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NEHRU ARTS AND SCIENCE COLLEGE
DEPARTMENT OF MICROBIOLOGY
MICROBIAL FOOD TECHNOLOGY
GROUP A - DIPLOMA IN QUALITY ASSURANCE IN MICROBIOLOGY DIPLOMA
PAPER II : MICROBIAL FOOD TECHNOLOGY
UNIT I
Food as a substrate – Incidence and types of microorganisms in food – Contamination
and Spoilage of Meat, Poultry, Sea foods, Vegetables, Fruits. Principles of food preservations:
Asepsis, Preservation by use of High temperature, Low temperature, Canning, Drying,
Radiation and Food additives.
UNIT II
Food poisoning – Food borne diseases- Bacterial and Non- Bacterial. Fermented foods Meat and fishery products – Country cured hams, Dry sausages,Katsuobushi. Fermented milk
products – Butter, Butter milk, Sour cream, Youghurt, Cheese, Kefir, Koumiss, Taette and
Tarhama.
UNIT III
In house Committee for quality assurance, Persons involved, Internal Microbial Quality
control Policy, Quality Check at every step from collection of raw materials till it reaches the
customer , Implementation of ISO standards and history, definitions, principles and use of
HACCP in Food Industry .
UNIT IV
Indicator organisms – Direct examination – culture techniques – enumeration methods –
plate – Viable & Total Count; Alternative methods – Dye reduction tests , electrical methods ,
ATP determination: Rapid methods, immunological methods – DNA / RNA methodology –
Laboratory accreditation.
UNIT V
Food laws and regulations
A. National – PFA Essential Commodités Act (FPO, MPO etc.)
B. International – Codex Alimentarius, ISO – 9000 series , ISO 22000 & BS 5750.
C. Regulatory Agencies – WTO
Consumer Protection Act - Relevance of Microbiological standards & criteria for food safety –
Sampling plans – Microbiological guidelines
Hygiene and sanitation in food sector
General Principles of Food Hygiene, GHP for commodities, equipment, work area and
personnel, cleaning and disinfect ion (Methods and agents commonly used in the hospitality
industry), Safety aspects of processing water (uses & standards) and Waste Water & Waste
disposal
References:
James. M. Jay, 1992, Modern food microbiology 4ed.
Frazier, W. C. and Westhoff D.C. 1989. Food Microbiology 8 ed.
Dubey. R.C. and Maheswari. D.K. A Textbook of Microbiology, 1999. 1 ed.
Water Analysis – A practical guide to Physico – Chemical & Microbiological water
examination and Quality assurance – W.Schneider, W.Fresenius & K.E. Quentin
Springer – Verlag Pub. Heidelberg.
Food Microbiology. 2 nd Edition – M.R.Adams & M.O.Moss – Panima Publishers.
UNIT-1
1.Define food microbiology.
The science that deals with the microorganisms involved in the spoilage, contamination, and preservation
of food.
2.Explain how food serves as a substrate for micro organisms. What are the
intrinsic factors of food that influence microbial growth?
Food and microorganisms
RELEVANCE OF MICROBIOLOGY
Food serves as a interacting medium between various living species because, it is a source of
nutrients for humans, animals as well as microorganisms. Food fit for human consumption is also a
medium for the growth and activity of microorganisms. Hence human food is always associated with a
variety of microorganisms. Since the primary function of microorganisms is self-perpetuation, they use
the human or animal food as a source of nutrients for their own growth and activity. Microbial activity in
a food can be beneficial in certain cases it leads to deterioration of the food and renders it unfit for human
consumption. Four aspects of microbial activity are of relevance to processing and preservation of food.
Fermented foods
Food chemicals from microorganisms
Food poisoning & food borne diseases &
Food spoilage.
Fermented foods:
Microorganisms can be used as processing aids in the production of fermented
foods. New and modified foods with better shelf stability; palatability, flavour and organoleptic properties
are produced by fermentation using specific microorganisms under controlled conditions.
Food chemicals from microorganisms:
A variety of food chemicals and additives produced by fermentation involving
select species of microorganisms In addition, microorganisms themselves may be used as food. The
biomass produced by fermentation can be harvested & used as a protein rich raw material for the
formulation of foods.
Food poisoning & food borne diseases:
Pathogenic microorganisms grow in the food utilizing the nutrients in the
food & produce toxins, which are detrimental to the health of the consumer when such food is consumed.
Food also serves as a vector or medium for certain pathogens that cause food infections & diseases.
Food spoilage:
The metabolic activity of various microorganisms not only utilizes the nutrients in food but also causes
the spoilage of food through undesirable enzymatic changes affecting the quality of the food. The
enzymatic changes include the formation of products, which contribute off-flavours & affect the
organoleptic, textural and keeping qualities of food.
BACTERIA, YEAST AND MOULD:
Introduction:
Thousands of genera and species of microorganisms have been identified and classified.
Several hundreds of these are associated in one way or other with food products. Many of them are of
industrial importance as they find use in the production of new foods and food chemicals by fermentation
and also in the preservation of food products. Microorganisms that are of importance in food
microbiology include bacteria, yeast and molds.
Bacteria:
Bacteria are unicellular organisms of aerobic or anaerobic nature and exhibit many
morphological forms. Three principal shapes have been well recognized, namely, spherical shapes of
cocci, rod shape of bacilli and spiral form of Spirilla and Vibrios.
All bacteria associated with food are small in size, typically a few micrometers long and
smaller in diameter. Bacteria form spores, which are seed like and far more resistant to heat, presence of
inhibitory chemicals and other adverse conditions during food processing. Most bacteria multiply best at
temperatures between 16 and 38C and are termed mesophilic. Psychrotropic or psychrophilic bacteria
can grow at low temperatures while thermophilic ones can grow at higher temperatures.
Morphological characteristics important in food bacteriology:
One of the first steps n the identification of bacteria in food is microscopic examination to ascertain the
shape, size, aggregation, structure and staining reactions of the bacteria present. The following
characteristics may be of special significance.
ENCAPSULATION:
The presence of capsules or slime may account for sliminess of ropiness of a food. In addition,
capsules serve to increase the resistance of bacteria to adverse conditions such as heat or chemicals. To
the organism they may serve as a source of reserved nutrient.
FORMATION OF ENDOSPORES:
Bacteria of the genera Bacillus, Clostridium, Desulfotomaculum, Sporolactobacillus and Sporosarcina
share the ability to form endospores. Of primary interest to the food microbiologists are the spore forming
species of the genera Bacillus and Clostridium. Endospores are formed at an intracellular site, are very
refractile, and are resistant to heat, ultraviolet light and desiccation.
Sporulation usually appears in the late logarithmic phase of growth, possibly because of nutrient depletion
or product accumulation. During this transition of vegetative cell to spore, the spore become refractile,
there is a massive uptake of Ca ions, and synthesis of dipicolinic acid(DPA) occurs, a compound
absent from vegetative cells. The acquisition of heat resistance by the forming spore is closely correlated
to the formation of DPA and the Ca 2+ uptake.
FORMATION OF CELL AGGREGATES:
It is characteristic of some bacteria to form long chains and of others to clump under certain
conditions. It is more difficult to kill all bacteria in intertwined chains or sizable clumps than to destroy
separate cells.
Cultural characteristics important in food bacteriology:
Bacterial growth in and on foods often is extensive enough to make the food unattractive in
appearance or otherwise objectionable. Pigmented bacteria cause discolorations on the surface of liquids,
growth may make surfaces slimy, or growth throughout the liquids may result in undesirable cloudiness
or sediment.
Physiological characteristics important in food bacteriology:
The bacteriologist is concerned with the growth and activity of bacteria and other
organisms in food and with the accompanying chemical changes. These changes include
hydrolysis of complex carbohydrates to simple ones, hydrolysis of proteins to polypeptides,
amino acids and ammonia or amines and hydrolysis of fats to glycerol and fatty acids.
O.R rxns, which are utilized by the bacteria to obtain energy from foods, yield such products as
organic acids, alcohols, aldehydes, ketones and gases. A knowledge of the factors that favour or inhibit
the growth and activity of bacteria is essential to an understanding of the principles of food preservation
and spoilage.
Genera of Bacteria important in food Bacteriology:
Bacteria that play significant roles in foods are often grouped on the basis of their activity in
foods without regard to their systemic classification.
Lactic acid bacteria ferment sugars to lactic acid and include species belonging to genera of
Leuconostoc, lactobacillus, streptococcus and pediococcus. Their activity is desirable in a variety of foods
such as sauerkraut and other pickled vegetables and dairy products for the production of flavour. They
cause spoilage of wines.
Acetic acid bacteria oxidize ethanol to acetic acid. Species of genera Acetobacter and
Gluconobacter are the most common. They are useful in vinegar manufacture but ate undesirable in
alcoholic beverages.
Butyric acid bacteria are mostly the spore forming anaerobes of the genus clostridium. They produce
butyric acid by fermenting sugars. Propionic acid bacteria produce propionic acid andbelong the genus
propioni bacterium.
Proteolytic bacteria include a heterogenus group of bacteria, which produce extracellular
proteases. Most species belonging to the genera of clostridium, Bacillus, pseudomonas and proteus.
Lipolytic bacteria are also a heterogeneous group of bacteria, which produce lipase. Organisms of
the genera pseudomones, Alcaligens, Staphylococcus, Serratia and Micrococcus are lipolytic.
Saccharolytic bacteria ydrilyze disaccharides and polysaccharides to sampler sygas. Ex: Bacillus
subtilis and Clostridium butyrium, which are also amylolytic.
Pectinolytic bacteria produce pectinases responsible for softening of plant tissues of loss of
getting power in various plant foods. Ex: Bacillus, Achromobacter, Aeromonas, Arthrobacter and
Flavobacterium are pectinolytic.
Thermiphylic and thermoduric bacteria are resistant to high temperature. Thermophilic bacteria
are resistant. Cause spoilage of low acid canned foods. Important species include Bacillus
steresthermiphilus and with thermosaccharoluticum. Thermiduric organisms survive heat treatment such
as pasteurization. Ex: Bacillus, clostridium,Micrococcus streptococcus Lactobacillus and Mycobacterium
are found in foods.
Psychrotrophic bacteria are able to survive and grow at refrigeration temperatures through their
optimum temperatures of growth in around 20 to 30oc. Ex: Pseudomonal, Achromobacter, Alcaligenes
and Flavobacterium are psychrotophic.
Halophilic bacteria include species of the genera Bacillus, Micrococcus, Vibrio, Moraxella,
Halobacterium organisms require certain minimal concentrations of dissolved Nacl for their growth and
survive at higher concentration of salt.
Osmophilic or saccharophilic bacteria grow in high concentrations of sugar. Ex: Leuconostoc
species.
Pigmented bacteria produce colours during their growth in foods. Ex: Flavobacterium (yellow to
orange), Serratia(red),Halococcus (red to orange) and Halobacterium (pink, red and orange),
Lactobacillus plantarum produces rust colour pigment discolouring cheese. Flavobacterium species
causes discolouration on the surface of meat and spoilage of Shell fish, poultry, eggs, butter and milk.
Slime or rope forming bacteria include Alcaligenes viscolactis, Enterobacter aerogenes and
Klebsiella oxytoca and some species of streptococcus and Lactobacillug plantarum causes ropiness or
ropiness in milk.
Gas forming bacteria include species of the genera of Leuconostic, Lactobacillus and
propionibacterium which produce carbon-di-oxide species of Eschericbis, Enterobacter proteus, bacillus
and Clostridium produce both carbon-di-oxide and hydrogen.
Off-flavour forming bacteria include those of genus streptomyces which produc undesirable
flavours and musty of earthy odour and taste. Manu species of pseudomonas produce a variety of
metabolites that affect the flavour of foods deleteriously.
Coliform bacteria ex. Escherichia coli and Enterobacter aerogenes. They cause spoilage of a
variety of foods producing off-flavours and sliminess.
Some of the important disease causing bacteria include the following:
Which batulinum produces a neutotoxin in canned meat products and causes the fatal disease
botulism.
Corynebacterium species includes the diphtheria organism which diptheriae.
Erwinia species are plant pathogens and damage plants and plant products causing bacterial soft
rot.
E. C oli species includes some serotypes which are pathogenic to humans.
Myco bacterium species includes the tubercle bacilli M. tuberculosis that causes tuberculosis
especially through raw milk from infected cows.
Salmonella species are enteric pathogens that grow in foods and cause food infection.
Shigella species is transported by foods and causes bacittary dysentery.
Staphylococcus species includes the important S.aureus which produces an enterotoxin causing
food poisoning.
Streptococcus species includes pathogenic S.agalartide which causes mastitis in cows and
S.pyogenes which causes septic sore throat, Scarlet fever and other diseases in humans.
Vibrio species is pathogenic to humans.
3.EXPLAIN ABOUT THE GENERAL CHARACTERISTICS, CLASSIFICATION AND
IMPORTANCE OF MOULDS, YEAST AND BACTERIA
GENERAL CHARACTERISTICS OF MOULDS IN FOOD MICROBIOLOGY.
1) Moulds are multicellular , filamentous fungi whose growth is recognized by its fuzzy
or cottony appearance.
2) They may be of white, coloured or dark or smoky.
3) The thallus or vegetative body is characteristic feature of moulds.
MORPHOLOGICAL CHARACTERISTICS:
I. HYPHAE AND MYCELIUM:
Hyphae
tubular, filamentous structure
Mycelium
interwined hyphae
Submerged hyphae growing within the food
Aerial hyphae
growing into air above the food
Sclerotia
tightly packed masses of modified hyphae,
often thick-walled.
More resistant to heat
Septate
cross wall dividing the hypha into cells
Aseptate
no cross walls
Apical growth
septate hyphae increase in length by means of
divisison of the
Tip cell
.
Intercalary growth
division of cells within hyphae
II. REPRODUCTIVE STRUCTURES OF PARTS:
Asexual spores
conidia
Arthroconidia
Sporangiospores
Chlamydospores
Sexual spores
Oospores
Zygospores
Ascospores
Basidiospores
III. CULTURAL CHARACTERISTICS:
Loose & fluffy, compact growth.
Upper surface may be velvety, dry, powdery, wet or gelatinous.
Pigmentation red, purple, yellow, brown, gray, black.
IV. PHYSIOLOGICAL CHARACTERISTICS:
Moisture requirements
– 14 to 15%
Temperature requirements
– mesophiles(25 to 30c)
– psychrophiles(-5 to -10c)
– thermophiles(above 40 to 60c)
Oxygen & pH requirements
-- aerobe, pH 2 to 8.5
Food requirements
-- from simple to complex
Inhibitors
-- fungicidal / mycostatic produced by certain moulds
CLASSIFICATION AND IDENTIFICATION OF MOULDS:
Kingdom : Myceteae
Identification:
1.
2.
3.
4.
5.
6.
Hyphae septate or aseptate.
Mycelium clear or dark.
Mycelium coloured or colourless.
Sexual spores oospores, zygospores or ascospores.
Asexual spores Sporangiospores, conidia or arthrospores (oidia)
Characteristics of the spore head:
a) Sporangia
size, colour, shape, location.
b) Spore heads bearing conidia single conidia, chains, budding conidia or masses, shape
and arrangement of sterigmata or phialides etc.,
7. Appearance of sporangiophores or conidiophores.
8. Microscopic appearance of asexual spores.
9. Presence of special structures stolons, rhizoids, footcell ,apophysis, chlamydospores, sclerotia
etc.
Classification:
Division
: Zygomycotina
Class
: Zygomycetes (non septate mycelium, reproduction by sporangiospores, rapid growth)
Order
: Mucorales
Family
: Mucoraceae
Genus
: Mucor
Rhizopus
Thamnidium
Division
: Ascomycotina
Class
: Pletomycetes(septate mycelium, ascospores(8))
Order
: Eurotiales
Family
: Trichocomaceae
Genus
:Byssochlamys
Eupenicillium
Emericella
Eurotium
Division
: Deuteromycotina
1. Class
: Coelomycetes
Genus
2. Class
Order
: Colletotrichum
: Hypomycetes (hyphae give rise to conidia )
: Hypomycetales
Family
: Moniliaceae
Genus
: Alternaria
Aspergillus
Aureobasidium ( Pullularia )
Botrytis
Cladosporium
Fusarium
Geotrichum
Helminthosporium
Monilia
Penicillium
Stachybotrys
Trichothecium
ORGANISM
CHARACTERISTICS
FOOD SPOILAGE
Non – septate hyphae.
Ripening of cheese.
Sporangium with sporangiospores.
Whiskers on beef & black spots (frozen mil
MUCOR:
M.racemosus
M.rouxii
No rhizoids / stolon.
RHIZOPUS:
R. stolonifer
Non septate hyphae.
(bread mold)
Stolons & rhizoids.
Spoilage of berries, fruits, vegetables, bre
apples.
Black spot on beef & frozen mutton.
Rhizoids are seen,
sporangiospores.
THAMNIDIUM
T. elegans
sporangium
with
(watery soft rot)
Sporangium with sporangiospores from Chill storaged meat – whiskers.
sporangiophore.
ASPERGILLUS
A. glaucus
A. repens
A. niger
Grows well in high sugar & salt conc.
Spoilage of grape jams & jellies.
Conidia are green, Ascospores are in asci.
Commercial production of citric, glucona
enzyme production
Spores are large, tightly packed, black,
brownish, black, purple brown & Conidia
are rough with pigment & are in chains.
A. flavus oryzae
Conidia are yellow to green in colour &
Black rot of peach, figs, citrus.
produce aflatoxin.
PENICILLIUM
P.expansum
Blue-green spared mold
P. digitatum
Olive/yellow-green conidia
Soft rot of fruit
P.camemberti
Grayish conidia
Soft root of Citrus
P.roqueforti
Bluish-green conidia
Ripening of camembert cheese
P. italicum
Blue green conidia
Ripening of blue cheese
Rotting of citrus fruit.
NEUROSPPORA
(Monilia)
Budding conidia with conidiophore
N. sitophila
Red bread mold – pink, loose textured grow
on bread.
Grows on sugarcane bagasse.
SPOROTRICHUM
S. carnis
Seen on chilled meat causing white spots.
Conidiophore with conidia
BOTRYTIS
B. cinerea
GEOTRICHUM
Disease in grapes – Gray mold of app
Conidiophore with swollen tips producing pears, citrus, grapes.
(Oospora/ Oidium)
G. candidum
(O.lactis) – Dairy mold
CLADOSPORIUM
C. herbarum
conidia septate mycelium
Sour rot of citrus, peaches.
Septate hyphae, Arthroconidia.
White to cream coloured growth.
Imparts flavour & aroma to cheese
Dairy cream, Meat & vegetables.
HELMINTHOSPORIUM
ALTERNARIA
A. citri
A. tenuis
A. brassicae
FUSARIUM
Black spot on the foods (beef), spoil butter.
Dark molds, septate hyphae.
Root on stone fruits, black rot of grapes.
Growth is velvety, Olive coloured to black,
Conidia are lemon shaped.
Plant ppathogen, Saprophytes on vegetables
TRICHOTHECIUM
T. roseum
-
AUREOBASIDIUM
(Pullularia)
BYSSOCHLAMYS
B. fulva
Soome sps produce mycotoxins, Rott
Septate mycelia, Brown, many celled citrus ( stem & black rot ) fruit, Black rots
conidia are in a chain on the conidiophore
stone fruits, apples, figs.
A. A
.
Grown on foods, Brown rot of citrus fruit
Pineapples, soft rot of figs.
Conidiophore produces conidia are of
macro & microconidia.
Septate hypphae with conidiophores & Pink rot of fruits.
produces mycotoxins.
Yeast like colonies
Asci with ascospores
Heat resistant
Blackk spot on beef, fruits & vegetables.
Spoilage of high acid canned foods.
Spoil canned & spoiled fruits.
4.Explain about the factors influencing the growth of micro-organisms.
FACTORS INFLUENCING THE GROWTH OF MICRO-ORGANISMS
Interactions between microorganisms and our foods are sometimes beneficial. Food is the
substrate, for the growth of microorganisms.
The type of microorganisms present and the environmental conditions are also important. The
food or substrate dictates what can grow and cannot grow.
The characteristics of the food or substrate one can make predictions about the microbial flora
that may develop.
The factor that favor or inhibit the growth of microorganisms is essential for the principles of
food spoilage and preservation.
The chief compositional factors of a food that influence microbial activity includes:
1. INTRINSIC FACTORS 1. pH
2.Moisture content
3. Oxidation –reduction potential (Eh)
4. Nutrient content
5.Antimicrobial constituents
6.Biological structures
2. EXTRINSIC FACTORS 1. Temperature
2. RH of the environment
3. Presence or concentration of gases in the environment
INTRINSIC FACTORS:
The parameters of plant and animal tissues that are inherent part of the tissues are
referred to as intrinsic factors.
1. Hydrogen ion concentration pH:
PH is one of the main factors affecting the growth of survival of microorganisms in
culture media
and in foods.
Example:- When pure water ionizes equal number of OH – and H+ are produced. Only a small
amount of water ionizes so that the concentration of these ions is very small, -1 X 10^-7 mol/L.
This can be summarized as follows:
H2O > OH- + H+
[H+] =[OH-] = 1 X 10^-7 mol/L
S solution containing equal number of H+ and OH – ions is neutral in reaction. A
solution containing more H+ ions than OH- ions is acid.
A solution containing more OH- than H+ ions is alkaline.
Example: A solution containing 10^-7 mole H+/L has a pH of 7 and is neutral.
A solution containing 10^-5 mole H+/L has a pH of 5 and is acid.
A solution containing 10^-8 mole H+/litre has a pH of 8 and is alkaline.
pH RANGES FOR MICRO-ORGANISMS:-
All microorganisms have a pH range in which they can grow and an optimum pH at
which they grow best. Saccharomyces cerevisiae, for example has a pH range of 2.35 – 8.6 with
an optimum at pH 4.5.
pH not only influence the growth rate of an organism within its pH range but is also has
an overall influence on the growth curve. This is illustrated in Fig. 6.10, which shows the effect
of pH on the growth curve. Notice that is pHs below the optimum:
EFFECT ON pH ON THE GROWTH RATE OF BACTERIA, YEAST, AND
MOULDS
growth rate decreases;
the maximum number of cells produces drops;
the length of the lag phase increases;
the length of the stationary phase shortens;
the death rate increases.
The temperature of the environment (incubation determines the pH minimum for an
organism
temperature in the laboratory), the nutrients that are available, the water activity and the presence
of inhibitors.
HOW DOES pH AFFECT MICROBIAL CELLS?
The internal pH of cells is maintained near to pH 7.0(this may be lower in some
organisms,
e.g., yeasts in which the cells pH has been measured at pH 5.8) and is the pH at which cells
metabolism works best.
Cells membranes are impermeable to H+ and OH- ions and, in addition, cells may have a
mechanism to pump out H+ ions.
When organisms are subjected to pHs outside their optimum but within the growth range, K+
and OH- ions affect the outer layers of the cells but not the internal pH. pHs above and below the
optimum for growth may affect the following:
The enzymes (permeases) need for the uptake of nutrients, including essential ions.
The production of extra cellular enzymes and their subsequent activity when released.
The mechanism of ATP production in the bacteria, which involves the cell membrane.
When the microbial cell is subjected to extreme pHs cell membranes become damages. H+
and OH- ions
can then leak into the cell where enzymes are denatured and nucleic acid molecules are
denatured, leading to cell death.
The effect of weak acids on microbial cells is temperature dependent. At concentrations
that inhibit growth and cause cell death, they have less effect as the temperature is lowered.
The order of activity of acids in terms of their antimicrobial effect is
Propionic > acetic > lactic > citric > phosphoric > hydrochloric.
pH and the growth of micro organisms in foods.
Foods are quire variable in terms of their pHs. Most are acidic ranging from the very
acidic to almost neural in reaction.
pH changes in foods due to the activity of micro-organisms. Milk sours as a result of latic acid
production by streptococi and lactrobacilli.
pHs of foods
Food
pH
Food
pH
Lemon
2.2-2.4
Meat
5.4-6.9
Strawberry
3.1-3.9
Halibut
5.6
Tomato
3.9-4.6
Lettuce
6.0
Pear
3.7-4.7
Cod
6.2-6.6
Banana
4.5-4.7
Milk
6.3-6.6
Carrot
5.0-6.0
Egg white
8.6-9.6
Potato
5.3-5.6
Strong inorganic acid is not often included in processed foods but hydrochloric and phosphoric
acids are used in the manufacture of carbonated and non-carbonated drinks. Coals, for example,
contain phosphoric acid.
pH ranges for food poisoning bacteria.
Organism
Minimum
Staph, aureus
4.0
Clostridium perfringens
5.5
Listeria monocytogenes
4.1
Samlonella spp
4.05
Vibro parahaemolyticus
4.8
Bacillus cereus
4.9
Campylobacter
4.9
Yersinia
4.6
Clostridium botulinum
4.2
Optimum
6.0-7.0
7.0
6.0 – 8.0
7.0
7.0
7.0
7.0
7.0-8.0
7.0
Maximum
9.8
8.0
9.6
9.0
11.0
9.3
9.0
9.0
9.0
2. Water activity
Water in the liquid state is essential for the existence of all living organisms. The cells of
living organisms have very high water content, i.e., more than 75%. The amount of water is
required to maintain the cell in an active state, and without liquid water living organisms,
including micro-organisms, will not grow or reproduced.
The ways in which water can become unavailable for growth are:
The water contains dissolved solute such as sugar or salts.
The water is crystallized as ice.
The water is present as water of crystallization or hydration.
The water is absorbed on to surface (matrix effects).
The amount of water available for microbial growth in terms of the water activity is the
amount of water
available in a food(or other materials) for microbial growth. More precisely:
Water activity
Vapour pressure of a substance or solution
= -----------------------------------------------------------Vapour pressure of water at the same temperature
The amount of water available to microorganisms in foods is normally indicated in terms
of water
Activity the water content is referred to as Equilibrium relative humidity (ERH) atmosphere
above a food at equilibrium with the food and is equal to the aw X 100%. Raoult’s law be used
to calculate the water activities.
THE WATER ACTIVITY OF FOODS:The water content of a food may be bare little relationship to its water activity. Fresh
meat, for example, has a water content of 75% but a water activity of 0.98. Muscle protein and
fat are the bulk of the solids present. These are not soluble in water, have little surface effect and
therefore do not contribute in any major way to the water activity. Water soluble materials
(glucose, amino acids, mineral salts and vitamins) are present in such small quantities that the
water activity of fresh meat is very high.
Foods may have low salt content but low water activity.
THE EFFECT OF WATER ACTIVITY ON MICRO-ORGANISMS:According to Raoult’s law:
n
aw
=
-----------N+n
Where n is the number of moles of solute and N the number of moles of solvent (water)
Another, more useful way of writing the equation is :
Xerophiles (Organism loving dry conditions). This term applied specifically to a group of
moulds (Xerophilic moulds) that can grow under very dry conditions, i.e., environments with
water activities as low as 0.61. They will not grow at water activities higher than about 0.96
and their optimum water activity is in the region of 0.9 – 0.85. These organisms can cause
spoilage of dries and salted fish, for example, the mould Xeromyces bisporus.
Halophiles (Salt-loving organisms).
a. Moderate halophiles are organisms that require sodium chloride but will grow only at
moderate concentrations, i.e. between 1 and 10%
Sodium ions are believed to be involved with the
transport mechanisms associated with the cell
membrane and the uptake of materials from the
environment.
For
example,
Vibrio
parahaemolyticus, 1-8% sodium chloride.
Effect of water activity on microorganisms:
b. Extreme halpohiles are organisms that will only grow at high sodium chloride
concentrations. Unlike most other bacteria, their cell walls are made of protein. Na + ions
appear to form ionic bonds that maintain the stability of these proteins and therefore the
structure of the wall. At high salt concentrations the cell wall is rigid and the cells take on a
cylindrical shape. As the concentration of Na+ in the environment decreases the cell shape
becomes more and more rounded until the cell wall disintegrates and the cells lyse. This
happens when the sodium chloride concentration in the environment reaches about 12%
Halobacterium Salinarum is associated with the spoilage of salted fish.
Halotolerant (haloduric) organisms: These organisms are able to grow at high sodium
chloride concentration but do not have a specific requirement for sodium chloride like the
halophiles.
Example:- Staphylococcus aureus can grow at sodium chloride concentrations as high as
20%(aw 0.83). Pediococcus halophilus can grow at 20% sodium chloride (aw 0.83)
Osmophilic yeasts:- ( yeasts loving high osmotic pressures) certain yeast that will grow where the water
activity is low. Example:- Saccharomyces rouxii (Zygosaccharomyces rouxii) will grow at sugar
concentration of 70% and above (aw 0.62).Saccharomyces rouxii can be responsible for the spoilage of
foods with high sugar concentrations, eg., soft-centered chocolates.
Osmotolerant organisms:-This terms is applied to organisms (mainly yeasts) that grow best at
high water activities but are also tolerant of high sugar concentration can grow at sugar
concentrations of 60% and above.
The effect of water activity on the growth curve is
Produces a slower growth rate;
Increases the length of the lag phase;
Causes the production of fewer cells when the stationary phase starts;
Causes cells to die more rapidly during the death phase.
Principle groups of foods and their water activity
S. No Aw valve
S. No
Aw valve
1
4
0.60-0.85
5
Below 0.60
2
Food involved
Fresh meat and fish
Fish fruits and vegetables
Milk and most beverages
0.98 and above Canned vegetables in brine
Canned fruits in light syrup
0.93-0.98
Evaporated milk
Tomato paste
Processed cheese
Bread
Canned cured meats
Fermented sausage
Canned fruits in heavy syrup
Gouda cheese
Food involved
Dried fruits
Flour
Cereals
Jams and jellies
Nuts
Some aged cheese
Intermediate moisture foods
Chocolate
Honey
Biscuits
Crackers
Potato chips
Dried eggs
Milk and vegetables
3
0.85-0.93
Dry or fermented sausage
Dried beef
Raw ham
Aged cheddar cheese
Sweetened condensed milk
Factors affecting the water activity of foods:
1. Kinds of solute:
Gel aW increases.
Sugar aW decreases
2. Nutritive value of food:
The better the medium for growth the lowest the limiting aw.
3. Temperature:
Temperature increases aW decreases
Temperature decreases aW increases
4. Oxygen supply:
Oxygen increases aW increases
Oxygen decreases aW decreases
5. pH:
pH decreases and aW increases survive
pH decreases and aW decreases organism donot survive.
6. Inhibitors:
Salt / sugar concentration inhibits aW.
Water tie up with ions so aW decreases.
Organism donot survive due to osmosis.
3.Oxidation – reduction potential:
Oxidation reduction potential or redox potential (OR or Eh) is a measure of
whether microbial/material has a tendency to gain electrons 9become reduced) or
lose electrons (become oxidized).
Microorganisms vary in their requirement for oxygen and their response to the
presence of oxygen in the environment.
