, especially raw meat and poultry
Kitchen hygiene
Clean all surfaces, equipment and tools thoroughly before and after use to eliminate all bacteria present
Good food hygiene practices
Any business dealing with food should rigorously apply the HACCP system
Correct storage of food.
Meat should be stored in a refrigerator at temperatures of 4°C or below as bacteria find it difficult to
multiply at this temperature
Separation of raw and cooked foods
Display, store, prepare raw and cooked meat/ foods separately to prevent contamination between raw and
cooked foods
Cooking thoroughly
All meat and meat products must be cooked thoroughly as E coli is destroyed by heat
Use a metal temperature probe to ensure joints are cooked thoroughly
Serve food very hot
Above 82ºC most bacteria die therefore if food is served at that temperature the bacteria will not have
time to multiply
Physical and chemical changes in food stuffs after preservation affecting structure, texture, colour
and nutritive value
The main aims when preserving food long term are to prevent
 microbial growth
 cellular breakdown caused by enzymes contained within the food
Preservation also aims to retain as many qualities, such as colour, flavour, texture and nutritional value of
the fresh food as possible.
a. Removal of moisture
Dehydrating
This is the oldest and simplest method of preserving food. Dehydration involves the removal of moisture
from the food by applying heat usually in the presence of a controlled flow of air. Micro- organisms and
enzymes, like all living things, cannot grow and multiply without moisture. Water is drawn out from the
cells and this concentrates natural salts or sugars which preserves the food
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It is important that the temperature used should not be too high, since this will cause undesirable changes
in the food and could result in the outside of the food becoming brittle and hard whilst moisture is
trapped in the centre of the food and is unable to “escape” through the food by diffusion
Removing water from food also reduces the bulk and the weight of the product.
The food will stay dehydrated until the water is put back into the product (rehydrated). Once water is
added back into the food, micro- organisms will start to grow and reproduce again. Dried food must
therefore be stored in a cool, dry place
The effects of dehydration
 Colour
The colour of the food may change completely, darkening as it becomes concentrated as the food
dries eg green grapes turn to brown sultanas or currents
 Texture
Food will become brittle (herbs) or hard (dried pulses) or it may crumble (coffee granules)
 Appearance
Food may wrinkle, shrink in size and become lighter in weight eg dried plums become prunes,
vegetables in dried soups
 Flavour
Food becomes sweeter or more salty as a result of the removal of the moisture
 Nutritional value
Some Vitamin C and Vitamin B1 (thiamin) may be lost.
Freeze drying (accelerated freeze-drying, AFD)
The food is first of all frozen and then subjected to a mild heating process in a vacuum cabinet. The ice
crystals formed during the freezing stage change directly from ice to water vapour.
This method of drying causes little damage to the food because the ice is driven off as water vapour and it
is therefore useful for heat-sensitive foods. The size and shape of the original food is retained. Since little
heat is used, there is little heat damage and no discolouration of the product colour - sometimes colour is
improved offering a more appealing product for consumers
Flavour is retained through the process and so taste is improved. Sensitive nutrients, such as the water
soluble vitamins, remain unharmed or just a minimal loss
A wide variety of products can be freeze dried including meat, vegetables, fruits, soups, dried milk,
coffee
b Use of Temperature
(i) Heat
Heat treatment is the most effective method of preserving foods. Most bacteria, yeasts, moulds and
enzymes are destroyed by heating at100ºC.
The main methods of heat treatment are:
Pasteurization
This process is commonly used for milk. In pasteurization the milk is heated to at least 72ºC for 15
seconds to kill harmful bacteria. After this it is rapidly cooled to less than 10ºC. This process does not
affect the appearance or flavour of the product. There is a decrease in vitamin C and thiamine.
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Pasteurization is used for other food items such as milk products, fruit juices, vegetable juices and liquid
egg for bakery products.
Ultra Heat Treated (UHT)
UHT is a sterilising process in which foods are rapidly heated to about 135 - 140C and held at that
temperature for a few seconds to kill any bacteria present.
The product is then rapidly cooled and packed in pre-sterilised containers. An airtight seal prevents
recontamination until the container is opened.
Examples are long-life milk and fruit juices. These should keep for at least three months at room
temperature.
However the high temperatures achieved in the process, lead to changes in the natural flavours,
appearance and smell of the items which may not be agreeable to consumers
Vitamin losses – Vitamin C , folic acid are similar to those losses during pasteurisation , for example, of
milk. However some fruit juices are fortified with vitamins to make up for the loss.
Sterilisation
Sterilised milk has been homogenised, filtered and heat treated to at least 100C. this ensures that it
remains in good condition for several weeks. The process does cause a change in flavour. The colour of
the milk is changed due to the caramelisation of sugar in the milk and to the Maillard browning reaction
between the sugar and the amino acids. The vitamin content is reduced with vitamin C and thiamine being
most affected
Canning
A simple explanation of canning is that the food is sealed in a can which is then heated to such a
temperature that all harmful bacteria and spores are destroyed and then it is cooled.
The conditions involved in canning - time and temperature- are carefully controlled as over processing
has an adverse effect on the quality of the product.
There are variations on the standard canning process depending on the food. Aseptic canning – where the
product and the containers are sterilised separately, then filled and sealed- is used mainly for liquid foods
which are heat sensitive. This could possibly be overcooked by the standard canning process eg custards
with resultant changes to flavour and colour along with a reduction in nutrients.
Some nutrient loss occurs during canning in particular vitamin C and thiamine. However, vegetables and
fruit are canned within a few hours of being picked so even after canning the total loss of vitamin C may
be less than fresh vegetables bought in a semi fresh state and cooked at home.
(ii) Cold
The main method of preservation involving cold temperature is freezing.
Freezing
Freezing is the reduction of temperature in a food to the point where not only does microbial activity
stops, but the natural decay and deterioration of the food by enzymes is halted for quite a length of time.
When a food is frozen, ice crystals are formed in it. The speed at which food is frozen is important. If
food is frozen quickly, small ice crystals will form reducing the damage to the structure and texture of
the food. When food is frozen slowly, large uneven ice crystals are formed which break through the cells
on thawing and affect the flavour, texture and nutritive value.
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Frozen foods bear a close resemblance to the original fresh food. Also the nutritive value of the food is
not usually affected by the freezing process. In the case of frozen fruit and vegetables the vitamin C
content may be higher than that of fresh as vitamin C content will be lost during transport and storage.
After picking, the fruit and vegetables are frozen quickly, after blanching.
Blanching inactivates enzymes which may affect the colour and stability of the food, particularly fruit and
vegetables
Foods containing fat dispersed in a colloidal form (an emulsion) may not freeze successfully because
during freezing , as the water is solidified it causes an increase in the concentration of the salt in the food
which may cause irreversible changes in the colloidal structure.
Before freezing, ascorbic acid, which reduces the browning in some fruits and vegetables, or anti
oxidants, which prevent any undesirable changes in any fat present, may be added to the food
Frozen foods are kept in good condition for a longer period of time as micro organisms are dormant at
these very low temperatures.
c. Acidity
Some acids are used as a preservative for example vinegar, citric acid, lactic acid and tartaric acid.
The acidity of a substance is measured by its pH value on a scale of 1 to 14. Substances that have a Ph of
1 to 6 are acidic – 1 being the most acidic. Most micro organisms cannot survive in acidic pH so food is
preserved
The acids that are used for preserving, such as vinegar for pickling, are usually fairly strong. They
usually have a pH of 2 – 3 and so are suitable for preserving less acid foods eg pickled onions.
Other preserves may use a mixture of acid, sugar and salt in their product eg chutneys
The strength of an acid used to preserve food has to be adjusted according to the type of micro organism
that would normally contaminate the food eg some moulds grow at pH 2 and yeasts grow at pH 4 - 4.5
If the pH is low or acid a sour taste will be noticeable and will affect the taste of the food product. A
bitter taste will be noticeable if the pH is high or alkaline.
d. Sugar
 Sugar is added to food for a variety of reasons. It is
- A preservative
- A sweetener
- An energy provider
 Sugar must be used in large quantities to act as a preservative eg in jam making.
 Micro organisms cannot grow in strong sugar solutions - a concentration of 60% sugar is
therefore recommended.
 Sugar is also used to preserve certain fruits and fruit peels by crystallisation.
 The large amount of water present in the fruit is exchanged for the strong sugar syrup when the
fruit is allowed to soak in a concentrated sugar solution.
 Sugar can also be a preservative when used in cakes and biscuits. Sugar helps these products to
stay moist which keeps them in good condition for longer and gives a longer shelf life.
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UNIT: Resource management
Content
Elaboration
Biochemistry, preservation and
Food additives
processing
 Preservatives
 Anti oxidants
 Emulsifiers
 Sweeteners
 Improvers
Specific commercial additives
 Anti foaming agents
 Colours
 Bleaches
 Flavour enhancers
 Nutritional additives
The benefits of additives and safeguards
regarding their use
1. Food Additives
Additives are natural or synthetic substances which are added to foods to serve particular purposes. The
legal definition of an additive from the Food Labelling Regulations 1984 is “any substance not commonly
regarded or used as a food, which is added to or used in or on food at any stage to affect its keeping
qualities, texture, consistency, appearance, taste, odour, alkalinity or acidity or to serve any other
technological function related to food.”
Additives must serve one or more of the following functions:
1. maintain the nutritional quality of food
2. improve the keeping quality of food
3. make food attractive to the consumer
4. provide essential aids in food processing
Additives may be:
1. natural substances which have been produced biologically and have been extracted from natural
sources, e.g. lecithin which is used as an emulsifier in mayonnaise and sauces.
2. synthetic compounds which are “nature identical”. These have been synthesized either
chemically or biologically to match naturally occurring counterparts, e.g. ascorbic acid (vitamin
C) which is used as an anti-oxidant and can be produced synthetically.
3. artificial compounds which are synthesized chemically and have no naturally occurring
counterpart, e.g. one additive used as a flour improver has to be synthesized by chemical methods.
The benefits of additives.
Food additives carry both benefits and risks to the consumer.
Additives are not new, they are an extension of traditional techniques, e.g. the use of salt for preserving
and the use of sodium nitrite for preserving and curing of hams.
Without additives it would be difficult to provide food in the enormous quantities required today. Shelf
life would not be as good, products would not be as attractive and they would be dearer. Today’s
consumer does not shop for food every day and expects food to be reasonably priced, nutritious,
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attractive, palatable and safe. It is the relationship between food additives and safety that is the centre of
current debate.
Food manufactures can only use additives that have been tested and found to be safe. Legally
manufacturers are forbidden to add substances to food that may injure health. However testing of food
additives may only take place in animals and on an individual basis. The exact consequences of eating
combinations of additives by humans, is not known. It is fair to say that some additives may present a
health problem but only to a small percentage of the population.
Manufacturers are finding that they have to justify the presence of additives and demonstrate a useful role
and many are redesigning their products to reduce or even omit additives. The fact that additives are not
present in a food is being used as a positive advertising feature. A statement on a label that the product is
free of artificial colourings means just that, and it will probably contain natural colourings, preservatives,
flavourings, etc. depending upon the actual product. Consumers must read the labels carefully as some
food manufactures may ‘play’ with words to give a false impression.
It is important that he risks of possible ill-effects from the presence of chemicals in foods should be
negligible compared with the benefits which ensue, and the food additives approved for use in Britain
perform useful functions without harming the vast majority of consumers.
Each additive should be considered on its merits
The use of synthetic colours is particularly difficult to justify. The risks, though small, are thought by
many people to outweigh substantially the dubious cosmetic benefits of the additives.
Additives are sometimes used to give manufactured foods properties associated with the presence of
traditional ingredients. Emulsifying agents used to decrease the amount of fat needed in the manufacture
of cakes and bread come into this category. Although these reduce the amount of fat required to produce
familiar physical properties in cake, they do not, of course, fulfil its nutritional functions. The amount of
fat lost in this way, when considered in terms of an individual is not large, but for someone living on a
barely adequate diet it may not be insignificant. Most people, however, eat too much fat and a reduction
in intake would be beneficial.
Synthetic cream and meringues are today often made from cellulose derivatives which have absolutely no
nutritive value. The use of colouring matter in cakes to give an impressing of richness is also open to
criticism. There are numerous other examples of the use of additives which contribute nothing to the
nourishment of the consumer. The more luxurious classes of foodstuffs lend themselves particularly well
to such sophistication and it may be argued that these are not, in any case eaten primarily for their
nutritive value.
The use of nitrates in meat products to prevent food poisoning by clostridium botulinum is well
established. There is the risk, however, that the nitrites in food are partly converted into a substance
which is known to produce cancer in animals. At low levels permitted in specified foods nitrites are now
not known to have caused any harm to any human being. Nevertheless, the risk remains and it is a matter
of judgement whether the risk is considered to be justified in the light of the known benefits.
The overall benefits of food additives can be summarised as follows:
 foods have a longer shelf life and so the consumer can store the products for a longer period of
time – convenience factor. This prevents the consumer having to do a lot of shopping daily as
foods can be safely bought and stored for an extended period of time.
 increased variety in the diet as foods can be imported in to the country and foods out of season can
be consumed.
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sensory value of the food is improved by the addition of additives If not added many foods which
are processed would lose flavour, colour and texture.
food is safer for longer periods of time as micro-organism infections is reduced or impaired. This
reduces wastage of food in the home.
have allowed the development of a wide variety of new foods that would previously been unable
to be developed.
has opened up an area of packaging of foods and so aids the consumer in term of choice and
storage.
many new lower fat products would not be available without the use of additives – related to
health improvement.
foods are more consistent with additives so that the consumer can buy standard products.
additive allow the use of cheaper ingredients although these economies are not always passed on
to the consumer.
some additives help to minimise nutrient losses during processing and storage.
Safeguards regarding the use of additives
Food additives are regulated and controlled on a European Union (EU) wide basis. The relevant directive
clearly states that food additives are allowed only if:
 they present no hazard to health at the level proposed.
 a reasonable technological need can be demonstrated
 they do not mislead the consumer.
The directive also states that all food additives must be re-evaluated whenever necessary in the light of
changing conditions of use and new scientific information.
The EU body responsible for evaluating the safety of food additives is the Scientific Committee on Food
(SCF) which is a group of experts composed mainly of toxicologists.
The SCF has issued guidelines setting out the tests that must be carried out on food additives in order to
demonstrate their safety. The guidelines require an extensive range of tests to assess the possible risk to
the consumer:
 metabolic studies (to understand how the body absorbs, distributes, metabolises and eliminates the
substance)
 genetic toxicity (potential for gene and chromosome damage);
 reproduction and teratogencity studies (life studies, including the potential for fertility and birth
defects);
 chronic and carcinogenicity studies (the potential for causing cancer).
The guidelines ensure a threshold level exists above which consumption is unsafe and below which
consumption is safe.
Then aim of testing is the identification of an adverse effect caused by the additive. When the SCF is
satisfied with the data collected from the tests, it reports its findings to the European Commission.
New additives are rigorously tested and the government advised by COT (the Committee on Toxicity of
Chemicals in Food, Consumer Products and the Environment) and the Food Advisory Committee before
permitting new additives. The committee set an Acceptable Daily Intake (ADI) for each additive, this
being the amount which, in the opinion of the committee, can be eaten safely each day, even over a
lifetime without risk to health.
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E-numbers
The SCF affixes an e-number to any additives which it has passed safet tests and has been approved for
use in the UK and in the rest of the EU.
Food Laws and the control of additives in the UK
 The statue currently in force is the Food Safety Act 1990
Food additives and their benefits
Preservatives
The function of preservatives is straightforward; to control the growth of micro-organisms which cause
decay in foods and beverages ensuring this food and drink is safe for consumers. This results in an
increase in transport and storage times which is beneficial to food manufacturers
Applications
Food preservatives are used widely. These include:
 soft drinks and other beverages
 cheeses, margarine, mayonnaise and dressings
 bakery products
 fresh and dried fruit preparations
 prepared salads, delicatessen products, pickled vegetables
 pasta products, fish and seaweed
Preservatives are not a substitute for good food hygiene practice. No preservative can bring spoiled
products back to an acceptable level or cover for the effects of poor quality processing. They must be
incorporated into stringently clean and hygienic methods of production.
The greatest threat to the quality and safety of food comes from microbial spoilage. Microbial spoilage
may result in the loss of sensory qualities leading to such things as bad taste, unpleasant smell and poor
appearance. It may result in the loss of nutrients. More importantly it may increase to a dangerous level
the presence of harmful micro-organisms or toxins (poisons) they produce. They help to prevent life
threatening- illness such as botulism poisoning.
Most preservatives today are actually fungistatic in their action that is, they are used to prevent the growth
of fungi moulds and yeasts. Their antibacterial activity is less pronounced but a combination of
preservatives, each with some antibacterial action can be used to give all round protection. Some of the
main preservatives are listed below:
1. Scorbic acid and its salts (E200-203) are the most important and widely used in food preservatives It
has two main advantages, namely:
 it is effective over a wide range of foods and beverages
 it imparts no flavour to the products
Scorbic acid is used in beverages, dairy products, fish and seafood, fat based products, fruit and vegetable
products, baked goods and confectionery products.
2. Benzoic acid and other benzoates (E210-E219) are used as preservatives to prevent yeasts and moulds
from growing, most commonly in soft drinks. They occur naturally in honey and fruit. Benzoates may
make the symptoms of eczema and asthma worse in children who already have these conditions. It may
also be linked to behavioural problems in children.
3. Sulphur dioxide and sulphites (E220-E228) are multifunctional;acting as preservatives, antioxidants
and stabilisers of colour. They have a very efficient bacterial effect more so than other preservatives and
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are therefore used when control of bacterial growth is essential. They are used in a wide range of
products including soft drinks, packet soup, dried bananas and apricots, tinned crabmeat, sausagemeat,
burgers, beer, wine quick frozen chips and jams. A few people with asthma have had an attack after
drinking acidic drinks containing sulphites, but this is thought to be unusual. Food labelling rules,
introduced in 2005, require pre packed food sold in the UK and the EU to show clearly if it contains
sulphur dioxide or sulphites at levels above 10mg per kg or per litre
4. Potassium nitrate and sodium nitrate (E249 and 250 respectively) are not naturally occurring
substances. They are multifunctional in the food industry having preservative, stabilising and flavouring
properties. There are health concerns about their use. However, without their contribution there would
undoubtedly be many more deaths from the disease botulism which is cause by the bacterium Clostridium
botulinum.
Specific benefits to the consumer
 help to keep food safer longer
 lengthens the shelf-life of foods
 enables manufactures to transport food in bulk which is cheaper and keeps costs down for the
consumer
 protects food from contamination by micro-organisms
 prevents wastage of foods for retailers/consumers as shelf-life is extended
 can be added to some fruits e.g. apples to prevent browning – unpleasant discolouration
Antioxidants
Oxidation can be a very destructive process. Oxidation of food can result in loss of nutritional value and
changes in chemical composition; the unpleasant and undesirable oxidation of fats and oils leading to
rancidity.
Functions
Antioxidants are added to food in order to slow down the rate of oxidation. None are capable of
preventing the process of oxidation completely. If used properly they can usefully extend the shelf life of
the ingredient and/or the food product in which they have been used. These additives protect the fat
soluble vitamins from combing with oxygen.
The products in which antioxidants are most commonly used:
 vegetable oil
 snacks (extruded)
 animal fat
 meat, fish, poultry
 margarine
 dairy products
 mayonnaise/dressing
 baked products
 potato products
Antioxidants can be used in pure fats and oils as well as in products which merely contain them. Even if a
food has a very low fat content it may still be necessary to employ the benefits of an antioxidant.
Some of the main antioxidants used are:
 ascorbic acid – vitamin C (E300) which is used to prevent browning reactions in fruits and fruit
products;
 vitamin E (E306) which is added to prevent rancidity in vegetable oils and polyunsaturated
margarines
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
butylated hydroxyanisole (BHA-E320) and butylated hydroxytoluene (BHT-E321) which are
also used as antioxidants in a wide range of products, e.g. if the food product is to be heated or
fried. These two antioxidants have been shown to adverse reactions in some individuals, and are
not allowed to be added to foods of young children and babies.
How do antioxidants work?
In food substances called peroxides are produced as a result of oxidation of fat. As fat decomposes and
reacts with oxygen, the amount of peroxides rise and leads to the decomposition of fats and rancidity.
Anti-oxidants stop the process.
Specific benefits to the consumer
 prolongs the shelf-life of foods by protecting against deterioration caused by exposure to air.
 Prevents fats becoming rancid so extending the shelf-life, preventing waste and preventing
unpleasant flavours
 Prevents colour changes in certain products so maintaining their aesthetic appeal
Emulsifiers / stabilisers
The purposes of each are as follows:
 Emulsifiers are used to make stable emulsions or creamy suspensions from oils and fats and water.
They are also used in baked foods to slow down the rate of staling.
 The stabilizers are used to improve the stability of emulsions and prevent the separation of their
components. They help maintain the physical characteristics of a product.
Emulsifiers are amongst the most frequently used types of food additives. The foods in which they are
most commonly found are:
 biscuits
 extruded snacks / breakfast cereals
 cakes
 margarine/spreads
 coffee whiteners / topping powders
 desserts / mousses
 peanut butter
 soft drinks
 chocolate coatings
 caramel / toffees
 chewing gum
 frozen desserts / ice cream
 dried potato
Emulsifiers are used in a wide range of products for the following reasons:
 to make foods appealing – they have a pronounced effect on the structure and texture of many
products
 to aid in the processing and preparation of foods – modern high speed food processing techniques
often require the use of emulsifiers to allow the product to be successfully produced.
 to maintain product quality and freshness – this role my well be expected to be filled by
preservatives or anti-oxidants. However, in many products emulsifiers play a similar role, for
example, the control of mould growth in low fat spreads by creating an emulsion with finely
dispersed small droplets of water.
 to increase choice – the functional properties of emulsifiers often allow a much wider choice of
raw materials for the manufacture resulting in greater choice for the consumer in the different
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product variations. Many common products would not exist at all, for example low fat spreads,
fatless sponges. Costs too can be lowered, without reducing the nutritional value of the food.
Stabilisers improve the stability of a mixture by increasing the viscosity. Stabilisers are most commonly
used in the following foods:

ice cream and ice lollies – to prevent the appearance of large, grainy ice crystals or ice lumps and
give ice cream the firm texture, smooth taste and good keeping qualities associated with the
modern product. Ice creams and ice lollies made without stabilisers tend to have a grainy feel in
the mouth. This is due to the formation of undesirable, large ice crystals. The use of stabilisers
helps to assist the formation of a smooth texture throughout the ice cream which enhances its
taste, resists melting and, just as importantly, retains these qualities until the product is consumed.

many reduced fat or low fat products – in their manufacture. Many consumers are aware of the
health benefits of reducing their intake of fats and oils. Reduced fat or low fat versions of
traditional products are now being produced. When a quantity of far or oil is removed from a
product, it must be replaced if the product it to be comparable with the traditional one. Often the
mass is replaced by adding water and either a gel, thickener stabiliser to restore the texture.

sauces and dressings – to avoid the separation of the oil and aqueous components. Stabilisers help
to maintain many sauces in good condition. Without their use the sauces, both in sweet and
savoury products, would at least separate into their original components. This is not unsafe but it
is unattractive to the consumer.
Specific benefits to the consumer of emulsifiers and stabilisers.
 prevent the ingredients separating again so maintaining a good product.
 allows the manufacturer to produce a consistent product which can remain stable on the shop
shelf, during transport and distribution.
 improve the consistency of the food.
 produce special characteristics required in certain products i.e. viscosity of the product (thickness
or thinness) smoothness and stability.
 help produce ‘healthy’ products e.g. low fat spreads and so contribute to consumer’s health.
Sweeteners
The function of sweeteners in a product is to provide a sweet taste.
Sweeteners are used in a wide variety of foods and beverages such as:
 beverages ( carbonated , non carbonated, milk-based and alcoholic)
 breakfast cereals
 confectionery (including chewing gum)
 desserts, fillings and topping (ice cream, sweet whipped cream)
 processed fruit and vegetable products (jam, jellies, baked beans, canned fruit)
 medicines
 syrups
 salad dressings and condiments
 baked goods
In an attempt to limit energy intake, a great demand has arisen for food and drinks which have fewer
calories (or kj) than their traditional counter parts. One way to accomplish this is to replace sugar with a
sweet tasting, non-calorific sweetener.
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Another reason for using sweeteners is too provide appropriate foods and drinks for diabetics. Diabetes
results from a failure of the pancreas to produce a hormone called insulin which regulates the amount of
glucose in the blood. Sweeteners allow diabetics to have sugar free, sweet tasting foods.
Sweeteners fall into two categories:
 intense sweeteners are many more times sweeter than sucrose and they are therefore used in low
concentrations.
 bulk sweeteners are about as sweet as sucrose and hence are used in roughly equal amounts.
There are five permitted intense sweeteners:
1. acesulfame potassium used in canned foods, soft drinks and table-top sweeteners
2. aspartame, used in soft drinks, yoghurts, dessert and drink mixes and sweetening
tablets
3. saccharin (and its sodium and calcium salts), used in soft drinks, cider, sweetening tablets;
4. thaumatin used in sweetening tablets and yoghurt;
5. neohesperidine dihydrochalcone (NHDC, E959) used in soft drinks and pharmaceutical preparations
such as vitamin pills.
The bulk sweetners are:
 mannitol (E421) are used in sugar-free confectionary
 sorbitol (E420) is used in sugar-free confectionary and jams for diabetics
 xylitol used in sugar-free chewing gum
 lactitol (derived from whey, a by-product of cheese manufacture) is used in reduced-sugar jellies
and jams.
Specific benefits to the consumer
 They can reduce the sugar content of the diet and can help weight reduction and help meet the
dietary target for sugar consumption
 They have little or no energy value and can therefore aid weight reduction as they have a lower
energy value
 Sugar substitutes especially intense sweeteners can be used in the “lite” market for foods and can
therefore help reduce the energy value of these products assisting in weight reduction.
 Can be used in confectionery, bakery goods and many other foods, increasing the range of
“Healthy Options” available and giving the consumer a wider choice of products
 Bulk sweeteners are used in sugar free confectionery and can help reduce the risk of tooth decay
and obesity
 Sorbitol does not require insulin to be metabolised and are therefore used in products suitable for
diabetics eg jam / jellies and so increases their food choice
Flour improvers
These substances are used to strengthen doughs.
Specific Commercial Additives
1.Anti-foaming agents
These are capable of preventing or stabilising any foams produced during manufacture, e.g. glucose
mixture which is transported round food manufactures factories in pipes could change texture if an antifoaming agent was not added. They are also used in cooking oils and bottled beers to prevent overfoaming.