1. Aerobic -Requires oxygen in order to generate cellular energy in the form
of ATP.
2. Anaerobic:(negative Eh values) - Generate cellular energy without
oxygen.
3. Obligate aerobe: (positive Eh value)
Requires oxygen for growth.
Energy production is by glycolysis, Kreb’s cycle.
Organic substrate oxidize to give CO2 and H2O (38 ATP).
Eg: Pseudomanas fluorescens, Penicillium sp., Pichia sp.,
Hansenula sp..
4. Microaerophiles :
Requires oxygen in minimum quantity eg. Campylobacter sp.1 – 10%,
Optimum – 6%
Oxygen concentration above 10% is toxic & kills the organism.
5. Facultative anaerobes:
Grows in the absence of oxygen. Energy production is by glycolysis,
Kreb’s cycle Eg. Saccharomyces cerevisiae produces 38 ATP. Eg. for food poisoning bacteria –
S. aureus, E.coli.
6. Obligate anaerobes:
Donot require oxygen eg. Clostridium botulinum, Cl. perfringens.
Redox of foods & Microbial growth:
The actual redox of food will depend on a number of factors :
1. the oxygen concentration in the environment of the food & its access to the food.
2. Density of the food structure, which affects the ability of oxygen in the environment
to penetrate.
3. Concentration & types of reducing substances in the food that resist changes in redox
towards the positive. Resistance to change in redox in a food is known as poising
capacity.
4. The way in which the food is processed.
5. The pH of food. For every unit decrease in pH the Eh increases +58mV.
The surface of solid foods in contact with the air will have a positive redox
whereas the interior may be negative.Eg. Carcass meat exterior - +ve200 mV [aerobes,
facultative anaerobes]
Interior - -ve150mV
Processing & mixing may alter the redox Eg. Milk during milking &
processing [microaerophiles]
Heating drives off oxygen & may increase quantity of reducing substances in
a food.
Eg. Canned foods negative redox (obligate anaerobes, facultative
anaerobes, oxygen independent organism).
Spoilage of canned foods Eg. Rhizopus sp. Byssochlamys fulva .
4. Nutrient content:
These are based on :
Foods for energy – Carbohydrates, Fats, Proteins, Esters, Alcohols, Peptides, Aminoacids,
organic acids.
Foods for growth _ Nitrogen containing foods.
Accessory food substances or vitamins.
5. Inhibitory substances & Biological structure:
Generally foods have some inhibitors:
Eg. Freshly drawn milk – Lactinins, Anticoliform factors.
Egg white – Lyzosyme.
Canberries – Benzoic acid
Propionibacterium – Propionic acid in Swiss cheese inhibits molds.
Streptococcus lactis – Nisin which inhibits lactate fermenting organism. Lactobacillus
inactivates nisin..
Yeast – Resistant to SO2
Heating lipids leads to autooxidation & concentrated sugar syrups during browning results
in production of furfural & hydroxy methyl furfural which are inhibitory to fermenting
organisms.
Food has certain shell / outer covering which prevents the entry of organisms called as
biological structures. Eg. Egg shell (vitelline) , Fish[scales], Fruits & vegetables[outer
skin].
EXTRINSIC FACTORS:
The extrinsic parameters of those properties of the storage environment that affect both the foods
and their microorganisms.
1. Temperature:-
Micro organisms are capable of active growth at temperatures well below freezing
to temperatures above
1000c.But each individual species has a far more restricted temperature range in which it can grow. The
range is determined largely by the influence that temperature has on cell membranes and enzymes and,
for a particular organisms, growth is restricted to those temperature at which its cellular enzymes and
membranes can function.
The relationship between growth rate and temperature for many microorganisms can be is
illustrated.
A is the minimum temperature, i.e., the temperature below which no growth occurs. At temperatures
below the minimum, the properties of cell membrane change so that they can no longer transport
materials into the cell.
B is the optimum temperature, i.e., the temperature at which the organisms grows at its fastest rate.
C is the maximum temperature, i.e., the temperature above which no growth occurs. At temperature
above the maximum enzymes become denatured and cease to catalyze essential cell reactions. These
temperatures also damage the proteins and lipids in the cell membrane, which cease to function
normally. So membrane collapse and the cell breakdown (thermal lysis).
The Cardinal temperature for Escherichia coli is
Minimum : 8oC
Optimum : 28oC
Maximum: 47oC
The minimum and maximum temperatures for growth normally quoted for an
organisms depend on the
Other factors that influence growth also operating at an optimum, e.g., pH and water activity. If these
environmental factors move way from the optimum then the minimum temperature for growth will
increase and the maximum temperature decrease. For example,The minimum growth temperature for the
food poisoning organism Staphylococcus aureus is 6.7oC and the maximum 48oC when the organism is
grown at the optimum ph of 7.0 and optimum water activity of 0.99. if the pH of the environment is
reduced to pH 5.0 and the water activity reduced by the addition of 3.0% sodium chloride to the growth
medium, then the organism will no longer grow at 48’C and the minimum temperature is increased to
30’C
On the basis of their cardinal temperatures for growth, microorganisms can be divided into five
groups:
Mesophiles
Obligate psychrophiles
Psychrotrophs
Thermophiles
Extreme thermophiles
Some microbiologist in factor, recognize a sixth category; facultative thermopiles, i.e., organisms that
have an optimum in the mesophilic zone but can grow well into the zone in which thermopiles grow
rapidly.
Groups of Microorganisms based on growth temperatures.
Group
Minimum0C
Optimum oC
Maximum oC
Obligate psychrophiles
-10
10-15
20
Pshychrotophy
-10
20-30
42
Mesophile
5
28-43
52
Thermophile
30
50-65
70
Extreme thermophile
65
80-90
100
Mesophiles (organisms adapted to growth in the middle Temperature Zone)
Adaptation man and other warm-blooded animals, and water in tropical and temperature climates.
An important characteristic of mesophiles is their lack of ability to growth at chill temperature (-1 to 5’C).
Example:- Bacteria, Yeasts & moulds
Many food spoilage organisms are also mesophilic.
Temperatures for toxin production by Staphylococcus aureus
Obligate psychrophiles(cold loving organisms)
Adaptations=> Arctic and Antartic Oceans, and land masses where temperatures are low throughout the
year(land below 0’C and oceans 1-5’C).
Example:-Flavobacterium
PSYCHROTROPHS(ORGANISMS FEEDING AT LOW TEMPERATURE)
Adaptation => water and soil in temperate climate(relatively high summer temperatures and low winter
temperatures). Minimum temperatures recorded for bacteria in this group are as low as –6.5 oC
(Pseudomonas fragii), - 10 oC(moulds) and –12.5 oC( the yeast Debariomyces hansenni).
Psychrotrophs are called facultive psychrophiles, referring to psychrophiles with the ability to
grow at relatively high temperatures.
Psychrotrophs are a very important group of organisms causing the spoilage of foods hed at chill
temperatures either on melting ice or in the refrigerator.
BACTERIA
YEAST
MOULDS
Pseudomonas
Candida
Penicillium
Alteromonas
Torulopsis
Aspergillus
Shewanella
Saccharomyces
Cladosporium
Bacillus
Debariomyces
Botrytis
Clostridium
Rhodotorula
Alternaria
Lactobacillus
Trichosporon.
In psychrotrophs, a higher amount of unsaturated fatty acid appears to maintain the plasma membrane in a
liquid and mobile state at temperature below 5 oC. This ensures that the membrane is biologically active
and capable of absorbing nutrients at low temperature.
THERMOPHILES(ORGANISMS LOVING HIGH TEMPERATURES)
Thermophiles are active in soils heated by sunlight compost heaps and silage, where the
temperature can reach as high as 70 0C. Thermophiles are responsible for the spontaneous combustion of
straw and hay. When the hay becomes damp, mesophiles grow; their metabolic processes generate heat
and, because of the high level of insulation in the stack, the temperature moves up into the thermophilic
zone .Growth of thermopiles takes over, increasing the temperature even further (up to 70 0C plus), when
chemical oxidation causes the stack to spontaneously combust.
Few thermophiles have any significance in foods. Bacillus stearothermophilus, Clostridium
thermosaccharolyticum and desulfotomaculum nigrificans(Clostridium nigrificans) are bacteria that cause
the spoilage of canned foods stored at elevated temperatures that allow thermophiles to grow.
Three factors seems to be involved:
The cell membrane of thermophiles are abnormally stable because of a high content of saturated fats.
Cells proteins, including enzymes, are unusually heat stable.
The ribosomes are heat stable.
What effect does temperature have on the lag phase of growth?
Temperature has a very important effect on the lag phase of growth. As the temperature
moves towards the minimum, not only dies growth rate decrease but the length of the lag phase
increases. This has important consequence in relation to the preservation of foods at chill
temperatures. The increase in storage life of foods held at chill temperature is associated not
only with a decrease in the growth rate of spoilage organisms but also in an extension of the lag
phase, when the population is not increasing in size. This increase in the length of the lag phase
may be as important as decrease in growth rate. The effect of temperature on length of the lag
phase and the rate of growth of psychrotroph is illustrated. The effect is not linear. A
psychrotroph having a lag phase of 1 hour at its optimum(25 0C) may have lag phase of 30 hours
at 5 oC and 60 hours at 0 oC. At temperatures very close to the minimum, lad phases may
become very long indeed; 414 days has been recorded for some organisms.
CHILLING INJURY:Microbial cells can be damages when they are cooled from ambient to chill temperatures,
a phenomenon known as chilling injury. There are two types of chilling injury.
Cold shock (Direct chilling injury) is associated with the process of cooling foods from
ambient temperature to chill temperature. The level of injury depends on the rate at which the
food is cooled. More cell damage occurs at slow rates of cooling than with fast rates. This
type of damage seems to be caused by changes in the structure of the cell membrane resulting
in the leakage of important cell metabolites, e.g., amino acids and ATP from the cell.
Actively growth cells are more susceptible than stationary phase cells.
Indirect chilling injury is associated with holding food at chill temperatures for prolonged
periods(several days) and is independent of the rate at which the food has been cooled, this
type of injury seems to be caused by lack of exchange of materials with the environment
leading to the accumulation of toxic metabolic products and/or the depletion of important cell
metabolites such as ATP resulting in cell starvation and, eventually, death.
Example:- Salmonella Sp.
How does Freezing cause cell injury and death?
Cells injury death caused by freezing depends on the cooling rate as follows:
Slow freezing.
When cooling is slow (freezing rates that occurs in domestic freezers) ice crystals from
outside the
cell. This causes an increase in the concentration of solute in the environment outside the cell
followed by plasmolysis, cell shrinkage and eventually death. There is no evidence hat any
mechanical damage is associated with the formation of ice crystals outside the cell. This type of
freezing damage is the most lethal.
Fast freezing:When cooling is fast (freezing rates used in the food industry) ice crystals form inside
cells. The
mechanism by which fast freezing causes damage is not well understood but possibilities are:
1. Mechanical damage to cell membranes and DND molecules cause by ice crystals;
2. An increase in the concentration of internal cell solutes leading to pH changes and an
increase in ionic strength which in turn damage cell protein and nucleic acids;
3. Formation of gas bubbles during thawing which cause mechanical damage to cell
membranes.
Ultra fast freezing:When cooling is ultra fast (freezing rate produced by plunging cells into liquid nitrogen at
–196’C)
water freezes to form a glass-like substance and the formation of damaging intracellular ice
crystals is reduced. Cell damage is minimized and most of the injury to cells appears to be
associated with thawing rather than the freezing process.
WHAT HAPPENS TO INJURED CELLS AFTER THAWING?
Cells that are injured but not killed can recover after thawing as long as there is an ample supply
of nutrients (damaged organisms often have growth factor requirements that are not normally evident) and
the environment does not contain inhibitors. Injured cells will recover quite readily in thawed foods.
Cells of food poisoning organisms that are injured rather than killed
2. RELATIVE HUMIDITY OF ENVIRONMENT :
The Rh of the storage environment is important both from the aw within foods & the
growth of microorganisms at the surfaces. When the aw of a food is set at 0.60, it is important
that this food be stored under conditions of Rh that do not allow the food to pick up moisture
from the air & thereby increase its own surface & subsurface aw to a point where microbial
growth can occur. When foods with low aw values are placed in environments of high Rh the
foods pick up moisture until equilibrium has been established.
Likewise, foods with a high aw lose moisture when placed in an environment of low Rh.
There is a relationship between Rh & temperature that should be borne in mind in selecting
proper storage of foods. In general, the higher the temperature is, the lower is the Rh &
viceversa.
Foods that undergo surface spoilage from moulds, yeasts & certain bacteria should be
stored under conditions of low Rh. Improperly wrapped meats such as whole chickens & beef
cuts tend to suffer surface in the refrigerator much before deep spoilage occurs, due to the
generally high Rh of the refrigerator & the fact that the meat spoilage flora is essentially aerobic
in nature, the changes of surface spoilage in certain foods by storing under low conditions of Rh,
it should be remembered that the food itself will lose moisture to the atmosphere under such
conditions & thereby become undesirable.
In selecting the proper environmental conditions of Rh, consideration must be given to
both the possibility of surface growth & the desirable quality to be maintained in the foods. By
altering the gaseous atmosphere, it is possible to retard surface spoilage without lowering Rh.
3. PRESENCE AND CONCENTRATION OF GASES IN THE ENVIRONMENT :
The storage of food in atmosphere containing increased amounts of CO2 upto about 10%
is referred to as controlled atmosphere [CA] or modified atmosphere [NA] storage. Usage of
this is employed in many countries with apples & pears. The concentration of CO2 generally
does not exceed 10% & is applied either from mechanical sources or by use of dry ice (solid
CO2).
CO2 has been shown to retard fungal rotting of fruits caused by a large variety of fungi.
The mechanism is unknown, but it acts as a competitive inhibitor of ethylene action.
Ethylene seems to act as a senescence factor in fruits, and its inhibition would have the
effect of maintaining a fruit in a better state of natural resistance to fungal invasion.
Ozone added to food storage environments has a preservative effect on certain foods.
At levels of several parts per million, this has been tried with several foods and found to
be effective against spoilage microorganisms.
It is a strong oxidizing agent; it should not be used on high lipid content foods, since it
would cause an increase in rancidity.
Both CO2 ozone are effective in retarding the surface spoilage of beef quarters under long
term storage.
5.Explain about contamination and spoilage of vegetables and fruits.
Introduction:
Spoiled food may be defined as food that has been damaged or injured so as to make it
undesirable for human use.
Food spoilage may be caused by insect damage, physical injury of various kinds such as
bruising and freezing, enzyme activity, or microorganisms.
It was estimated that 20 % of all fruits and vegetables harvested for human consumption
are lost through microbial spoilage by one or more of 250-market diseases.
Vegetables and fruits are fresh, dry, frozen, fermented, pasteurized or canned.
Contamination:
1. During harvesting => boxes, lugs, baskets, trucks, containers.
2. Soil
3. During transportation.
4. Mechanical damage => processing / trimming
5. Washing
preliminary soaking
distribute spoilage organisms.
a. Re-circulated or reused water may add micro organisms (washing with detergent/
germicidal solution reduce number of micro organisms).
Storage
containers / bins
Handling
Spray water and ice
growth of psychographs
Equipment
tables, blanches, press, filters, cloth, wooden surface.
General microbiological profile of harvested fruits and vegetables:
Vegetables:
Fruits:
Molds
Fusarium,
Alternaria,
Aureobasidium,
Penicillium,
Sclerotinia, Botrytis,
Rhizopus
Bacteria
Pseudomonas,
Alcaligenes
Erwinia
Anthomonas
Micrococci
Bacillus
Lactic acid bacteria
Corynebacterium.
Molds
Cladosporium
Phoma
Trichoderma
And above
organisms.
Bacteria
Pseudomonas,
Alcaligenes
Erwinia
Anthomonas
Micrococci
Bacillus
Lactic acid bacteria
Corynebacterium
Some microorganisms involved in the spoilage of fresh vegetables.
Bacteria
Microorganisms
Corynebacterium sepedonicum
Pseudomonas solanaceanum
Erwinia carotovora
Var.atroseptica
Streptomyces scabies
Vegetables
Potato
Potato
Potato
Symptom
Ring rot of tuber
Soft rot
Soft rot
Potato
Scab
Xanthomonas campestris
Fungi
Botrytis cinerea
Botrytis allii
Mycocentrospora acerina
Trichothecium roseum
Fusarium coeruleum
Aspergillus alliaceus
Brassicas
Black rot
Many
Onions
Carrots
Tomato
Cucurbits
Potato
Onion
Garlic
Grey mould
Neck rot
Liquorice rot
Pink rot
Dry rot
Black rot
Preservation of vegetables:
1. Asepsis
sanitization of equipments.
2. Removal of microbes
washing
chlorinated water, lye solution, and detergents.
3. Blanching / trimming / blanching
washing with hot water at 90-100c, inactivate food
enzymes and surface sterilization).
4. Heat
canning
5. Chilling
cold water i.e., refrigerator, vaccum cooling
Hydro cooling
cold H2O spray
Controlled atmosphere
Co2 / ozone. Eg potatoes
2.2 to 4.4 c
6. Freezing
survival of Micrococus, Achromobacter, Enterobacter, spores of
Clostridium and Bacillus.
7. Drying
explosive puffing
Small pieces of diced
partially dehydrated vegetables are placed in a closed rotating
chamber.
Heat applied, chamber is pressurized to a pre-determined level
Pressure is released instantaneously
Results internal loss of water
Increased porosity simplifies further drying
8. Preservative
rutabagas and turpips are parafinned.
o Lettuce, beets, spinach => ZnCo3 (to prevent mold).
o Controls Fusarium on potato => biphenyl vapours, Co2 and ozone used.
o Saueskraut / cauliflower / lemon => Nacl (2.25 to 2.5%)
High protein vegetable => Nacl (18.6 to 21.2%)
o Brine solution
o Salad freshers => sulfites
o Sugars
9. Irradiation
gamma radiation (insect) – potato, onion, garlic.
Preservation of fruits:
1. Asepsis
2. Removal of microbes => trimming
3. Use of heat => blanching, canning=> fruit juices
Low PH food => tomatoes, pears, pineapple.
High PH food => berries
4. Use of low T
Chilling => before chilling – propionate, borax, NaHCo3, biphenyl phenols, orthophenyl
phenols, hypochloride, So2, thiourea, thiobendazole, dibromotetra chloroethane added to avoid
shrinking and surface sterilization occurs.
5. Controlled atmosphere =>increases Co2 and decrease O2 content (Co2 storage) to prevent
molds).
6. Modified atmosphere => 100% N2 (N2 gas storage).
Co2 storage
apples, citrus, grapes, pears, plums,banana peaches
Ozone
2-3 ppm (strawberries, grapes, raspberries)
Ethylene
ripening (color Changes)
7. Freezing, drying
dehydration, sulfuring, blanching
8. Preservative
Na, o- phenyl, phenates, waxes, hypochlorites, biphenyl alkaline
Wrapper
I2, S, biphenyl, O – phenyl phenol + hexamine, ozone, So2.
Spoilage:
S.no Kinds of spoilage
Bacterial soft rot
1
(Soft, mushy bad odour)
2
3
Organism involved
Erwinia carotovora, Ps.marginatus, clostridium sp, Bacillus
sp.
Gray mold
Botrytis cinera (gray mycelium)
Rhizopus soft rot
R.stolonifer (Soft mushy black dot sporangia)
Anthracnose spots of
Collectotfichum lindemuthianum C.coccodes
4
leaves
5
Aiternaria rots
Alternaria tenuis (greenish – brown / black spots)
6
Blue mold rot
Penicillium digitatum (bluish green rot)
7
Downy mildew
Phytophthora, Bremia (white woody masses)
8
Watery soft rot
Sclerotinia sclerotium (vegetable)
9
Stem end rot
Diplodia, atternaria, Fusarium
10
Black mold rot
Asp,niger (Dark brown – black smut)
11
Black rot
Alternaria
12
Pink mold rot
Trichothecium roseum
13
Fusarium rot
Fusarium
14
Green mold rot
Cladosporium sp,Trichoderma sp
15
Brown rot
Sclerotinia sp
16
Sliminess / souring
Saprophytic bacteria in piled, wet, heating vegetables
Fungal spoilage of vegetables often results in water soaked, mushy areas, while fungal
rots of fleshy fruits such as apples, peaches frequently show brown or cream colored
areas in which mold mycelia are growing in the tissue below the skin and aerial hyphae
and spores may appear.
Some types of fungal spoilage appear as dry rots, where the infected area is dry and hard
and often discolored.
Rots of juicy fruits may result in leakage.
Molds are favoured due to deficiency in vitamin B.
Spoilage may be by;
Damage by mechanical means, plant pathogens or bad handling will favors
entrance.
Direct contact with moist soil – roots, tubers or bulbs. eg carrots, beets, radishes,
potatoes
Direct contact with surface soil. Eg: strawberries, cucumbers, and peppers.
Spoilage of fruit and vegetable juices:
1. Molds can grow on the surface of juices due to high moisture content, acidity, low in sugar.
2. The removal of solids from the juices by extraction and sieving raises the oxidation –
reduction potential and favors the growth of yeasts.
3. Most fruit juices are acid enough and have sufficient sugar to favors the growth of yeasts.
4.Deficiency of vitamin B discourages some bacteria.
Yeast /
5. Fruit juice
acetic acid
Alcohol
acetic acid
bacteria
Lactic acid bacteria
Lactic acid
6. Fruit juices undergo changes like;
a. LA fermentation of sugars
L.pastorianus
L.brevis
Leuonostoc mensenteroides (apple or pear juice)
Lactobacillus rabinosus
L.leichmanii
Microbacterium
b. Fermentation of organic acids of juice by LA bacteria
i.e, malic acid
lactic and succinic acids
quinic acid
dehydroshikimic acids
Citric acid
lactic and acetic acids
c. Slime production by L.mesenteroides, L.brevis and L.plantarum in apple juice and
L.plantarum and streptococci in grape juice.
7. Vegetable juices also contain a plentiful supply of accessory growth factors for
microorganisms and hence support the good growth of fastidious lactic acid bacteria.
8. Acid fermentation of raw vegetable juice by these and other acid forming bacteria causes
yeasts and molds to growth.
Mold
6.Explain about contamination and spoilage of eggs (poultry products)
spoilage
INTRODUCTION
The hen’s egg is an excellent example of a product that normally is well protected by its
intrinsic parameters.
Externally, a fresh egg has three structure, each of which is effective to some degree in
retarding the entry of microorganisms
I. The outer, waxy shell membrane
II. The shell
III. The inner shell membrane.
Internally, lysozyme is present in egg white
effective
against
gram-positive
bacteria.
CONTAMINATION:
1. Faecal.
2. Soil
3. Cage => shell => gram positive organisms, Salmonella, Streptococcus, Staphylococcus,
Micrococcus, Sarcina, Bacillus, Alcaligenes, Flavobacterium, Proteus, Serratia,
Aeromonas, molds, like Penicillium, Mucor.
PRESERVATION:
Eggs have some protective barrier;
a. Shell => cuticle / bloom (layer on shell, polished) if cuticle is removed then organism enters.
b. Shell membrane.
c. Albumin content => anti Proteolysis factor
PH 9 to 13 has lyzozyme
Any organism cannot survive
It is less dense
If org entered yolk means organism survive.
1. Asepsis => equipment sanitize, handling must be care and prevent contamination.
2. Removal of microbes => dry cleaning by sandblasting (washing with hot water)=>
removes bloom so not advisable.
* Mechanical egg washer;
1 % hypochlorite => to sanitize equipment.
2% acetic acid => very effective but reduce the size of shell => don’t store, use immediately as
bloom removal.
3. Use of heat => heating in water but avoid coagulation
i.e, 57.5 C => 800 sec
60 C => 320 sec
Heating in oil => 60c for 1 min
54.4 C for 30 min
Immersion in hot detergent
sanitizer 43.3 to 54.4 c
Thermo stabilization => slight coagulation of albumin.
Pasteurization => before this add Aluminium and salt to adjust PH
4. Use of low T
chilling
-1.7 to –0.55c with air circulation.
Rh is 70 to 8 (6 months)
For this eggs are selected by candling
This removes
a. Increased air sac
b. Infected eggs
c. Rotten eggs
Avoid moisture on the shell
Impregnation of eggshell with colorless, odorless, oil improves their quality.
Freezing
Rinse 200-500 ppm of Cl2 / I2
Frozen in 30- or –50lb tin can/ container
Add 5% sugar / salt/ glycerol before freezing
T –17.8 to –20.5 C
Drying
Removal of glucose prevent browning / maillard rxn
Removal of glucose may be by
1. Fermentation using Group.D stretococci, Enterobacter aerogenes or
Saccharomyces sp.
2. Using the enzyme glucose oxidase at 10c
Dryers used are
Spray dryer, Drum, Rotor, air, pan and tunnel dryer (60-71C)
Final moisture content => 5 to 1% was retained
Before drying pasteurization was carried out
After drying some organisms can act as contaminants from handlers, equipment
or through air and soil. They are Micrococci, str. facealis, coliforms, Salmonella,
spore formers and molds.
6. Use of preservative
waxing, oiling prevent O2 entry and maintain dry shell.
a. Materials used for dry packaging of eggs are salt, lime, and saw dust, sand and ashes.
b. Solution of sodium silicate for dipping.
c. Others => borates, permanganates, benzoates, salicylates, formats.
d. Washing of eggs with hot solution of germicides;
1. Hypo chlorites
2. Ly solution
3. Acids
4. Formalin
5. Quaternary ammonium compounds
6. Sealing of shells
solution of dimethylourea inhibits mold growth.
7. Mycostatic
sodium pentachlorophenate
8. Fumigation
gaseous ethylene oxide
9. Co2 + ozone (CA)
0.6 pp for clean eggs
1.5 ppm for dirty eggs
10. N2 storage.
11. – 0.55 C to 90% Rh
keeps eggs fresh for 8 months
12. Radiation
rays is used to prevent salmonella.
Spoilage:
1. General appearance.
2. Candling with transmitted light.
3. Broken egg
These are obvious for spoilage.
Defects in fresh egg:
Fresh eggs may have cracks, leaks, loss of bloom or glass, stained or dirty spots on
exterior as well as meat spots (blood clots), general bloodiness, or translucent spots in the yolk
when candled. From among these, any breaks in the shell or dirt on the egg will favors spoilage
on storage.
Changes during storage:
1. Microbial.
2. Non – microbial
1. Changes due to non- microbial agents:
1. Egg breakage.
2. Storage of old eggs results in protein denaturation.
3. Air sac increased.
2. Changes due to microbes:
Bacteria:
Green rots
Pseudomonas. fluorescens
1
Bright green colour, fruity / Swedish odour, not detected by
candling.
Colorless rots
Pseudomonas, Acinetobacter, Alcaligenes, coliforms.
2
Identified by candling, odour, white incurstation
Black rots
Proteus, Pseudomonas, Aeromonas, Pr.melanovegenes
3
Odour – H2S, putrid – muddy brown.
Pink rots
4
Pseudomonas
Pinkish ppt of yolk
Red rots
Serratia
5
Mild odour
Others
Enterobacter, alcaligenes, Escherichia, Flavobacterium,
6
Paracolobacterium
Fungi:
1. Pin spot molding:
1. Penicillium
yellow / blue / green spot
2. Cladosporium
dark green / black spot
3. Sporotrichum
pink spot
2. Superficial fungal spoilage:
*Fuzz / whiskers on shell during storage increase RH and no air circulation.
Fungal rotten
Penicillium, Cladosporium, Sporotrichum, Mucor, Thaminidium, Botrytis,
Alternaria.
3. Fungal red rot
Sporotrichum
4. Black rot
Cladosporium Achromobacter peolens
Pseudomonas. graveolen
Off flavour / musty odour
Pseudomonas. mucidolens
Bad odour (hay flavour)
Enterobacter cloacae (due to faecal contamination)
Cabbage water flavour (fishy flavour)
E.coli (due to faecal contamination).
7.Explain about contamination and spoilage of meat and meat product.
Introduction
Meat are the most perishable of the important foods, in which the chemical
composition of a typical adult mammalian muscle postmortem is presented.
Meat contain an abundance of all nutrient required for the growth of bacteria,
yeasts,and molds, and an adequate quantity of these constituents exist in fresh
meats in available form.
When spoiled meat products are examined, only a few of the many genera of
bacteria, molds ,or yeasts are found.
Almost all cases one or more genera are found to be characteristic of the spoilage
of a given type of meat product.
Frequently isolated microorganisms from meat
S. no
Product
Microorganisms isolated
1
Fresh and refrigerated meat
Bacteria
Acinetobacetr,
Moraxella
Pseudomonas
Aeromonas
Alcaligenes
Micrococcus
Molds
Cladosporium
Geotrichum
Sporotrichum
Mucor
Thamnidium
Yeasts
Candida
Torulopsis
Debaryomyces
Rhodotorula
2
Processed meat and cured meats
Bacteria
Lactobacillus and other lactic acid
bacteria.
Acinetobacter
Bacillus
Micrococcus
Serratia
Staphylococcus
Molds
Aspergillus
Pencillium
Rhizopus
Thamnidium
Yeast
Debaryomyces,Torula
Torulopsis,Trichosporon
candida
Contamination:
1. Lymph node (more number of micro organisms)
staphylococcus, streptococcus,
clostridium, salmonella
2. Flesh => good culture media as it contains protein, carbohydrate, lipids and vitamins.
3. Bleeding, handling, processing (enter – full circulation in body). Skimming, cutting,
knife.
4. Hide, hooves, hair
5.
6.
7.
8.
Soil, H2o, feed, manure, air, wood (slaughter house)
Intestinal organism coli forms, pathogenic fungi
Container, boxes
Meat surface – molds => Cladosporium, Sporotrichum, Geotrichum, Thamnidium,
Mucour, Penicillium.
9. Pseudomonas, Acinetobacter, Moraxella, Alcaligenes, Micro cocci, Flavobacterium,
Proteus
utensil contamination and salt tolerant
Found in meet products.
Characteristics of some Gram negatives associated with meat.
Gram negative
Not fermentative in OF medium
Oxidase –ve
Oxidase +ve
Motile
non motile
Pseudomonas
(formerly Moraxella)
Psychrobacter
(formerly Moraxella-like)
non motile
Acinetobacter
(Achromobacter)
Polar flagella
Not oxidase
in OF medium
Pseudomonas
Shewanella
(Alteromonas)
Oxidase
in OF medium
Pseudomonas
(Achromobacter
Preservation:
1. Asepsis:
Sanitation and H2o spray (before cutting) (utensils)
After cutting => hot H2O / detergents etc
2. Use of heat:
Canning
1. Commercially sterile (Self stable)=> 90C (11 lbs)
Process by increasing heat + Nacl / salt solution
2. Non self stable => stable for some pots (controlled atm) => heat process (65C with 22
lbs) – canning => refrigeration.