2.Colours
The purpose of adding colour to food is to improve its general appearance. Colour additives are used for
sensory purposes such as taste, smell and appearance. They can be added to replace natural colour lost
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during food processing. The examples of foods which contain added colours is extremely varied from soft
drinks, confectionery and sauces through to tinned peas, soups and fish fingers
When colours are used in food, they must be declared in the list of ingredients as “colour”, plus either
their name or E number.
Colouring of food products takes place to:
 enhance the natural colour. The ingredients used to produce a particular food may well have their
own colour. However, this is often weaker than the colour normally associated with this food and
its flavour.
 to ensure uniformity of colour in foods from batch to batch. A food such as jam bought in
December would expect to look like a similar pot bought in August
 replace colour which may have been lost during the processing procedures and subsequent
storage of the product. Colour can also be bleached out by the use of preservatives or affected by
light during lengthy storage
 add colour to those products which otherwise be entirely lacking in colour. Many drinks and
boiled sweets fall into this category.
Consumers expectation of food quality is to a certain extent colour dependent. Many permitted colours
are of natural origin and they include saffron, cochineal, carotenes. The list of permitted colours includes
some synthetic dyes. Thousands of such substances are known but most are too toxic to be used in foods
and some are known to be carcinogenic(i.e. able to cause cancer). For this reason only a limited number
have been approved for use in food. Most of them are approved for use throughout the EU (i.e. they have
E numbers), Colouring matter must not be added to meat, fish, poultry, fruit, cream, milk, honey,
vegetables, wine, coffee, tea and condensed or dried milk. No colours may be added to foods intended for
babies and infants except riboflavin (and its phosphate), lactoflavin and B-carotene, all of which occur
naturally in other foods. It is use of synthetic dyes that has probably attracted most criticism from the
anti-additive body.
Research has shown that some colourings may cause allergic reactions, irritation to suffers of asthma and
eczema and may cause behavioural/ hyperactivity problems in children. The Food Standards Agency has
issued advice to parents that if their child shows signs of hyperactivity then they should avoid giving
them food which contains the following artificial colours – sunset yellow, quinoline yellow, carmoisine,
allura red, tartrazine and ponceau 4R. These colours are contained in soft drinks, sweets, cakes and ice
cream. The FSA are encouraging manufacturers to work towards finding alternatives to these colours.
The final choice is dependent on a number of factors:
 for products with a long shelf life, such as soft drinks which are bottled in transparent containers,
light stability is an important factor
 some colours are sensitive to the discolouration brought about by reducing agents such as vitamin
C. In some cases colours not sensitive to this particular reaction must be used.
Specific benefits to the consumer
 restores the colour lost due to processing so improving their appearance
 enhances the colour of certain foods to make them more attractive.
3.Flour bleaching agents
These substances are added to flour in order to whiten it, e.g. chlorine dioxide.
4.Flavour and flavouring enhancers
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Function
Flavourings are added to food products to give, enhance or intensify flavour. There are several thousand
flavouring agents available to the food industry including both natural and synthetic flavours. At present
flavourings may be used in foods without restriction. It is intended that they will in time, be subject to
control in the same way as other additives. The problems to be overcome in doing so, however, are very
great because of the large number of flavourings available and the minute concentrations in which they
are used.
Natural flavouring agents include essential oil of cloves, oil of lemon. Herbs and spices contain many
essential oils and other flavouring compounds and are widely used as flavouring agents.
Synthetic flavours are usually copies of natural forms.
Flavourings are used in a wide variety of food products, e.g.
 some products like ice cream and margarine, would be unacceptable without the addition of
flavourings
 new foods such as meat substitutes made from spun vegetable protein would, without added
flavour, be uninteresting, despite being extremely nutritious.
 some products, like table jelly, would be completely lacking in flavour without the addition of
flavourings
 some products like strawberry yoghurt, have natural flavour present but possibly at a low
intensity. Flavourings may be added to enhance the natural flavour
Flavour Enhancers
Monosodium glutamate (E621) or MSG as it is commonly known, is the most widely used flavour
enhancer. MSG is a sodium salt of glutamic acid, an amino acid which is a common component of
proteins. It occurs on soy sauce, which is made by fermenting soya beans and it has long been used in this
form as a flavour enhancer in Chinese food.
Most dehydrated soups and stock cubes contain MSG and it is also present in many other ‘meaty’
prepared foods. Some people react unfavourably to MSG and suffer from what has come to be known as
the ‘Chinese restaurant syndrome’ if they eat food containing it. This can result in palpitations, chest or
neck pain and dizziness. The cause is not known and the ill-effects soon disappear. MSG is not thought to
be harmful but, as a precautionary measure, it is not now added to food manufactured for babies and
infants.
The flavour-enhancing capacity of MSG is much intensified if it is used in conjunction with inosine
monophosphate (E631) or guanosine mono-phosphate (E627) which are known as IMP and GMP
respectively.
Specific benefits to the consumer
 makes flavour in some foods stronger.
 added to foods in small amounts to improve taste.
 added to foods in small amounts to give odour.
 Used to produce artificial flavours in foods where ‘real’ flavours may add to cost (e.g. yoghurt).
 Used to add flavours to foods which when processed could not replicate natural flavour.
5.Nutritional Additives
Nutritional additives are added to food to maintain nutritional value and also to improve the product. This
is known as “food fortification”. In some cases the added nutrients replace those lost during processing.
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Such addition of nutrients may be either a legal requirement to safeguard public health or may be
completely voluntary by the manufacturer.
Some examples of legal requirement would be:
 the enrichment of margarine with vitamins A and D to make its vitamin content equivalent to that
of summer butter is obligatory
 the addition of nutrients, e.g. calcium to flour.
Some examples of a voluntary nature by the manufacturer would be:
 fortification of breakfast cereals with a range of vitamins and minerals
 the addition of vitamin C to soft drinks and juices
By adding nutrients to basic, low cost foods, people on low incomes would hopefully be able to purchase
these foods and so ensure these nutrients in the diet.
See also Functional Foods
6.Humectants
These substances absorb water and therefore help to prevent food from drying out. Glycerol is added to
sweets and icing for this purpose. Sorbitol is added to packaged cakes, bread and pastries.
7.Anti-caking agents
Anti-caking agents or free flow agents are added to foods and food ingredients, usually when they are in
powdered form. Many food processing plants have problems with handling powders due to:



the nature of the powders
the design of the machinery
a combination of these factors
Improving the flow characteristics of the powders can improve the efficiency of the manufacturing
process. Examples of foods that contain anti-caking agents are:

vending machine powders These are exposed to high humidities and temperature. Their flow
must be maintained to ensure dependable machine operation and consistent measures. Chocolate,
coffee, soup powder, meat extracts and dried fruit drinks are all materials which can have flow
problems.
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milk and cream powder substitutes(non-dairy creamers) These normally have a high
vegetable oil content, causing the particles to stick together during processing, packaging and
subsequent storage and use.
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cheese Cheese which has been grated for convenience of use, e.g. pizza topping tends to stick
together due to being compressed during storage. This undermines the benefit of the grating to
the user.
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Sugar When subjected to a humid atmosphere, sugar, especially icing and brown, tends to cake
easily. Incorporation of a free-flow aid before grinding will prevent adhesion, of the sugar to
processing equipment. It also reduces the tendency of the powdered sugar to cake.
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8.Acidulants
Acidulants are food additives used to impart a sharp, characteristic taste to foods. They also assist in the
setting of gels, e.g. jams and also act as preservatives. As the food industry has developed, so has the
growth in production of processed foods. Many of these need the inclusion of an acidulant to impart an
acidic or sour taste.
Many foods are quite strongly acidic and the clear sharp taste is due to the natural acids found in the food
itself, e.g. lemons are rich in citric acid and yoghurts contain lactic acid. Acidulants find wide use in
processed foods such as soft drinks, desserts, jams, sweets, soups and sauces. They contribute to taste but
are also used to preserve foods by creating an acid environment which prevents the growth of microorganisms. Citric acid, originally extracted from lemons but now manufactured by a fermentation process,
is the most likely acidulant. Phosphoric acid is used in cola drinks to compliment and accentuate the
characteristic cola flavour.
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UNIT: Resource management
Content
Elaboration
Biochemistry, preservation and
Organic Food
processing
ORGANIC FOOD
Organic Agriculture is safe, sustainable farming system, producing healthy crops and livestock without
damage to the environment. It avoids the use of artificial chemical fertilisers and pesticides on the land
and the use of genetically modified organisms is prohibited. It relies instead on developing a healthy,
fertile soil and growing a mixture of crops. In this way, the farm remains biologically balanced, with a
wide variety of beneficial insects and other wildlife to act as natural predators for crop pests and a soil full
of micro-organisms and earthworms to maintain its vitality. Animals are reared without the routine use of
an array of drugs antibiotics and wormers which form the basis of most conventional livestock farming.
The Organic Food Federation has explained organic food as follows:
In order to receive a Certificate of Registration, a grower of organic food has to prove that he does not use
any agro-chemical inputs and has not done so during a conversion period of two years. All the organic
raw materials are supplied from certified organic sources. In order to use the word organic as part of a
product or description of a manufactured product, it must have no less than 95% of its agricultural raw
materials produced or grown organically. Only ingredients and additives which are specifically nominated
for use by the regulations may be used in any organic formulation. Certification is provided by
independent inspectors approved by the UK Register of Organic Food Standards (UKROFS).
Organic standards
‘Organic’ is a term defined by law and all organic food production and processing is governed by strict
set of guidelines.
Producers, manufacturers and processors each pay annual fee to be registered and are required to keep
detailed records ensuring a full audit track from farm, or production plant, to table. Any major
infringement of this results in suspension of licence and withdrawal of products from the market. All
organic farmers, food manufacturers and processors are annually inspected, as well as being subject to
random inspections.
The standards are stringent and cover every aspect of registration and certification, organic food
production, permitted and non-permitted ingredients, the environment and conservation, processing,
packaging and distribution. The standards are regularly updated and are then enforced by certification
bodies – most of which operate higher standard than are required by law.
The governing body is the independent UK Register of Organic Food Standards (UKROFS), which sets
the basic standards to which the various organic bodies and producers have to adherer to. UKROFS
standards in turn, conform to the European Community directive to organic production.
Each certification body has its own symbol and EU code number. These are the marks to look for on
organic products, and are visible proof that they have met the required UKROFS standards and any others
set above those by that certification body.
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The two most important Certification Bodies are as detailed below:
UK Register of Organic Food Standards (UKROFS)
This is an independent body set up to regulate the production and marketing of organic food.
The UKROFS standards set strict requirements on the use of manure’s, fertilisers and mineral additives.
They require crop rotations and list permitted methods and substances for pest and disease control. They
also require methods to consider the environment and wildlife habitats and specify certain packing
materials. Farms and production processes must be regularly inspected and farmers must keep detailed
records.
Producers registered with the following certification bodies may also use the UKROFS logo if they wish
to.
Soil Association Certification (SA Cert)
This is the country’s leading certification body, certifying approximately 70% of organic food produced
in the UK. It was founded in 1946 and its symbol is probably the most familiar to Consumers. It operates
its own set of standards, which are more specific and generally stricter than those laid down by UKROFS.
The soil association investigates farming methods and advises consumers on organic methods. They
promote organic methods and produce to consumers and publish information which help consumers make
wise choices in supermarkets. The consumer is reassured that the food displaying the symbol is of an
organic nature.
To avoid confusion with non-organic produce, most organic food is pre-packaged. Always check for the
symbol and/or number of recognised certification bodies. Where produce is sold loose, proof of
certification must be available to consumers.
All manufacturers must be registered with a certification body. Some shops pay a certification fee to
register as organic in their own right. This gives added assurance to customers. Any shop that repackages
good out of sight of customers, or cooks its own food and labels it ‘organic’, must also have its own
licence to do so.
Consumers are also protected by:
1. The Advertising Standards Authority
2. Trading Standards
The Advertising Standards Authority
In relation to organic food the Advertising Authority will:
 Prevent false misleading advertisements promoting organic food
 Investigate complaints against advertisements or advertisement claims
 Ensure a standard of advertising that consumers can trust
 Protect consumers from advertisements which aim to mislead them into buying the food
 Investigate advertisement claims to ensure they are truthful.
Trading Standards
In relation to organic foods, the Trading Standards department are responsible for enforcing:
 the Trades Description Act of 1968 – this protects consumers from traders who either deliberately
or accidentally mislead their customers
 Food Labelling Regulations under the Food Safety Act 1990
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There are several advantages of buying organic foods:
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Many people buy organic foods as they believe they taste better than non organic. This could be
because organic fruit and vegetables tend to grow more slowly and have a lower water content,
which may contribute to the flavour – as yet there is no consistent evidence that organic food
does taste better.
Only 32 of the 290 food additives approved for use across the EU are permitted in organic food.
The Soil Association have banned the use of the following:
Phosphoric acid, which is a highly acidic ingredient used in cola drinks. It can leave the bones
brittle and porous and lead to osteoporosis.
Aspartame, the most widely used artificial sweetener. Reported reactions to aspartame include
headaches, nausea, diarrhoea, convulsions and seizures.
Monosodium glutamate, which is thought to be responsible for dizziness, headaches and asthma
attacks.
Sulphur Dioxide which can often cause problems in people who have asthma.
Hydrogenated fat, which is linked to heart disease, is banned under organic standards.
Consumers buy organic because they believe it is free from chemicals or pesticide residues and
therefore better for health – fewer side effects or allergies. It is seen as a safe nutritious,
unadulterated food. Over 440 pesticides are routinely used in non organic farming and residues
can be found in the food.
According to the government’s Pesticide Residues Committee, over 40% of all non organic fruit,
vegetables and bread tested in 2005 contained pesticides. Organic farmer do not use man-made
chemicals, however there’s no guarantee that organic food is always completely residue-free.
Pesticides can linger in the soil over many years.
Scientists are divided over the issue of whether pesticide residues in food and drink do us any
harm or not. Many think that residues don’t pose any significant health risks. But some scientists
remain uncertain about the long term health risks.
The food is free of hormones and antibiotic additives, which may be injected into some farm
animals or added to the food to speed up growth. These can find their way into the food chain and
are linked with bacterial resistance in humans to the same or closely related antibiotics
It is considered to be better for health – less allergies and other side effects caused by pesticides
Several studies have shown higher levels of protein, vitamin C, calcium, magnesium, iron,
potassium and anti oxidants in organic vegetables. But there is little conclusive evidence that
organic food offers any significant nutritional advantage. The extra vitamins and minerals could
be lost if the juices or cooking water aren’t retained.
It is claimed that organic milk is naturally higher in omega 3 fatty acids, vitamin E, vitamin A
(beta carotene) than non organic milk.
People buy organic food because it doesn’t damage the environment. Many farmers changed to
organic methods because they too felt that invasive farming techniques were destroying the land
and environment.
Concerns over pollution, non organic agriculture uses artificial fertilisers /pesticides which can
add to water pollution and affect river fish.
The “green” image may appeal to some consumers. It is considered that organic farming produces
crops and livestock without damage to the environment
Concern for animal welfare is another factor which may encourage consumers to buy organic.
Animals are reared without routine use of drugs, antibiotics and wormers
One of the main goals of organic farming is to develop, ”sustainable agriculture”. This means
resources are retained and recycled within the farming system. For example most organic farms
have cattle and their manure is used to fertilise the soil. Helps farms to remain biologically
balanced
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Pesticides are designed to kill living organisms. So, while they kill unwanted pests they might also
kill beneficial insects such as ladybirds and bees as well as harm wildlife. A wide variety of
beneficial insects and wildlife can act as natural predators for crop pests
Organic farmers grow hedgerows to encourage the numbers of beneficial insects which prey on
unwanted pests. Artificial fertilisers and pesticides also add to water pollution.
Consumers are reassured that organic food does not contain genetically modified ingredients.
Vastly increased ranges in supermarkets means there is a much wider range of goods to choose
from and there is increased promotion of organic products
Increased demands are bringing cost of organic foods down
Increased popularity of delivered organic vegetable ‘box’ schemes
People concerned with ‘food miles’ may choose to buy from farmers markets which sell organic
foods
It has become more fashionable to choose organic food it is now seen as a mainstream choice as
opposed to something unusual to purchase
Some councils use local organic produce to support local communities so encouraging
consumption
Organic food comes from trusted sources. All orgainic farms and food companies are inspected at
least once a year to ensure the standards for organic food are being met.
There could be several disadvantages to buying organic foods, namely:
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Pesticides can drift over from conventional farms so crops would not be able to be termed truly
“organic”
Higher price for organic food makes it too expensive for those on a lower income. The cost of
organic produce is much more expensive compared to non organic produce. Foods can be more
expensive due to:
Packaging costs – because organic fruit and vegetables have to be kept separate so that they do not
get mixed up with conventional fruit and vegetables, most are packaged which adds to the cost.
- Farming Methods
a. The price of organic food is also pushed up by traditional farming methods on which it relies.
Organic farming prohibits the use of
man-made fertilisers, pesticides,
growth regulators, biological pest control and mechanical weeding ( conventional growers
spray on herbicides to kill weeds).
b. Organic farms tend to be smaller so their scale of production is smaller.
They, also rely on crop diversity (planting several different crops) rather
than concentrating on a single crop. They use this crop diversity (planting
several different crops) rather than concentrating on a single crop. They use
this crop diversity, as well as crop rotation to build soil fertility. But this
means it’s not always economic to use large specialised, often expensive
machinery for harvesting and packing produce. Using more manual labour
and less efficient machinery increase costs.
- Storage and transport
After harvesting, produce is usually stored. Conventional farmers often use
post-harvest treatments to prevent pests, moulds and other damage to their
food while it’s in store. Organic farmers do not use these treatments: instead
they put their produce in cold storage. This costs more and is less reliable so
organic farmers can lose more of their produce than other growers at this stage.
Even transporting and sorting organic food can be more expensive, mostly
because of the small volumes involved.
It is likely , that prices could fall as farmers invest in equipment which will
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result in an increase in production.
Smaller scale farming means lower yields and this affects availability and cost.
Appearance of foods, especially vegetables may not be as standard and appealing as non organic
so may not appeal to consumers
Fresh vegetable products may not have such a long shelf life
No guarantee that the product is completely residue free
Some scientists believe there are no nutritional benefits so consumers would be spending more
money with no added nutritional benefit
Natural pesticides produced by plants can be more harmful than synthetic ones
Concern over the occurrence of E-coli bacteria in the manure used as fertilizer and the safety of
organic crops Allegations have been made about the safety of organic food production and the
occurrence of E-coli bacteria in the manure used as fertiliser. There is still much debate over this
issue. Organic farming is less likely to be a source of E-coli contamination and should therefore
produce safer food, because organic livestock is far less likely to harbour these dangerous
bacteria, which are not favoured by the healthier lifestyles inherent in organic farming.
High levels of toxins in organic foods could be hazardous to health e.g. green potatoes
Foods may be contaminated by copper and sulphur containing fungicides
A recent study has shown that organic chicken is less nutritious, contains more fat and tastes
worse than free range or battery farmed meat in addition to being more costly. Organic chicken
contains lower levels of the anti oxidant Vitamin E which preserves the flavour of the meat. It
also had lower level of Omega 3 fatty acids and some chicken had higher cholesterol levels
There is now concern that the increasing industrialisation of organic farming to meet demands has
led to a dilution of its “green” credentials and quality
A recent government report claims that despite its eco-friendly image, some organic farming
creates greater pollution and contributes to global warming.
Certain organic foodstuffs– such as milk, chicken and tomatoes – produce more greenhouse gases,
create more soil and water pollutants and require more energy and land for their production than
those farmed by conventional methods
May have an adverse effect on the sustainability of farming particular crops
Some consumers may have concern over foreign organic food standards and authenticity.
Imported Organic Food
Each EU country has its own national organic certification authority which conforms to EU standards,
much like UKROFS, and within each there are various certification bodies. As in the UK, each
certification body may apply additional specifications on top of the EU standards. EU standards, in turn,
are subject to those laid down by the International Federation of Organic Agriculture Movements
(IFOAM)
For food imported from outside Europe into the EU, the situation is slightly more complicated, but is still
subject to the same rigorous checks and guarantees. Imported produce must come from countries
recognised as applying equivalent standards and inspection procedures, or where national standards do
not exist, importers may apply on behalf of specific organic producers. They are then inspected by one of
the EU recognised certification bodies and thereafter subjected to annual inspections in the usual way.
Storage facilities for imported produce must be open to inspection at all times.
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UNIT: Resource management
Content
Elaboration
Biochemistry, preservation and
Genetic modification
processing
GENETIC MODIFICATION
Biotechnology has been used inn the production of foods, e.g. cheese, yoghurts, wine and bread for a long
time. However, the potential of biotechnology has been expanded enormously in its ability to genetically
modify organisms.
What is genetic modification?
Every organism has its own “blueprint” in its genes. Genetic modification means making changes to those
genes and in the way they are combined
Genes hold all the information about the characteristics of any living thing and are made up of DNA.
Genetic modification is carried out by either altering DNA or by inserting genetic material from one
living thing to another. Genes can be in introduced from one plant to another plant , from a plant to an
animal, from an animal to a plant or from an animal to another animal.
Genetic engineering could change agricultural and food processing industries. It could replace traditional
techniques of producing new animal and plant varieties. Whereas traditional breeding techniques
generally limited cross-breeding to animals or plants that were related, genetic engineering allows genes
from almost any form of life to be introduced into any other form of life. Organisms produced using these
techniques are called genetically modified organisms (GMO’s).
Genetic engineering includes a number of different techniques and is part of biotechnology. The most
important technique is termed “recombinant DNA technology”. This involves using an enzyme to cut the
DNA, inserting a second piece of DNA, often containing another gene from a different species, and
sticking them together. It is often referred to as “gene splicing” because it is similar in principal to
splicing pieces of tape together. By this method, the gene can be identified that will give the desired
effect, e.g. leanness in a farm animal or a pest resistance in a crop. The desired gene can then be inserted
into the plant or animal.
Other biotechnology techniques are:
 cloning where cell, organisms or genes are copied identically
 cell fusion where cell are joined
 fermentation in which micro-organisms are grown
All kind of organisms are being modified from bacteria. The aims of these changes are various, e.g.:
 reduce crop losses and food production costs
 alter the quality/flavour etc of the food
The importance of genetic modification
Genetic modification is widely predicted to be of great importance for economic development.. However,
much controversy exists over GM foods.
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Arguments for the genetic modification of foods
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fewer crops are lost as biotechnology as helped to reduce losses to our food supplies by using
genetic modification to make food crops resistant to disease and pests, e.g. a variety of maize
(corn), first grown in North America, is resistant to the corn borer insect which can destroy up to
20% of a crop. This achieved by altering the genetic make up of the plant so that it produces a new
protein which enables it to resist the insect.
Genes can be “switched” on or off to change the way a plant or animal develops. Herbicides are
used to kill weeds in fields of crops but they can also affect the crops that they are trying to
protect. By using genetic modification , a gene that is resistant to a specific herbicide can be
introduced into the crop plant so that when the field is sprayed with herbicide it will kill the weeds
but not affect the growth of the crops. An example of this is:
General purpose herbicides, which kill a wide range of growing Soya plants, can only be used
before the crop emerges from the soil. Once the crop is visible a more selective herbicides or weed
killers have to be used to combat weeds without damaging the crop. A variety of Soya has now
been modified to produce a protein which enables it to tolerate the general purpose herbicide.
Farmers can therefore control weeds amongst the growing Soya plants and choose the best time at
which to spray for maximum effect. It is claimed that, since less of this herbicide is need to
control the weeds compared with selective weed killers this technology offers a number of
benefits. Using fewer chemicals is considered better for the environment and also saves energy
because of the lower use of farm machinery. Additionally, better crop management leads to higher
yields and improved crop quality.
Altering the DNA of a plant can also make it more resistant to insects that attack it so increasing
crop yield
It may also be possible to further reduce the need to use pesticides on our crops without risking
poor harvests which can result from disease
In some common crop diseases, the crop continues to look healthy for some time after it is
infected. By the time the effects of the disease appear, it may have done significant damage. This
means the farmers often spray against diseases as a precaution and therefore may be applying
pesticides when there is no disease in their crops. By using diagnostic kits farmers could tell
whether their crops were infected and spray only when the disease was present. This would
ultimately benefit the consumer.
Genetic modification can enable plant breeders to develop new crops much more rapidly and with
more certainty that their new variety will do what they want. Conventional plant breeding is slow
and uncertain. Using two distantly related varieties in order to combine their best characteristics,
for example yield in one case and drought tolerance in the other, is a laborious and can take many
years to achieve some degree of success. If genes for drought tolerance can be identified, it might
be possible to snip them out of that variety and splice them into a high yielding one, significantly
speeding up the development of a new, useful variety of crop. Genetic modification makes it
possible to transfer genes between plants that do not usually breed with one another. This could
help breeders make useful changes to crop plants which are difficult to make at present; increase
levels of nutrients such as vitamins, better taste and texture, improving keeping quality and higher
resistance to pests and diseases are examples. Two other examples would be drought resistant
crops and nitrogen fixing crops. Drought resistance in plants would enable farmers to extend both
the growing season and a number of places where the crops could grow. This is not just a problem
in hotter countries as water availability is a limiting factor nearly everywhere plants are grown,
even in the UK. Plants need nitrogen to grow. Certain bacteria, found in the roots of peas and
beans can take nitrogen from the air and covert or “fix” it for use in plant growth. Scientists are
trying to use genetic modification so that these bacteria can live in the roots of cereal crops to
provide a ready-made source of fertiliser. This could be cheaper and more environmentally
friendly than the fertilisers used at present.
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Reduces losses in the supply of certain foods such as crops and so results in a constant supply of
food and stable pricing. This also means less waste for the retailers.
It can assist in the preservation of food by preventing the ripening of fruits and vegetables,
enabling a longer shelf life.
Longer lasting fruit and vegetables are possible. Genetic modification is used to slow down the
softening will provide fruits that last longer. Tomatoes with this characteristic are sold in the USA
A similar tomato grown in California and processed into tomato puree is on sale in the UK. Slow
ripening apples, raspberries and melons have also been produced and this benefit is likely to be
transferable to other fruit and vegetable crops including bananas, pineapples, sweet peppers,
peaches, nectarines, mangos and strawberries. The farmer in the third world will benefit from
crops.
It can increase the shelf-life of fresh food without the use of preservatives or additives. The is
advantageous for individuals with food intolerance
It can increase and improve the variety, flavour, texture, appearance and quality of food and so
increase consumer choice for example:
tomatoes which do not soften with age and have been engineered by turning off the softening gene
in the plant
potatoes have been given resistance to potato leaf roll virus, a major disease of this crop
the “ice-minus” bacterium, when applied to plants, competes with bacteria which promote the ice
formation on plants. Prevention of frost damage to potatoes and strawberries has resulted.
research is being conducted to genetically modify yeast in order to make bread rise quicker and
for use in the brewing industry
An improvement in quality, flavour and texture is possible in a wide variety of foods Many
consumers would like tastier tomatoes that did not bruise easily. Genetic modification of existing
varieties may be able to provide these improvements. Some of the best tasting potatoes are very
susceptible to disease whilst less flavoursome varieties are not.