3. Use of low T:
Chilling:
o -1.4 to –2.2C
o Particularly maintained or else spoilage => beef => 30 days
o Pork, lamb, mutton => 1-2 weeks
o Real (calf meat) => shorter period
o (CA) + Addition of Co2 + ozone => increase Co2 / ozone leads to formation of
metmyoglobin, from myoglobin change the colour.
o Co2 10 to 30% for most meet
100% for bacon.
o ozone => 2.5 to 3 ppm (92% Rh) => 60 days maintained
o Chilling T => Pseudomonas, Acinetobacter, Moraxiella, Alcaligenes, Pediococcus
cerevisiae, (salt tolerant) => does not effect in curing.
Freezing:
-1.22 to –28.9 C (Pseudomonas, Moraxiella, Acinetobacter, Alcaligenes,
Micrococcus, Lactobacillus, Flavobacterium, Proteus).
4. Use of radiation:
i. UV [air]
surface of meat products
ii. rays
Depend meat products [Hard Meat – Increase rays]
iii. Increase rays – Pork
iv. 20 – 70 K-Grays – Normal
5. Drying:
Slice & Dried
Sodium nitrites – to dry the surface of meat
6. Freeze drying:
Meat Products generally are not freeze
Bleeding – removal of liquid to outside
Freeze burn – Change in colour – brown colour
Smoking
7. Curing:
Addition of Salt
NaCl – 15% salt (immerse meat)
o 24% salt [inject to meat)
Preservating & flavouring agent
o NaNo3
Colour Fixative [bright red] &
bacteriostatic
Increased concentration lead to brown colour
Sugar – adds flavour and serves as an energy source for nitrate –
reducing bacteria
4 Methods of introduction of curing agents into meat;
1. Dry
2. Pickle
3. Injection
4. Direct-Addition
Spoilage of Meat:
Oxidation occurs
Due to protease, lipases
Factors that influence the invasion of Microbes:
Load in the gut
Physiological condition of animal
Method of killing & bleeding
Rate of cooling
Aerobic condition influences the growth of bacteria, molds, yeast.
Factors that influence the growth of Microbes in Meat:
Kinds of no. of microbes
Physical properties of meat
Chemical properties of meat RH, PH [5.7 to 7.4 based on glycogen], chemical
composition of meat.
Availability of O2.
Temperature
Animal pathogen Salmonella, Camphylobacter, Pseudomonas
.
Spoilage under Aerobic Conditions:
1. Surface Slime:
Pseudomonas, Acinetobacter, Alcaligenes, Moraxella, Streptococcus, Leuconostoc,
Bacillus, Micrococcus, Lactobacillus.
2. Discolouration of Meat Pigment:
Autolysis also occur
Generally meat has heamoglobin; myoglobin due to oxidation produces metmyoglobin.
Meat
Hb, Myoglobin
Oxidation
Metmyoglobin
[Purplish Pink]
[Brown]
Blooms i.e., Red Green / Brown / Grey
Oxidizing compounds peroxidase, H2S results in spoilage.
Organisms involved may be Lactobacillus sp., Leuconostoc sp and other
heterofermentative organism
3. Changes in Fat:
Oxidation of unsaturated fats catalyzed by light & copper
Lipolytic organisms Pseudomonas, Achromobacter yeast
Oxidative rancidity (degradation of fat) results in tallowy odour
4. Phosphorescence:
Luminous bacteria
Photobacterium on the surface of meat
5. Discolouration of meat due to Bacterial Pigment:
Red spot
Serratia marcesens
Yellow
Micrococcus, Flavobacterium, Chromobacter
lividium
Greenish / Blue / Brownish Black
Proteus & others
6. Taint [Off flavour and odour]:
By yeast, Actinomycetes results in musty / earthy flavour
Yeasts produce acetate, formate, butyrate & propionate.
Aerobic Growth of Molds:
1. Stickness
2. Whiskers
Thamnidium Chaeotocladioides, T.elegans, Mucor, M.Mucida,
M.raceonogus, Rhizopus.
3. Black Spot
Cladosporium herbarum
4. White Spot
Sporotrichum Carmi
5. Green pathches P.expansum, P.oxalium, P.asperulum.
6. Decomposition of Fat
7. Taint
Musty flavour Thaminidium taint by Thaminidium sp.
Spoilage under Anaerobic Conditions:
1
Souring
Due to formate, acetate, propionate, lactate, succinate and fatty
acids.
By clostridium & other facultative anaerobes
After protein / fat lysis in aerobic leads to anaerobic condition
2
. Putrefaction
Anaerobic decomposition of protein leads to fowl smell and
results in production of H2S, mercaptans, indole, skatole, NH3,
amines
Caused by Clostridium and other facultative anaerobes
3
Taint
Bone Taint Souring / putrefaction next to bones
Spoilage of Different Kinds of Meat:
Fresh Meat:
1
Refrigeration
Pseudomonas, Actinetobacter, Moraxiella
2
Shine form
LA bacteria
3
Green discolouration
Lactobacillus, Leuconostoc
4
Souring
Streptococcus, Pediococcus, Brevibacterium
Fresh Beef:
1. Oxidation of mycoglobin & Hb.
2. White, green, black, greenish blue, yellow, brown, black spots.
3. Phosphorescence.
4. Shine formn bacteria, yeast
5. 10 C Meat
Pseudomonas
6. Whisters & Stickiness
Hamburger:
1
Putrefaction
at RT
2
Souring
Near freezing
3
Low Temperature Pseudomonas, Acinetobacter, Moraxella, Micrococcs,
Flavobacterium, Alcaligenes
4
High
Bacillus, Clostridium, E.coli, Micrococcus, Sarcina, Mucor,
Temperature
Lactobacillus, Leuconostoc, Penicillium, Alcaligenes,
Streptococci, Enterobacter, Proteus, Pseudomonas
Fresh Pork Sausage:
1
Souring
0 – 11 C
Lactobacillus,Micrococcus, Microbacterium
2
Colour spot
Molds
3
Dark spot
Alternaria [on refrigeration]
Cured Meat:
1
Cured meat
Salted Meat [NaCl / NaNo3]
2
Nitrite
Anaerobic NaNo3 favours LA bacteria, G+ve orgs, yeasts,
molds.
Dried Beef / Beef Hams:
Factor
H2O, Rh
1
Spongy
Bacillus
2
Sour
LA bacteria
3
. Red
Halobacterium salinarium,
4
Bacillus
Blue
Ps.syncyaneae, Penicillium
5
spinulosum, Rhodotorula.
. Gas in jars
Pseudomonas.fluorescens
6
Co2 in jars
Bacillus.
7
Sausage:
Slime
Moisture Micrococci & Yeasts
Decrease Fuzziness discolouration Molds
Sour
Leuconostoc , Lactobacillus
Swell package due to Co2 by heterfermentative LA bacteria.
Fading red colour to chalky grey
Bacteria
Greening of sausage
Leuconostoc, Lactobacillus
Production of Nitric oxide
Nitrate reducing bacteria.
Bacon:
Mold
Aspergillus, Alternaria, Mucor, Rhizopus, Penicillium
Ham:
* Souring
Alcaligenes, Bacillus, Pseudomonas, Lactobacillus, Proteus, Micrococci.
* Putrefaction Odour – Mercaptans, H2S, Amines, Indole.
Refrigerated Packed Meat:
* Due to packaging film & Co2 Pseudomonas, Acinetobacter, Moraxella
* Off flavour, shine & putrefaction.
8.Explain about contamination and spoilage of fish and seafood.
Introduction
Both salt-water and fresh water fish contain comparatively high levels of proteins and
other nitrogenous constituents.
The carbohydrate content of these fish is nil. While fat content varies from very low to
rather high value depending upon species.
Of particular importance in fresh flesh is the nature of the nitrogenous compounds. the
relative percentage of total –N and protein-N are presented from which it can be seen that
not all nitrogenous compounds in fish are in the form of proteins.
Among the non-protein nitrogen compounds are the free aminoacids, volatile nitrogen
bases such as ammonia and trimethylamine, creatine, taurine, the betaines, uric acid,
anserine, carnosine, and histamine.
(CH3) 3 N
O
Trimethylamine oxide
TMO reductase
(CH3) 3 N
Trimethylamine
Contamination:
1. Flora of fish depends on the waters in which they live.
2. Slime that covers the outer surface of fish is Pseudomonas, Aeromonas, Acinetobacter,
Moraxella, Alcaligenes, Micrococcus, Flavobacterium, Corynebacterium, Sarcina,
Serratia, Vibrio, and Bacillus.
3. Northern Waters
Psychrophiles
Tropical Waters
Mesophiles
Fresh Waters
Aeromonas, Lactobacillus, Brevibacterium, Alcaligenes,
Streptococcus.
4. Intestine of fish
Alcaligenes, Pseudomonas, Flavobacterium, Vibrio,
Bacillus, Clostridium, Escherichia.
1. Boats, boxes, bins, fish houses & fishers become heavily contaminated with three
bacteria & transfer them to fish during clearing.
2. Oysters, other shell fish
Pick up organisms from soil & water
Alcaligenes, Flavabacterium, Moraxella,
Acinetobacter, G+ve sp.
7. Shrimps, Crabs, Lobsters s
Bacillus, Micrococcus, Pseudomonas, Acinetobacter,
Moraxella, Flavobacterium, Alcaligenes, Proteus.
Fish and fish products:
Cooked, frozen products
Frozen fish
Dried fish
Vacuum packing
Fresh fish
Canned
Fermented fish
Marinades
Cured,smoked fish
Spoilage:
1. Autolysis
2. Oxdn or bacterial activity
3.Combination of these.
Fish flesh is perishable because of this rapid autolysis of fish enzymes and because of less
acid r x n of fish flesh that favours microbial growth.
Unsaturated fish oils are susceptible to oxdn.
Rigos mortis [stiffness of body after death] is hastened by struggling of the fish, lack of O 2,
warm T and is delayed by a low pH and adequate cooling of the fish.
Muscle glycogen
low pH
Lactic acid
Bacteria
Factors influencing kind and rate of spoilage:
1. Kind of Fish:
Flat fish spoil more rapidly than round fish.
Flat fish;
i. PH 5.5 of its flesh
ii. Oxidation of unsaturated fats
In certain fishes high in trimethylamine oxide soon yield appreciable amounts, of stalefishy trimethylamine.
2. Condition of Fish when caught:
Feedy fish [full of food when caught, more perishable than those with an empty intestinal
tract].
Fish that are exhausted result of struggling, lack of O2 excessive handling spoil more
rapidly.
3. Kind and Extent of Contamination of Fish Flesh with Bacteria:
Micro organisms may come from mud, H2O, handlers, exterior’s slime and intestinal
content of fish and to enter gills and pass through vascular system and invade the flesh and
entry to body cavity.
Greater the load of bacteria leads to easy spoilage of fish.
4. Temperature:Cooling 0 to –1 C
5. Use of an Antibiotic Ice / Dip
Evidences of Spoilage:
1. Fresh condition
Staleness
2. Colour of fish fade, dirty, yellow, brown discoloration
3. Shine on skin increases flaps & grills.
4. Eyes sink & shrink, pupil – Cloudy, Cornea – Opaque.
5. Gills turn to a light pink to grayish –yellow colour.
6. Softening Juice Extraction squeezed Identified by the finger.
7. Reddish – brown discoloration towards the tail due to oxidation of Hemoglobin.
8. By odors.
Normal, fresh, seaweedy odor Sticky sweet
Stale fishy (trimethylamine)
Ammoniacal
Final putrid (H2S) (Indole & other malodorous
compounds)
9. Fatty fishy & rancid odors.
Bacterial Spoilage:
1. Pseudomonas, Acinetobacter, Moraxella, Flavobacterium chilling.
2. Higher Temperature
Micrococcus, Bacillus.
3. atmospheric temperature
4. Bacteria on Surface
Escherichia, Proteus, Serratia, Sarcina, Clostridium.
Penetrate the flesh
N2 and glucose favour growth
[putrescine, cadaverine], lower fatty acids, CHO, H2 and other
Sulfides, mercaptans, indole.
Indicative of putrefaction
5. Musty odor / Muddy odor & taste Streptomyces
Discolouration:
6. Yellow to greenish yellow colours Ps.fluorescens
7. Yellow
Micrococci
8. Red / Pink colours
Sarcina, Micrococcus, Bacillus, Yeasts & molds.
9. Chocolate brown colour
Asporogenous yeast.
Spoilage of Special kinds of Fish & Sea Foods:
1. Salt fish
Salt tolerant / halophilic bacteria of Serratia,
Micrococcus, Bacillus, Alcaligenes, Pseudo.
2. Smoked fish
Molds
3. Marinated (sour pickled) fish
Molds (if acidity increases growth favours)
4. Japanese fish sausage
Souring by volatile acid production by
Bacilli or to putrefaction
5. Shell fish
As on fish spoilage
6. Chilled shrimp
Acinetobacter, Moraxella, Vibrio, Increases
in Pseudo, increases Flavobacterium,
Micrococcus, Bacillus
7. Crab meat
Chilling Pseudo, Acinetobacter,
Moraxella
High T Proteus
8. Ran lobsters
Pseu, Alcaligenes, Flavobacterium, Bacillus
9. Crabs and oysters
Vibrio, V.parachemolyticus
Oysters
Kept alive in shell at chilling Temperature.
Decompose rapidly when they are dead
Not only rich in protein but also in sugars
Near freezing spoilage occurs by Pseudomonas,Acinetobacter, Moraxella,
Flavobacterium, Micrococcus.
Spoilage called as sourcing (Proteolytic)
At high Temperature souring may be result of
Fermentation of sugars by coliforms, Streptococcus, Lactobacillus, yeast
to produce acids and a sour odor.
o Pink oysters Asporogenous yeast
o Others are Pseu, Serratia, Proteus, Clostridium growth occurs.
9.Explain about preservation of food using high temperatue.
principles of food preservation
1.Prevention or delay of microbial decomposition:
a) By keeping out microorganisms (asepsis).
b) By removal of microorganisms (filtration).
c) By hindering the growth and activity of microorganisms.
Eg; by low temperature, drying, anaerobic conditions, chemicals.
d) By killing the microorganisms.
Eg; by heat or radiation.
2. Prevention or delay of self-decomposition of food:
a. By destruction or inactivation of food enzyme. Eg; blanching.
b. By prevention or delay of purely chemical reactions. Eg; prevention of oxidation by
means of an antioxidant.
3.Prevention of damage because of insects, animals, mechanical causes etc.,
METHODS OF PRESERVATION:
1) Asepsis
2) Removal of microorganisms.
3) Maintenance of anaerobic conditions eg: in a sealed, evacuated container.
4) Use of high temperature.
5) Use of low temperature.
6) Drying.
7) Use of chemical preservative.
8) Irradiation.
9) Mechanical destruction of microorganisms grinding, high pressure.
ASEPSIS:
1) It refers Combination of two or more of the above methods.
2) to keeping out of microorganisms.
3) Inner tissues of healthy plants and animals are free of microorganisms, if they are present
leads to initiate the spoilage.
4) If there is protective covering the spoilage may be delayed or prevented. Eg; shells of nuts,
skins of fruits and vegetables, husks of ear corn, shells of egg, skin or membranes or fat on
meat or fish.
5) The food technologists are concerned with bioburden of microorganisms where they consider
both kinds and numbers of microorganisms in food.
6) Packaging of foods is a widely used application of asepsis. Eg; loose carton or wrapping.
7) Dairy industry concentration is made during milking process, handling.
8) Canning industry sealing can prevent contamination.
9) Meat packaging industry sanitary methods of slaughter, handling and processing reduce
the load and thus improve the keeping quality of meat or meat products. Intestinal flora must
be removed in animals.
REMOVAL OF MICROORGANISMS:
Removal of microorganisms may be by;
1) FILTRATION:
The liquid is filtered through a previously sterilized bacterioproof filter made of
sintered glass,
Diatomaceous earth, unglazed porcelain, membrane pads or similar material and the liquid is
forced through by positive or negative pressure. Eg; fruit juices, beer, soft drinks, wine and
water.
2) CENTRIFUGATION: (SEDIMENTATION)
It is not very effective. Sedimentation is used in the treatment of drinking water.
When centrifugation (clarification) is applied to milk, the main purpose is not to remove
bacteria but to take out other suspended materials, although centrifugation at high speeds
removes most of the spores.
3) WASHING:
It can act as surface sterilization. Eg; removal of soil microorganisms on the
surface is by washing in fruits, vegetables, (cabbage, cucumber) etc. Washing foods may be
dangerous if the water adds spoilage organisms or increases the moisture so that the growth
of spoilage organisms is encouraged.
4) TRIMMING:
Removal of the spoiled particles of a food or discarding spoiled samples is
important. Eg; Trimming the outer leaves of cabbage heads is recommended for the
manufacture of sauerkraut.
MAINTENANCE OF ANAEROBIC CONDITIONS:
Sealed packaged foods involve anaerobic conditions.
Canned foods headspace is filled by carbon dioxide or nitrogen where maintains
anaerobic conditions.
Anaerobic conditions prevent the growth of aerobes, aerobic spore formers.
PRESERVATION BY USE OF HIGH TEMPERATURE:
The killing of microorganism by heat is due to;
1. denaturation of proteins.
2. inactivation of enzymes.
3. control of metabolism.
FACTORS AFFECTING HEAT RESISTANCE:
1.TEMPERATURE-TIME RELATIONSHIP:
Time for killing cells or spores under a given set of conditions decreases as the
temperature is increased.
EFFECT OF TEMPERATURE OF HEATING ON TIME NEEDED TO KILLSPORES
OF FLAT SOUR BACTERIA:
TEMPERATURES
TDT IN
MINUTES
100
1200
105
600
110
160
115
70
120
19
125
07
130
03
135
01
2. INITIAL CONCENTRATION OF SPORES OR CELLS:
If spores and cells are in greater amount then there is need of increased heat treatment to
kill them.
EFFECT OF INITIAL NUMBERS OF SPORES ON TIME REQUIRED TO KILL
THEM:
INITIAL
TDT MIN. AT
CONCENTRATION OF 1200C
SPORES (NO./ML)
5000
14
5000
10
500
09
50
08
3.PREVIOUS HISTORY OF THE CELLS OR SPORES:
A) CULTURE MEDIUM:
Spores are more resistant in soil than medium.
Glucose increases the heat resistance.
If there is increased sugar concentration, in turn acid production is increased results in
decreased heat resistance.
Phosphate and magnesium said to decrease the resistance of bacterial spores.
B) TEMPERATURE OF INCUBATION:
As the temperature increases the resistance also increases. Eg; optimum temperaturehighly resistant. Minimum/Maximum temperature – highly sensitive.
C) PHASE OF GROWTH/AGE:
Log phase decreased heat resistant.
Lag and stationary phase increased heat resistant.
Immature spores less resistant than mature ones.
First week of storage (some spores) increase in resistant but later decrease in
resistant.
Dry spores harder to kill than moist spores.
4. CONCENTRATION OF SUBSTRATE:
A) MOISTURE CONTENT:
If moisture content is increases it is easy to sterilize while the dried food requires
increased temperature.Eg: spores of Bacillus subtilis in steam 10 min at 1200c, in glycerol
1700c for 30 min.
B) pH:
Neutral pH heat resistant (optimum)
Acid/alkali pH heat sensitive (min/max)
Cameron classified the foods into;
Low acid foods
pH (above 5.3),eg; ear ,corns, meat, fish, poultry, milk. Heat
resistant.
Medium acid foods
pH (between 5.3 and 4.5). Eg; spinach, beets, pumpkin.
Acid foods
pH (between 4.5 and 3.7). Eg; tomatoes,pears,pineapple.
High acid foods
pH (3.7 and below). Eg; berries,sauerkraut. Heat sensitive.
C) SUGARS/SALTS:
Due to increased concentration they can be easily destroyed.
Antiseptic or germicidal substances in the substrate aid heat in the
destruction of organisms.
H2O2 + heat is used to reduce the bacterial content and is the basis of
a process of milk.
HEAT RESISTANCE OF MICROORGANISM AND THEIR SPORES:
THERMAL DEATH TIME:
It is defined as the time it takes at a certain temperature to kill a stated
number of organisms under specified conditions. It is also referred to as the absolute thermal
death time to distinguish it from the majority thermal death time for killing most of the cells or
spores present.
THERMAL DEATH TIME:
Expressed as the rate of killing.
THERMAL DEATH POINT:
It is the temperature necessary to kill the entire organism in 10 minutes.
1. HEAT RESISTANCE OF YEASTS AND YEAST SPORES:
The resistance of yeasts and their spores to moist heat varies with the
species and even the strain, with the substrate in which they are heated.
1. Vegetative cell of ascospores 5 – 100c for destruction.
2. Spores of yeasts 600c for 10 –15 min but few are resistant.
3. No survival 1000c
4. Vegetative yeasts 50 –580c for 10 – 15 min.
5. Yeasts in bread (interior) 970c
2.. HEAT RESISTANCE OF MOLD AND MOLD SPORES:
Most molds and their spores are killed by;
1. Moist heat 600c in 5 – 10 min.
2. Asexual spore are more resistant than ordinary mycelia ( 600c) ie.,5 – 100c rise.
3. Aspergillus, Mucor, Penicillium are more resistant to heat.
4. Pasteurization kills spores and vegetative cells.
5. Sclerotia are difficult to kill by heat and they can survive at 90- 100 0c to spoil canned
fruits. They can be killed at 1000 min at 830c or 300 min at 850c.
6. Mold spores are resistant to dry heat.
3.HEAT RESISTANCE OF BACTERIA AND BACTERIAL SPORES:
1. Cocci are more resistant than rods.
2. Higher the optimal and maximal temperature of growth, greater the resistance to heat.
3. Capsule is difficult to kill.
4. Cells high in lipid content are harder to kill.
ORGANISM
T0 WITH TIME
Bacillus anthracis
1000c for 1.7 min
B.subtilis
1000c for 15-20 min
Cl.botulinum
1000c for 100 – 330 min
Cl.calidotolerance
1000c for 520 min
N.gonorrhoea
500c for 2- 3 min
Salmonella typhi
600c for 4.3 min
4.HEAT RESISTANCE OF ENZYMES:
1. Enzymes are inactivated at 79.40c for 10 min.
2. Pasteurization of milk can be checked by the presence of bovine
phosphatase. If this enzyme is observed then the process was not
carried out properly is understood.
10.write
a short notes on heat pentration in food substance.
Heat penetration:
The rate of penetration of heat into a food must be known in order to calculate the thermal
process necessary for its preservation. Every part of the food in a can must have to obtain the adequate
heat treatments to prevent spoilage may be by
1. Conduction – near the center (slow in food, rapid in metals)
2. Convection – heat passes from molecules to molecule.
When solid particles of food are suspended in a liquid, the particles heat by conduction and liquid
heats by convection.
Factors involved are:
1. The material of which the container is made.
2. The size and shape of the container.
3. Initial temperature of the food.
4. Retort temperature.
5. Consistency of can contents and size and shape of pieces.
a. Pieces that retain their identity.
b. Pieces that cook apart and become mushy or viscous.
c. Pieces that layer.
6. Rotation and agitation.
Methods involved:
a. Below 100C
b. At 100 C
c. Above 100 C
Pasteurization:
Pasteurization is a heat treatment that kills part but not all of the microorganisms present
and usually involves the application of temperature below 100C.
1. When more vigorous heat treatments might harm the quality of the product. E.g.: market milk.
2. To kill pathogens. E.g. market milk.
3. Main spoilage organisms are not very heat resistant.
E.g.: yeast in fruit juices.
4. When process requires additional chilling.
5. When competing organisms are to be killed, allowing desired fermentations, usually by added starter
organisms. E.g.: cheese making.
Preservative methods used to supplement pasteurization include;
1. Refrigeration.
2. Asepsis.
3. Maintenance of anaerobic conditions.
4. Addition of high concentration of sugar. E.g.: sweet condensed milk.
5. Addition of chemical preservative. E.g.: Pickles
1.Pasteurization time and temperature:
1. Milk Low temperature / long time
LTH / [holding]
62.8C for 30 min
High temperature short time
[HTST]
Ultra pasteurization
2. Ice cream mix
71.7C for 15 sec
137.8 C for 2 sec
LTH
71.7 C for 30 min
HTST
82.2 C for 16-20 sec
3. Grape wine
82 –85 C for 1 min
4. Fruit wine
62.8 C for 30 min
5. Beer
60 C for 15 min
6. Dried food
85 C for 30 –90 min
7. Bottled grade juice
76.6 C for 30 min
8. Bottled apple juice
60 C for 15 min
9. Bulk apple juice
85-87.8 C for 30-60 sec
10 Vinegar
65.6 C for 30 min
If pasteurization is not proper, then there is the presence of enzyme bovine phosphatase. Q fever
may be transmitted by milk.
2. Heating at 100 C:
1. Boiling
2. Blanching:
It is process where fresh vegetables before freezing or drying involves heating at about 100 C.
3. Baking:
The internal temperature of break, cake or other bakery products approaches but never reaches
100 C as long as moisture is present.
4. Simmering:
Simmering is gentle boiling with the temperature about 100 C.
5. Roasting:
In meat, the internal temperature reaches only about 60 C in rare beef, up to 80C in well-done
beef, 85 D in a pork roast.
6. Frying:
The outside of the food very hot, but the center ordinarily does not reach 100 C.
7. Cooking:
Cook implies a specific time and temperature for a thermal process.
8. Warming up:
A small increase in temperature up to heating to 100 C.
3.Heating above 100C:
Milk can be heated to temperatures up to 150C by use of steam infection or steam
infusion followed by flash evaporation of the condensed steam and rapid cooling. This is referred
to as UHT processes.
Canning / appertization:
Canning is defined as the preservation of foods in sealed containers and usually implies heat
treatment as the principal factor in the prevention of spoilage. Canning is the general term and is replaced
by hermetically sealed containers. Nicolas appert has been called the “Father of canning”.
Cans:
1. Initially glass vessels are used.
2. Later metals, plastics are used.
3. Corks were also used.
4. Recently cans are made of tin.
5. Enamels are coated on to flat sheets of plate before the manufacturer of cans to prevent or slow
discoloration or corrosion.
6. Aluminum parts are used for products that do not require high vacuums or high -T processing. E.g.:
Beer, foreign fruits, cheese.
7. Plastic flexible pouches or bags are used or plastic laminated with foil are employed mostly for
packaging frozen, dried or unprocessed foods. They are also used for foods that can be packaged hot,
although steam – pressure sterilization of foods in pouches has been accomplished.
E.g.: Jams, dried food products.
8. Tin cans were first used by Peter Durand.
Food has sulphur and tin has Fe combine to form FeS. Standard enamel is used for cans for
highly colored fruits and berries or for beets to prevent the fading of colour caused by tin plate. Enamels
are coated with Zno, so that the white ZnSo4 is formed instead of dark FeS, When low acid, sulfur –
bearing foods such as corn as canned and darkening of the interior of the can be avoided.
Meat, fat-containing foods should not be stored in cans containing Zno as they split the fats.
Special enamels may be employed for certain products. E.g.: milk, meat, wine, beer, soups and some fruit
juices.
Food => Remove the spoiled food by trimming => wash with sterile water (Surface sterilization)
Blanching / steam sterilization and cooling
Blanching sets the colour, softens the tissues and kills some microbes
Add sugar / salt solution
Evacuated before sealing
Usually by heating headspace / unfilled part of the container by mechanical means.
Canned food (commercially sterile or practically sterile or bacterially inactive)
Other methods:
1. HTST
2. HC7 / Heat cool fill method.
3. Steam pressure E.g. Tomato juice may be presterilised at 121 C to 132 C to kill spores of B. coagulants
before canning and then the sealed cans of juice are given a milder heating.
4. SC / Sterilizing and closing.
5. PFC / Pressure filler cooker.
6. Dehydrocanning.
E.g.: apple slices, food is dried to about half its original weight before canning.
7. Direct gas flame.
8. Steam injection.
9. Flash 18
10. Addition of preservation / irradiation / chemicals.
Pressurized packaged foods / aerosols:
They are packed under pressure of a propellant gas, usually
1. Co2 => inhibits many microbes => aerobic bacteria and molds not lactic acid bacteria. E.g. B.
coagulans, Strep. facelis or yeasts.
2. N2 => inhibit anaerobes not aerobes.
3. Nitrous oxide = represses fungi.
E.g.: whipped cream, beverage toppings, salad dressings, oils, and jellies.
Cooling process:
The cans may be cooled by
1. Immersion in cold water.
2. Spray of water.
3. Large cans are cooled slowly to avoid strain or breakage.
4. By means of air currents.
Canning in the home:
1. Boiling
2. Steam pressure
3. Micro over
4. Cold pack method => not for vegetables and meats.
11.write short notes on preservation of food using low temperatue?
preservation by use of low temperature
Low temperature preservation is used commonly to retard chemical reactions and action of food
enzymes. Therefore there is a gradual decrease in the activity of microorganism and also the spoilage of
food.
The growth and metabolic reaction of microorganisms depend upon the enzymes and the rate of
enzyme reactions directly affected by temperature.
During low temperature metabolic activity is arrested. Food enzymes are inactivated.
Low temperature methods:
1. Chilling / cold storage.
2. Freezing / frozen storage.
3. Freeze during / Lyophilization.
Chilling / cold storage:
1. It involves cooling by ice or by mechanical refrigeration.
2. It is used to prevent the growth and reduce the metabolic activity of microbe.
3. Temperature is 0 –15C.
4. Ice crystals can be used to store fish, meat during transportation.
5. Use of mechanical refrigerator. E.g. food storage in industry.
Factors:
1. Temperature:
Lower the temperature of storage, the greater the cost. The temperature is selected on the basis of
1. Kind of food.
2. Time.
3. Condition of storage. Certain foods have an optimal storage temperature or range of temperature well
above the freezing point and may be damaged by lower temperature.
E.g.: banana should be kept in the refrigerator, best at about 13.3 to 16.7C.
2. RH:
The optimal Rh depends on the temperature, composition of the atmosphere, ray treatments.
Low RH => loss of moisture and hence weight, witting and softening of vegetables and shrinkage of
fruits.
High RH => growth of spoilage microorganisms.
E.g.: yeast => 90 –92%
Molds => 85 –90%
Changes in RH and T during storage may cause sweating or precipitation of moisture on the food,
so favors microbial spoilage. E.g.: slime on the moist surface of sausage.
3. Ventilation:
To prevent the development of stale odors and flavors, and maintain uniform RH throughout the
room. It adequate ventilation is not provided; food in local areas of high humidity may undergo microbial
decomposition.
4. Composition of storage atmosphere:
It is controlled by the introduction of Co2, ozone or other gases called as gas storage.
1. Food remains unspoiled for a longer period.
2. Rh may be maintained.
3. Keeping quality is maintained.
4. Higher storage temperature can be used without shortening the keeping time of food eg. Optimal CO 2
concentration.
Eggs 2.5 %, Beef 10%, Bacon 100%, Apples concentration of O2 and CO2 is
significant.
5. Irradiation :
UV lamps have been installed in rooms for the storage of meat & cheese.
Freezing / Frozen storage :
The selection & preparation of foods for freezing – fruits & vegetables are selected on the basis
of their suitability for freezing & their maturity & are washed, trimming, cut vegetables are scalded/
blanched & fruits may be packed in a syrup.
Meats are selected to minimize enzymatic & microbial changes. Most foods are packaged before
freezing, but some foods in small pieces. E.g. Strawberries may be frozen before package.
Scalding or blanching is done:
1.
Inactivation of plant enzymes that involve toughness.
2.
Reduction in microorganisms of the food.
3.
enhancement of green color
4.
wilting of leafy vegetables making them pat
Freezing of foods:
Freezing of foods depends on;
1. Temperature.
2. Circulation of air.
3. Kind of food
4. Size and shape of package.
Freezing
Quick freezing
Sharp /slow freezing
1. –15 to –29 C for 30 min
1. –15 to –29 C for 3-4 hrs till 72 hrs
2. No food damage
2. Damage of food by crystal formation.
3. Done by:
3. Done by the natural air circulation or
a. Direct immersion of food / package in
through electrical fans.
Refrigerant. E.g.: fish in brine
b. Indirect contact (-17.8 to –45.6 c)
c. Air blast freezing (-17.8 to –34.4C)
Rigid air is blown.
Advantage of quick freezing:
1. Shorter period.
2. Prompt prevention of microbial growth.
3. Rapid slowing of enzyme action.
Dehydrofreezing: fruits and vegetables have about half there moisture removed before freezing.
Changes during freezing:
1. Expansion in volume of food.
2. Ice crystals formation may crush cells.
3. Frozen condition chemical and enzymatic reaction proceed slowly.
E.g.: meat, poultry, fish products, proteins may irreversibly dehydrated.
Oxidation
Meat -> red myoglobin ------------- brown metmyoglobin
On surface
Fats (meat, fish) ----- oxidized and hydrolysed
4. Metacryotic liquid:
Unfrozen, concentrated solutions of sugars, salts may ooze from packages of fruits or
concentrates during storage as a viruses material.
5. Fluctuation in temperature results in ice crystal formation.
6. Deracination may occur.
7. Freeze burn :
when ice – crystals evaporate from the area at the surface this defect is observed. The spot
appears dry, grainy and brownish, tissues become dry and tough.
E.g.: fruits, vegetables, meat, poultry and fish.
8. During freezing vegetative cells die soon but some may remain for a longer period of time.
Changes during thawing:
1. Drip / bleeding:
The pink or reddish liquid that comes from meat during thawing.
2. Leakage:
The liquid oozing out of fruits or vegetables on thawing.
3. The wilting and flabiness of physical damage during freezing.
4. Thawing refers to sudden heating and sudden cooling. The damage of food is due to the freezing and
storage but do not become evident earlier. Some of the liquid during thawing may be reabsorbed by the
food particles or may remain as such.
If the thawed fleshed foods are below 3.3 C can be used but otherwise food should be discarded.
Effects of freezing:
1. Lethal effects:
Rapid cooling of cells from optimal to 00 c may also result in death and referred to as cold shock,
where there is change in lipid membrane damage the permeability of cell or to the release of repair
enzyme inhibitors. E.g.: ribonuclease inhibitors
2. Sub – lethal effects:
During enumeration of frozen food there may be reduction but not tree death of organisms. Some
may be injured or damaged are called as freeze – injured, frost injured or metabolically injured. Freezing
of micro organisms in a food may result in cryoinjuiry.
Response of microorganisms to freezing:
Freezing depends on type of microorganisms usually found in foods involved in preservation.
There are various factors involving freezing.
1. On the basis of sensitivity of microorganisms during freezing they can be classified as 3 different
groups:
a. Susceptible or sensitive => e.g.: yeast, mould, gram-negative bacteria, and vegetative cells.
b. Moderately resistance => e.g. Staphylococcus, Enterococcus, gram-positive bacteria.
c. Resistant => e.g. Spore forming organisms.
2. Freezing also depends on the freezing rate. Critical range of temperature lead to death of microbes than
during rapid freezing.
3. It also depends on the kind of food normally used for presentation. The food used for preservation by
freezing usually gets spoiled due to
a. High moisture content.
b. Availability of O2
c. Salt and sugary environment.
4. Freezing also depends on the change in PH or altered acidity or alkalinity in food.
5. During freezing there is increase in moisture content and formation of intracellular crystals. This
usually results in altered permeability in membrane and cell wall. Thus results in osmotic imbalance or
osmotic shock favoring cell lyses. Intracellular lie crystals are harmful to cells than extra cellular ice
crystals.
6. The initial killing rate during freezing is rapid, but it is followed by a gradual reduction of
microorganisms are referred as storage death.
PRESERVATION BY USE OF DRYING
Introduction:
Drying is referred to as the removal of water or lowers the water activity or reduces
the amount of available moisture.
E.g., Dried fish => salt, condensed milk => sweet.
a). Sun Drying Drying of food by exposure to suns rays.
b). Dehydrated / Desiccated Drying by artificial means under controlled air flow, T and RB
c). Condensed Drying where moisture removal from liquid substances
d). Evaporated Similar to dehydrated.
Product
1. Milk
2. Egg
3. Beef
Before drying moisture %
90
After drying moisture %
5
4. Apple juice
74
2.9
60
1.5
86
6.2
Methods of drying:
1. Solar drying:
Direct sun’s rays
E.g., Raisins, figs, pears, peaches, rice, fish
2. Drying by mechanical dryers:
Passage of heated air to food under controlled RH.
a) Use of KLIN / EVAPORATOR:
They are used in form house
Natural draft from heated air brings drying.
b) Forced draft drying:
Heated air moves across the food usually in tunnels or food moved in conveyor belts
through heated air.
c) Spray dried:
Spraying of liquid into a current of dry, heated air.
d). Drum dried:
Passage over a heated drum, with or without vacuum.
3. Freeze drying:
Sublimation of water from frozen food by means of a vacuum and heat.
E.g., Meat, Poultry, seafood’s and fruits.
4. Drying during smoking:
E.g., wool smoke desired flavors and preservative are uses.
Meat 43 – 71 C for few hrs to several days prevents mold growth.
It has HCHO, phenol, cresol, methyl and ethyl esters, ketones etc.
5. Other methods:
a. Electronic Heating
b. Foam – mat drying ->Lipid whipped to foam, dried with warm air, crushed to powder, as
is pressure – gun puffing of partially dried foods to give a porous structure facilitate
further drying.
c. Tower Drying ->Dehumified air at 30 C or less.
E.g. Tomato concentrate, milk and potatoes.
Factors:
1. Temperature
2. Relative humidity of air
3. velocity of air
4. time of drying
If all these not accounts may lead to case hardening where rapid, evaporation of moisture from
the surface than diffusion from the interior leads to hard, horny, impenetratable surface film that
hinders further drying.
Process:
Before Drying, Drying and after Drying:
Before reception into plant:
Food has to be inspected without any contamination as;
1. Milk -> Pure from udder in low, may be contaminated by handlers, process, and
equipments.
2. Meat/ Poultry -> Due to soil, intestinal activity, handlers, equipments.
3. Fish -> By intestinal activity, surface slime, and handlers.
4. Egg -> Handlers, equipments, hatched hen and soil.
Before Drying:
1. Selection:
a. Elimination of spoiled foods.
b. Rejection of cracked, dirty foods.
c. Sorting for size, maturity and soundness.
2. Washing:
Especially fruits and vegetables. These procedures are followed to remove soil and
adhering materials and removes microbes. Water must be pure as it may also acts as a source of
contaminate if poor quality of water is used.
E.g., Egg -> Moisture helps the bacteria to penetrate the shell.
3. Peeling:
May be done by hand, machine, lye bath or abrasion. It reduce the number of
microorganisms are on the surface.
4. Sub division:
Slicing, cutting should not increase number of organisms but will do so if equipment is
not adequately cleansed and sanitized
5. Alkali Dip:
It may reduce the microbial population.
E.g., Raisins, Grapes, etc -> Hot 0.1 – 1.5 % lye / Na2CO3
6. Scalding / Blanching:
a. Sulfuring of light colored fruits and certain vegetables.
b. Fruits -> 1000 – 3000 ppm of SO2 gas
c. Vegetables -> dipping after blanching or spraying of sulfite solution.
d. Helps to maintain an attractive light color, conserve vit C, vit A, repels insect,
kills many microorganisms.
Drying:
1. Heat
2. Freeze drying
After Drying:
1. Sweating:
Storage in boxes or tins. It is for equalization of moisture or addition of moisture to a
desired level.
E.g., Dehydration of meat at 60 C -> leads to growth of Staph. aureus ., so that 1000C applicable.
2. Packing:
Packed the foods after drying for protection against moisture contamination with
microbes, insects.
3. Pasteurization:
Fruits usually during package -> 30 to 70 min – time, 70 to 100% - RH, 65.6 to 850C –
Temperature.
Microbiology of dried foods:
1. Dried fruits: Mold spores may be seen.
2. Dried vegetables: Few 100’s per gram to million of organisms due to the improper
pretreatment. E.g.: Bacillus, Micrococcus, Clostridium, E.coli, Enterobacter,
Pseudomonas, Streptococci and Lactobacillus, Leuconostoc.
3. Dried eggs: Coli forms, spore formers, molds, Micrococcus, Streptococci.
4. Dried milk: Spore formers, Thermoduric, Streptococci, Micrococcus.
Intermediate moisture foods: (IMF)
1. Commercially prepared foods haves 20-40% moisture and are non-refrigerated shelf stability
are IMF.
2. They have reduced water activity.
E.g.: Candies, Jams, jellies, honey, bakery items etc.
3. Aw may be 0.75 and 0.85 for IMF.
4. They can be adjusted by the addition of sugar, salt or glycerols.
4.
WRITE SHORT NOTES ON PRESERVATION OF FOODS BY FOOD ADDITIVES.
PRESERVATION OF FOODS BY FOOD ADDITIVES
INTRODUCTION
1)
A food additive is a substance or mixture of substances, other than the basic food
stuff, is present in food as a result of any aspect of production, processing, storage or
packaging.
2)
The definition emphasizes one interpretation of a food additive, i.e.; it is an intentional
additive. There food additives are specifically added to prevent the deterioration or
decomposition of a food have been referred to as chemical preservatives.
3)
This decomposition may be caused by micro organisms, by food enzymes, or by
purely chemical reactions. The inhibition of the growth and activity of micro
organisms is one of the main purposes of the use of chemical preservatives
4)
Preservatives may inhibit micro organisms by interfering with their cell membranes,
their enzymes activity or their genetic mechanisms.
Factors that influence the effectiveness of chemical preservatives in killing micro organisms or
inhibiting their growth.
a. Concentration of the chemical
b. Kind, number, age & previous history of the organism
c. Temperature
d. Time
e. The chemical & physical characteristics of the substrate in which the organism is found.
The ideal antimicrobial preservative:
A chemical preservative should have a wide range of antimicrobial
activity.
Should be nontoxic to human being or animals
Should be economical
Should not have an effect on the flavor, taste or aroma of the original food
Should not be inactivated by the food or any substance in the food
Should encourage the development of resistant strains
Should kill rather than inhibit micro organisms
Organic acids and their salts:
Lactic, acetic, prop ionic & citric acids or their salts may be added to or
developed in foods
.
Citric acid is used in syrups, drinks, Citric acid is used in syrups, drinks,jams &
Jellies
Lactic and acetic acids are added to brines of various kinds, green olives, etc.
Propionates:
Sodium or calcium propionate is used most extensively in the prevention of mold growth & rope
development in baked foods & for mold inhibition in many cheese foods and spreads.
Experimentally, or on a limited scale, they have been used in butter, jams, jellies, apple slices & malt
extract
They are effective against molds, with little or number inhibition of most yeast and bacteria.
Benzoates:
The sodium salt of benzoic acid has been used extensively as an antimicrobial agent in foods.
It has been incorporated into jams, jellies, carbonate (beverages, fruit salads, pickles, fruit juices etc.
Sorbates:
Sorbic acid, as the calcium, sodium or potassium salt, is used as a direct antimicrobial additive in foods.
It is widely used in cheeses, cheese products, baked goods, beverages, syrups, fruit juices, jellies, jams,
dried fruits & pickles.
Sorbic acid & its salts are known to inhibit yeast & molds but are less effective against bacteria.
Acetates:
Derivatives of acetic acid
Dehydroacetic acid has been used to impregnate wrappers for cheese to inhibit the growth of molds
Acetic acid is more effective against yeast & bacteria than against molds.
Nitrites and Nitrates
Combinations of these various salts have been used in curing solutions & curing mixtures for meats.
Nitrites decompose to nitric acid, which forms nitrosomyoglobins when it reacts with the heme pigments
in meats & thereby forms a stable red colour.
They are currently added in the form of sodium nitrite, potassium nitrate.
Recent works has emphasized the inhibitory property of nitrites towards Clostrium botulinum in meat
products.
Sulfur dioxide and Sulfites:
The Egyptians and Romans burned sulfur to form sulfur dioxide as a means of sanitizing their wine –
making equipments & storage vessels.
Today sulfur dioxide and sulfites are used in the wine industry to sanitize equipment to reduce the normal
flora of the grape must.
Ethylene propylene oxide:
Ethylene oxide kills all micro organisms; propylene oxide, although it kills many micro organisms.
The primary uses have been as sterility for packaging materials, fumigation of water houses, & “cold
sterilization” of numerous plastics, chemicals, pharmaceuticals, syringes & hospital supplies.
They have also been used successfully in dried fruits, dried eggs, cereals, dried yeast and spices
Sugar and salts:
Sodium chloride is used in brines & curing solutions or is applied directly to the food
Enough may be added to slow or prevent the growth of microorganisms or only enough to permit an acid
fermentation to take place.
Salt has been reported to have the following effects.
It causes with osmotic pressure & hence plasmolysis of cells
It dehydrates foods by drawing out from the microbial cells.
It ionizes to yield the chlorine ion, which is harmful to organism
It reduces the solubility of oxygen in the moisture,
It sensitizes the cells against carbon dioxide
It interferes which the action of proteolysis enzymes.
Sugars, such as glucose or sucrose, owe their effectiveness as preservatives to their ability to
make water unavailable to organisms and to their osmotic effect.
Examples of foods preserved by high sugar concentration are sweetened condensed milk, fruits in
syrups, jellies & candies.)
UNIT-2
1.Discuss the food poisoning and food borne inflections.
FOOD BORNE INFECTIONS & INTOXICATIONS
Introduction :
Food borne diseases may be of 2 types,
1. food borne infections
2. food borne intoxications.
Food borne intoxication is by the presence of microbial toxin formed in the food.
Food borne infection is caused by the microbe’s entry into the body through ingestion of
contaminated food & the reaction of the body to their presence or to their metabolites.
Food borne infection can be divided into 2 types are
[i] food that does not support growth of pathogens but merely carries them. Eg. Diphtheria, Dysentry,
Typhoid fever, Brucellosis, Cholera, Infectious hepatitis, Q fever.
[ii] food that serve as a culture medium for the growth of the pathogens to no.s that will increase the
infection of the consumer of the food. Eg. E. coli, Salmonella, V.parahaemolyticus.
Outbreak of infections are explosive in 2nd type.
CLASSIFICATION OF FOOD BORNE DISEASES
Food borne diseases
Poisonings
Infections
Chemical poisonings
Invasive
Systemic
Poisonous
Other
Intoxications
Poisonous
Enterotoxigenic
Microbial
Sporulation
Growth
Intestinal
Plant tissues
Animal tissues intoxications
& lysis
mucosa
Tissues
Algal
Mycotoxins
Bacterial toxins
Muscle
Toxins
Enterotoxins
Neurotoxins
Interferes with
Carbohydrate
metabolism
FOOD BORNE DISEASES [BACTERIAL]
Intoxications
1. Staphylococcal intoxication – an enterotoxin -
S. aureus.
2. Botulism – neurotoxin – Cl. botulinum.
Gastroenteritis
Infections
1. Salmonellosis– Enterotoxin &
cytotoxin
2. Cl. Perfringens - Enterotoxin
3. B. cereus – Exoenterotoxin 4. Enteropathogenic E.coli –
Enterotoxin - EPEC
5. Others: Vibrio parahemolyticus,
Yersiniosis,
Shigellosis, Bacillus.
Liver
FOOD BORNE INTOXICATION
Staphylococcus
Introduction:
Food poisonings is caused by the ingestion of the enterotoxin formed in food during the growth of
S. aureus.
The toxin is enterotoxin because it causes gasteroenteritis or inflammation of the lining of the
intestinal tract.
Organism:
Cluster of grapes or in pairs and short chains, Golden yellow colonies are formed on solid media.
Coagulase positive, aerobes, facultative anaerobes, some strains are salt tolerant [10-20% Nacl].
Fairly tolerant of dissolved sugars [50-60% sucrose], Fermentative & preteolytic but do not
produce obnoxious odour [unattractice].
Based on serology, 6 distinct enterotoxins are classified [type A, B, C1, C2, D, E], A most
effective toxin, Toxin production varies with food involved.
Water activity [0.86 – aerobes, 0.90 – anaerobes], pH [ 4.8 – aerobes, 5.5 – anaerobes],
Temperature [370C – optimum growth, 25 – 45oC – minimum, 4 – 460C - Survive], 660C
– 12 mins, 600C – 78 to 83 mins are necessary to destroy the organisms in food.
D value – 60oC – 7.7 mins – Decimal reduction time, Radiation to kill Staphylococci is
gamma rays on moist foods – 0.37 to 0.488 Mrad of gamma rays on moist foods.
Enterotoxin character :
Simple protein with molecular weight between 26,000 – 30,000 is a single polypeptide
chain are cross linked by a disulphide bridge to form a cystine loop.
Organism is heat labile but toxin is heat stable. Type A & D mainly cause disease.
Increased concentration of toxin is necessary to cause disease.
Toxin gets inactivated at 190.6oC. Temperature affects the toxin production [ 370C – 12
hrs,
180C – 3 days, 90C – 7 days, 4 – 6.70C - 4 days].
Foods involved :
Bakery food products [cream biscuits], Milk and milk products, Cured meat, Ham,
Poultry and poultry products, Salads, egg and egg products.
Disease :
Incubation period [2 – 4 hrs] – first symptom seen. Common symptoms are salivation,
nausea, vomiting, abdominal cramping, diarrhea, dysentry.
In some cases, vomiting, headache, muscular cramping, sweating, chills, weak pulse,
respiratory tract problems [ cannot swallow] these may be the secondary symptoms.
Decreased death rate and disease can be cured within 4 days.
Active organism secretes enterotoxin into food Food eaten
Enterotoxin affects
gut giving
gasteroenteritis
Enterotoxin ingested along with food affects cells
Enterotoxin affects vomit receptors
Water & Sodium pumps out of the
cell
Vomiting center in the brain stimulated
Diarrhea, fluid and electrolyte
loss.
Vomiting
Dehydration
Conditions for outbreak :
Food must contain enterotoxin producing Staphylococci.
Food must be a good culture medium for growth & toxin production by the
Staphylococci.
Temperature must be favourable and enterotoxin bearing food may be ingested.
Prevention of outbreaks :
Prevention of contamination of food with Staphylococci.
Killing of Staphylococci growth.
Prevention of Staphylococci growth.
Contamination of foods can be reduced by :
1. general methods of sanitation.
2. Using ingredients free from cocci – eg. Pasteurised milk than raw milk.
3. By keeping employees away from foods who have colds, boils, carbuncles, etc.
4. Adequate refrigeration of food.
5. Addition of bacteriostatic substances such as serine or antibiotic.
CLOSTRIDIUM BOTULINUM [INTOXICATION]
Introduction :
Neurotoxin is produced by Clostridium botulinum which causes disease called Botulism.
Death in infants is within 3 – 6 days & adults is 6 – 9 days.
Organism is Gram positive, anaerobes, gas forming rod shaped bacteria which occurs in soil.
Antigen are classified based on toxigenicity as A,B,C,D,E,F,G – 7 types.
Type A
Highly toxic to humans than B
Type B, F & G Less toxic to man.
Type C Cow, Cattle, other animals.
Type D Cattle.
Type E Fish and fish products.
Growth and toxin production :
The factors that influence the growth of organism are nutrient content of food [canned food, meat
& fish], pH, temperature, oxidation - reduction potential, salt concentration, moisture content.
Contamination of food may be due to soil.
Toxin is produced at pH 4.5, Organism must autolyse or sporulate to produce toxin.
Non-proteolytic toxins are fully activated, These can be activated by binding with trypsin.
Medium must have glucose or maltose for growth & toxin production.
Medium should have nitrogen source, carbon source, casein and protein.
Temperature [350C], pH [acidic – toxin production, Neutral – growth, anaerobic environment.
Nacl inhibits the growth of the organisms.
Toxins :
Toxins are protein substances produced by the organism during the growth and it is thermolabile.
Denaturation of the toxin is at 800C for 5 – 6 mins [type A], 900C for 15 mins [type B].
Radiation is used for toxin denaturation because it sterilizes deeply.
Type A & B spores are highly heat resistant and the D valve is 1210C – 0.21 min – Type A,
1000C – 0.003 to 0.017 mins – Type E.
Foods involved :
Meat, string beans, sweet corn, beets, fish, asparagus, spinach, canned foods [ proteolytic – odor,
non-proteolytic – gas production].
Disease :
Incubation period [12 – 36 hrs], symptoms include nausea, vomiting, diarrhea, fatigue, dizziness,
headache, constipation, double vision, difficult in swallowing & speaking, mouth dryness, throat
constriction, swollen & coated tongue.
Temperature is normal or subnormal, involuntary muscles become paralyzed, paralysis spreads to
the respiratory tract, heart & death results due to respiratory failure.
Symptoms are similar for type A,B,E poisoning but nausea, vomiting & urinary retention usually
more severe with type E toxin.
Treatment [antitoxin administration, artificial respiration, keeping the patient isolated,
maintaining the fluid balance in the body].
Neurotoxin ingested with food Neurotoxin passes through gut mucosa into blood stream
Toxin spreads throughout the body through
bloodstream
Toxin binds to nerve at the junction
This results in paralysis.
Conditions for outbreak :
Presence of the spores of type A, B, E.
A food in which the spores can germinate & the clostridia can grow & produce toxin.
Survival of the spores of the organism eg. Because of inadequate heating in canning or inadequate
processing.
Environmental conditions after processing that will permit germination of the spores, growth &
toxin production by the organism.
Insufficient cooking of the food to inactivate the toxin.
Ingestion of the toxin bearing food.
Prevention of outbreaks :
Use of approved heat processes for canned foods.
Rejection of all gassy [swollen] or otherwise spoiled canned foods.
Refusal even to taste a doubtful food.
Avoidance of foods that have been cooked, held & not well heated.
Boiling of a suspected food for atleast 15 mins.
Avoidance of raw or precooked foods.
To prevent botulism from smoked fish :
1. good sanitation throughout production & handling.
2. fish heated to atleast 820C – 30 mins in coldest part.
3. fish be frozen immediately after packaging & kept frozen.
4. all packaged be marked “ perishable – keep frozen”.
Infant botulism :
Infants --> predisposed constipation.
Weakness, lack of sucking, loss of head control, diminished gag reflex.
Death within 3 – 6 days.
Milk, canned food [cereals] may cause intoxication.
Through mother’s infection.
2.Discuss The Food Borne Infection Of Salmonellosis
Introduction :
Causes gastroenteritis, Gram negative rods, non-spore formers, non-lactose fermenting
organisms, facultative anaerobes, ferments glucose to produce gas and belongs to
Enterobacteriaceae family.
Classification :
S. tyhi [ infect humans], S. typhimurium [infect animals].
Serotypes --> Somatic Ag [O], Capsular Ag [Vi], Flagellar Ag [H].
Temperature [370C – optimum, 450C – maximum, 6.7 – 7.80C - Minimum], pH [ neutral –
optimum,
4.1 – minimum, 9 - maximum].
Increased H2S S. typphimurium, S. enteritis, decreased H2S S. typhi.
Grows well in low acid foods [5.5 – 5.7].
Heat sensitive bacteria [ 660C – 12 mins, 600C – 78 to 83 mins].
D value [600C for 0.06 – 11.3 mins].
More concentration of bacteria can cause disease atleast 100 sp.
Very less infective S.pullorum, Highly infective S.enteritis.
Sources of Salmonella contamination :
Humans [ Direct / Indirect, feces, handling, water contamination.]
Animals [Direct / Indirect] – Dogs, cattle, cat [feces, infection, infected animal meat
contamination, poultry products – hen, chicken, meat & egg] due to improper processing, egg
coated with fecal material. Increased refrigeration results in increased moisture & forms the pores
& through this the organism enters.
Bakery products – sources through flies, cockroach, insects from infected to normal food.
Foods involved :
Bakery products, Meat, Chicken, Milk and milk products – cheese, egg and egg products, cream
cakes, Bacon & ham.
Disease :
Incubation period [12 – 36 hrs]. Symptom includes gastrointestinal infection are nausea,
vomiting, abdominal pain, diarrhea, headache, chills.
Other evidences are watery, greenish, foul-smelling stool, prostration, muscular weakness,
faintness, moderate fever, restlessness, twitching, drowsiness.
Mortality is low [1%]. Diarrhea to death in 2 – 6 days.
Symptoms persist for 2 – 3 days, followed by uncomplicated recovery. Carriers – 0.2 to 5 %.
Organism ingested along with the food
Organisms grows in the host gut
Organism
affects gut
giving gastroenteritis
Bacterial cells ingested along with the food
Cells invade the tissues & release endotoxin
Fever, vomiting , Diarrhea [fluid & electrolyte loss] --- It leads to loss of water & sodium ions
Conditions for outbreak :
Food must contain or become contaminated with the salmonella bacteria.
Good culture medium.
Viable organism must be ingested.
Prevention of outbreak :
Avoidance of contamination of food [diseased human beings, animals, carriers, contaminated
eggs].
Destruction of the organisms in food by heat.
Prevention of the Salmonella growth in foods by adequate refrigeration or by other means.
In the prevention of contamination :
1. care and cleanliness in food handling & preparation.
2. Food handlers should be healthy & clean.
3. Rats & other vermin & insects should be kept away from foods.
4. Ingredients used in food should be free of Salmonella.
5. Food should not be allowed to stand at room temperature for any length of time.
GASTROENTERITIS
CLOSTRIDIUM PERFRINGENS
Organism :
Gram positive, non-motile, anaerobic, spore forming rods.
Temperature [43 – 470C], pH [ 5 – 9 ], D value [900C – 0.015 to .71 mins].
Organism growth is inhibited by 5% Nacl.
Toxins produced are A, B, C, D, E where A is infective and C is less infective.
Foods :
Raw foods, soil, sewage, animal feces, meat, fish, poultry.
Disease :
Incubation period [8-24 hrs].
Abdominal pain, diarrhea, gas, fever, nausea, vomiting are the symptoms.
Enterotoxin released in the gut during sporulation results in fluid accumulation in the intestine.
Toxin is heat labile [ 600C – 10 mins – inactivated].
Symptoms:
1. Enterotoxin heat labile
2. Inactive at 60c for 10 min
3. Abdominal pain, diarrhoea with gas trouble, fever, nausea, vomiting.
4. Mortality is low.
Conditions for outbreak :
Food contaminated with the organism.
Food is not maintained properly.
Inadequate cooling.
Food is consumed without reheating.
Cells sporulate & produce enterotoxin
Infective dose:
Large number of vegetative cells in a food are required to produce food poisoning. The minimum
seems to be about 7 x 105/g of food ingested but numbers as high as 108 /g or greater may be required.
Prevention of outbreaks:
1. Eat meat immediately after cooking.
2. Cool cooked meats rapidly to 7ºC or below for storage and reheat to an internal T of above 70ºC
before consumption.
3. Store cooked chilled foods correctly and heat to an internal T of 70 C or above.
4. Foods held hot before consumption should be maintained at 60 C or above.
5. Avoid transferring spores from raw to cooked meat during boiling, slicing, mincing but not using
common utensils and observing good hygiene.
6. Adequate & rapid cooling of cooked foods.
7. Reheating.
8. Personal hygiene.
9. Sanitation.
3.What is foodborne disease?
Foodborne disease is caused by consuming contaminated foods or beverages. Many
different disease-causing microbes, or pathogens, can contaminate foods, so there are many
different foodborne infections.
In addition, poisonous chemicals, or other harmful substances can cause foodborne
diseases if they are present in food. More than 250 different foodborne diseases have been
described.
Most of these diseases are infections, caused by a variety of bacteria, viruses, and
parasites that can be foodborne. Other diseases are poisonings, caused by harmful toxins or
chemicals that have contaminated the food, for example, poisonous mushrooms.
These different diseases have many different symptoms, so there is no one "syndrome"
that is foodborne illness. However, the microbe or toxin enters the body through the
gastrointestinal tract, and often causes the first symptoms there, so nausea, vomiting, abdominal
cramps and diarrhea are common symptoms in many foodborne diseases.
Many microbes can spread in more than one way, so we cannot always know that a
disease is foodborne. The distinction matters, because public health authorities need to know
how a particular disease is spreading to take the appropriate steps to stop it.
For example, Escherichia coli O157:H7 infections can spread through contaminated
food, contaminated drinking water, contaminated swimming water, and from toddler to toddler at
a day care center. Depending on which means of spread caused a case, the measures to stop
other cases from occurring could range from removing contaminated food from stores,
chlorinating a swimming pool, or closing a child day care center.
4.What are the most common foodborne diseases?
The most commonly recognized foodborne infections are those caused by the bacteria
Campylobacter, Salmonella, and E. coli O157:H7, and by a group of viruses called calicivirus,
also known as the Norwalk and Norwalk-like viruses.
Campylobacter is a bacterial pathogen that causes fever, diarrhea, and abdominal cramps. It is
the most commonly identified bacterial cause of diarrheal illness in the world. These bacteria
live in the intestines of healthy birds, and most raw poultry meat has Campylobacter on it.
Eating undercooked chicken, or other food that has been contaminated with juices dripping from
raw chicken is the most frequent source of this infection.
Salmonella is also a bacterium that is widespread in the intestines of birds, reptiles and
mammals. It can spread to humans via a variety of different foods of animal origin. The illness
it causes, salmonellosis, typically includes fever, diarrhea and abdominal cramps. In persons
with poor underlying health or weakened immune systems, it can invade the bloodstream and
cause life-threatening infections.
E. coli O157:H7 is a bacterial pathogen that has a reservoir in cattle and other similar animals.
Human illness typically follows consumption of food or water that has been contaminated with
microscopic amounts of cow feces. The illness it causes is often a severe and bloody diarrhea
and painful abdominal cramps, without much fever. In 3% to 5% of cases, a complication called
hemolytic uremic syndrome (HUS) can occur several weeks after the initial symptoms. This
severe complication includes temporary anemia, profuse bleeding, and kidney failure.