It can produce foods in greater quantities, ensuring supply. This could also have the effect of
lowering the price
If combined with clear labelling it could allow consumers to make choices concerning the
purchase of such products
It can improve the nutritional value of foods to produce additional health benefits as follows
Lack of protein is a major cause of malnutrition in many countries of the world. Genetic
modification could be used to produce palatable, high protein crops, e.g. transferring the genetic
traits from the pea family to rice to produce a higher protein rice, hence improving its nutritional
value.
Modified fat foods, e.g. maize, soya, oilseed rape (canola) and other oil crops could be modified to
alter their saturated fat content. A potato with, a higher starch content would absorb less oil during
frying, providing an alternative method of producing lower fat products such as chips and crisps.
Higher vitamin content is possible for fruit and vegetables by modifying them to contain higher
levels of nutrients, e.g. vitamin C and E. Current research suggests these changes could offer some
protection against chronic diseases such as certain cancers and heart disease.
It can help to modify foods stuffs to meet consumer demand, e.g. leaner meat to help meet dietary
targets GMO’s have been used to produce growth hormones to make animals grow more quickly
and with leaner meat
Throughout the ages micro-organisms such as moulds and yeasts have been used to create many
different foods and drinks, e.g. moulds cause blue veins in Stilton and Gorgonzola cheese.
Genetically modified micro-organisms could offer many other benefits in food production, e.g. the
genetic formation for the chymosin enzyme in calf rennet (which cause the milk clotting reaction)
it has been identified and copied into yeast cell. These micro-organisms produce pure chymosin
which is identical to the animal enzyme. This means that cheese can now be made without using
animal rennet and is therefore acceptable to vegetarians.
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The genetic modification of certain seeds could provide raw materials for the pharmaceutical
industry. Bacteria synthesising human insulin is already being produced
Genetic modification in the animal world is much less developed than in the plant world. It is also
far more controversial. Subject to the controversy being resolved, modern biotechnology could
bring about a number of benefits, not just for mankind but for the animals also. Some examples of
possible benefits are given below:
Vaccines. Genetically modified medicines are being developed to protect cattle, pigs and poultry
against a variety of serious diseases.
Disease diagnosis. When vets take samples from sick animals it can take several days for them to
be analysed. In the future it could be possible for problems to be analysed on the spot with
diagnostic kits developed with biotechnology. This is obviously better for animal welfare.
Reduced stress. Some pigs suffer from porcine stress syndrome (PSS), a genetic disorder which
causes distress for the animal and has an effect on the quality of the meat. A simple DNA test has
been developed to identify those pigs affected so that breeders will be able to eliminate the
condition for the benefit of future generations.
Cloning. Cloning is a technique that has attracted much attention. At its simplest, cloning is what
happens when cells divide; producing more cells of the same type. This is how yeast, bacteria and
other simple living beings reproduce. In reproductive cloning, cells are taken from an animal and
cultured in the laboratory. The genetic material is then removed from just one of these cells and
placed into an egg which has had its genetic material removed. This egg is then planted without
fertilisation by sperm, into a surrogate mother, where it develops. Dolly the sheep, born in 1996,
was the first example of reproductive cloning. Using this technique, farmers could incorporate into
their herds the genetic make up of animals with the most desirable genetic traits, e.g. better yield
of milk, higher quality of meat etc, without having to breed from the donor animal itself.
However, reproductive cloning is not yet a technique that could have general applications in
farming. It is extremely expensive and although in theory a simple process, the physical
production of cloned animals is extremely difficult.
Genetic modification can also be used to increase the amount of food we get from animals, e.g.
faster growing larger fish (Tilapia) are being developed which could be particularly beneficial in
areas, such as parts of Africa, where protein are relatively limited. Some people see such
developments as a simply an extension of intensive farming methods designed to produce food
more efficiently. Others believe that such developments are inherently wrong
The concerns about genetic modification
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The reaction of consumers to genetically modified foods has been so adverse that the
supermarkets have refused to sell genetically modified food to consumers and many promote
products clearly as ”GM free”.
Opponents of genetic modification argue that we do not know enough about the science and that
altering the genes could lead to unforeseen problems in future generations.
Concern that food should be natural and not tampered with. Nobody really knows the effect that
GM foods will have on the body. Until at least 2009, no fresh GM produce has been approved for
sale or consumption in the UK. However many processed foods such as cooking sauces, biscuits
and food coatings will include a low level of GM ingredients if they use soya or maize as an
ingredient.
Fear of the unknown in terms of ensuring that such developments will not affect the quality and
safety of food
Muslims, Sikhs and Hindus have ethical, moral, religious and or cultural objections to consuming
organisms which contain copy genes from animals that are included in dietary restrictions for their
religion.
Strict vegetarians would object to using copy genes of animal origin in a plant
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In most cases consumers cannot tell that a food has been genetically modified by looking at the
label but the Co-op was the first food retailer to label their vegetarian cheese as being genetically
modified.
Legislation is needed to require genetically modified food to be clearly labelled. Currently food
made with GM crops has to be labelled as such. But food made using GM technology or products
from animals which have been given GM feed, do not need to be labelled. This means that
consumers could be unaware that they are eating GM ingredients.
Risks to the environment Consumers may be concerned about the environmental aspect of genetic
modification
A main concern of genetic engineering is that copy genes incorporated into a plant could “escape”
and transfer to another species with unwanted consequences. For example it is argued that
herbicide-tolerant crops could cross-pollinate with seeds and so become herbicide-tolerant
themselves. Thus “superweeds” could be created.
Some consumers and farmers are also concerned that making crops herbicide-tolerant might lead
to an increase in herbicide use, as the crops could withstand higher doses.
GMO’s could become the pollution of the future, i.e. biogenetic pollution. This is because the
organisms are alive and can reproduce, migrate and mutate. They would be growing, moving and
changing the form of pollution. Once released, they will often be impossible to recall. The Royal
Commission on Environmental Pollution report on the release of GMO’s recognised that some
organisms released to the environment will become established. Most may not be a hazard but
some could have serious environmental impacts.
Dangers include the threat of GMO’s spreading out of control and the possibility of genetic
transfer. This could lead to disruptive changes in the balance of some species.
Hybrids of crops and wild plants are common, thus it may be possible for genes to be introduced
into crops to be passed to the wild plant or to other non GM crops
Ethical and animal welfare issues
Some people, for whatever reason, are often worried by what they see as being “unnatural” and
“playing God”, manipulating the basic blueprint of life for human corporate ends. They question
the impulse to totally control nature for human ends.
They also worry about the “integrity of species” which is threatened by genetic engineering. In
order to patent a plant or animal it is necessary to claim that this is an “invention” which is
contrary to the view that plants and animals are part of nature.
Ethical concerns come into sharp focus when the effect of genetic engineering on the welfare of
animals is concerned.
Genetic engineering can have detrimental effects on animal welfare. The effects of inserting a
foreign gene into an animal are not always predictable. More work on genetically engineered
animals means more animal experiments. Therefore, the gains from such results have to be
weighed against the suffering that might be caused. During an American study, cows were
rejected with a milk-boosting hormone which caused swelling where the cows were injected and
metabolic stress.
Legislation affecting genetic modification
In the U.K., The Food Safety Act 1990 requires that all food must be fit for consumption, i.e. it must not
be injurious to health, be unfit or contaminated.
A specific set of safeguards controls the use of genetic modification in foods and food ingredients. These
foods are assessed by a number of committees of independent experts, most of which include consumer
representatives, i.e.
 The Advisory Committee on Novel Food Processes (ACNFP)
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The Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment
(COT)
The Food Advisory Committee (FAC)
The Regulations on Novel Foods and Novel Ingredients has been adopted. It came into force on 15 th May
1997, in order to harmonise procedures for the approval of all novel foods, including those produced
using modern biotechnology.
Special rules govern the labelling of all foods regarded as “novel”, including genetically modified foods.
According to EU Regulation on Novel Foods and Novel Ingredients, adopted in 1997, such foods must be
labelled if they are no longer equivalent to their conventional counter parts. This would include when they
have a different composition, use or nutritional value to the conventional food, i.e. fruit and vegetables
genetically modified to be higher in vitamins would be covered by this regulation.
Ethical concerns are also covered in the regulation, e.g. since vegetarians might object to incorporating
copy genes from animals into plants, such a plant would have to be labelled.
Applications to market GM plants, or their products for use as foodstuffs, are governed by The Novel
Food Regulations 1997. In the U.K., applications are submitted to DEFRAand are reviewed by other
government departments in conjunction with a third independent advisory committee, namely The
Advisory Committee on Novel Foods and Processes (ACNFP). Advice on food labelling is provided by
The Food Advisory Committee (FAC) and advice on toxicology from The Committee on Toxicity of
Chemical in Food, Consumer Products and the Environment (COT). Again if a member state is satisfied
that a marketing consent should be issued, the application is circulated to all Member States of the EU for
review. If a consent to market a GM food is issued it will therefore be valid across the EU. It is interesting
to note that several countries in the EU have unilaterally banned the import of specific GM products
already granted EU approval. This highlights the importance of harmonising the approach to this
technology across Europe.
Genetic modification of food is extremely controversial and will need considerable public debate to
determine if what is possible is acceptable.
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UNIT: Resource management
Content
Elaboration
Biochemistry, preservation and
Food Irradiation
processing
Definition
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Food irradiation is a process in which food products are exposed to a controlled amount of radiant
energy to kill harmful bacteria
 The foods are given small doses of radiation while packed in cartons on a conveyer belt. Radiation
is energy transmitted by electromagnetic waves or rays
 It is called ionising radiation and is similar to X-rays. Ionising radiation in the form of gamma
rays is very effective in killing micro organisms that would otherwise cause food borne disease
 When food is irradiated, energy passes through it and harmful bacteria are killed
Three different irradiation technologies exist
1. Gamma rays
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Gamma rays penetrate deeply – several feet- and can be used for preserving food. These rays are
emitted by a radio active isotope and heavy shielding for safety is needed
 Since gamma rays are highly penetrating they are able to pass through large containers of food
and thus food can be treated in bulk or in its final packaging.
2. Electron beams or e beams
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This is a stream of high energy electrons propelled out of an electron gun
Electron beams can penetrate food only up to a depth of 3cm so that the food to be treated must
be no thicker than that to be treated all the way through
 Two opposing beams can be used to treat food that is twice as thick
3. X – ray irradiation
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This is the newest technology for food irradiation and is a more powerful version of the machines
used in hospitals
X rays can pass through thick foods and require heavy shielding for safety
Consumer and other groups who monitor what is in the interests of the public still remain unconvinced of
the total safety and control of this technological development.
In Britain only certain types of irradiated food may be sold and the treatment must be carried out under
licence. The Food (Control of Irradiation) Regulations 1990 allow the irradiation of food from seven
groups in the UK. These groups are: fruit, vegetables, cereals, bulbs and tubers(potatoes, onions, garlic
etc), spices, fish and shellfish, and poultry.
By law food which has been irradiated must be labelled as such - the word “irradiated” has to be in a
prominent position on the food label. Unfortunately it is difficult to enforce these regulations and as yet
there is no reliable detection test which could monitor irradiated ingredients present in foods.
Labelling is compulsory throughout the EU but it appears labels are NOT appearing and thus the process
is not being controlled properly.
With so much importing of foods, legislation regarding different countries’ laws on irradiation is proving
difficult.
Arguments for the use of irradiation
 It has been known since the last century that living organisms can be damaged or killed by exposure
to certain forms of radiation, so the process is not new as many believe
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Traditional preservation methods e.g. drying, smoking, curing, addition of salt all change the way
the food looks or tastes – irradiation may overcome this as low levels of irradiation have no effect
on the texture or flavour of food.
Increasing demands and pressures on food production systems in recent years have led to large
sections of the food chain being contaminated, e.g. poultry frequently contaminated with
salmonella, as much as 75% in Europe. The contamination problems using conventional methods of
preservation have led scientists to try to improve these techniques, irradiation may be the answer
The idea of using radiation in this way was proposed in the 1930’s but it was too expensive and
specialised, development has been rather slow considering the possible benefits
International organisations such as the UN International Atomic Energy Agency promote its use
surely meaning it is an economic and viable method of preservation
The Worlds Health Organisation (WHO) has supported food irradiation as it sees it as a means of
reducing food borne disease
Many governments also have concerns about food borne disease and feel irradiation is an easy way
to provide safe food
Many governments have concerns about food shortage and irradiation may help with this problem
Some food producing countries such as Ghana and Brazil use decontamination methods which are
presently banned on health and safety grounds. Irradiation would help the food export problems
they are facing at the moment
It also has some specific advantages as a food treatment process in certain countries e.g. it is the
only process that can be used to treat raw food such as the Thai Nahm Sausage which consists of
raw pork. It is also the only way of treating sea foods that are traditionally eaten raw
Some food manufacturers support irradiation as it enables them to extend the shelf life and storage
periods of foods, this allows them to reduce waste and to deliver foods to the shops when it is
economically advantageous to do so. Irradiation inactivates enzymes and destroys spoilage microbes
Irradiation can make foods safe by killing or reducing harmful micro organisms such as salmonella,
listeria and campylobacter
It can delay or stop the ripening/decay process so foods can be stored for longer
It enables foods such as tropical fruits to be transported all over the world economically
Since 1961 exhaustive studies have been carried out regarding the safety of irradiated foods
Modern irradiation plants are completely automated and computer controlled so time and dose
levels can be strictly monitored and people are not exposed to radiation at any time
Irradiation plants have to be licensed and are subject to strict inspections
Storage and transport also licensed and subject to strict inspection control
Transportation and storage also subject to close monitoring by government controlled agencies
It can kill many insects and pests that infest foods such as grains, herbs and spices without
appearing to affect them
It can completely sterilise a food making it suitable for vulnerable patients in hospitals
Arguments against the use of irradiation
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Effect of radiation on foods varies, it only works successfully on a small number of foods
In some foods the dosage is critical, a slight overdose can cause foods to have an unpleasant taste
and texture
Cannot be used with all foods – causes undesirable flavour change in dairy products and causes
tissue softening in some fruits e.g. peaches
Despite the results from many studies, consumer experts are dissatisfied with some of the
conclusions and argue that key experiments have been ignored and that risk assessment methods are
suspect
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Concern that manufacturers may use irradiation to “clean up” foods that have decayed, which will
then enter the food chain.
Although there is no hard evidence to show irradiation dosage levels used are dangerous or have
harmful effects, very few of the studies have been done for any length of time on humans
Consumer experts fear that changes produced by irradiation may have subtle chemical effects, but
that the results may not show up for many years
Studies done have been on selected foods and little is known about the effects on pesticides and
other chemical residues on foods
Tests done have been in controlled circumstances, and effects may change when the process is
scaled up in a manufacturing environment
Consumer groups protested about the original irradiation label which gave it a positive image, they
one and the label in use is less biased
Although all irradiated foods must carry a label intimating the fact, it is difficult to enforce as it is
difficult to detect
No cheap and reliable detection test available
If irradiation is to be more widely adopted, a cheap and reliable detection system should be a matter
of priority for monitoring organisations to use
It can only be used on a very limited range of foods
It is relatively expensive so irradiated foods may cost more. If use becomes widespread then costs
may drop.
Vitamin E levels can be reduced by 25% and Vitamin C by 5-10%, many consumers are unaware
of this
At the dose given about 90% of micro organisms are killed so care still has to be taken with foods
otherwise the remaining organisms will multiply
It is ineffective against viruses
The more initial contamination there is in food, the higher doze of irradiation it would take to
eliminate possible pathogens and the greater the change in taste and quality of food.
It can create new substances called radiolytic products – there is controversy over whether such
products are dangerous
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Content
Biochemistry , preservation and
processing
Elaboration
Functional foods
The market for functional foods is growing as consumers become more health
conscious. In 2007, £613million was spent on them in the UK.
Definition
 A functional food is a food modified in such a way that:
- the amount of a beneficial component is increased or
- new beneficial components are added or
- harmful components are replaced/eliminated or
- a component is added to preserve the beneficial effects
 Functional foods contain ingredients which have health promoting properties over
and above their nutritional value.
 They are foods which have been altered to enhance or improve health though diet
and so reduce the incidence of illness or a particular disease
Functional foods include a very broad range of products – from foods generated for a
particular functional ingredient to staple foods which have been fortified with a
nutrient
It is generally accepted that ‘health promoting’ claims rather than disease prevention
or medical claims can be made. From a legislative point they are categorised as foods
not medicines. Currently in the UK there is no specific legislation covering claims for
functional foods. The relevant food law that identifies the boundaries for such claims
is embodied in the Food Safety Act 1990, which states that claims must not mislead
the consumer as to the nature or quality of a food, and the Food Labeling Regulations
1996 which allow declaration of the nutrient content of foods and claims such as ‘low
fat’ or ‘high fibre’ but prohibit medicinal claims such as ‘prevents’ or ‘treats’ or
‘cures’ a disease.
It is essential that robust science exists to underpin the claims being made. Ideally
this should include evidence that;
 the substance is absorbed or reaches its site of action
 that consumption of the food beneficially influences a physiological
function (e.g. blood pressure) or
 that it is recognised to impact on health (e.g. blood cholesterol) and,
ideally, that this effect has a direct impact on health status.
The level of consumption of the food that is required to achieve a beneficial effect on
health is also an important consideration. In particular, it should be possible to
achieve the required level of intake of the functional food or ingredient within normal
dietary patterns.
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Types of functional foods
1.Dairy Foods
Margarine and spreads
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Currently spreading fats constitute one of the biggest functional foods sector in the
UK
 Margarines and spreads eg Benecol, Flora pro-active can include the plant sterols
or stanols which have been shown to lower cholesterol and so help reduce the risk
of CHD
 Plant sterols and stanols are found naturally in fruit, vegetables, cereals and other
plant food in small amounts
 Taking 2- 3g of plant sterols or stanols daily has been shown to lower cholesterol.
In a typical days diet approximately 0.4g of plant sterols or stanols are consumed.
 The way that these work is by blocking the absorption of cholesterol from the
small intestine into the blood, therefore there is less cholesterol circulating in the
blood.
 Research claims that using such products has been shown to reduce LDL levels by
between 10-15 % in a few weeks but are most beneficial to those with high
cholesterol.
 Another area is the incorporation of mono or polyunsaturated fatty acids so
helping to reduce the risk of heart disease through altering cholesterol levels
 Some spreads provide Omega 3 fatty acids from oily fish which could help to
lower triglyceride fats in the blood but the amount of Omega 3 provided is usually
insignificant
 However they may be useful to some people who dislike oily fish and do not eat
the recommended amount weekly
 margarines/spreads/butter are fortified with Vit. D – assists absorption of calcium
 Bovine milk may be considered functional food due to presence of number of
immunomodulatory factors (conjugated linoleic acid may have potent anti-cancer and
immunomodulatory properties)
 Milks/ yoghurts have Omega 3 added and so could play a role in prevention of
CHD
Yoghurts / fermented milk products
Another large functional food area is that of yoghurts and fermented milk products
containing”friendly” bacteria.
Probiotics
 The history of probiotics, in the form of fermented milk products, goes back many
centuries. It is important that probiotics are strong enough to survive the acid in our
stomach and reach the large intestine where they than can colonise and so balance out
own gut bacteria. Probiotics are usually found in types of milk products/yogurts.
 probiotics are a ‘live microbial supplement’ which improves the intestinal
microbial balance so claiming to promote good intestinal health and act as an aid to
digestion.
 Evidence for the benefits of probiotics have been increasing in recent years - but
this is an area of debate - and include:
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Bifidobacteria may help fight a range of harmful and food poisoning bacteria,
including the potentially fatal E Coli 0157
Lactobacillus GG can be helpful in treating antibiotic-associated diarrhoea
Taking a course of antibiotics may cause major changes to the balance of
bacteria in the gut. Some studies have been undertaken that show probiotoc
will help protect people from getting diarrhoea when taking antibiotics.
Lactobacillus GG has also been shown effective at treating some cases of
traveller’s diarrhoea. Some studies have shown that probiotics can reduce the
chance of getting travellers diarrhoea, other studies have concluded they will
make no difference
Other studies have shown that Bifidobacteria and Strotococcus thermophilus,
both bacteria found in bio yoghurt, can prevent young children suffering from
diarrhoea in the first place or for shortened duration of diarrhoeal disease in
children
Other suggested benefits are inhibition of Helicobacter pylori, improved well
being among patients with Crohn’s disease, amelioration of symptoms in
adults and children with allergies and increased increased resistance to
respiratory infections in children
Studies have shown that probiotics may help to reduce the symptoms of
irritable bowel syndrome – severe diarrhoea or constipation, together with
bloating.
Bio yoghurt that contains Lactobacillus acidophilus can reduce the incidence
of vaginal infections, including thrush and bacterial vaginosis. Gut
colonisation of Candida albicans, the thrush causing organism, also decrease
significantly.
Supplementing with probiotics may also help reduce certain food allergies
according to some research. This may be because the bacteria reinforce the
barrier properties of the gut so that improperly digested compounds cannot
leak through
some trials have shown reduction in numbers who tested positive for the
bacteria called Clostridium perfringens
Probiotics only have a transient effect and regular daily consumption is needed
to bring about health benefits
Prebiotics
 Prebiotics are non digestible carbohydrates that selectively stimulate the growth
of beneficial bacteria in the colon.
 Eating prebiotics therefore causes more good gut bacteria to grow in our gut.
Sources of prebiotics in the diet include chicory, artichoke, leeks, onions, garlic ,
asparagus and banana
 Prebiotics are increasingly used in supplements and can have a more long lasting
effect as they encourage the growth of good bacteria such as Bifidobacteria already
present in the gut.
2.Fruit/ Vegetables
 The quality of tomatoes, cereals and other crops may be improved in the future by
using new genetic modified crops with a greater content of antioxidants, such as
natural flavonoids or other phenolic compounds. Because of the healthy profile of
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these antioxidants, which are believed to have a protective effect against
cardiovascular diseases and some forms of cancers, these new crops are considered as
functional foods.
 Flavonoids are naturally present in most fruits and vegetables. They are as good
antioxidants as carotenoids and vitamin E or C. These antioxidants are thought to
work by scavenging oxygen radicals, thus protecting against oxidative break down of
biopolymers such as DNA, proteins and lipids. Breakdown of DNA molecules in cells
is believed to be the most prominent mechanism for initiation of cancer cells and
oxidation of lipoproteins for increasing the risk of arteriosclerosis.
 Scientists are trying to identify key genes responsible for flavonoid production
and have started to grow the very first generation of tomato plants possibly high in
flavonoids. After completion of this work, they will intend to transfer their knowledge
to other crops, in particular cereals.
 US scientists have created purple tomatoes which have the anti-oxidant pigment
from red wine which is believed to prevent heart disease
 Biologically active plant chemicals now known as ‘phytochemicals’ can reduce
cancer risk
 Benefits of garlic added to foods include cancer chemopreventive, antibiotic,antihypertensive, cholesterol lowering properties
 Cranberry juice is recognized as helping in the treatment of urinary tract infections
and may be considered a functional food by some although no specific ingredient has
been added
3.Drinks
 Tea, especially green tea has beneficial effect on cancer risk and may be
considered by some to be a functional food.
 Drinks are a fast developing area of functional foods, for example some are
fortified with the anti oxidant vitamins A,C and E, some with calcium (and others
with herbal extracts)
 Some drinks claim to help overcome problems ranging from PMS to a lack of
energy
 Orange juice with added plant sterols to reduce cholesterol levels is available in
USA
4.Meat/Fish/Eggs
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During the last few years the scientific trend has been to improve the health
profile of traditional raw materials, e.g. meat, vegetable oil, dairy products and
grains, using traditional breeding or changed animal feeding.
Improvement of the health profile of beef - to produce a functional red steak. The
objective will be met through improvement of the fat composition by decreasing
saturated fatty acids and increasing conjugated fatty acids (CLA) as well as
omega-3 fatty acids (PUFA) with related health benefits
This tendency to improve food raw materials by traditional breeding, by genetic
modification, or by changing the feeding of animals is often seen: health improved
meat by improving the fatty acid profile of animal feed; health improved eggs by
adding fish oils to the chicken feed
Beef is a source of conjugated linoleic acid (CLA) which has been shown to
modulate tumour development
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More recently CLA has been investigated for its ability to change body
composition suggesting a role as a weight-reduction agent
Eggs with added Omega 3 – reduce cholesterol levels lowering risk of CHD
5.Cereals and Grains
 This is area where calcium and mineral fortification is strong – added to both
breakfast cereals and fortified cereal bars
 calcium- enrichment of foods, (and beverages) can allow up to 30 times the
amount of calcium present in an equivalent volume of milk to be incorporated –
could address issues such as osteoporosis and other calcium related diseases
 Oats are source of cholesterol-lowering soluble fiber b-glucan which can reduce
LDL cholesterol thereby reducing the risk of CHD
 Soy is thought to play preventative & therapeutic roles in cardiovascular disease
(CVD), cancer, osteoporosis and the alleviation of menopausal symptoms.
 Flaxseed consumption has been shown to reduce total and LDL cholesterol as well
as platelet aggregation
 Burgen is a, bread containing soya flour and linseeds which provide
phytoestrogens, natural substance which mimic the structure of the hormone
oestrogen. Phytoestrogens have been said to enhance oestrogen levels when
hormonal level are low (i.e. at the menopause) or to weaken the effects of
oestrogen when level are high. This action may protect against both hot flushes
and breast cancer.However quite a lot of this type of bread would have to be eaten
– at least 6 slices daily on a long term basis for any health benefit to be noticed.
 In USA ‘men’s bread’ is on sale containing soya isoflavones and Omega 3&6
 Breads with the prebiotic inulin added to it are on sale in Germany & Australia
 In Japan bread which offers cosmetic benefits is proving popular
 In Germany, bread enriched with L-Carnitine claims to boost energy particularly
among active people/ sports enthusiasts
 Development of bread fortified with soya isoflavones and trehalose to increase
calcium absorption is under way
 In UK Allied Bakers have launched a soy-enriched bread said to lower cholesterol
and improve heart health
Much research continues into the value of functional foods
So what are the positive arguments for the use of functional foods?
 When taken as part of a balanced diet and healthy lifestyle, functional foods have
the potential to improve health and reduce the risks of certain diseases
 Functional foods appeal to some consumers because they are convenient for
today’s lifestyle in bringing about health benefits quicker than would normally be the
case through eating conventionally healthy foods alone
 If family history points to heart disease, selecting a functional spreading fat which
could help control cholesterol within the family
 Allows consumers to take greater control of their health through food choices ,
knowing that some foods will provide specific health benefits
 Some foods eg breakfast cereals will provide a reasonably inexpensive source of
additional minerals and vitamins in the diet.