Calicivirus, or Norwalk-like virus is an extremely common cause of foodborne illness, though
it is rarely diagnosed, because the laboratory test is not widely available. It causes an acute
gastrointestinal illness, usually with more vomiting than diarrhea, that resolves within two days.
Unlike many foodborne pathogens that have animal reservoirs, it is believed that
Norwalk-like viruses spread primarily from one infected person to another. Infected kitchen
workers can contaminate a salad or sandwich as they prepare it, if they have the virus on their
hands. Infected fishermen have contaminated oysters as they harvested them.
Some common diseases are occasionally foodborne, even though they are usually
transmitted by other routes. These include infections caused by Shigella, hepatitis A, and the
parasites Giardia lamblia and Cryptosporidia. Even strep throats have been transmitted
occasionally through food.
In addition to disease caused by direct infection, some foodborne diseases are caused by
the presence of a toxin in the food that was produced by a microbe in the food. For example, the
bacterium Staphylococcus aureus can grow in some foods and produce a toxin that causes
intense vomiting.
The rare but deadly disease botulism occurs when the bacterium Clostridium botulinum
grows and produces a powerful paralytic toxin in foods. These toxins can produce illness even if
the microbes that produced them are no longer there.
Other toxins and poisonous chemicals can cause foodborne illness. People can become
ill if a pesticide is inadvertently added to a food, or if naturally poisonous substances are used to
prepare a meal. Every year, people become ill after mistaking poisonous mushrooms for safe
species, or after eating poisonous reef fishes.
5.How are foodborne diseases diagnosed?
The infection is usually diagnosed by specific laboratory tests that identify the causative
organism. Bacteria such as Campylobacter, Salmonella, E. coli O157 are found by culturing
stool samples in the laboratory and identifying the bacteria that grow on the agar or other culture
medium.
Parasites can be identified by examining stools under the microscope. Viruses are more
difficult to identify, as they are too small to see under a light microscope and are difficult to
culture. Viruses are usually identified by testing stool samples for genetic markers that indicate a
specific virus is present.
Many foodborne infections are not identified by routine laboratory procedures and require specialized,
experimental, and/or expensive tests that are not generally available.
If the diagnosis is to be made, the patient has to seek medical attention, the physician must decide
to order diagnostic tests, and the laboratory must use the appropriate procedures. Because many ill
persons to not seek attention, and of those that do, many are not tested, many cases of foodborne illness
go undiagnosed.
For example, CDC estimates that 38 cases of salmonellosis actually occur for every case that is
actually diagnosed and reported to public health authorities
6.How are foodborne diseases treated?
There are many different kinds of foodborne diseases and they may require different
treatments, depending on the symptoms they cause.
Illnesses that are primarily diarrhea or vomiting can lead to dehydration if the person
loses more body fluids and salts (electrolytes) than they take in. Replacing the lost fluids and
electrolytes and keeping up with fluid intake are important.
If diarrhea is severe, oral rehydration solution such as Ceralyte*, Pedialyte* or Oralyte*,
should be drunk to replace the fluid losses and prevent dehydration. Sports drinks such as
Gatorade* do not replace the losses correctly and should not be used for the treatment of
diarrheal illness.
Preparations of bismuth subsalicylate (e.g., Pepto-Bismol)* can reduce the duration and
severity of simple diarrhea.
If diarrhea and cramps occur, without bloody stools or fever, taking an antidiarrheal
medication may provide symptomatic relief, but these medications should be avoided if there is
high fever or blood in the stools because they may make the illness worse.
*CDC does not endorse commercial products or services
7.How do public health departments track foodborne diseases?
Routine monitoring of important diseases by public health departments is called disease
surveillance. Each state decides which diseases are to be under surveillance in that state.
In most states, diagnosed cases of salmonellosis, E. coli O157:H7 and other serious
infections are routinely reported to the health department.
The county reports them to the state health department, which reports them to CDC.
Tens of thousands of cases of these "notifiable conditions" are reported every year. For
example, nearly 35,000 cases of Salmonella infection were reported to CDC in 1998.
However, most foodborne infections go undiagnosed and unreported, either because the
ill person does not see a doctor, or the doctor does not make a specific diagnosis. Also,
infections with some microbes are not reportable in the first place.
To get more information about infections that might be diagnosed but not reported, CDC
developed a special surveillance system called FoodNet. FoodNet provides the best available
information about specific foodborne infections in the United States, and summarizes them in an
annual report.
In addition to tracking the number of reported cases of individual infections, states also
collect information about foodborne outbreaks, and report a summary of that information to
CDC.
About 400-500 foodborne outbreaks investigated by local and state health departments
are reported each year. This includes information about many diseases that are not notifiable and
thus are not under individual surveillance, so it provides some useful general information about
foodborne diseases.
8.What are foodborne disease outbreaks and why do they occur?
An outbreak of foodborne illness occurs when a group of people consume the same
contaminated food and two or more of them come down with the same illness.
It may be a group that ate a meal together somewhere, or it may be a group of people who
do not know each other at all, but who all happened to buy and eat the same contaminated item
from a grocery store or restaurant.
For an outbreak to occur, something must have happened to contaminate a batch of food
that was eaten by a the group of people. Often, a combination of events contributes to the
outbreak.
A contaminated food may be left out a room temperature for many hours, allowing the
bacteria to multiply to high numbers, and then be insufficiently cooked to kill the bacteria.
Many outbreaks are local in nature. They are recognized when a group of people realize that
they all became ill after a common meal, and someone calls the local health department.
This classic local outbreak might follow a catered meal at a reception, a pot-luck supper,
or eating a meal at an understaffed restaurant on a particularly busy day.
However, outbreaks are increasingly being recognized that are more widespread, that
affect persons in many different places, and that are spread out over several weeks.
For example, a recent outbreak of salmonellosis was traced to persons eating a breakfast
cereal produced at a factory in Minnesota, and marketed under several different brand names in
many different states.
No one county or state had very many cases and the cases did not know each other.
The outbreaks was recognized because it was caused by an unusual strain of Salmonella,
and because state public health laboratories that type Salmonella strains noticed a sudden
increase in this one rare strain.
In another recent outbreak, a particular peanut snack food caused the same illness in
Israel, Europe and North America. Again, this was recognized as an increase in infections
caused by a rare strain of Salmonella.
The vast majority of reported cases of foodborne illness are not part of recognized
outbreaks, but occurs as individual or "sporadic" cases.
It may be that many of these cases are actually part of unrecognized widespread or
diffuse outbreaks. Detecting and investigating such widespread outbreaks is a major challenge to
our public health system.
This is the reason that new and more sophisticated laboratory methods are being used at
CDC and in state public health department laboratories.
9.List out the information centers for food safety and foodborne diseases?
National Food Safety Initiative
CDC's Food Safety Initiative home page
U.S. Food and Drug Administration
U.S. Food Safety and Inspection Service (FSIS)
U.S. Environmental Protection Agency
Role of the federal agencies in food safety
Gateway to government food safety information
Partnership for Food Safety Education/Fight BAC!TM
Food Safety Training and Education Alliance
Foodborne Illness Information Center
National Food Safety Education Month
Travelers' Health
LABORATORY TESTING:
The procedure to be followed in testing the samples of food or specimens from human source upon
receipt in the laboratory will depend on the type of food and the information available about the outbreak
of food illness.
The first act in most laboratories is to make a microscopic examination of a preparation of the food
stained by the Gram’s method. The smear is made from liquid or from the sediments from homogenized,
centrifuged food.
The microscopic examination may give a clue to the causative if the sample has been properly
refrigerated.
Preventive measures:
To keep foods as free as possible from contamination which pathogenic agents by selection of
uncontaminated foods, by adequate pasteurization or other heat processing, by avoiding contamination
from infected food handlers or carriers, and by generally good sanitary practice throughout the handling,
preparation and serving of foods.
To eliminate opportunities for the growth of pathogens, toxigenic or infectious, in foods by adjustment of
the composition, by prompt consumption after preparation, and by adequate refrigeration of perishable
foods if they must be hold for any considerable time, keeping foods warm for long periods is especially to
be avoided.
To reject suspected foods
To educate the public better concerning the causes and prevention of food borne illness and the dangers
involved.
FOOD SANITATION AND PLANT SANITATION:
Employee health standards:
Introduction:
The food industry sanitarian is concerned which specific aseptic practices in the preparation,
processing, and packaging of the food products of a plant and the health of cleanliness and sanitation of
plant and the health of employee.
Food and plant sanitation:
Specific duties in connection which the food products may involve quality control and storage of raw
products, the provision of a good water supply; prevention of the contamination of the foods at all stages
during processing from equipment, personnel, & the vermin; and supervision of packaging and ware
housing of finished products.
The supervision of cleanliness and sanitation of plant and premises includes not only the
maintenang of clean and well sanilized surfaces of all equipment toughing the foods but also generally
goods house keeping in and the plant and adequate treatment and disposal of wastes.
Employee health standards:
Duties affecting the health of the employees include provision of a potable water supply,
supervision of matters of personal lygiene, regulation of sanitary facilities in the plant and in plant
operated of plant lighting, heating and ventilation. The sanitarian may also participate in training
employees in sanitary practices.
For the most part, sanitarians concern themselves chiefly with general aspects of sanitation, making
inspections, consulting with personnel responsibless for details of canitation and executives directing such
work, and training personnel in sanitation.
SEWAGE WASTE TREATMENT AND DISPOSAL:
INTRODUCTION:
The food sanitation is concerned directly or indirectly with the adequate treatment and disposal of wastes
from the industry. Solid and concentrated wastes ordinarily are kept separate the watery wastes and may
be used directly for food, feed fertilizers, or other purpose; may first be concentrated dried, or fermented
(ex: pea vine silage);or may be carted away to available land as unusable waste.
WASTE TREATMENT:
Care is taken to keep out of the waste waters as much wasted liquid or solid food material as possible by
taking precautions to avoid introduction into the watery waste of drip, leakage, overflow, spillage, large
residues in containers, foam, frozen on and food dust during the handling and processing of the food.
I t is recommended that sewage of human origin be kept separate from other plant waters because of the
kept separate from other plant waters because of the possible presence of human intestinal pathogens.
Such sewage may be turned in to a municipal system.
Wastes from food plants ordinarily contain a variety of organic compounds, which range from simple and
readily oxidizable kinds to those which are complex and difficult to decompose.
The strength of the sewage or food waste containing organic matter is expressed in terms of biochemical
oxygen
demand ( BOD), which is the quantity of O2 used by aerobic microorganisms and reducing compounds in
the
Stabilization of decomposable matter during a selected time at a certain temperature.
A period of 5 days at 20oC is generally used, and results are expressed as 5 days BOD.
Wastes from a food plant to be emptied into a body of water must either be so greatly diluted by that
water must be treated first to reduce the oxidizable compounds to a harmless level.
Preliminary treatments of food- plant wastes by chemical means may be employed, but most systems of
treatment and disposal depend on
1. Screening out of large particles.
2. Floating of fatty and other floating materials
3. Sedimentation of as much of the remaining solids
4. Hydrolysis, fermentation and putrefaction of complex organic compounds and finally
5. Oxidation of the remaining solids inn the water to a point where they can enter a municipal sewage
treatment and disposal systems.
BIOLOGICAL TREATMENT AND DISPOSAL:
Dilution, by running waste waters into a large body of water.
Irrigation, in which wastewaters are sprayed onto shallow artificial ponds (with or without treatments)
Use of trickling filters; made of crushed rock, coke, filter tile, etc.,
Use of the activated- sludge method, in which wastewater is inoculated heavily with sludge from a
previous reaction.
Use of anaerobic tanks of various kinds, where settling, hydrolysis, putrefaction and fermentation take
place.
FOOD BORNE:
POISONINGS, INFECTION AND INTOXICATION
NON BACERIAL:
Introduction:
Some food borne disease outbreaks are not caused by bacteria or their toxins but results from mycotoxins,
viruses, rickettsiae, parasitic worms, or protozoa or from the consumption of food contaminated with
toxin substances.
10.Write a detailed account on mycotoxins and the key management steps to
prevent mycotoxin contamination.
Mycotoxins:
Mycotoxins are fungal metabolites. Some are highly toxic to many animals potentially toxic to human
beings. Recent concern is related to their carcinogenic properties and their presence in many food items.
FUNGI AND HUMAN BEINGS:
The fungi include the moulds, yeasts, blights, rusts and mushrooms.
Many fungi are useful. Some are edible. Ex: Mushrooms and single cell protein from yeast.
Other is widely used in industrial and food fermentation.
Ex: Aspergillus oryzae is used in the production of soy sauce, miso and sake and moulds take part in the
ripening of certain cheese.
Some mushrooms are harmful or poisonous to humans, but in contrast, moulds have generally been
regarded as harmless.
Many fungi can be isolated from plants, including Alternaria, Rhizopus, Fusarium, Cladosporium,
Helminthosporium and Chaetomium.
The two predominant genera of fungi in stored products are probably Penicillium and Aspergillus,
members of which produce mycotoxins.
The syndrome resulting from the ingestion of toxin in a mold- contaminated food is referred to as
mycotoxicosis.
AFLATOXIN:
Aflatoxins are produced by certain strains of A.falvus and A. parasiticus.
CHEMISTRY:
The two major metabolites or aflatoxins have been designated B, and G1 because they fluoresce Blue(B1)
and Green (G1).B2 and G2 are the dihydroderivatives of B1 and G1.
TOXICITY:
Aflatoxin B1, the most toxic of the aflatoxins, is toxic to various animals. Many of the other aflatoxin
have been shown to be toxic or carcinogenic to different species of fish, mammals and poultry.
SIGNIFICANCE IN FOODS:
Many foods will support the growth of toxigenic strains if inoculated, including various dairy
products, bakery products, fruit juices, cereals and forage crops.
In most cases, the growth of a toxigenic strain and the elaboration of aflatoxin occurs following
harvesting or formulation of the product.
Peanuts, cottonseeds, and corn, however, differ significantly in that these products are susceptible
to fungal invasion, growth and mycotoxin production before harvesting.
The contamination and potential for aflatoxin production in these crops is related to insect damage,
humidity, weather conditions.
OTHER TYPES OF MYCOTOXIN:
Patulin:
Produced by Penicillium expansum
Ochratoxin
Produced by Asperillus ochraceus
Luteoskyrin
Produced by Penicillium islandicum
Roquefortine
Produced by P. roqueforti
QUALITY CONTROL:
Quality of foods and food products may be defined as the degree of excellence of the various
characteristics that influence consumer acceptance as well as consumer safety.
The selection of a particular food by a discerning consumer is made by the judgment of all the
physical senses that is, tough, smell, taste and hearing.
Consumer safety requires the evaluation of food quality with respect to nutritional quality, hygienic
condition and keeping storage.
MICROBIOLOGICAL EXAMINATION OF FOOD:-
Introduction
The stated chief purposes of microbiological criteria for foods are to give assurance:
1. That the foods will be acceptable from the Public health standpoint that is will not be
responsible for the spread of infectious disease or for food poisoning.
2. That the foods will be of satisfactory quality
3. The foods will have keeping qualities that should be expected of the product.
4. Sampling for tests is a problem since the lack of homogeneity in most foods makes
location, size and number of samples significant.
5. Standards usually are based on total numbers of organisms, numbers of organisms,
numbers of indicator organisms or numbers of pathogens.
INDICATOR ORGANISMS:-
It may be necessary to carry out a microbiological examination of a food for one or more of a number
of reasons.
Escherichia coli is a natural component of the human gut flora and its presence in the environment, or
on foods, generally implies some history of contamination of faecal origin.
Traditional the group chosen has been designated the coliforms- those organisms capable of
fermenting lactose in the presence of bile at 37C.
This will include most strains of E. coli but also includes organisms such as Citrobactor and
Enterobactor.
DIRECT EXAMINATION:. When examining foods, the possibility of detecting the presence of microorganisms by looking at a
sample directly under the microscope should not be missed.
. A small amount of material can be mounted and teased out in a drop of water on a slide, covered with
a cover slip, and examined.
CULTURAL TECNIQUES:The full microbiological examination usually requires that individual viable propagules are encouraged to
multiply in liquid media or on the surface, or with in the matrix, of a medium solidified with agar.
A SELEATION OF MEDIA COMMONLY USED IN FOOD MICROBIOLOGY:
MEDIUM
USE
1. Plate count agar
Aerobic mesophilic count
2. Mac Conkey broth
MPN of coliforms in water
3. Brilliant Green/Lactose/ Bile broth
MPN of coliforms in food
4. Violet red/ bile/Glucose agar
Enumeration of Enterobacteriaceae.
5. Crystal violet /Azide / Blood agar
Enumeration of faecal Streptococci.
6. Baird- Parker agar
Enumeration of S. aureus
7. Vassiliadis broth
Selection enrichment of Salmonella.
8. Thiosulfate / bile/ citrate/ Sucrose agar
Isolation of Vibrios
9. Rose Bengal/ Chloramphenicol agar
Enumeration of moulds and yeasts
10. Mac Conkey agar
E. coli
ENUMERATION METHODS:-
Plate counts
It has already been suggested that to count microorganisms in a food sample by direct microscopy
has a limited sensitivity because of the very small sample size in the field of view at the
magnification needed to see microorganisms, especially bacteria.
In a normal routine laboratory the most sensitive methods of detecting the presence of a viable
bacterium is to allow it to amplify itself to form a visible colony.
This forms the basis of the traditional pour plate and spread plate and most probable number
counts.
ALTERNATIVE METHODS
.Cultural methods are relatively labour intensive and require time for adequate growth to occur.
. Many food microbiologists also consider that the traditional enumeration methods are not only too
slow but lead to an over dependence on the significance of numbers of colony forming units.
. A number of methods have been developed which aim to give answer of redox to as “Rapid
methods”.
1. Dye- reduction test:
A group of tests which have been used for some time in the dairy industry dependent on the
response of a number of redox dye to the presence of metabolically active microorganisms.
They are relatively simple and rapid to carry out at low cost.
The redox dyes are able to take up electrons from an active biological system and this results in a
change of colour.
2. Immunological methods:ELISA.
3. DNA/RNA methodology:PCR method
11.Write an account on idli fermentation and the micro organisms involved
in the fermentation.
FERMENTED FOOD
IDLI:
The idli , also romanized "idly" or "iddly" and plural "idlis", is a savory cake popular throughout
South India. The cakes are usually two to three inches in diameter and are made by steaming a
batter consisting of fermented black lentils (de-husked) and rice. The fermentation process
breaks down the starches so that they are more readily metabolized by the body.
Most often eaten at breakfast or as a snack, idlis are usually served in pairs with chutney, sambar,
or other accompaniments. Mixtures of crushed dry spices such as milagai podi are the preferred
condiment for idlis eaten on the go.
History
Although the precise history of the modern idli is unknown, it is a very old food in southern
Indian cuisine. One mention of it in writings occurs in the Kannada writing of Shivakotiacharya
in 920 AD,[1] and it seems to have started as a dish made only of fermented black lentil.
Chavundaraya II, the author of the earliest available Kannada encyclopaedia, Lokopakara
(c. 1025), describes the preparation of Idli by soaking Urad dal (black gram) in butter milk,
ground to a fine paste and mixed with the clear water of curd, and spices.[2] The Kannada king
and scholar Someshwara III, reigning in the area now called Karnataka, included an idli recipe in
his encyclopedia, the Manasollasa, written in Sanskrit ca. 1130 A.D. There is no known record of
rice being added until some time in the 17th century. It may have been found that the rice helped
speed the fermentation process. Although the ingredients used in preparing idli have changed,
the preparation process and the name have remained the same.
In ancient Tamilnadu, Puttu or pittu (made out of rice flour)was a very popular food and the
recipe was very similar to modern idli .
Idli was derived from a tamil word "Ittu Avi" means pour it (or put it)and steam it. Later it turned
into (maruviyadu) Ittavi and then into ittali.
The earliest Tamil writings are traced to about 300 BC, but references to edibles and food habits
abound in literature between 100 BC and 300 AD (Idaicchangam). Dosai and Vadai, as said
above, were popular. Tamils ate meals of all kinds, as well as fish.
Preparation
Idli batter is poured into the round indentations of the idli pans (pictured) and placed into a pressure
cooker.
To make idli, two parts uncooked rice to one part split black lentil (Urad dal) are soaked. The
lentils and rice are then ground to a paste in a heavy stone grinding vessel (attu kal). This paste is
allowed to ferment overnight, until it expands to about 2½ times its original volume. In the
morning, the idli batter is put into the ghee-greased molds of an idli tray or "tree" for steaming.
These molds are perforated to allow the idlis to be cooked evenly. The tree holds the trays above
the level of boiling water in a pot, and the pot is covered until the idlis are done (about 10-25
minutes, depending on size). The idli is somewhat similar to the dosa, a fried preparation of the
same batter.
In the olden days, when the idli mold cooking plates were not popular or widely available, the
thick idli batter was poured on a cloth tightly tied on the mouth of a concave deep Cooking pan
or tava half filled with water. A heavy lid was placed on the pan and the pot kept on the boil until
the batter was cooked into idli. This was often a large idli depending on the circumference of the
pan. It was then cut into bite-size pieces and eaten.
Contemporary Idlis and variations
Southern Indians have brought the popular idli wherever they have settled throughout the world.
Cooks have had to solve problems of hard-to-get ingredients, and climates that do not encourage
overnight fermentation. One cook noted that idli batter, foaming within a few hours in India,
might take several days to rise in Britain. The traditional heavy stones used to wet-grind the rice
and dal are not easily transported. Access to Indian ingredients before the advent of Internet mail
order could be virtually impossible in many places. Chlorinated water and iodized salt interfere
with fermentation.
Newer "quick" recipes for the idli can be rice- or wheat-based (rava idli). Parboiled rice, such as
Uncle Ben's can reduce the soaking time considerably. Store-bought ground rice is available, or
Cream of Rice may be used. Similarly, semolina or Cream of Wheat may be used for rava idli.
Yoghurt may be added to provide the sour flavor for unfermented batters. Prepackaged mixes
allow for almost instant idlis, for the truly desperate. However, the additional health benefits of
fermentation process will be lacking. Idli Burger is another variation that can be made easily.
Besides the microwave steamer, electric idli steamers are available, with automatic steam release
and shut-off for perfect cooking. Both types are non-stick, so a fat-free idli is possible. Tablemounted electric Wet grinders may take the place of floor-bound attu kal. With these appliances,
even the classic idlis can be made more easily.
The plain rice/black lentil idli continues to be the popular version, but it may also incorporate a
variety of extra ingredients, savory or sweet. Mustard seeds, fresh chile peppers, black pepper,
cumin, coriander seed and its fresh leaf form (cilantro), fenugreek seeds, curry leaves , fresh
ginger root, sesame seeds, nuts, garlic, scallions, coconut, and the unrefined sugar jaggery are all
possibilities. Filled idlis contain small amounts of chutneys, sambars, or sauces placed inside
before steaming. Idlis are sometimes steamed in a wrapping of leaves such as banana leaves or
jackfruit leaves.
A variety of idlis are experimented these days, namely, standard idli, mini idlis soaked in
sambar, rava idli, Kancheepuram idli, stuffed idli with a filling of potato, beans, carrot and
masala, ragi idli, pudi idli with the sprinkling of chutney pudi that covers the bite-sized pieces of
idlis, malli idli shallow-fried with coriander and curry leaves, and curd idli dipped in masala
curds.
Ramasseri Idli : Ramasseri, an offbeat village in Palakkad is known all over Kerala for the
idlies it make - the delicious Ramasseri Idli. Spongy and soft Ramasseri Idli is slightly different
in shape from the conventional idlies. It is a little flat and round. Ramasseri Idli is eaten with
Podi mixed in coconut oil. The beginning was from a Muthaliyar family living near Mannath
Bhagavathi Temple in Ramasseri near Elappullly.The recipe of Ramasseri idli dates back to
about one century,which again is a trade secret. The Muthaliyar family was migrated to Palakkad
from Kanchipuram in Tamil Nadu. The new generation in the profession says that the secret of
the recipe and taste were handed down to them from grand old women of the community. Now
the idli business is confined to four families in Ramasseri. Selection of rice is very important in
making Ramasseri idli. Usually the verities used are Kazhama, Thavalakannan, Ponni etc. The
taste starts from the boiling of paddy itself. Drying and dehusking are also important. It is done
in a particular way. The combination of rice and black gram is also equally important. For 10 kg
of rice, one kg of black gram is used. Idli is made only after four hours of fermentation. Boiling
of the idli is done on a cloth covered on the mud pot using firewood. This provides special taste
to the preparation.
Leftover Idli can be torn into crumbs and used for preparing dishes such as Idli fry and Idli
Upma.
Picture gallery
The South Indian staple
breakfast item of idli,
Idli and Vada served with
sambar, and vada served on Tatte Idli:
sambar and two type of
a banana leaf. Note the
variations from
chutneys (green and red)
stainless steel plates and
Karnataka
on banana leaf.
cups; characteristic of south
Indian dining tables.
Sambar idli: Idli
soaked in sambar.
Chutney is the best
companion for this
dish.
Button Idli. This usually
contains fourteen idli and is
MTR idli: Famous Mavalli therefore called "fourteen
Tiffin Room idli served idli". However this name
Sanna(s), a Goan
came from Floating idli
with pure ghee and
variant of idli.
(small idlies floating on
sambar. Pure ghee is
poured on steaming idli sambar, rasam or butter
and relished with chutney milk)
or sambar.
12.Write a brief account on bread making.
BREAD
Bread is one of the fermented food products, the fermentation being brought about mainly by
yeast.
Methods of bread production:The bread is made by a number of procedures. But the most common methods utilized
are,
1. Sponge dough
2. Straight dough
3. Continuous mix
4. Liquid ferment.
Sponge dough:This is the predominant bread making method using by the baking industry.
Sponge comprises of about 65% of about total flour + a portion of total dough water +
yeast & yeast food, its first mixed. This mixing period is brief. The sponge is then discharged
into a trough where it will undergo a fermentation period of 4-5 hrs from starting temperature of
about 25 0 C to a final rise by 6 0C. Due to exothermic reactions brought about by yeast activity.
Sponge volume will increase due to CO2 production.
At the end of sponge fermentation, the sponge is transferred into a dough mixture. The
balance of the flour, water remaining ingredients are added into the mixture and allow mixing.
First at low speed & at higher speed until the dough is completely mixed. At this point dough has
been transformed from a sticky wet appearing nature into smooth cohesive dough characterized
by glossy sheen, upon addition of water & input of energy wheat protein & lipids form gluten.
The dough due to the unique nature of gluten able to retain the gas & is thereby leavened.
The mixed dough is placed in troughs & allows resting for 20-30 minutes.
Dividing the dough is the next stage. The dough is cut into pieces of desired weight by a
machine & conveyed on a belt to a rounder where the rough appearing pieces are removed such
that the pieces are held for a rest period of 8-12minutes to compensate for the loss of gas.
The dough pieces are conveyed to moulding machines, which transform the round dough
pieces into cylinders. Automatic moulders feed the dough cylinders into bread pans.
Pans-containing dough pieces are placed in fermentation unit called proof-boxes, for last
fermentation period prior to baking. They are held at 35-43 0C at a relative humidity of 80-95%
for 60minutes. The proof lobes are placed in oven for baking. Gas within the dough expands.
Steam & alcohol vapors also contribute to this expansion. Enzymes are active until the bread
reaches 75 0C. At this temperature starch gelatinizes & dough structure is set. When the bread
surface temperature reaches the 130-140 0C sugars & soluble proteins react chemically to
produce an attractive crust colors. The center of the leaf doesn’t exceed 100 0c.
Remaining stages in bread making process includes cooling of the baked bread, slicing,
wrapping & distribution to stores.
Function of yeast in bread making:Major function of yeast in bread making includes:
1. Leavening
2. Flavor development
3. Dough maturing
1. Leavening:Dough is usually leavened by bread yeast which ferment the sugars in the dough & produce
Co2 &
alcohol. There is little or no growth during the first 2hrs, after the yeast is added to dough, but
some growth in 2-4hrs & then there is a decline in growth in 4-6hrs. Fermentation by the yeast
begins as soon as the dough mixed & continuous until the temperature of oven inactivates the
yeast enzyme.
During fermentation conditioning of the dough takes place when the flour proteins
(gluten) mature i.e., it becomes elastic & springy & are therefore capable of retaining maximal
amount of CO2 produced by the yeast. The conditioning results from action on the gluten by:
Proteolytic enzymes in the flour from the yeast & Malt.
Reduction in pH by the acids added & formed.
Dough conditioners called yeast foods are added which include ammonium salts to stimulate
the yeast &
various salts.
Example:- Kbro3,Cao,KIO 3 to improve dough characteristics.
Adding increases the rate of gas production by the yeast,
More yeast.
Sugar or amylase bearing malt
Yeast food.
The main objective of the baking during leavening is to have enough gas produced & to
have dough
that will hold the gas at the right time.
Heterofermentative lactic acid bacteria & saccharolytic anaerobes can accomplish
leavening. Leavening by chemicals is accomplished by using baking powder or by C02 gas,
which may be incorporated directly, or ammonium bicarbonate may be used.
2. Flavor development:Fresh bread has a pleasing & appealing flavor. Bread flavor is derived from 2 main sources.
Yeast fermentation
Crust browsing
Yeast fermentation:The characteristics flavor yeast raised bread arises from yeast fermentation & subsequent
reaction of
fermentation products with other dough compounds during baking. During baking some of these
flavor compounds escape & other react with amino acids & other compounds of the dough to
yield characteristic flavor of bread. Fermentation byproduct formed during yeast fermentation is
organic esters, acids, alcohol, carboxyl compounds. Some of the organic compounds formed
during fermentation may arise from bacterial action.
Lactic acid bacteria found in dough are associated with yeast. In addition to
Saccharomyces cerevisiae other yeast may be responsible for characteristic flavor of certain
breads.
Breakdown products of flavor proteins play an important role in flavor & color
development. Yeast proteolytic enzyme modify peptones & polypeptides for growth, a portion
of these product react with sugars to impart desirable flavor upon baking.
Crust Browning:The extent of crust browning is influenced by previous activities of in the Saccharomyces
cerevisiae dough. A part of bread flavor is formed in the crust during baking & then diffuses
into crumb where it becomes observed.
Compounds produced during Fermentation & Baking:Organic acids
compounds
Aldehydes/Ketones
Alchol
Carbonyl
Butyric
Acetaldehyde
Ethanol
Furfural
Succinic
HCHO
n-propanol
Glyoxal
Propionic
Acetone
Isobutanol
Methional
Isobutyric
furfural
Diacetyl
Amyl alcohol
Hydroxy methyl
Isovaleric
Acetoin
Isoamyl alcohol
Palmitic
Acetic
Lactic
Formic
Caproic
Valeric
Lauric
Myristic
3. Dough Maturing:The changes caused by yeast in the dough are called dough maturing or ripening. A
properly matured
dough exhibits optimum rheological properties [optimum dough balance of extensibility &
Elasticity] such that it may be machined well & will lead to bread with desirable volume &
crumb characteristics, some of the reactions leading to dough maturing are as follows.