 Increased range now available so more choice for consumers and easier to obtain
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 For certain age groups functional foods may be beneficial.Inactivity, a poor
appetite and a low food intake can contribute to physical frailty in elderly people and
result in a poor nutritional and health status. One study undertaken with this age group
showed beneficial effects of nutrient enriched foods
Negative points
 Some consumers may come to over rely on functional foods for added health
benefits instead of learning about dietary advice and so consume foods that could
provide the same benefits. Functional foods should not be seen as alternative to a
varied/balanced diet
 Generally functional foods would have to be eaten in a fairly large quantity and on
a long term basis to effect any improvement on health so no immediate health
improvements occur
 In many cases, functional foods are more expensive and it is possible to get the
same beneficial ingredients more cheaply and naturally from a balanced diet
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Content
Biochemistry , preservation and
processing
Elaboration
Fast foods
- reasons for growth of the fast food
industry
- role of technology
- impact of fast food on food habits
- in a social context e.g. schools,
hospitals
Fast/Junk Foods
The consumption of fast or junk foods has increased hugely in recent years and with
this, an increased levels of obesity, particularly childhood obesity. Across Scotland as
a whole a third of twelve year olds were clinically overweight in 2006, thereby greatly
increasing their risk of heart disease, diabetes and cancer in later life
One in five children is now considered to be obese. While most childeren are still not
fat, not changing eating habits mean nearly all are at risk of becoming obese. Eating
200g of junk food, or a couple of burgers twice a week means an extra 59,808
calories a year which is enough to put on almost 8kg. A junk food diet can lead to a
range of conditions from heart disease to asthma or cancer. Type two diabetes,
usually only associated with adults and caused by poor diet, has become evident in
children for the first time during the past few years.
The govenrment has attempted to improve chldren’s diet in the folowing ways
- free fruit in primary schools
- healthier school meals and vending machines
- restrictions on advertising ‘junk food’ to children
- legislation to promote healthy eating and combat childhood obesity.
But still the consumption of fast/junk food continues. It is only in recent years that
these occasional treats have turned into daily meals, which is where the problems
start.
While campaigners want to see unhealthy foods banned in schools, others argue
there’s no such thing as junk food, only a junk diet.
What is fast food?
This term usually describes food that is quickly prepared, usually outwith the home
situation. A large percentage of these foods are high in fat, sugar and salt and they
have often been criticised for their lack of nutrition.
What is junk food ?
No one seems to know where the term ‘junk food’ originated, but it is generally
agreed that it defines any food with little or no nutrients and an excess of fat and
calories. Often this means heavily processed food, but it doesn’t necessarily exclude
meals made at home.
We all think we recognise junk food when we see it; a bag of crisps, a fizzy drink,
chocolate, but what about a prepacked sandwich? A take-away pizza? A home baked
cake?
The Food Standards Agency is currently working on defining junk food, using a
model that rates the nutrient, fat, sugar and salt content. The problem with the current
lack of definition is that without agreed terms of reference it is difficult to introduce
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guidelines on junk food promotion or to encourage manufacturers to introduce better
labelling.
Why is fast/junk food consumption rising?
Manufactures
Junk and fast foods are very tempting. Manufacturers have spent many years and
millions of pounds developing their products to make then as attractive as possible.
Some ingredients are chosen for their practical application- saturated fat for example,
is used because it is cheap and can withstand cooking at very high temperatures.
But most recipes include plenty of added extras for sensory appeal.
Artificial colourings are added to make products more attractive and appealing for
consumers.
Flavour enhancers such as monosodium glutamate either add smell to food that has
lost it during processing or enhance existing smells
Emulsifiers make products such as ice cream smooth
Artificial sweeteners such as aspartame or saccharin give a more intense sweetness
than sugar alone.
One reason why habits are proving so hard to change may be the addictive nature of
junk and fast foods. Research has shown that sugar can be addictive in some
circumstances and that eating junk food releases the same chemicals into the brain
which play a large part in drug or alcohol addiction.
A survey of school children by the Consumers’ Association in 2003 found that almost
half were deficient in zinc; this reduces the ability to taste and smell and so prompts
cravings for very sweet, salty or spicy food.
Reducing the amount of junk food in the diet is not easy. Advertising, marketing
schemes, financial incentives to purchase ‘super size’ portions all encourage
consumption of this kind of food. Recent research showed that typical menus in fast
food outlets contained 65 calories more per bite than an average British meal and
more than twice that of a recommended healthy diet.
Promotion
Television advertising - Despite attempts to limit the timing of unhealthy food
adverts to children, they will view about 5000 television adverts every year with about
¾ of them promoting high calorie, low nutrient foods.
The promotion and marketing of junk food is ingrained in everything we do - from
celebrity endorsements to sponsorship of sport and entertainment events: from
enticing displays at the supermarket to glossy features in magazines.
Lifestyle
Many mothers work and do not wish to spend the time preparing meals. A take away
or processed foods is seen as an easy option. Fast-food restaurents, are responding to a
real societal need – the inability of many families in which both parents work to find
time to cook for themselves.
Fast foods are seen as helpful to those who have limited time for shopping, preparing,
cooking and eating foods
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Many of the fast foods are designed to be eaten quickly and easily eaten from the
hand.
Due to the large number of fast food outlets there is a tremendous variety of foods on
offer. Often these appeal greatly to children due to the promotional gifts and foods
that are provided for children.
Many of the fast foods are reasonably priced, quickly and efficiently served and are of
consistent quality.
Double incomes means that there is more money available for buying processed
foods.
If children are not used to home cooked meals then they become more reliant on
processed/ takeaway foods and so his junk food habit is continued. Habits become
then too hard to break
Many teenagers know what they are eating is considered ”bad” and choose
deliberately these foods, rebelling against “healthy eating” advice. Fast foods can be
low in fruit and vegetable content and high in fat and salt.
Encouraging children to eat healthily is not as easy as simply banning junk food.
Junk food should be seen as a special treat, not a way of life. It may be that attitudes
need to change - it may not be what we eat but the quantities we eat that is the
problem.
In Britain the “no-time-to cook” culture continues to grow. “Grazing” has become a
way of eating – people eating what and when they felt like it. The belief is that
cooking can be abandoned and yet a healthy diet can still be eaten.
In 2005 the FSA admitted that the ever growing consumption of ready meals/fast
foods was having a bad effect on the nation’s health and the food industry was
encouraged into making its techno- food healthier
Today’s working woman can no longer expect everyone in the family to eat the same
meal as the “no cook” culture makes it possible for everyone to something different.
As a result shopping now has to take account of everyone’s likes and dislike. One
study found that 43% of mothers make up 3 different meals each night.
Role of Technology
The increased variety and use of fast food restaurants has been made possible by rapid
technological change. Such changes include:
 the availablity of transport for all families encourages eating out at fast food
outlets and the fact that many fast food restaurants operate a drive through
facility encourages the consumption of fast foods without even getting out of
the car to order
 preservation techniques such as freezing, cooking methods such as
microwaving, kitchen equipment for food preparation, equipment which
monitors and controls temperatures and cooking times have all contributed to
the incrrease in fast food consumption.
 The demand for standardised products have also resulted in changes to how
food is grown and distributed. The huge purchasing power of fast food
chains allow them to dictate their requirements with regard to the quality,
quantity of food grown. As a result food food chains can control a
considerable amount of the food
supply chain from production,
transportation, preparation to consumption.
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Computer technology has also contributed to the operation of fast food
outlets in the following ways
Pre programmed computerised cash registers make it quick to enter details,
price the order and the change to be given
Computers in some drive through restaurants allow customers to enter their
order so saving time and staff costs
Computers can control cooking operations, so eliminating humar error and
reducing the risk of food poisoning and encouraging consistency of product
standards
With the aid of technology the supply side has become easier. Standard
amounts are delivered, for example, raw ingredients arrived in measured
amounts, hamburgers are of uniform weight- this precise portion control alows
for standardisation of product, cost control and profitability
Food habits
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Fast foods have become a major feature in many peoples diets as opposed to
the occasional treat
Fast food targets family units. Families have difficulty fitting in all their
desired pursuits so fast foods meets the need for supplying food quickly.
Food is available on demand with many fast food outlets open late so
consumers do not have to stick to traditional meal times. This also encourages
grazing.
Fast food can also be cheap and easily accessible so cooking skills at home
become devalued
The fast food culture has also had an effect on traditional events such as
children’s birthday parties. Parents can now hand over responsibilty to fast
food restaurants to provide the food and additional entertainments such as
playground structures
Some school lunches are based on a mock fast food outlet such as a noodle
bar to encourage uptake. Since these must follow the guidelines of “Healthy
Eating in Schools” published buy the Scottish government then pupils are
assured of a healthy fast food option.
Fast food has come to play a dominant role in the provision of food but at the same
time has exerted a negative effect on health, especially that of children
So what are the implications for children’s health of a diet high in ‘junk food’.
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Many junk foods are of low nutritional value, children who have smaller
appetites require nutrient dense diets to ensure they receive a variety of
nutrients, a variety of deficiency diseases could result e.g. anaemia
If consumed only occasionally they may not be harmful to children if
examined in comparison to the child’s diet as a whole.
Many fast foods contain additives which could lead to hyperactivity
Fast foods may become addictive which encourages dependency on these
foods which could result in obesity in later life
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High salt levels in junk foods may increase blood pressure which could lead to
a stroke or heart attack. However individual sachets of seasoning may be
available to control salt intake.
High fat levels may contribute to overweight and lead to heart disease in later
life. Large portion sizes are also available which contain more calories.
High levels of sugar in these foods may contribute to obesity, tooth decay or
diabetes type 2 in later life. Many fast food outlet now offer sugar free drinks
Diets high in junk foods tend to be low in fruit and vegetables which may
mean –
low intake of NSP increases risk of bowel disorders such as constipation,
bowel cancer, diverticulitis and a low intake of anti-oxidant vitamins,
increases risk of CHD and some cancers
Many fast food outlets have a wide range of salads, fruit smoothies and
prepared fruits which help increase fruit and vegetables in line with dietary
targets and decreases the desire to snack on fatty/sugary junk foods
There is a link between nutrition and mental health. The sugar content of
fizzy drinks on offer in fast food outlets may raise blood sugar levels to the
level where children’s concentration and moods are affected.
Some fast food outlets and cafe chains, are piloting a Government scheme to display
the calories count on their menus to try to encourage people to make healthy choices
when they are eating out. The fat, sugar and salt contents are not displayed and this
has met with criticism. Some low calories snacks for example could be high in salt
and this would put consumers at risk of high blood pressure and heart disease
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Content
The Psychology of Food
Unit: Resource Management
Elaboration
 influence on food development
 influence on consumers
 consumer attitudes to food issues
 role/impact of the media
 consumer behaviour
Psychology of Food
Influence on food development and consumers
“What will I eat today?” How often have we asked ourselves that question? Before we
begin to answer this question we need to think a bit about what it means. Food choice
is influenced by many inter related factors. The key reason for eating is hunger and
satiety but what we choose to eat is not solely by physiological or nutritional needs.
The first thing to consider is that we have a choice of food. In affluent, developed
countries such as the UK there is an abundant variety of food. Most people make a
choice of food at least two or three times a day. All human beings require food to
survive. The availability of a wide choice of foods makes it easier to choose foods that
are nutritionally good for us. However the opposite of this is also true, having a wide
choice may encourage less healthy choices.
Factors which influence food development and consumer choice are shown below.
Human factors
Cultural influences,
psychological
influences, age, sex
Personal factors
Appetite emotions,
peer, pressure, family
pressure, personality,
expectation
Religious and Cultural factors
Beliefs, traditions, culture and race
Socio-economic factors
Social back ground and
status, disposable family
income, food costs
Factors that
Influence
Food
Preferences
Factors inherent in food
Flavour, texture, smell, quality,
temperature, appearance,
preparation, presentation
Educational factors
Health education,
hygiene education,
family influences,
nutrition education
External factors
Environment, seasonal
influences, media
advertising, social
pressures
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Physiological and psychological attributes
Most people, if asked why they eat would respond “to stay alive” or “because of
hunger”. Both of these are appropriate answers; the body has a physiological need for
food when deprived for even a short period of time a sensation of hunger of hunger is
experienced. This is a normal physiological response, designed to balance output and
storage of nutrients with their input from food
In addition, however, people eat for a number of reasons, namely:
 In the West eating is a matter of habit because food is usually widely
available, often at all hours of the day or night.
 There also socially accepted “mealtimes” when there is an expectation of
eating, regardless of hunger.
 There are social norms associated with eating, which define what behaviour is
and is not acceptable.
Food provides us with sensory satisfaction, it is usually pleasant to eat, and this aspect
of certain foods can induce people to eat when they have no physiological need do so.
We have a very personal relationship with food. It is something which we deliberately
take into our body, which becomes part of us. This can have very profound meanings
for some people, but for everyone it implies that there are psychological influences on
eating.
How do we appreciate food?
Eating is a very individualistic activity but generally there are basic reasons for eating
food namely:
 eating is a pleasure
 eating satisfies hunger
 we also appreciate the appearance of food
 we also appreciate the aroma of food
 we also appreciate the flavour of food
 we also appreciate the texture of food
These sensations are often inter-related.