Alcohol & Co2 are derived from yeast fermentation. Alcohol is water miscible & since
appreciable amounts are formed. It influences the colloidal nature of the flour proteins &
alters the interfacial tension within the dough. Some of the CO2 dissolves in aqueous phase
& form carbonic acid, which lowers the pH of the system. CO2 also distends the dough work
into the dough system.
Ammonia from ammonium sulphate & ammonium chloride added to the dough, as yeast
foods are assimilatory S. cerevisiae causing a liberation of H2SO4 & HCl. These acids along
with carbonic aid lower the pH, Which in turn influences
Gluten hydration & Swelling
The reaction rate of enzyme in the dough
Oxidation-reduction reactions &
Various chemical reactions.
ACIDOPHILUS MILK
Use:
A lactobacillus acidophilus organism are able to get themselves implanted in the large intestine of
human beings through regular consumption of product and thereby controls GI disorders such as diarrhea,
dyspepsia, constipation, flatulence, colitis in adults and children.
13.Write a brief account on Wine production.
Harvest in late summer (August), without tools,
mainly by men.
Grapes were placed into baskets.
The baskets were emptied into a treading vat.
Treading the grapes underfoot.
The remainder was pressed (wrung out) in a cloth or
a sack to gather all liquid.
Fermentation (i.e. grape juice turns into wine - sugar
turns into alcohol); the wine has to be sealed,
otherwise it turns into vinegar.
one or two days of fermentation - light
wine
several weeks - heavy wine
longer period - wine turns into vinegar
From the scant evidence it seems that red wine was
very common in ancient Egypt; white wine is first
securely attested in the third century AD.
In the tomb of Tutankhamun wine jars were found
with the inscription: irp nDm 'Sweet wine'. Partly
dried grapes, (because they contain concentrated
sugar) were used for producing sweet wine.
'Blended wine' (irp smA), appears on labels found at
Malqata. It is not certain whether wine of different
years, vineyards or types were mixed.
Other wines mentioned in Egyptian texts were made
from sweet fruits, such as dates and fig.
14. Explain the production of Beer.
There are four main ingredients in a real Beer:
Sweet wines have a high alcohol content and
are therefore longer resistant
WATER - The quantity and variety of dissolved salts in the water used will play a great part in
the character of the final beer. The salts play a part in the extraction of fermentable sugars from
the grain as well as affecting the way the yeast behaves during fermentation. The total salts in
Pilsen's water amounts to around 30 parts per million whereas in Burton on Trent UK, the
content is 1220 parts per million. The main salts of interest are as follows; Calcium - increases
the extract (efficiency of extracting sugars during mashing). It can also help to make the beer
clearer. Sulphates - enhance the bitterness of the hops. It was Calcium Sulphate in the local water
in Burton on Trent that helped to create the pale ale style of beer. Chlorides - help to enhance
sweetness. These are relatively high in the waters of Dublin and London. This is where Porters
and Stouts originated. Part of the modern brewing process involves modifying the content of
these key ions to produce a water that is best suited to the style of beer being produced. .
MALT - Grapes can be made to release their sugars simply by crushing. In more Northern
latitudes where grapes and sweet fruits do not readily grow ancient people turned to another
source. It was probably discovered by accident that as a harvested grain started to germinate, it's
sugar content seemed to increase. This was due to the conversion of starches in the grain into
sugars as the seed began to germinate. If this process is stopped by drying at an optimal point in
this process, the grain will contain some sugars plus a quantity of enzymes to aid the extraction
of fermentable sugars. The process of mashing (see below) makes use of these enzymes to do
just this job.
HOPS - Winemakers used to add aroma to their wines through adding spices and fruit. The
favourite for brewers is to add the flower of the hop vine. When wine makers moved to ageing
their wines in oak casks, they discovered that the wood performed a similar job but most modern
beers are too light in flavour to cope with this process. The herbs and spices once added to wine
also acted as a preservative. The hop cones added to beer also perform very well in this respect.
The hops add alpha and beta acids that provide bitterness and aroma to the final product. Hops
are chosen for their content in these products as required by the beer being produced. They are
also added at different stages in the process depending on whether they are being used to provide
bitterness or aroma. Our beers use hops to provide both bitterness and aroma.
YEAST - The first winemakers did not realise the spontaneous fermentation of their grapes was
caused by the wild yeasts that collected on the skins of the grapes. Some styles of beers still
make use of wild yeasts but as the yeast has such a contribution to make to the character of the
final beer, most modern brewers prefer to control the yeast culture. They style of ales we produce
uses top fermenting yeast. These are yeasts that form a foam on the top of the beer during
fermentation. This foam is skimmed at a certain stage in the fermentation and used to start the
next beer fermenting. These yeasts are used at higher temperatures. They are pitched in at around
15 deg C and the fermentation temperature rises as the yeast culture grows. The temperature can
rise to 25C or more but must be controlled to prevent undesirable products being produced that
can affect the final flavour. The sugar content of the liquid is monitored throughout the
fermentation and the process is stopped when the desired alcohol strength is reached.
The Process
The malt is cracked (rolled between precisely set rollers) to just split the grains but not produce
flour. This stage is critical as we just need grains that are split to release the sugars and enzymes.
Grains that are crushed to a flour prevent the mash from being effective and can block filters etc
later in the process. This cracked grain is mixed with water at a precisely controlled temperature
of around 67 C. This is a temperature that stimulates the enzymes in the malt to convert starches
to sugars that are released into the liquid now called a wort.
A process known as sparging is used to try to maximise the extraction by adding more water
until the volume of liquid is correct and then recirculating the wort through the grain. Once the
sugar extraction is completed 90-120 minutes, the wort is pumped through to a large boiler
known as a 'copper'. The wort is now brought to the boil at which point the first batch of hops is
added. Hops added at this stage are for bitterness. Any aroma imparted from the hops added at
this stage will be boiled off. The wort is boiled for around 90 minutes before the aroma hops are
added and the heat removed. After a short period of time, the wort is rapidly cooled and
transferred to a fermentation vessel at around 17 deg C. The yeast is added as soon as conditions
are right and fermentation generally starts in a few hours. It is important that the temperature is
controlled within tight limits as this affects the fermentation products and hence characteristics
of the final beer. After a few days, the sugar content and alcohol content reach a target value and
the fermentation is stopped by cooling the beer below the yeast activation temperature. The yeast
is removed and the beer is then pumped to conditioning tanks. It remains in these tanks for a few
days to mature before being transferred to casks or bottles. Bottling involves an additional
process to encourage further conditioning in the bottle. The bottled beer is not filtered or
pasteurised so that the beer continues to develop once bottled as long as the environment is
suitable. If the bottles are stored upright at 14-17 deg C, the yeast continues to ferment slightly
and adds some condition to the beer. This yeast will also fall to the bottom of the bottle so the
beer should be decanted in one go to prevent the yeast returning to suspension.
It is the control of this process from start to finish that ensures a high quality product. Realising
this, we at 'Le Brewery' make great efforts to carefully control this process so that every bottle
tastes as good as the last.
We look forward to your visit and feel sure you will enjoy our hand crafted traditional beers.
15.Write a brief note on Plant based fermented foods.
Miso is a traditional Japanese food produced by fermenting rice, barley and/or soybeans, with
salt and the fungus kōjikin (the most typical miso is made with soy). The typical result is a thick
paste used for sauces and spreads, pickling vegetables or meats, and mixing with dashi soup
stock to serve as miso soup called Misoshiru a Japanese culinary staple. High in protein and rich
in vitamins and minerals, miso played an important nutritional role in feudal Japan. Miso is still
very widely used in Japan, both in traditional and modern cooking, and has been gaining worldwide interest. Miso is typically salty, but its flavor and aroma depend on various factors in the
ingredients and fermentation process. Different varieties of miso have been described as salty,
sweet, earthy, fruity, and savory, and there is an extremely wide variety of miso available.
History
The predecessor of miso originated in China during the 3rd century BC or earlier, and it is
probable that this, together with related fermented soy-based foods, was introduced to Japan at
the same time as Buddhism in the 6th century AD
During the Edo period miso was also called hishio and kuki.
Until the Muromachi era, miso was made without grinding the soybeans, somewhat like natto. In
the Kamakura era, a common meal was made up of a bowl of rice, some dried fish, a serving of
miso, and a fresh vegetable. In the Muromachi era, Buddhist monks discovered that soybeans
could be ground into a paste, spawning new cooking methods where miso was used to flavor
other foods.
Variety
By flavor
The taste, aroma, texture, and appearance of any specific miso vary by miso type as well as the
region and season for which the miso was made. The ingredients used, temperature and duration
of fermentation, salt content, variety of kōji, and fermenting vessel all contribute. The most
common flavor categories of soy miso are:
Shiromiso, "white miso"
Akamiso, "red miso"
Kuromiso, "black miso"
Hatchomiso
White and red (shiromiso and akamiso) are the basic types of miso available in all of Japan as
well as overseas. Different varieties are preferred in particular regions. For example, in the
eastern Kantō region that includes Tokyo, the lighter shiromiso is popular, while in the western
Kansai region encompassing Osaka, Kyoto, and Kobe, darker brownish hatchomiso is preferred,
and akamiso is favoured in the Tokai area.
By ingredient
The raw materials used to produce miso may include any mix of soybeans, barley, rice,
buckwheat, millet, rye, wheat, hemp seed, and cycad, among others. Lately, producers in other
countries have also begun selling miso made from chick peas, corn, adzuki beans, amaranth, and
quinoa. Fermentation time ranges from as little as five days to several years. The wide variety of
Japanese miso is difficult to classify, but is commonly done by grain type, color, taste, and
background.
mugi : barley
tsubu : whole wheat/barley
aka : red, medium flavor
hatchō : aged (or smoked), strongest flavor, along with 'shiro' is most commonly used
shiro : rice, sweet white, fresh, along with 'hatcho' is most commonly used
shinshu: rice, brown color
genmai : brown rice
awase : layered, typically in supermarket
moromi : chunky, healthy (kōji is unblended)
nanban : chunky, sweet, for dipping sauce
inaka : farmstyle
taima : hemp seed
sobamugi : buckwheat
hadakamugi : rye
meri : made from cycad pulp, Buddhist temple diet
gokoku : "5 grain": soy, wheat, barley, proso millet, and foxtail millet
Many regions have their own specific variation on the miso standard. For example, the soybeans
used in Sendai miso are much more coarsely mashed than in normal soy miso.
Miso made with rice (including shinshu and shiro miso) is called kome miso.
Using miso
Storage and preparation
Miso typically comes as a paste in a sealed container, and should be refrigerated after opening. It
can be eaten raw, and cooking changes its flavor and nutritional value; when used in miso soup,
most cooks do not allow the miso to come to a full boil. Some people, especially those outside of
Japan, go so far as to only add miso to preparations after they have cooled, to preserve the
biological activity of the kōjikin. Since miso and soy foods play a large role in the Japanese diet,
there are a variety of cooked miso dishes as well.
In food
Miso is a part of many Japanese-style meals. It most commonly appears as the main ingredient of
miso soup, which is eaten daily by much of the Japanese population. The pairing of plain rice
and miso soup is considered a fundamental unit of Japanese cuisine. This pairing is the basis of a
traditional Japanese breakfast.
Miso is used in many other types of soup and souplike dishes, including some kinds of ramen,
udon, nabe, and imoni. Generally, such dishes have the title miso prepended to their name (for
example, miso-udon), and have a heavier, earthier flavor and aroma compared to other Japanese
soups that are not miso-based.
Many traditional confections use a sweet, thick miso glaze, such as mochidango. Miso glazed
treats are strongly associated with Japanese festivals, although they are available year-round at
supermarkets. The consistency of miso glaze ranges from thick and taffy-like to thin and drippy.
Soy miso is used to make a type of pickle called "misozuke".These pickles are typically made
from cucumber, daikon, hakusai, or eggplant, and are sweeter and less salty than the standard
Japanese salt pickle. Barley miso, or nukamiso, is used to make another type of pickle.[4]
Nukamiso is a fermented product, and considered a type of miso in Japanese culture and
linguistics, but does not contain soy, and so is functionally quite different. Like soy miso,
nukamiso is fermented using kōji mold.
Other foods with miso as an ingredient include:
dengaku (charcoal-grilled miso covered tofu)
yakimochi (charcoal-grilled miso covered mochi)
miso braised vegetables or mushrooms
marinades: fish or chicken can be marinated in miso and sake overnight to be grilled.
corn on the cob in Japan is usually coated with shiro miso, wrapped in foil and grilled.
sauces: sauces like misoyaki (a variant on teriyaki) are common.
Nutrition and health
The nutritional benefits of miso have been widely touted by commercial enterprises and home
cooks alike. However, claims that miso is high in vitamin B12 have been contradicted in some
studies [1]. Part of the confusion may stem from the fact that some soy products are high in B
vitamins (though not necessarily B12), and some, such as soy milk, may be fortified with vitamin
B12. Some, especially proponents of healthy eating, suggest that miso can help treat radiation
sickness, citing cases in Japan and Russia where people have been fed miso after the Chernobyl
nuclear disaster and the atomic bombings of Hiroshima and Nagasaki. Notably, Japanese doctor
Shinichiro Akizuki, director of Saint Francis Hospital in Nagasaki during World War II,
theorized that miso helps protect against radiation sickness. Also some experts suggest that miso
is a source of Lactobacillus acidophilus.
Olive:
The Olive (Olea europaea) is a species of small tree in the family Oleaceae, native to the coastal
areas of the eastern Mediterranean region, from Lebanon, Syria and the maritime parts of Asia
Minor and northern Iran at the south end of the Caspian Sea. Its fruit, the olive, is of major
agricultural importance in the Mediterranean region as the source of olive oil.
Description
The Olive Tree is an evergreen tree or shrub native to the Mediterranean, Asia and parts of
Africa. It is short and squat, and rarely exceeds 8–15 meters in height. The silvery green leaves
are oblong in shape, measuring 4–10 cm long and 1–3 cm wide. The trunk is typically gnarled
and twisted.
The small white flowers, with four-cleft calyx and corolla, two stamens and bifid stigma, are
borne generally on the last year's wood, in racemes springing from the axils of the leaves.
The fruit is a small drupe 1–2.5 cm long, thinner-fleshed and smaller in wild plants than in
orchard cultivars. Olives are harvested at the green stage or left to ripen to a rich purple colour
(black olive). Canned black olives may contain chemicals that turn them black artificially.
History
The olive is one of the plants most cited in recorded literature. In Homer's Odyssey, Odysseus
crawls beneath two shoots of olive that grow from a single stock.[1] The Roman poet, Horace
mentions it in reference to his own diet, which he describes as very simple: "As for me, olives,
endives, and smooth mallows provide sustenance."[2] Lord Monboddo comments on the olive in
1779 as one of the foods preferred by the ancients and as one of the most perfect foods.[3]
The leafy branches of the olive tree, olive leaf as a symbol of abundance, glory and peace, were
used to crown the victors of friendly games and bloody war. As emblems of benediction and
purification, they were also ritually offered to deities and powerful figures: some were even
found in Tutankhamen's tomb.
Olive oil has long been considered sacred; it was used to anoint kings and athletes in ancient
Greece. It was burnt in the sacred lamps of temples as well as being the "eternal flame" of the
original Olympic Games. Victors in these games were crowned with its leaves. Today it is still
used in many religious ceremonies.
According to Greek mythology the Olive tree, her gift to the people of Attica, won Athena the
patronage of the city of Athens over Poseidon.
Cultivation and uses
An example of black olives.
The olive tree has been cultivated since ancient times as a source of olive oil, fine wood, olive
leaf, and olives for consumption. The naturally bitter fruit is typically subjected to fermentation
or cured with lye or brine to make it more palatable.
Green olives and black olives are washed thoroughly in water to remove oleuropein, a bitter
carbohydrate. Sometimes they are also soaked in a solution of food grade sodium hydroxide in
order to accelerate the process.
Green olives are allowed to ferment before being packed in a brine solution. American black
("California") olives are not fermented, which is why they taste milder than green olives.
It is not known when olives were first cultivated for harvest. Among the earliest evidence for the
domestication of olives comes from the Chalcolithic Period archaeological site of Teleilat
Ghassul in what is today modern Jordan.
The plant and its products are frequently referred to in the Bible, the Book of Mormon, the
Qur'an, and by the earliest recorded poets. Farmers in ancient times believed olive trees would
not grow well if planted more than a short distance from the sea; Theophrastus gives 300 stadia
(55.6 km) as the limit. Modern experience does not always confirm this, and, though showing a
preference for the coast, it has long been grown further inland in some areas with suitable
climates, particularly in the southwestern Mediterranean (Iberia, northwest Africa) where winters
are mild.
Olive plantation in Andalucia, Spain.
Olives are now cultivated in many regions of the world with Mediterranean climates, such as
South Africa, Chile, Australia, Mediterranean Basin, Israel, Palestinian Territories and California
and in areas with temperate climates such as New Zealand, under irrigation in the Cuyo region in
Argentina which has a desert climate. They are also grown in the Córdoba Province, Argentina,
which has a temperate climate with rainy summers and dry winters (Cwa)[11]; the climate in
Argentina changes the external characteristics of the plant but the fruit keeps its original
characteristics [12]. Considerable research supports the health-giving benefits of consuming
olives, olive leaf and olive oil (see external links below for research results).
The olive tree provides leaves, fruit and oil. Olive leaves are used in medicinal teas.
Subspecies
There are at least five natural subspecies distributed over a wide range:
Olea europaea subsp. europaea (Europe)
Olea europaea subsp. cuspidata (from Eritrea and Ethiopia south throughout East Africa, also in
Iran to China)
Olea europaea subsp. guanchica (Canaries)
Olea europaea subsp. maroccana (Morocco)
Olea europaea subsp. laperrinei (Algeria, Sudan, Niger, India)
Cultivars
Small Olive Tree
Large Olive Tree
Olive Tree Leaves
Olive Tree Trunk
Olive Flowers
A young olive plant, germinated from a seed
Monumental tree in Apulia Region - Southern Italy
There are thousands of cultivars of the olive. In Italy alone at least three hundred cultivars have
been enumerated, but only a few are grown to a large extent. The main Italian cultivars are
'Leccino', 'Frantoio' and 'Carolea'. None of these can be accurately identified with ancient
descriptions, though it is not unlikely that some of the narrow-leaved cultivars most esteemed
may be descendants of the Licinian olive. The Iberian olives are usually cured and eaten, often
after being pitted, stuffed (with pickled pimento, anchovies, or other fillings) and packed in brine
in jars or tins.
Since many cultivars are self sterile or nearly so, they are generally planted in pairs with a single
primary cultivar and a secondary cultivar selected for its ability to fertilize the primary one, for
example, 'Frantoio' and 'Leccino'. In recent times, efforts have been directed at producing hybrid
cultivars with qualities such as resistance to disease, quick growth and larger or more consistent
crops.
Some particularly important cultivars of olive include:
'Manzanillo', a large, rounded-oval fruit, with purple-green skin. Rich taste and thick pulp. A
prolific bearer, grown around the world.
'Frantoio' and 'Leccino'. These cultivars are the principal participants in Italian olive oils from
Tuscany. Leccino has a mild sweet flavour while Frantoio is fruity with a stronger aftertaste. Due
to their highly valued flavour, these cultivars are now grown in other countries.
'Arbequina' is a small, brown olive grown in Catalonia, Spain, good for eating and for oil.
'Empeltre' is a medium-sized black olive grown in Spain, good for eating and for oil.
'Kalamata' is a large, black olive with a smooth and meatlike taste, named after the city of
Kalamata, Greece, used as a table olive. These olives are usually preserved in vinegar or olive oil.
Kalamata olives enjoy PDO (Protected designation of origin) status.[13]
'Koroneiki' originates from the southern Peloponese, around Kalamata and Mani in Greece. This
small olive, though difficult to cultivate, has a high yield of olive oil of exceptional quality.
'Pecholine' or 'picholine' originated in the south of France. It is green, medium size, and
elongated. The flavour is mild and nutty.
'Lucques' originated in the south of France (Aude département). They are green, large, and
elongated. The stone has an arcuated shape. Their flavour is mild and nutty.
'Souri' (Syrian) originated in Lebanon and is widespread in the Levant. It has a high oil yield and
exceptionally aromatic flavour.
'Nabali' is a Palestinian cultivar[14] also known locally as 'Baladi', which along with 'Souri' and
'Malissi' are considered to produce among the highest quality olive oil in the world.[15]
'Barnea' is a modern cultivar bred in Israel to be disease-resistant and to produce a generous crop.
It is used both for oil and for table olives. The oil has a strong flavour with a hint of green leaf.
Barnea is widely grown in Israel and in the southern hemisphere, particularly in Australia and
New Zealand.
'Maalot' (Hebrew for merits) is another modern Israeli, disease-resistant, Eastern Mediterranean
cultivar derived from the North African 'Chemlali' cultivar. The olive is medium sized, round, has
a fruity flavour and is used almost exclusively for oil production.
'Mission' originated on the California Missions and is now grown throughout the state. They are
black and generally used for table consumption.
Growth and propagation
Olive trees show a marked preference for calcareous soils, flourishing best on limestone slopes
and crags, and coastal climate conditions. They tolerate drought well, thanks to their sturdy and
extensive root system. Olive trees can be exceptionally long-lived, up to several centuries, and
can remain productive for as long, provided they are pruned correctly and regularly.
The olive tree grows very slowly, but over many years the trunk can attain a considerable
diameter. A. P. de Candolle recorded one exceeding 10 m in girth. The trees rarely exceed 15 m
in height, and are generally confined to much more limited dimensions by frequent pruning. The
yellow or light greenish-brown wood is often finely veined with a darker tint; being very hard
and close-grained, it is valued by woodworkers.
The olive is propagated in various ways, but cuttings or layers are generally preferred; the tree
roots easily in favourable soil and throws up suckers from the stump when cut down. However,
yields from trees grown from suckers or seeds are poor; it must be budded or grafted onto other
specimens to do well (Lewington and Parker, 114). Branches of various thickness are cut into
lengths of about 1 m and, planted deeply in manured ground, soon vegetate; shorter pieces are
sometimes laid horizontally in shallow trenches, when, covered with a few centimetres of soil,
they rapidly throw up sucker-like shoots. In Greece, grafting the cultivated tree on the wild form
is a common practice. In Italy, embryonic buds, which form small swellings on the stems, are
carefully excised and planted beneath the surface, where they grow readily, their buds soon
forming a vigorous shoot.
Occasionally the larger boughs are marched, and young trees thus soon obtained. The olive is
also sometimes raised from seed, the oily pericarp being first softened by slight rotting, or
soaking in hot water or in an alkaline solution, to facilitate germination.
Where the olive is carefully cultivated, as in Languedoc and Provence, the trees are regularly
pruned. The pruning preserves the flower-bearing shoots of the preceding year, while keeping
the tree low enough to allow the easy gathering of the fruit. The spaces between the trees are
regularly fertilized. The crop from old trees is sometimes enormous, but they seldom bear well
two years in succession, and in many instances a large harvest can only be reckoned upon every
sixth or seventh season.
A calcareous soil, however dry or poor, seems best adapted to its healthy development, though
the tree will grow in any light soil, and even on clay if well drained; but, as remarked by Pliny,
the plant is more liable to disease on rich soils, and the oil is inferior to the produce of the poorer
and more rocky ground.
In general, a temperature below 14 °F (-10 °C) may cause considerable injury to a mature tree,
but (with the exception of juvenile trees) a temperature of 16 °F (-9 °C) will normally cause no
harm.
Fruit harvest and processing
Most olives today are harvested by shaking the boughs or the whole tree. Another method
involves standing on a ladder and "milking" the olives into a sack tied around the harvester's
waist.Using olives found lying on the ground can result in poor quality oil.
In southern Europe the olive harvest is in winter, continuing for several weeks, but the time
varies in each country, and also with the season and the kinds cultivated. A device called the olinet wraps around the trunk of the tree and opens to form an umbrella-like catcher; workers can
then harvest the fruit without the weight of the load around their neck. Another device, the
oliviera, is an electronic tool that connects to a battery. The oliviera has large tongs that are spun
around quickly, removing fruit from the tree. This method is used for olives used for oil. Table
olive varieties are more difficult to harvest, as workers must take care not to damage the fruit;
baskets that hang around the worker's neck are used.
The amount of oil contained in the fruit differs greatly in the various cultivars; the pericarp is
usually 60–70% oil. Typical yields are 1.5-2.2 kg of oil per tree per year.
Traditional fermentation
Olives freshly picked from the tree contain phenolic compounds and oleuropein, a glycoside
which makes the fruit unpalatable for immediate consumption. There are many ways of
processing olives for table use. Traditional methods use the natural microflora on the fruit and
procedures which select for those that bring about fermentation of the fruit. This fermentation
leads to three important outcomes: the leaching out and breakdown of oleuropein and phenolic
compounds; the creation of lactic acid, which is a natural preservative; and a complex of
flavoursome fermentation products. The result is a product which will store with or without
refrigeration.
One basic fermentation method is to get food grade containers, which may include plastic
containers from companies which trade in olives and preserved vine leaves. Many bakeries also
recycle food grade plastic containers which are well sized for olive fermentation; they are 10 to
20 litres in capacity. Freshly picked olives are often sold at markets in 10 kg trays. Olives should
be selected for their firmness if green and general good condition. Olives can be used green, ripe
green (which is a yellower shade of green, or green with hints of color), through to full purple
black ripeness. The olives are soaked in water to wash them, and drained. 7 litres (which is 7 kg)
of room temperature water is added to the fermentation container, and 800 g of sea salt, and one
cup (300g) of white vinegar (white wine or cider vinegar). The salt is dissolved to create a 10%
solution (the 800 g of salt is in an 8 kg mixture of salt and water and vinegar). Each olive is
given a single deep slit with a small knife (if small), or up to three slits per fruit (if large, eg 60
fruit per kg). If 10 kg of olives are added to the 10% salt solution, the ultimate salinity after some
weeks will be around 5 to 6% once the water in the olives moves into solution and the salt moves
into the olives. The olives are weighed down with an inert object such as a plate so they are fully
immersed and lightly sealed in their container. The light sealing is to allow the gases of
fermentation to escape. It is also possible to make a plastic bag partially filled with water, and
lay this over the top as a venting lid which also provides a good seal. The exclusion of oxygen is
useful but not as critical as when grapes are fermented to produce wine. The olives can be tasted
at any time as the bitter compounds are not poisonous, and oleuropein is a useful antioxidant in
the human diet.
The olives are edible within 2 weeks to a month, but can be left to cure for up to three months.
Green olives will usually be firmer in texture after curing than black olives. Olives can be
flavored by soaking them in various marinades, or removing the pit and stuffing them. Herbs,
spices, olive oil, feta, capsicum (pimento), chili, lemon zest, lemon juice, garlic cloves, wine,
vinegar, juniper berries, and anchovies are popular flavorings. Sometimes the olives are lightly
cracked with a hammer or a stone to trigger fermentation. This method of curing adds a slightly
bitter taste.
16.Write a brief note on Tempeh Production.
Tempeh is a nutritional super hero. It is high in protein, dietary fiber, iron, potassium, calcium, and
phytochemicals like isoflavones. It has been shown to lower cholesterol, high blood pressure and the risk
of heart attack and stroke; reduce the risk of some cancers, like colon, breast, ovarian and prostate; ease
certain menopausal symptoms; prevent and possibly even reverse the effects of osteoporosis and diabetes.
To obtain these protective properties, researchers recommend consuming a minimum of 25 grams soy
protein and 30-50 milligrams isoflavones daily. This works out to about 1-2 servings a day. One serving
of tempeh, which is 1/2 cup (4 ounces), provides on average 19 grams soy protein, 60 milligrams
isoflavones and 7 grams dietary fiber (28% RDA). Tempeh made with only soybeans has more soy
protein and isoflavones than those with added grain. Whatever variety you choose, tempeh is the best
source and easiest way to get lots of high quality protein, isoflavones and fiber in a minimally processed
soy food. Each serving also supplies about 100 milligrams calcium (10% RDA), 550 milligrams
potassium (16% RDA), and 5 milligrams iron (30% RDA).
2. Tempeh is a great choice for people who have difficulty digesting plant-based high-protein foods like
beans and legumes or soy foods such as tofu. Because tempeh is a fermented soy product, its enzymes are
partially broken down, making it easier to metabolize. It does not produce the unpleasant gastrointestinal
discomfort and gas that some other plant-based proteins do. This fermentation process actually allows
your body to more easily assimilate and absorb tempeh's nutrients. Besides being a terrific cholesterolfree easy-to-digest meat alternative, it is also ideal for people on low sodium diets. Unlike other
fermented soy products, like miso which is very salty, tempeh is extremely low in sodium.
3. Tempeh has a pleasant, wonderfully unique nutty/mushroom flavor. It's rich and savory taste and firm
texture makes it easy to create fantastic meals without a lot of fuss. It does not need much preparation or
cooking time, making it a marvelously healthy fast food. Just add a little soy sauce or liquid hickory
smoke seasoning to enhance its flavor. Then stir-fry, sauté, microwave, stew or bake it to make a variety
of delightful dishes and sandwiches. To make a hearty entree in a short amount of time, all you need is
tempeh, onions, mushrooms, peppers, olive oil, liquid seasoning, and some cooked brown rice or pasta.
Thinly slice the tempeh. Sprinkle some soy sauce or liquid hickory (or mesquite) smoke seasoning on
both sides of the slices. Slice the onions, mushrooms and peppers, and sauté in a little olive oil for a few
minutes. Add the seasoned tempeh slices and sauté until lightly browned. Salt and pepper to taste.
17. Write a brief note on Country Salt Cured Ham and Bacon.
The dilemma facing pioneer mountain cooks was how to keep freshly butchered meat from spoiling
without refrigeration. Hogs were butchered in the late fall when the temperature was down around 33
degrees, and while the meat was fresh, it was salt cured. The next spring any leftovers would be smoked
under a fire of green hickory or peppered. Sausage was packed in the intestines of the hog, tied off and
also hung in the smokehouse for curing. Salting, peppering, and smoking protected the meat from
spoiling and from insects. Today it's that salt, pepper, and smoky flavor that we love in country ham,
bacon, and sausage.
Clifty Farm's Country Ham
Clifty Farms country ham is from Tennessees oldest smokehouse. Slow bake or boil this salt
cured and hickory smoked ham to serve with your home made biscuits or rolls and your holiday
dinner will be one to remember. Serve lightly re-fried leftovers at breakfast with red-eye gravy.
Four hours soaking recommended.
Ogi:
Ogi is a fermented cereal porridge from West Africa, typically made from maize, sorghum, or
millet. Traditionally, the grains are soaked in water for up to three days, before wet milling and
sieving to remove husks. The filtered cereal is then allowed to ferment for up to three days until
sour. It is then boiled into a pap, or cooked to make a stiff porridge.
The fermentation of ogi is performed by various lactic acid bacteria including Lactobacillus spp,
and various yeasts including Saccharomyces and Candida spp.
Soy sauce:
Soy sauce (US), soya sauce (Commonwealth), or shoyu (Japan) is a fermented sauce made from
soybeans (soya beans), roasted grain, water and salt. Soy sauce was invented in China, where it
has been used as a condiment for close to 2,500 years. In its various forms it is widely used in
East and Southeast Asian cuisines and increasingly appears in Western cuisine and prepared
foods.
Production
Soy sauce is made from soybeans.
Traditional
Authentic soy sauces are made by mixing the grain and/or soybeans with yeast or kōji (麹, the
mold Aspergillus oryzae or A. sojae) and other related microorganisms. Traditionally soy sauces
were fermented under natural conditions, such as in giant urns and under the sun, which was
believed to contribute to additional flavours. Today, most of the commercially-produced
counterparts are fermented under machine-controlled environments instead.
Although there are many types of soy sauce, all are salty and earthy-tasting brownish liquids
used to season food while cooking or at the table. Soy sauce has a distinct basic taste called
umami by the Japanese (鮮味, literally "fresh taste"). Umami was first identified as a basic taste in
1908 by Kikunae Ikeda of the Tokyo Imperial University. The free glutamates which naturally
occur in soy sauce are what give it this taste quality.
Soy sauce should be stored away from direct sunlight.
Artificially hydrolyzed
Many cheaper brands of soy sauces are made from hydrolyzed soy protein instead of brewed
from natural bacterial and fungal cultures. These soy sauces do not have the natural color of
authentic soy sauces and are typically colored with caramel coloring, and are popular in
Southeast Asia and China, and are exported to Asian markets around the globe. They are
derogatorily called Chemical Soy Sauce "化學醬油" in Chinese, but despite this name are the most
widely used type because they are cheap. Similar products are also sold as "liquid aminos" in the
US and Canada.
Some artificial soy sauces posed potential health risks due to their content of the chloropropanols
carcinogens 3-MCPD (3-chloro-1,2-propanediol) and all artificial soy sauces pose health risks
due to the unregulated 1,3-DCP (1,3-dichloro-2-propanol) which are minor byproducts of the
hydrochloric acid hydrolysis [1].
Types
Soy sauce has been integrated into the traditional cuisines of many East Asian and South East
Asian cultures. Soy sauce is widely used as a particularly important flavoring in Japanese, Thai,
and Chinese cuisine. However, it is important to note that despite its rather similar appearance,
soy sauces produced in different cultures and regions are very different in taste, consistency,
fragrance and saltiness. As such, it may not be appropriate to substitute soy sauces of one culture
or region for another.
Chinese soy sauce
A bottle of Chinese soy sauce, artificially hydrolyzed, as clearly evident from the discoloration of the
bottle due to addition of caramel coloring to mask the production method
Chinese soy sauce (simplified Chinese:; traditional Chinese:; pinyin: jiàngyóu; or chǐyóu) is
primarily made from soybeans, with relatively low amounts of other grains. There are two main
varieties:
Light or fresh soy sauce :A thin (non-viscous), opaque, dark brown soy sauce. It is the main soy
sauce used for seasoning, since it is saltier, but it also adds flavour. Since it is lighter in color, it
does not greatly affect the color of the dish. The light soy sauce made from the first pressing of
the soybeans is called tóuchōu (simplified Chinese: 头
抽; traditional Chinese: 頭
抽), which can be
loosely translated as first soy sauce or referred to as premium light soy sauce. Touchōu is sold at
a premium because, like extra virgin olive oil, the flavor of the first pressing is considered
superior. An additional classification of light soy sauce, shuānghuáng (雙
璜), is double-fermented
to add further complexity to the flavour. These latter two more delicate types are usually for
dipping.
Dark/old soy sauce: A darker and slightly thicker soy sauce that is aged longer and contains
added molasses to give it its distinctive appearance. This variety is mainly used during cooking
since its flavour develops under heating. It has a richer, slightly sweeter, and less salty flavour
than light soy sauce. Dark soy sauce is partly used to add color and flavour to a dish.
In traditional Chinese cooking, one of the two types, or a mixture of both, is employed to achieve
a particular flavour and colour for the dish.
Other types:
Thick soy sauce :Dark soy sauce that has been thickened with starch and sugar. It is also
occasionally flavored with MSG. This sauce is not usually used directly in cooking but more
often as a dipping sauce or poured on food as a flavorful addition.
Dark soy paste: Although not really a soy sauce, it is another salty soy product. It is one of the
main ingredients in a dish called zhajiang mian, lit. "fried paste noodles").
Japanese soy sauce
Koyo organic tamari sauce
Buddhist monks introduced soy sauce into Japan in the 7th century, where it is known as
"shoyu". The Japanese word "tamari" is derived from the verb "tamaru" that signifies "to
accumulate," referring to the fact that tamari was traditionally from the liquid byproduct
produced during the fermentation of miso. Japan is the leading producer of tamari.
Japanese soy sauce or shō-yu, is traditionally divided into 5 main categories depending on
differences in their ingredients and method of production. Japanese soy sauces include wheat as
a primary ingredient and this tends to give them a slightly sweeter taste than their Chinese
counterparts. They also have an alcoholic sherry-like flavor. Not all soy sauces are
interchangeable.
Koikuchi
Originating in the Kantō region, its usage eventually spread all over Japan. Over 80% of the
Japanese domestic soy sauce production is of koikuchi, and can be considered the typical
Japanese soy sauce. It is produced from roughly equal quantities of soybean and wheat. This
variety is also called kijōyu (生醤油
) or namashōyu (生しょうゆ) when it is not pasteurized.
Usukuchi
Particularly popular in the Kansai region of Japan, it is both saltier and lighter in color than
koikuchi. The lighter color arises from the usage of amazake, a sweet liquid made from fermented
rice, that is used in its production.
Tamari
Produced mainly in the Chūbu region of Japan, tamari is darker in appearance and richer in
flavour than koikuchi. It contains little or no wheat; wheat-free tamari is popular among people
eating a wheat free diet. It is the "original" Japanese soy sauce, as its recipe is closest to the soy
sauce originally introduced to Japan from China. Technically, this variety is known as misodamari (味
噌溜
り), as this is the liquid that runs off miso as it matures.
Shiro ("white")
A very light colored soy sauce. In contrast to "tamari" soy sauce, "shiro" soy sauce uses mostly
wheat and very little soybean, lending it a light appearance and sweet taste. It is more commonly
used in the Kansai region to highlight the appearances of food, for example sashimi.
Saishikomi ("twice-brewed")
This variety substitutes previously-made koikuchi for the brine normally used in the process.
Consequently, it is much darker and more strongly flavored. This type is also known as kanro
shoyu (甘
露醤
油) or "sweet shoyu".
Shoyu (koikuchi) and light colored shoyu (usukuchi) as sold in Japan by Kikkoman, 1 litre bottles.
Newer varieties of Japanese soy sauce include:
Gen'en ("reduced salt")
Low-salt soy sauces also exist, but are not considered to be a separate variety of soy sauce, since
the reduction in salt content is a process performed outside of the standard manufacture of soy
sauce.
Amakuchi
Called "Hawaiian soy sauce" in those few parts of the US familiar with it, this is a variant of
"koikuchi" soy sauce.
All of these varieties are sold in the marketplace in three different grades according to how they
were produced:
Honjōzō hōshiki
Contains 100% naturally fermented product.
Shinshiki hōshiki
Contains 30-50% naturally fermented product.
Tennen jōzō
Means no added ingredients except alcohol.
All the varieties and grades may be sold according to three official levels of quality:
Hyōjun
Standard pasteurized.
Tokkyū
Special quality, not pasteurized.
Tokusen
Premium quality, usually implies limited quantity.
Other terms unrelated to the three official levels of quality:
Hatsuakane
Refers to industrial grade used for flavoring, powder.
Chōtokusen
Used by marketers to imply the best.
Perhaps the most well-known producer of Japanese soy sauce is the Kikkoman Corporation.
Taiwanese soy sauce
The history of soy sauce making in Taiwan can be traced back to southeastern China, in the
provinces of Fujian and Guangdong. Later, the cultural and political separation between Taiwan
and China since the end of the First Sino-Japanese War in 1895, when China ceded Taiwan to
Japan, brought changes to traditional Chinese soy sauce making in Taiwan. Some of the top
Taiwanese makers, such as Wan Ja Shan, Wei-Wong and Ve-Chung have adopted the more
sophisticated Japanese technology in making soy sauce for the domestic market and more
recently foreign markets as well.
Korean soy sauce
Korean soy sauce, (called Joseon ganjang, 조선간장, in Korean) is a byproduct of the production
of doenjang (Korean fermented soybean paste). Joseon ganjang, thin and dark brown in color, is
made entirely of soy and brine, and has a saltiness that varies according to the producer. Wide
scale use of Joseon ganjang has been somewhat superseded by cheaper factory-made Japanese
style soy sauce, called waeganjang (hangul). Currently, Korean soy sauce is made from dripping
soy sauce chicken into a pan. This process is widely used because in the process of making soy
sauce, you get the benefit of regular chicken. According to the 2001 national food consumption
survey in Korea, traditional fermented ganjang comprised only 1.4% of soy sauce purchases.
Vietnamese soy sauce
Vietnamese soy sauce is called xì dầu, nước tương, or sometimes simply tương.
Indonesian soy sauce
Kecap manis Indonesian thick and sweet soy sauce is nearly as thick as molasses.
In Indonesia, soy sauce is known as kecap (or ketjap) (a catchall term for fermented sauces) from
which according to one theory the English word "ketchup" is derived. Two main varieties exist:
Kecap asin
Salty soy sauce, which is very similar to Chinese light soy sauce, but usually somewhat thicker
and has a stronger flavor; it can be replaced by light Chinese soy sauce in recipes.
Kecap manis
Sweet soy sauce, which has a thick, almost syrupy consistency and a pronounced sweet, treaclelike flavor due to generous addition of palm sugar. It is a unique variety; in a pinch, it may be
replaced by molasses with a little vegetable stock stirred in.
Kecap inggris ("English fermented sauce"), or saus inggris ("English sauce") is the Indonesian
name for Worcestershire sauce. Kecap Ikan is Indonesian fish sauce.
Malaysian soy sauce
In Singapore and Malaysia, soy sauce in general is dòuyóu (豆油); dark soy sauce is called
jiàngyóu (醬油) and light soy sauce is jiàngqīng (醬清). Angmoh tauyew (紅貌豆油, lit. "foreigners'
soy sauce") is the Hokkien name for Worcestershire sauce.
Malaysia, which has cultural links with Indonesia, uses the word 'kicap' for soy sauce. Kicap is
traditionally of two types: kicap lemak and kicap cair. Kicap lemak is similar to kecap manis but
with very much less sugar while kicap cair is the Malaysian equivalent of kecap asin.
Filipino toyo
A popular condiment in the Philippines, it is called toyo (pronounced TOH-yoh), and is usually
found beside other sauces such as patis (fish sauce, pronounced pah-TEES) and suka (sugar cane
vinegar, pronounced SOO-kah). The flavor of Filipino soy sauce, made from soybeans, wheat,
salt, and caramel, is interestingly milder compared to its Asian counterparts--possibly an
adaptation to the demands of the Filipino palate and its cuisine. It is thinner in texture and has a
saltier taste compared to its Southeast Asian counterparts, much more similar to the Japanese
shōyu. It is used as a staple condiment to flavor many cooked dishes and as a marinade during
cooking, it is also a table condiment, and is usually mixed and served with kalamansi (a small
Asian citrus-lime). Popular Philippine brands are Marca Piña, Silver Swan, Lauriat, Datu Puti,
Toyomansi and UFC (Universal Food Public Company).
Hawaiian shoyu
A unique type of soy sauce produced by Aloha Shoyu Company since 1946 is a special blend of
soybeans, wheat, and salt, historically common among local Hawaii residents. Hawaii residents
rarely use the term "soy sauce," opting to use the Japanese loanword "shoyu" instead. However,
while the Japanese word shōyu is pronounced like show you, Hawaii residents prounounce the
word like shoi-yu.
18.Write a brief note on Dry Sausage Preparation.
Dry Sausage:
A sausage is a prepared food, usually made from ground meat, animal fat, salt, and spices
(sometimes with other ingredients such as herbs), typically packed in a casing. Sausage making
is a traditional food preservation technique.
Traditionally, casings are made of animal intestines though are now often synthetic. Some
sausages are cooked during processing, and the casing may be removed after that. Sausages may
be preserved by curing, drying in cool air, or smoking. When cooking sausages it is important to
ensure they are pricked with a fork or similar implement first in order to prevent their
disintegration and to prevent loss of flavour.
Classification of sausages
Sausages from Reunion Island
Swojska (Polish)
Krajańska (Polish)
Szynkowa (Polish)
A frankfurter sausage contains a lot of protein, yet low calories/fat (for meat)
Sausages may be classified in any number of ways, for instance by the type of meat and other
ingredients they contain, or by their consistency. The most popular classification is probably by
type of preparation, but even this is subject to regional differences of opinion. In the Englishspeaking world, the following distinction between fresh sausages, cooked sausages and dry
sausages seems to be more or less accepted:
Cooked sausages are made with fresh meats and then fully cooked. They are either eaten
immediately after cooking or must be refrigerated. Examples include hot dogs, Braunschweiger
and liver sausages.
Cooked smoked sausages are cooked and then smoked or smoke-cooked. They are eaten hot or
cold, but need to be refrigerated. Examples include Gyulai kolbász, kielbasa and Mortadella.
Fresh sausages are made from meats that have not been previously cured. They must be
refrigerated and thoroughly cooked before eating. Examples include Boerewors, Italian pork
sausage, breakfast sausage and Yarraque.
Fresh smoked sausages are fresh sausages that are smoked. They should be refrigerated and
cooked thoroughly before eating. Examples include Mettwurst and Romanian sausage.
Dry sausages are cured sausages that are fermented and dried. They are generally eaten cold and
will keep for a long time. Examples include salami, Droë wors, Sucuk, Landjäger, and summer
sausage.
The distinct flavor of some sausages is due to fermentation by Lactobacillus, Pediococcus and/or
Micrococcus (added as starter cultures) or natural flora during curing.
Other countries, however, use different systems of classification. Germany, for instance, which
boasts more than 1200 types of sausage, distinguishes raw, cooked and pre-cooked sausages.
Raw sausages are made with raw meat and are not cooked. They are preserved by lactic acid
fermentation, and may be dried, brined or smoked. Most raw sausages will keep for a long time.
Examples include cervelat, mettwurst and salami.
Cooked sausages may include water and emulsifiers and are always cooked. They will not keep
long. Examples include Jagdwurst and Weißwurst.
Pre-cooked sausages are made with cooked meat, and may include raw organ meat. They may be
heated after casing, and will keep only for a few days. Examples include Saumagen and
Blutwurst.
In Italy, the basic distinction is:
Raw sausage (salsiccia)
Cured or cooked sausage (salume)
The US has a particular type called pickled sausages, commonly found in gas stations and small
roadside delicatessens. These are usually smoked and/or boiled sausages of a highly processed
frankfurter (hot dog) or kielbasa style plunged into a boiling brine of vinegar, salt, spices (red
pepper, paprika...) and often a pink coloring, then canned in wide-mouth jars. They are available
in single blister packs, e.g., Slim Jim meat snacks, or in jars atop the deli cooler. They are shelf
stable, and are a frequently offered alternative to beef jerky, beef stick, and kippered beef snacks.
Certain countries classify sausage types according to the region in which the sausage was
traditionally produced:
France: Montbéliard, Morteau, Strasbourg, Toulouse, Merguez...
Germany: Frankfurt, Thuringia, Nuremberg, Pomerania, ...
Austria: Vienna, ...
Italy: Merano (Meran)
UK: Cumberland, Chiltern, Lincolnshire, Glamorgan ...
Slovenia: Kranjska (klobasa), after the Slovenian name for the province of Carniola
Spain: botifarra catalana, chorizo riojano, chorizo gallego, chorizo de Teror, longaniza de
Aragón, morcilla de Burgos, morcilla de Ronda, morcilla extremeña, morcilla dulce canaria,
llonganissa de Vic, fuet d'Olot, sobrassada mallorquina, botillo de León, llonganissa de Valencia,
farinato de Salamanca, ...
Poland: kielbasa krakowska (Kraków-style), toruńska (Toruń), żywiecka (Żywiec), bydgoska
(Bydgoszcz), krotoszyńska (Krotoszyn), podwawelska (literally: "from under Wawel"),
zielonogórska (Zielona Góra), rzeszowska (Rzeszów), śląska (Silesia), swojska, wiejska,
jałowcowa, zwyczajna, polska, krajańska, szynkowa, parówkowa ...
Hungary: kolbász gyulai (after the town of Gyula), csabai (after the city of Békéscsaba),
Debrecener (after the city of Debrecen).
19.Write a brief note o Katsuobushi Preparation.
Katsuobushi:
Katsuobushi is the Japanese name for a preparation of dried, fermented, and smoked skipjack
tuna (Katsuwonus pelamis, sometimes referred to as bonito). Katsuobushi and kombu (a type of
kelp) are the main ingredients of dashi, a broth that forms the basis of many soups (such as miso
soup) and sauces (e.g., soba no tsukejiru) in Japanese cuisine. It is today typically found in bags
of small pink-brown shavings. Larger, thicker shavings, called kezurikatsuo, are used to make
the ubiquitous dashi stock. Smaller, thinner shavings, called hanakatsuo, are used as a flavoring
and topping for many Japanese dishes, such as okonomiyaki. Traditionally, large chunks of
katsuobushi were kept at hand and shaved when needed with an instrument called a katsuobushi
kezuriki, similar to a wood plane, but in the desire for convenience this form of preparation has
nearly disappeared. Katsuobushi, however, retains its status as one of the primary ingredients in
Japanese cooking today.
Katsuobushi's umami flavor comes from its high inosinic acid content. Traditionally made
katsuobushi, known as karebushi, is deliberately planted with fungus (Aspergillus glaucus) in
order to reduce moisture.
When hanakatsuo is added as a topping to a hot dish, the steam has the effect of making the
flakes move as if dancing; because of this, katsuobushi topping is also known as dancing fish
flakes.
Uses
Other than the main ingredient of dashi stock, other popular uses of katsuobushi include:
Okaka, finely chopped katsuobushi dressed with soy sauce.
o As a stuffing for rice balls (onigiri).
As a topping for rice. Popular for bentō, often covered with nori. A bentō with okaka and
nori is called "nori-ben".
o Dried okaka is used as an indredient of furikake rice topping (called "okaka furikake").
As a seasoning for cold tofu along with grated ginger and Welsh onion (a type of spring onion.)
Sprinkled with sesame seeds and chopped nori atop cold soba noodles (zarusoba).
As a topping on takoyaki and okonomiyaki.
As a seasoning on century egg along with sesame oil and soy sauce.
As a high-protein treat for cats sold at pet stores.
o
Popular culture
Katsuobushi was the inspiration for the title of the John Lennon album Shaved Fish.
The original Iron Chef Japanese on the television show Iron Chef, Rokusaburo Michiba, was
known on the show for his trademark "broth of vigor", created from katsuobushi.
20.Write a brief note on fermented dairy products.
FERMENTED DAIRY PRODUCTS:
KEFIR
Introduction:
Kefir is the self-carbonated fermented milk product with high nutritional status and
therapeutic value.
It requires a special culture called kefir grains.
The grain consists of casein and gelatinous colonies of microorganisms, which live, in
symbiosis.
The organism isolated is yeast such as Torula and Saccharomyces kefir and bacteria such as
L.acidophilus, Streptococcus lactis and L.kefiranofaciens.
The yeast represents 5 – 10 % of the total micro flora.
The grains are irregular in shape, yellowish in color and insoluble in water.
Dried grains retain their activity for more than a year when stepped in milk the grains swell.
During fermentation process Lactobacillus sp. produces lactic acid and lacto fermenting yeast
cell produce alcohol and CO2. All activities are controlled by incubation temperature.
Uses:
Starter organisms produce risin, lactimine, streptocine is widely used in hospitals.
It is included in diets of patients suffering from intestinal diseases, anemia, metabolic
disorders, hyper toxicity, and allergic diseases.
It is beneficial for the treatment of tuberculosis.
The product in diet reduces serum cholesterol level in infants.
CULTURED BUTTER MILK
Uses:
1) It is highly nutritious and suited as a supplement to local foods.
2) Fermentation predigests several milk constituents, synthesizes water soluble vitamin of
B complex and makes a nutritionally upgraded milk.
It is a fermented product made by using mesophilic starters.
Production:
Milk free from antibiotics & detergents with fat content of 0.5 – 1 % is homogenized at 150c
Heated at 900c – 13 mins & cooled to 230c.
Starter culture [Str. lactis, Str. cremoris – acid production, Str. diacetylactis, Leuconostoc citrovorum –
aroma & flavor 1-2%].
Fermentation time is 16 – 20 hrs, acidity – 0.9%, mixed, cooled, bottled & stored at 50c.
Final product is viscous, drink with pleasing aroma, flavour.
KUMISS
Prepared from mare milk, which is inoculated with starter culture of 10 – 20%.
Cow milk or skimmed milk with 2.5% sucrose is used due to non-availability of mare milk.
Microflora includes Lactobacillus delbrueckeii ssp bulgaricus, L. acidophilus, Kluveromyces
lactis.
Use:
Kumiss from mare milk is a good supplementary remedy for treatment of TB.
BUTTER
Introduction:
Butter is a concentrate of one of the 3 main constituents of milk ie., fat, proteins, lactose. The
later 2 are present only in small proportion. Butterfat also contains the yellow coloring matter carotine
and or its transformation products vitamin A and D.
Composition:
Butter and moisture
16%
Milk fat
80%
Milk solids
2%
Butter making process:
1.Preparation of cream, pasteurization, cooling and starter addition:
Cream is produced by mechanical separation of unhomogenized whole milk. Cream is
pasteurized between 88 – 930 c. It may be subjected to vacuum cooling to ripening temperature of 16-210
c and ripened with 4% of mixed starter culture having;
1.acid producers like Streptococci lactis /S.cremoris.
2.flavor producers like L.mesenteroides, S.diacetylactics.
The ripening may be in 2/3 stages to produce soft, firm butter.
2. Churning, washing and salting:
The cream is loaded for churning in machines. The machine has 3 sections;
1.churning
2.separating
3.working sections
The churning section consists of a horizontal cylinder and a rotating variable speed rotator/beater
[0-1000 rpm] since churning lasts for 1-2 sec it is important to adjust the beater velocity to obtain
optimum butter grain size.
The separating section consists of a horizontal cylinder. The first part of the cylinder is equipped
with beaters for further treatment mixtures of butter grains and butter milk which is fed from the churning
sections.
The second part of the cylinder is designed as a sieve for draining buttermilk. It is equipped with wire
gauze, which retains even small butter grains.
The working section consists of inclined sections for transport of the butter. In the production of
salted butter, a salt slurry [40-60%] is pumped into the first working section, in which it is worked into
the butter before butter proceeds to the second working section. Any adjustment of butter moisture also
takes place in the first working section. Water dosing is done automatically.
Quality of wash water:
The chill water used for washing butter granules is an important source of contamination
of butter. The treatment of butter with wash water has 2 purposes:
1. To wash away the free butter milk from the butter granules.
2. To control the temperature of the granules for subsequent working process. The following
organisms are known to infect butter through wash water.[P.putrifaciens, P.fluorescens, P.fragi,
P.methicica]
Packaging:
Butter is packed either in bulk or in consumer’s size containers. Normally vegetable
parchment is used to line butter boxes and also a wrapper for consumer packs. Polyethylene
films replace parchment paper. Giving sodium propionate treatment can control mold growth.
Flavor of butter:
The flavor of butter is produced by the fermentation of citric acid by Leuconostoc and
Streptococcus lactis. Citric acid is converted into pyruvate, co2 , acetic acid. Pyruvate is again
metabolized to form CO2 and acetaldehyde. Acetaldehyde under neutral and acidic conditions forms
acetic acid and ethanol. Under acidic conditions these products are further metabolized into diacetyl and
acetyl methyl carbinol.
Production:
Cream separation [unhomogenised whole milk] was pasteurized at 88 – 930c, cooled at 16-210c.
Starter culture was added [Strep. lactis, Strep. cremoris – acid producers, Leuconostoc mesenteroides,
Strep. diacetylactis – flavor producers].
Churning [adding colour], Draining butter milk, Washing.
Adding salt [40-60%], Working [salt enters butter], Washing
Packing & storage at 50c.
Spoilage and defects:
Many of the defects of butter originate in the cream, from which it is made especially if
the cream is held for several days. During this time lactic acid bacteria and other spoilage
organisms may grow which may be followed by the growth of the molds, Geotrichum candidum.
Flavor defects:
The main defects developing in butter during storage are;
1. Oxidative rancidity
2. Hydrolytic rancidity 3. Putrefactive taints
Growth of microorganisms in cream and in the milk from which it is separated may result in
any of the following bad flavors.
S.no
Defects
Organism involved
1
Acid
Taste like cultured buttermilk due to souring of cream.
2
Barny flavor
Enterobacter
3
Rancidity
Resulting from lipolytic bacteria and mold.
4
Cheeseiness
Lactobacillus
5
Yeast
6
Musty
Flavor similar to bakers yeast results from growth of yeast in
cream or butter.
Produced by molds and Actinomycetes.
7
Flat
Lacking typical flavor Pseudomonas sp.
8
Malty
Produced by Streptococcus lactis
9
Unclean
Intense old cream flavor caused by coliforms
10
Surface taint/rabbito/putridity
P.putrefaciens
11
Ester like flavor
P. fragi
12
Fishiness
Aeromonas hydrophila
13
Metallic
Suggestive of metal caused by metal catalyzed oxidation.
14
Feed
Aromatic flavor[feeds eaten by cows]
Colour defects:
1. Dark smoky discolouration
2. green colouration
3. Brown colouration
4. Orange/yellow spots
5. Dry reddish pink area
6. Pink colonies
Chemical defects:
1.Rancidity
Alternaria, Cladosporium
Penicillium
Alternaria
Geotrichum
Fusarium culmorum
yeast
lipase in cream
2.Tallowiness
oxidation of unsaturated fats catalyzed by copper and bacterial
enzymes and favored by low pH, T0 , salt,air, ozone.
3.Fishiness
Trimethylamine is produced from lecithin.
21.Write a brief note on Cheese Production.
Cheese
Introduction:
Cheese making is a convenient way of converting fat & protein present in milk into a
nutritious
product with good keeping qualities. Microorganisms play an important role in this process to
provide texture & flavor to the product. It is one of earliest method of preserving milk solids.
Cheese is a compressed fermented milk product.
Classification:Cheese can be classified into several types based on several criteria;
a.
b.
c.
d.
e.
f.
Based on the firmness of cheese. [Moisture]
Source of milk. [Cow, buffalo]
Ripening. [Fungi/bacteria]
Country of origin. [eg: cheddar English, Roquefort Southeast France]
Content of fat. [Skim milk, full cream milk]
Manufacturing process.
The basic procedure of manufacturing is same for all types of cheese. There are 4
major steps in the
Production of cheese.
1. Control of the properties of milk.
2. Coagulation
3. Separation of whey & curd
4. Cheese ripening
I. Control of the properties of milk:Good quality milk is more important for cheese making because it is not possible to
pasteurize
Cheese milk intensively. The bacterial content of milk used for cheese making should be low
because microorganisms growing in raw milk may develop unwanted flavour & enzyme. Some
organisms survive pasteurization & cause fault in cheese. The number of psychrotrophs &
thermoduric organism should be low. The physical, chemical & biological properties of the milk
should be controlled.
Basic stages involved in cheese making:*Standardization:Standardization of milk is done to adjust for fat or to have a balance rate of fat & casein
(1: 0.7).
*clarification:The clarifier is an effective alternative for filtration for the removal of extraneous matter,
leucocytes & Some bacteria. It is carried out at 32- 380 c Centrifugally.
Bactofugation:If centrifuged milk is passed through the unit the 2nd time about 90% of the remaining
10% bacteria
is removed. The sludge can be sterilized & reincorporated into the milk.
Homogenization:Milk is homogenized at low pressure the purpose is to reduce the whey exudation from
the coagulum
to make cheese whiter & make promote fat hydrolysis.
Thermization:When raw milk must be stored for a few days using for cheese it is subjected to heat
treatment 630 c
for 10-15 sec & cool to 50c prior to storing.
II. Coagulation:It is carried out by the use of any of the following methods:
Use of lactic acid.
Addition of bacteria like lactobacillus sp. Or addition of milk clotting enzyme rennet.
Application of heat.
By the addition of salt.
Alteration of pH.
Among these only a few methods are applicable. The commonly used method is by the
adjustment
of pH.
Coagulation by pH adjustment or Ripening of milk:This is achieved by heating the milk at around 30-33 0 C & adding the starter bacteria.
The organisms grow using lactose as an energy source & converting it into lactic acid by a
complex series of reaction by involving many different enzymes. Selected strains of lactic acid
organisms are used which increase the acidity.
Functions of the starter:
Ensures consistent acid development.
Aids rennet reaction & subsequent coagulation by the developed acidity.
Helps expulsion of whey from the curds.
Contributes to flavor & texture of cheese during ripening.
Suppresses the growth of undesirable organisms.
Microorganisms used for cheese making are;
Type
Function
1. Strep. lactis
Acid formation
2. Strep. cremoris
Acid formation
3. Strep. diacetylactis
Acid, gas & flavor production.
4. Strep. thermohiles
Acid production in high scald cheese.
5. L. bulgaricus
Acid production.
6. Strep. faecalis
Acid & flavor in high scald cheese.
7. Propionibacterium shermanii
Gas & flavor production.
Starters are used at concentration ranging from 0.5 to 2% of milk. The organism multiply
during cheese making from about 10 7 CFU/ml in milk to around 10 9 cfu/gm of the curd. The
growth gets checked at the salting cheese stage. All additives are added & mixed separately
before rennet addition. To provide uniform colour to cheese annatto colour [alkaline extract
from seeds of Bixa orelana] is added to get yellow tint. Calcium chloride at 0.01 to 0.03% of the
milk is used to improve the firmness of the coagulation by rennet. The addition of 15gms of salt
per 100kg of cheese milk prevents blowing (development of too much of gas in the cheese)
caused by coliform bacteria or butyric acid or propionic acid bacteria.
Rennetting:After a mild increase in acidity of milk created by starter rennet extract is added to milk
& uniformly distributed to effect coagulation of milk. The coagulation enzymes are,
Type
* Animal
Source of Enzymes
Calf (Chymosin or pepsin )
Pig (Pepsin)
* Bacteria
B. Subtilis
B. Polymyra
B. mesenteroides
* Fungi
Mucor meihei
M. pusilus
Endothica parasitica.
The enzymes act in 3 phases;
1. Primary / Enzymatic phase:It results in the conversion of one of the milk protein from a colloidal suspension to a
fibrous network. This is done in the presence of calcium.
1. Secondary/Clotting phase:The coagulation of the other function of enzymatic activity & coagulation can be achieved by
an increase
in temperature or decrease in pH.
2. Tertiary/ Proteolytic phase:Chymosin hydrolyze the milk protein to polypeptides. A part of polypeptides are broken
down to
peptides & amino acids.
III. Separation of curd & whey:Separation can be done by mechanical means. Whey separation depends on temperature,
pH & physical characteristics of the curd. Increased temperature enhances whey separation.
Whey separating is carried out by the following methods:
By cutting the curd & allowing the whey to flow.
By placing the curd in perforated containers & allowing the whey to drain through the
perforations.
The curd can also be collected on a clean cloth & whey can be filtered out.
For cutting the curd, special knives are used for different sizes of cubes.
Scalding:High scald cheese the temperature may be 52-58 0 C, in medium scald 30-42 0 C & in low
scald around 30-35 0 C. During combined action of stirring & heat, lactic acid with the curd
particle is formed by the starter organisms, embedded in cheese particles & curd cubes shrinks in
size. When the desired development in the curd has reached whey is drained for texturing the
curd
Draining the whey:The curd is allowed to settle, acidity measured, when it has reached desired level, the
whey is run off until the compact mass of curd is formed in the vat.
Milling:It helps in uniform distribution of salt (1-2%) salt acts as a preservative & flavor
enhancer.
Pressing:The curd is filled in moulds & pressed. The degree of pressing & length of time various
with the type of cheese.
Packaging & storing:-
Packaging protects
flavor contamination
Entry to external molecules.
Loss of moisture.
Enhances appearance.
Wax coating /plastic film for hard cheese.
Aluminium / plastic film for semi-hard cheese.
Maturing period is 2-24 months. The cheese is stored in increased T 0 in fermentation room
& shifted to ripening room having lower temperature for the development of proteolysis,
lipolysis, aroma & texture.
IV . Cheese ripening:It refers to the changes in the body to texture accompanied by the development of
characteristic flavor typical to that of cheese. Flavor & aroma is produced by the action of
microorganisms & enzymes which breakdown,
Carbohydrate producing lactic acid, acetic acid, Co2 & diacetyl.
H2O insoluble proteins to protease, peptons, peptides, amino acids, organic acids, NH3.
Fat to lower fatty acids, their esters & Ketones.
These changes are brought about by enzymes from,
-> Lactic acid bacteria in starter culture.
-> Miscellaneous non-starter bacteria in milk.
->Rennet & its substitutions used to coagulate the milk.
->Other microorganisms growing within or surface of cheese.
The cheesy flavor is mainly due to carboxyl, nitrogenous compound, fatty acids, sulphur
compounds etc.
Manufacture of Cheddar cheese.
Raw milk
Pasteurize at 71 – 750C – 15 secs [pasteurization reduces the number of spoilage organisms & lactic
acid bacteria & kills most pathogens]
Cool & incubate in cheese vat at 300c [add starter culture Lactococcus lactics ssp cremoris 1 – 1.5%]
[lactic acid fermentation develops]
Milk with 0.19 to 0.21 % lactic acid [rennet added].
[curd’s formation]
Cutting of curds.
[ whey released]
Scalding 38 – 400c & stirring [acid production continues without starter culture].
Cheddaring – Squeezing & Stretching the curd [acid production continues without starter growth
giving a final lactic acid concentration of 0.6 – 0.8 % - primary metabolism].
Milling and salting [ salting prevents further starter activity, assists in preservation & adds flavor &
further release of whey]
Moulding & pressing [further release of whey]
Ripening
[secondary metabolism- Proteinase enzyme released from starter organism produce aminoacid , indole,
sulphur compounds and phenol to enhance flavor. H2O2 and bacteriocin to inhibit pathogen and
spoilage organisms]
[moisture content]
Soft cheese
Semi-soft cheese
[50-80 %]
[39-50%]
Hard cheese
Very hard cheese [ Very low
[34 – 39%]
moisture].
Eg: unripened cottage cheese
Ripened camembert cheese
Salt cured feta cheese
Eg: Ripened by moulds Roquefort cheese
Ripened by bacteria Brick, Gowda, Limburger
SPOILAGE OF CHEESE:
1.DURING MANUFACTURING:
Eg: cheddar cheese
RAW MILK:
Eg: Grana, Parmesan, Asiago old.
Off flavor is produced by gas forming organisms. Eg: Clostridium, coliforms, yeasts.
Gassiness is produced by Clostridium, Bacillus polymyxa [produces gas and defects in ripening
cheese].
Bitter flavor is produced by coliforms, Micrococci, Yeasts [acid proteolytic bacteria].
Leuconostoc produces Holes/openness in cheddar cheese.
Proteolysis, gas production is by undesirable microbes.
Sliminess/Off flavor is produced by Pseudomonas fragi, Alcaligenes metaalcaligenes.
2.DURING RIPENING:
Physical changes [hole formation, change nature of texture]
Chemical changes [undesirable end product, metal discoloration]
Gas holes/eyes/cracks/splitting [Clostridium-butyric acid+gas]
Undesirable acid [Propionibacterium sp.]
Bitterness [Streptococci]
Acid + proteolytic [coliforms, Micrococci]
Yeast flavor/sweet fruity flavor [yeast]
Putrefaction [Clostridium tyrobutyricum, Cl.lentoputrescens, Cl.sporogenes]
Discoloration ;
Eg: rusty spots
Lactobacillus plantarum, L.brewis
Yellow/pink/brown Propionibacterium
Reddish brown to grayish brown due to oxidation of tyrosine by bacteria.
3.FINISHED CHEESE:
OOSPORA [GEOTRICHUM]
Dairy mold G.lactis
Red colour G.rubrum/G.crustacea
Red spot G.aurianticum
Cheese cancer G.caseocorans
4.BLACK SPOT/OFF FLAVOR Monilia sp.,/M.nigra
CLADOSPORIUM [DARK/SMOKY
COLOUR]
5. DISCOLOURATION
Dark green to black colour C.herbarum
PENICILLIUM [GROWS IN CRACKS]
6.Yellow /red growth
Aspergillus/Mucor/
Alternaria/ Scopulariopsis
Brevibacterium linens
Green sporesP.puberulum
Yellowish brown spot P.casei
Camembert discolouration P.aurantiovirens
22.Write a brief note on Yoghurt Production.
Yoghurt [Bulgarian milk].
Yoghurt is the fermented milk product characterized by its viscous consistency, a strong
acidulous taste due to high acidity [pH 4.6] and a distinct aroma caused mainly by acetaldehyde.
Large-scale manufacture only started in the UK in the 1960s but since then yoghurt has become
an increasingly important dairy product with many different varieties now available in
supermarkets and other retail outlets.
Spoilage:
1. Bloom cartons/frothy consistency and yeasty off flavor, odour yeast ferments sugar into CO2 and
ethanol.
2. Mould growth is less but spoils the surface of yoghurt particularly in under filled cartons.
Prevention:
1. Sterilization of filling equipment.
2. Careful storage of packaging.
3. Installation of filtered air laminar and airflow facilities in filling rooms.
4. Use of UV in filling areas.
5. Periodic fumigation of filling rooms.
6. Control of spillages.
7. Use of sulphate in fruit.
8. Heat treatment of final product.
9. Use of preservative in the final product.
10. Proper use of fruit and fruit syrups to prevent contamination.
Whole milk, Skim milk + water, Whole milk + cream
Pasteurization [850c – 30 mins batch process,90 - 950 c – 10minutes continuous ] inhibits Salmonella,
Listeria, Camphylobacter.
Homogenize [60 – 650c] – smooth texture
Emulsifier’s addition [agar, gums, alginate to increase the viscosity]
Sweeteners addition [5% sugar inhibit lactic acid production].
Heat [90 – 950c] & cool
Inoculate with starter [Strep. salivarius ssp thermophilus, Lactobacillus delbreukii ssp bulgaricus]
Incubate [4 – 16 hrs at 30 – 450c] & Cool [ 10 – 150c]
Add fruit and flavor
Package [Maintain at chill temperature at 4.50c – 2 wks].
Recently, a different type of yoghurt has been produced that uses a mixture of;
L.acidophilus+Bifidobacterium bifidum AB yoghurt
L.acidophilus+Bifidobacterium bifidum+S.salivarius thermophilus ABT yoghurt
These bio or therapeutic yoghurt are said to have health promoting properties. Manufacture of
this type of yoghurt involves direct vat inoculation with the starter followed by incubation at 370 c for
about 16 hrs giving a final product with a pH of 4.2 to 4.4 and a milder creamier flavor.
Nutritive value of yoghurt:
During fermentation of milk the composition of minerals remain unchanged while proteins,
carbohydrates, vitamins and fats to some extent are subjected to changes. The substances formed are
lactic acid, alcohol, CO2 ,antibiotics and vitamins. The following processes make yoghurt
1.Proteolysis:
Proteolysis in milk takes place by exopeptidases and endopeptidases of lactic acid bacteria.
So biological value increases 85.4 to 90%. This increases due to breakdown of proteins into
peptides,
amino acids. The contents of essential amino acid such as leucine, isoleucine, methionine, phenyl
alanine, tyrosine, tryptophan and valine increases which offers special advantage.
2.Hydrolysis of lactose:
Lactose in milk is hydrolysed by metabolic activity of bacteria. Lactic acid inhibits the
growth of putrifactants. It is important for organolectic properties and calcium absorption.
3.Lipolysis:
The homogenization process reduces the size of globules which become digestible, as a result of
lipolytic activity the free fatty acid increases, which have some physiological effect.
4.Changes in vitamins:
There is more than 2 fold increase in vitamins of B group especially thiamine, riboflavin and
nicotinamide.
5. Antibacterial activities:
The antibiotic properties are associated with Lactobacilli in yoghurt and materials responsible are
lactic acid, H2O2 and lactobacilline.
6.Therapeutic properties:
1. Easy absorption and better assimilation. Eg; milk [32% in 1 hr], yoghurt [91% in 1 hr].
2. Improves appetite due to its pleasant refreshing and pungent taste. It is highly nourishing
invigorating.
3. Gastric juice secreted by the action of yoghurt and desirable ratio of calcium and phosphorous
induced by it leads to a high digestive capacity.
4. Removes excessive fat from liver and enhances bile secretion. It has therapeutic importance in GI
disturbances hepatitis, nephritis, diarrhea, colitis, anemia, and anorexia.
5. It provides relief to chronic diarrhea in spruce and ulcerative colitis. Fat free yoghurt is
importance to those who suffer from heart diseases.
6. Yoghurt possesses potent anti-tumour activity. Pathogenic bacteria are not able to survive due to
low pH.
23.Write a brief note on Saurkraut Production.
Fermented Vegetables
Sauerkraut
The sauerkraut fermentation is an example of a microbial succession. Microbial
succession involves the growth of a group or species of micro organisms in an environment, the
conditions of which then change as a result of their activities so that another group or species is
favoured and becomes dominant. The microbial succession involved in the fermentation of
sauerkraut can pass through 3 phases.
Phase 1:
1. Leuconostoc mesenteroides initiates the fermentation. The organism is
heterofermentative, converting sugars in the brine into lactic acid, acetic acid, ethanol and
Co2.
Sugars
L.mesenteroides
L.A + A.A + Ethanol + Co2
2. The role of this organism in the fermentation is complex and fundamental to the
production of good quality sauerkraut.
a. Rapid reduction of pH [below 4.0] within 2 days due to fermentation of lactic and
acetic acids. This reduces and inhibits the bacteria other than lactic acid bacteria
that may cause the cabbage to putrefy and enzymes that may cause the cabbage to
soften.
b. Co2 production helps to purge O2, from the brine. This creates an anaerobic
condition which is important in restricting the growth of organisms other than
lactic acid bacteria. Co2 will also inhibit the growth of some G-ve bacteria and
stimulate the growth of other lactic acid bacteria that form part of the
fermentation flora.
c. The anaerobic conditions produced stabilize vitamin C in the cabbage so that a
large percentage of the vitamin present in the raw material is retained.
d. Reducing sugars produced from the breakdown of excess sucrose in the brine can
cause the product to darken by combining with amino acids present [Maillard
Browning] Leuconostoc prevents this process by converting fructose to mannitol
and glucose to dextran. Both are available as a carbohydrate source to other lactic
acid bacteria and although the dextran produces a slime, this is only temporary.
e. Leuconostoc may produce growth factors that help to stimulate the growth of
more fastidious lactic acid bacteria.
f. Leuconostoc contributes in a major way to the final flavour and aroma of the
finished product.
Early in this phase [the 1st 15 hrs] there is also some growth of gram-negative organisms. These
organisms, mainly coliforms, help to remove oxygen from the brine and disappear within a day
or two.
Phase II:
As lactic acid accumulates in the brine and the pH drops, the more acid-tolerant
Lactobacillus brevis and Lactobacillus plantarum start to increase in numbers. Both organisms
produce lactic acid [L.brevis is heterofermentative and L.plantarum is homofermentative] and
after about 6-8 days become the dominant flora.
Phase III:
After about 16-18 days the numbers of L.brevis decline and the population becomes
dominated by L.plantarum. The organism continues to ferment any residual sugars to produce
lactic acid and a fully stable product in which all the sugars have been fermented.
The final sauerkraut has a stable pH of 3.8 and contains 1.7 to 2.3% acid [calculated as
lactic acid] with a ratio of acetic : lactic acid of about 1 : 4. Diacetyl, acetaldehyde and a number
of esters have been identified in the final product, which contribute to its characteristic odour and
flavour.
Microbiological Problems:
1. High Temperature:
At high temperatures of 32 C and above growth of Leuconostoc mensenteroides is
prevented and the population becomes dominated by Lactobacillus plantarum and pediococcus
pentosaceous. Both organisms are homofermentative, their growth resulting in product that
darknes readily and has a poor flavour.
2. Aerobic conditions:
Aerobic conditions produced when the fermenting cabbage is not covered properly or air
pockets are allowed to form when the cabbage is packed into vats, will allow the growth of
yeasts and moulds. Discolourations E.g., the pink colour is due to growth of the yeast
Rhodotorula, off flavours [yeasty or mouldy flavour] and softening due to pectinolytic activity of
moulds are resulting defects.
3. Uneven or Low salt Concentrations:
Uneven or low salt concentrations may allow putrefactive bacteria to grow, resulting in a
spoiled product.
Sauerkraut Defects and Spoilage:
Sauerkraut may be inferior quality because of abnormal fermentation and excessively high T
inhibits the growth of Leuconostoc and consequently the flavour production. It may permit the growth of
pediococcus cerevisiae and development of undesirable flavours. Low T may prevent lactic bacteria and
encourages the growth of containments from soil. E.g., Enterobacter and flavobacterium. The long
fermentation may favour the growth of L.brevis which yields a sharply acid flavour. Too much salt may
encourage Pediococcus and Yeast. Abnormal fermentation of cabbage may result in cheese like odour
caused by propionic butyric, caproic and valeric acid along with isobutyric and isovaleric acid.
1. Soft Kraut:
It may result from a faulty fermentation and from exposure to air or excessive pressing
and / or tamping.
2. Dark Brown / Black Kraut:
It is due to oxidation during exposure to air and is caused by combined action of plant
enzyme and microorganisms destruction of acid by film yeast and molds make cardition
favourable for proteolytic and pectolylic microorganisms to rot the kraut. Darkening is
encouraged by uneven salting and high T. Brown colour may result from iron in hoops and
tanning from barrels.
3. Pink Kraut:
It is caused by red asporogenous yeast in the presence of air and high salt that has been
distributed unevenly. The development of pink colour is favoured by high T, dirty vats, low
acidity and iron salts.
4. Ropy Krauts / Slimy Krauts:
It is caused by encapsulated varieties of L.plantarum. The sliminess may disappear on
longer holding and cooking of the kraut.
Sauerkraut is subjected to spoilage at its surface, where it is exposed to air. Film yeasts and molds
destroy the acidity permitting other microorganisms to grow and cause softening.
5. Salt Burn:
If salt concentration increases the surface may be darken to black. [high salt and high T]
PICKLES
Cucumber pickles may be prepared without fermentation or partial or complete
fermentation. They can be pasteurized to improve their keeping quality. Brined acidified
cucumbers are heated so that the interior of the cucumber will be maintained at 73.9 C for atleast
15 min. Both heating and cooling should be rapid. These are 2 chief types of fermented pickles;
a. Salt or salt stock pickles
b. Dill pickles.
I. Preparation of Salt or Salt Stock Pickles:
Immature cucumber are washed, placed in barrels or tanks and brined. Sometimes about
1% of glucose is added if the cucumbers are low in sugar. The addition of sugar will favour the
production of gassy pickles or bloaters.
Addition of Salt:
The rate of addition of salt and total amount added varies considerably 2 methods of
salting, low salt method and high salt method.
High salt method 50 salometer [10.5% NaCl] and final 60 salometer [15% NaCl]
Low salt method 30 salometer [8% NaCl] and final 45 salometer
The cucumbers are keyed down under a surface layer of brine and fermentation begins. In both
methods salt is added at weakly intervals to increase the salometer reading by about 3 salometer
up to 60. In the low salt method the increase is about 2 per week up to 50. In warm climates the
salt content of brine may be increased more rapidly and cool climates a weaker brine may be
added initially.
1. The Traditional Fermentation:
The traditional process usually takes 6-9 weeks for completion, depending on he salting
method and T employed. The number of salt tolerant sp. Of bacteria may grow initially in the
newly brined fresh cucumbers. These may be marked difference in the kinds of bacteria growing
in different lots, depending on the number of and kinds introduced by the cucumbers or dirt left
on them and by the water of the brine, initial concentration of sodium chloride and rate of
increase, and the T of the brined cucumbers. Low salt concentration will favour more kinds of
bacteria, faster the acid production and greater the acidity. First to grow is Pseudomonas and
Flavobacterium, types considered undesirable. Bacillus sp are likely to come on from the soils on
the cucumber and their growth is undesirable. In brines of low salt content coliform bacteria,
Leuconostoc mesenteroides, str. Faecatis, Pediococcus cerevisiae may grow and form acid and in
15% brines gas forming cocci may produce some acid. Later L.brevis may contribute to acidity if
the salt concentration is not too high. L.plantarum developes acidity in both low and high salt
brines. It becomes decreasingly active as the salt concentation increased. The total lactic acid
content is 0.6 to 0.8%. Heterofermentative lactics yield pickles that are firm and have better
density than homofermentative lactics.
Yeast may grow after some acid has been formed by the bacteria. Two types,
1. Film / Oxidative yeast:
Which grows on the surface of the brine and destroy lactic acid by oxidation. E.g.,
Debaryomyces, Endomycopsis, Candida.
The control includes daily agitation of the surface or the addition of the mineral oil,
sorbic acid or other substances. Pickle vats are located out in the sunlight which inhibits surface
growth on the brine.
2. Fermentative Yeast:
Which grows down in the brine and ferment sugar to alcohol and Co2. E.g., Torulopsis,
Zygosaccharomyces, Hansenula.
Gas produced by these yeast, bubbles from the brine and may be responsible for bloated
pickles.
When the cucumber are first brined they are chalky white and opaque but during the
fermentation and cure the colour changes from bright green to yellowish green and the flesh
becomes increasingly translucent. The salt pickles are prepared for use in making special
products such as sour, sweet sour, mixed pickles, relishes or other products.
2. The controlled fermentation:
This process is designed to eliminate or minimize the defects of the traditional
fermentation. First the cucumbers are washed, brined and sanitized [cl – 80 ppm] in the vat. The
chlorimated brine is then acidified with glacial acetic acid. These 2 process suppers the growth of
undesired bacteria. Following a purge with N2, sodium acetate is added [0.5%] to buffer the
brine. This ensures effective utilization of all the fermentable carbohydrate present. After 10-24
hrs they are inoculated with special cultures of pediococcus cerevisiae and L.plantarum. During
the active fermentation [10-14 days] N2 purges are repeated and additional salt is added to
maintain 25 salometer.
II Preparation of Dill pickles:
1. They are named because of the addition of dill herb and spices.
2. They may be unfermented or fermented or made from salt stock.
3. The fermentation to produce dill pickles have a lower concentration of salt and brine is
acidified with vinegar at the start. The low salt content favours and increased rate of acid
production, but adds to the risk of undesirable microbial changes. The flavouring
materials dill, spices, garlic etc., also act as a source of undesirable micro organisms
treated spices containing low micro organisms are available 2 types of fermented dill
pickles
a. Overnight
b. Genuine
S.No.
Overnight
Genuine
1
Slow acid fermentation [20 sal]
Org L.mesenteroides Str.faecalis,
P.cerevisiae, L.plantarum
2
Weak acidified brine
Vinegar added
3
Cured weed of dill added
T 15-30 C
4
Lactic acid 0.3 to 0.6%
Acid 1-1.5%
5
Salt concn 5.3%
Salt concn initial 7.5 to 8.5%
6
Kept in cold
Final concn 3.4 to 4.5%
Defects and Spoilage:
Fermented pickles are subjected to a number of defects most of which are caused by
bacteria.
1. Hollow Pickles:
If cucumbers are allowed to stand for a while after harvesting and before fermenting or it
may be due to loose packing in vat, insufficient weighting, too rapid a fermentation and too
strong or too weak a brine cause hollow pickles.
2. Floaters or Bloaters:
It may result from gas being formed by yeast, L.plantarum or coliform which can produce
Co2. This can be controlled by purging the brine with N2 to remove dissolved Co2. Floaters are
favoured by thick skin that doesnot allow gas to diffuse out, by rapid gas production during
fermentation, high initial salt by added sugar or / and acid.
3. Slippery pickles:
It occurs when cucumbers are exposed to air permitting the growth of encapsulated
bacteria. Slipperiness also may be due to broken scums of film yeast that have grown on the
surface of the brine and dropped on to the cucumber.
4. Soft Pickles:
They are made so by pectolytic enzymes mostly from molds and from cucumber flowers.
These molds are mostly of the general Penicillium, Fusarium, Cladosporium, Alternaria.
Bacteria Bacillus, Aeromonas, Coliforms.
These can degrade;
Pectinase
Pectin
Pectin Esterase
Pectinic acid
Poly methyl galacturnose
Galactournoic acid
Softening is favoured by;
a. An insufficient amount of salt.
b. Too high a T
c. Low acidity
a. Presence of air favouring the growth of film yeast or mold.
b. Infusions of may blossoms.
5. Black Pickles:
May owe their colour due to the formation of H2S by bacteria and combination with iron
in the water to yield black ferrous sulfide. It is also due to the growth of black pigmented
Bacillus nigrificans and B.subtilis.
i.e.,
Iron
Water
Sulphide
From Vat / H2O / CaCo3 [Gypsum]
6. Ropy Pickle Brine:
Favoured by unidentified motile, Gram –ve encapsulated rods.
Favoured by
i. Low salt
ii. Low acid
iii. High
FERMENTED DAIRY PRODUCTS:
KEFIR
Introduction:
Kefir is the self-carbonated fermented milk product with high nutritional status and
therapeutic value.
It requires a special culture called kefir grains.
The grain consists of casein and gelatinous colonies of microorganisms, which live, in
symbiosis.
The organism isolated is yeast such as Torula and Saccharomyces kefir and bacteria such as
L.acidophilus, Streptococcus lactis and L.kefiranofaciens.
The yeast represents 5 – 10 % of the total micro flora.
The grains are irregular in shape, yellowish in color and insoluble in water.
Dried grains retain their activity for more than a year when stepped in milk the grains swell.
During fermentation process Lactobacillus sp. produces lactic acid and lacto fermenting yeast
cell produce alcohol and CO2. All activities are controlled by incubation temperature.
Uses:
Starter organisms produce risin, lactimine, streptocine is widely used in hospitals.
It is included in diets of patients suffering from intestinal diseases, anemia, metabolic
disorders, hyper toxicity, and allergic diseases.
It is beneficial for the treatment of tuberculosis.
The product in diet reduces serum cholesterol level in infants.
CULTURED BUTTER MILK
Uses:
3) It is highly nutritious and suited as a supplement to local foods.
4) Fermentation predigests several milk constituents, synthesizes water soluble vitamin of
B complex and makes a nutritionally upgraded milk.
It is a fermented product made by using mesophilic starters.
Production:
Milk free from antibiotics & detergents with fat content of 0.5 – 1 % is homogenized at 150c
Heated at 900c – 13 mins & cooled to 230c.
Starter culture [Str. lactis, Str. cremoris – acid production, Str. diacetylactis, Leuconostoc citrovorum –
aroma & flavor 1-2%].
Fermentation time is 16 – 20 hrs, acidity – 0.9%, mixed, cooled, bottled & stored at 50c.
Final product is viscous, drink with pleasing aroma, flavour.
KUMISS
Prepared from mare milk, which is inoculated with starter culture of 10 – 20%.
Cow milk or skimmed milk with 2.5% sucrose is used due to non-availability of mare milk.
Microflora includes Lactobacillus delbrueckeii ssp bulgaricus, L. acidophilus, Kluveromyces
lactis.
Use:
Kumiss from mare milk is a good supplementary remedy for treatment of TB.
BUTTER
Introduction:
Butter is a concentrate of one of the 3 main constituents of milk ie., fat, proteins, lactose. The
later 2 are present only in small proportion. Butterfat also contains the yellow coloring matter carotine
and or its transformation products vitamin A and D.
Composition:
Butter and moisture
16%
Milk fat
80%
Milk solids
2%
Butter making process:
1.Preparation of cream, pasteurization, cooling and starter addition:
Cream is produced by mechanical separation of unhomogenized whole milk. Cream is
pasteurized between 88 – 930 c. It may be subjected to vacuum cooling to ripening temperature of 16-210
c and ripened with 4% of mixed starter culture having;
1.acid producers like Streptococci lactis /S.cremoris.
2.flavor producers like L.mesenteroides, S.diacetylactics.
The ripening may be in 2/3 stages to produce soft, firm butter.
2. Churning, washing and salting:
The cream is loaded for churning in machines. The machine has 3 sections;
1.churning
2.separating
3.working sections
The churning section consists of a horizontal cylinder and a rotating variable speed rotator/beater
[0-1000 rpm] since churning lasts for 1-2 sec it is important to adjust the beater velocity to obtain
optimum butter grain size.
The separating section consists of a horizontal cylinder. The first part of the cylinder is equipped
with beaters for further treatment mixtures of butter grains and butter milk which is fed from the churning
sections.
The second part of the cylinder is designed as a sieve for draining buttermilk. It is equipped with wire
gauze, which retains even small butter grains.
The working section consists of inclined sections for transport of the butter. In the production of
salted butter, a salt slurry [40-60%] is pumped into the first working section, in which it is worked into
the butter before butter proceeds to the second working section. Any adjustment of butter moisture also
takes place in the first working section. Water dosing is done automatically.
Quality of wash water:
The chill water used for washing butter granules is an important source of contamination
of butter. The treatment of butter with wash water has 2 purposes:
3. To wash away the free butter milk from the butter granules.
4. To control the temperature of the granules for subsequent working process. The following
organisms are known to infect butter through wash water.[P.putrifaciens, P.fluorescens, P.fragi,
P.methicica]
Packaging:
Butter is packed either in bulk or in consumer’s size containers. Normally vegetable
parchment is used to line butter boxes and also a wrapper for consumer packs. Polyethylene
films replace parchment paper. Giving sodium propionate treatment can control mold growth.
Flavor of butter:
The flavor of butter is produced by the fermentation of citric acid by Leuconostoc and
Streptococcus lactis. Citric acid is converted into pyruvate, co2 , acetic acid. Pyruvate is again
metabolized to form CO2 and acetaldehyde. Acetaldehyde under neutral and acidic conditions forms
acetic acid and ethanol. Under acidic conditions these products are further metabolized into diacetyl and
acetyl methyl carbinol.
Production:
Cream separation [unhomogenised whole milk] was pasteurized at 88 – 930c, cooled at 16-210c.
Starter culture was added [Strep. lactis, Strep. cremoris – acid producers, Leuconostoc mesenteroides,
Strep. diacetylactis – flavor producers].
Churning [adding colour], Draining butter milk, Washing.
Adding salt [40-60%], Working [salt enters butter], Washing
Packing & storage at 50c.
Spoilage and defects:
Many of the defects of butter originate in the cream, from which it is made especially if
the cream is held for several days. During this time lactic acid bacteria and other spoilage
organisms may grow which may be followed by the growth of the molds, Geotrichum candidum.
Flavor defects:
The main defects developing in butter during storage are;
2. Oxidative rancidity
2. Hydrolytic rancidity 3. Putrefactive taints
Growth of microorganisms in cream and in the milk from which it is separated may result in
any of the following bad flavors.
S.no
Defects
Organism involved
1
Acid
Taste like cultured buttermilk due to souring of cream.
2
Barny flavor
Enterobacter
3
Rancidity
Resulting from lipolytic bacteria and mold.
4
Cheeseiness
Lactobacillus
5
Yeast
6
Musty
Flavor similar to bakers yeast results from growth of yeast in
cream or butter.
Produced by molds and Actinomycetes.
7
Flat
Lacking typical flavor Pseudomonas sp.
8
Malty
Produced by Streptococcus lactis
9
Unclean
Intense old cream flavor caused by coliforms
10
Surface taint/rabbito/putridity
P.putrefaciens
11
Ester like flavor
P. fragi
12
Fishiness
Aeromonas hydrophila
13
Metallic
Suggestive of metal caused by metal catalyzed oxidation.
14
Feed
Aromatic flavor[feeds eaten by cows]
Colour defects:
7. Dark smoky discolouration
8. green colouration
9. Brown colouration
10. Orange/yellow spots
11. Dry reddish pink area
12. Pink colonies
Chemical defects:
1.Rancidity
Alternaria, Cladosporium
Penicillium
Alternaria
Geotrichum
Fusarium culmorum
yeast
lipase in cream
2.Tallowiness
oxidation of unsaturated fats catalyzed by copper and bacterial
enzymes and favored by low pH, T0 , salt,air, ozone.
3.Fishiness
Trimethylamine is produced from lecithin.
Cheese
Introduction:
Cheese making is a convenient way of converting fat & protein present in milk into a
nutritious
product with good keeping qualities. Microorganisms play an important role in this process to
provide texture & flavor to the product. It is one of earliest method of preserving milk solids.
Cheese is a compressed fermented milk product.
Classification:