Appearance is probably the first sensation that we judge food by; does it look fresh
and attractive. When we look at food we judge both colour and texture. Early
experiences of food condition us to relate certain colours with certain foods. If the
food is an unfamiliar colour we may reject it. The colour of food is good guide to its
freshness. Stale food looks dull. Certain colours are also associated with certain
flavours e.g. lemon-flavoured desserts are usually coloured yellow. Many
manufactured products contain permitted chemical colourings to make them look
attractive. We also judge the appearance of food by its aroma, texture and taste. All
these qualities are important in our appreciation of food. They are the qualities we
remember food by and recall to mind when choosing food. If the food looks attractive,
smells appetising and tastes good we are likely to want these foods
What motivates us to eat food?
Frequently we eat food to satisfy one or more of the following reasons:
 eating is a comfortable habit;
 it soothes inner tensions
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it soothes anxieties.
for a baby food is a symbol of love, comfort and security.
All our lives, having food available when we need it satisfies our need for security.
Being without food even for a short while will cause anxiety. For some people eating
food can provide an emotional outlet for loneliness, boredom and depression. At other
times, some people eat almost absent-mindedly whilst doing something else, such as
watching television or sports.
Food is sometimes used as a reward, for example to reward a child for good
behaviour. Adults also “reward” themselves with food and drink.
If food is used to often to satisfy these psychological needs, it is easy to eat too much.
Why do we buy the food we do?
Although our food may be controlled by the factors already described, it is also
affected by how foods are sold to us.
The convenience, hygienic conditions and the quality of food in local shops, markets
and supermarkets influence discriminating consumers in the choice of food
Research as shown that apart from the cost, the attributes that consumers look for
when buying food are:
 safety,
 sensory appeal,
 convenience,
 added value,
 authenticity,
 luxury,
 novelty,
 ethical production,
 functional, nutritional and compositional quality.
Of all these attributes the most important to consumers would seem to be
convenience, safety and sensory quality (although this is largely subjective and
dependent on individual preferences).
Consumer attitudes to food issues
One major shift in attitudes in the West is the move away from concern about price to
concern about quality and health. Market research shows that many people are trying
to eat healthily or believe that they are eating more healthily. Although we often have
misconceptions about what this means, e.g. the belief that polyunsaturated-rich
margarines have less fat than butter.
One National Health Survey concluded that there has been a shift in emphasis from
concern with the diet as a whole. People’s ratings of the healthiness of meat declined,
and the survey identified that 45% of women reported having cut down on
consumption. Healthiness rating for low-fat spreads increased over the five years,
those for butter and hard margarine declined. The main components of healthy food
are seen as vitamins, non starch polysaccharides, protein and freshness along with a
low amount of fat. Additives seem to be a declining concern.
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Another recent and fast-growing development is the concern with the environment
and the emergence of the “green consumer”. Organic and Fair Trade products are the
best established of the environmentally-friendly foods.
The genetic modification of foods has caused much debate.
Another major issue in the UK over the last few years is that of food safety. This has
been prompted by the scares associated with microbiological problems such as E coli,
salmonella and listeria, diseases in animals, chemical contamination through accidents
in production, and criminal tampering with packaged food. The public may feel that
they have little control over food safety issues like these and there is evidence to
suggest that we are complacent about our own personal susceptibility to diet-related
risks but safety will undoubtedly remain of basic importance to consumer confidence
in the food industry.
The role/impact of the media in food choice
Information is essential to choice. We need full, reliable relevant information about
the products about the products on supermarket shelves before we decide which ones
are right for us. Much of this information comes from the industry itself – in
television, radio, magazine and poster advertising, as well as food labels and
packages. How useful and reliable is this information? How much does it influence
our choice as consumers?
Every year around ten thousand new products are launched on to the market. Only on
in ten will survive for twelve months, while only one in twenty are still on the market
after two years. Only a portion of these new products will be heavily advertised with
lavish design budgets for the label and packaging, but it shows that consumers will
not accept uncritically any food product on the market. Even those new products that
are advertised on television will find a far from uncritical audience.
Studies have demonstrated convincingly that television viewers take the advertising as
a cue to make a cup of tea, going to the toilet, making a phone call. There appears to
be no comparable research for printed advertising or radio but some psychological
theories suggest that human beings do not normally pay much attention to detail. This
is borne out by research on food labelling, some of which indicates that consumers
rarely read ingredients lists or nutrition information or have difficulty interpreting the
information.. This is not to say that we as consumers ignore everything that appears
on a food label or advert .Evidence suggests that we take notice of simple messages,
especially those that confirm what we believe, or want to believe. In other words
advertising and labelling may not change our food choice, it might simply reassure us
that the choice we have made is the right one. However, can we really believe that the
food and soft drinks industry spend £500 million on TV advertising just to entertain
us? Or that food labels, for most of us, have no more significance than attractive
wrapping paper?
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Manufacturers persuade consumers to buy their products by:
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By apparently providing reliable relevant information about products so
consumers can decide for themselves
Information is provided from a variety of media – television, radio, internet, text
messages magazines, poster advertising, food labelling and advertising
The use of simple messages in adverts and food labels which reassure consumers
that they have made the correct choice eg Special K message of a slim female
Revamping packages design of foods eg milk is available in plastic bags to fit
into fridge jugs
Changing the image of foods eg soups are now heavily promoted as part of the
daily 400g required
Changing the name of an existing product to revamp the appeal of a product
Appealing to brand loyalty – consumers will stay with an existing brand name
they recognise and will choose new products based on brand loyalty
Adverts which appeal to snobbery – e.g. after dinner mints
Adverts which appeal to sentimentality
Sex appeal in adverts
Concerns over public health issues e.g. concern over additives has encouraged
manufacturers to jump on the band wagon for additive free food promotion on
packages
Emphasising the health and environmental benefits of organic foods
Ensuring adverts are aimed at the correct target group for example by timing of
television adverts. Manufacturers of high fat or sugar products will screen their
products during programmes which both adults and children watch
Promoting the convenience of food products in to-days busy lifestyles eg
microwave pasta sauces
Promoting the product as contributing to “healthy eating” given consumers’
concern over diet as a whole
Manufacturers rely on the “pester power” of children to persuade parents to buy
their food products. One survey on television advertising found that 85% of
children surveyed had asked a parent to buy them something they had seen
advertised on television. Two thirds of these children claimed they got what they
asked for and given the “pester power” of children this is not hard to believe.
Although parents feel that they ought to resist, the certainty that the purchase will
not be wasted is a powerful motivator especially for families on low incomes.
Special offers and special introductory offers by manufacturers eg buy one get one
free/ buy two get third free
Sampling in supermarkets to persuade purchase
Product placement within the supermarket to encourage sales eg sweets placed
near the checkout at child height often leads to additional purchase, popular
products placed at eye level
Use of celebrities to promote product e.g. sports people, super models, celebrity
chefs, soap stars etc.
Use of competitions, tokens for promotional gifts will also encourage purchase
and repurchase
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Another very effective weapon used by food manufacturers is to target young
children. Advertisers are well aware of children’s vulnerability and some target their
advertising and labelling at children quite deliberately.
How does the media in influence children’s food choices?
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The media is very powerful when it comes to influencing children’s food
choices and use a variety of techniques
Advertisers target young children by using well known characters to sell food
Free gifts with food, when promoted encourage pester power
Characters used to sell products e.g. spiderman spaghetti promoted to children
Promotional characters/films used to entice children into fast food outlets
The media use events such as football matches to advertise their products e.g.
posters round the pitch
Food adverts and labelling will make use of familiar cartoon characters which
are already familiar to children. The Simpson’s, Disney characters, are some
of the famous media “personalities” used to appeal to children and sell food
and soft drinks to children
Children’s affection and loyalty to these characters and the accompanying
songs and jingles will help to sell the products. Their enjoyment of song and
jingles sell products.
Children susceptible to brand name adverts so manufacturers take advantage
of this. Research has shown that children were three times more likely to
remember brand adverts than adults, needing to see less advertising than adults
to produce the same response
Product placement in films and TV programmes aimed at children
Adverts put pressure on children to pester parents into buying foods
Children’s magazines/comics are used to target particular children
Jingles, slogans and humour are used to attract their attention
Celebrities are used to create images round foods
Promotion of free schools equipment through purchase of foods can encourage
children to buy or parents to buy for children
Websites may promote foods to children
Multi global branding allows all channels from all over the world to bombard
children with the same messages
The media could be used in a positive way to encourage children to improve
their food choices
Unhealthy/junk foods are not allowed to be broadcast during the hours when
popular childrens programmes are on the TV. However children watch TV at
other hours of the day so may still see adverts for products high in fat, sugar
or both. These foods are precisely the ones which children should be eating
less frequently
However as controls are placed on advertising these foods, companies are
finding new ways to promote their products to children by using techniques
more suited to the technology of today such as
campaigns such as “text2win” competitions can be found printed on food
packaging.
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Companies create a branded presence in chat rooms by forming on line
communities in which children can eat and drink cyber versions of the junk
foods banned on the television
Junk food can also be placed in the background of many popular games
Advertising and labelling can therefore do more than reinforce existing spending
patterns. They can push at the boundaries of what consumers believe they want to eat.
This is not to say that the food industry alone can change the eating habits of a nation.
The recent trend towards healthier eating owes at least some debt to other forms of the
media such as:
 health and consumer groups
 food and drink programmes
 celebrities from popular soaps recommending a healthy diet
 celebrities from the world of sport or music
 food game shows like “Ready Steady Cook”
 cookery skills programmes like “Can’t Cook, Won’t Cook” and “Come Dine
with me”
For many of us choosing food that will enhance our diet and lifestyle can be a
daunting thought, because we don’t know what foods to choose and once we have
made our selection what to do with them or how to make them taste good. The media
has a contribution to make, by encouraging and enabling people to choose, prepare
and cook food, through lively and entertaining programmes. In this way the media can
play its part in helping to achieve current dietary targets.
Consumer Behaviour
Most people think that they have a good enough diet. We know about healthy eating
advice, but do not think that the messages contained in it imply that we ourselves
need to change. Although we are exposed to many messages about nutrition, diet and
health throughout the week some are more likely to persuade us than others. The
effectiveness of a message is determined by its wording.
Messages need to be:
 reasonable (we should understand the message and the reason for it)
 practical (we should find the change possible)
 compelling (we should want to do it)
We are likely to be influenced by advice that fits in with our existing beliefs and
behaviour rather than that which seems alien to us. What then are these beliefs and
behaviour patterns?
Culture
The major factors influencing the eating habits within a culture are the food available
and the foods acceptable to that culture. What and when we eat can reflect who we
are, the society we live in, our upbringing and how we perceive ourselves. Acquisition
of food habits is established at an early age from our parents. Our tastes and
preferences are often those handed down through generations of our family. However,
changes in eating habits can come from cultures. One example is the increase in
female employment which has led to a dramatic increase in the development and
consumption of convenience foods to cater for the lifestyle of the working mum.
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Availability
The increase in microwave and freezer ownership means that meals can be ready in
minutes. The growth in popularity of dishes from different cultures and the
introduction of new foods as a result of the advances in technology such as irradiated,
genetically engineered and cook-chill foods and modern packaging have all increased
the shelf life of foods and make a much wider choice easily available to consumers.
Cost
People can eat what they can afford. There is an increasing number of marketing
techniques used by food retailers that can be accessed by the prudent consumer to
make the budget for food go further. Techniques like buying in bulk, buying
supermarket own brands, taking advantage of special offers, e.g. three for the price of
two and using in-store loyalty cards to save points which can help reduce the food
bill. Unfortunately consumers see the food budget as one of the more flexible items in
the household expenditure. If income is small or decreased for some reason then food
cuts are made and the variety of food eaten becomes smaller with the result that the
diet can become monotonous.
Preference
Most people select food from a relatively small number of items which appear
frequently in their diet. New foods may be tried on occasions, often as a result of
advertising or promotion of the product in the media.
Moral
Special diets may be adopted for moral reasons and these can impose constraints on
individual food choice. The most prevalent in Britain in recent years is the vegetarian
diet.
Social
Different foods have different status, those that are more expensive or difficult to get,
such as caviar, grouse or venison, are perceived as being high status. On the other
hand food such as tripe has a low status because of its association with low income
diets. The status of food can change with time. In the last century wholemeal or
brown bread was considered coarse and fit only for the lower classes, whereas now it
is seen as a healthy and desirable in the diet and its status has increased considerably.
Gender
Food preferences of men and women can often differ. In some cultures most men eat
more meat and women eat more fruit and vegetables. Women tend to eat more foods
that are regarded as “healthy”. These differences may be associated with different
gender roles which still exist in society. Women remain in charge of food related
activities and therefore know more about food. Information about healthy diets tends
to be seen more by women as it features in women’s magazines or leaflets available in
supermarkets. Despite there greater knowledge decisions about what is eaten in the
home are shown to be dictated in many families by the men and children rather than
the women.
Security
For most of us food represents security from an early age, so much so at times that in
times of stress it can form an important support. Anxiety can provoke eating as a
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means of coping with tension, although in some people stress can result in a loss of
appetite and an inability to eat. Abnormal eating patterns have also been linked with
uncertainty about a person’s role or position in society. It has been suggested that both
obesity and anorexia might originate from confusion about the socially desirable body
image and that with which the individual feels psychologically at ease. In the case of
obesity it has been argued that overeating can occur as a deliberate attempt to add
substance to the body in an effort to cope with the demands of the world. Whereas,
with anorexia , the body size is deliberately reduced to escape from the pressures of
society on the adult female and return to the child shape.
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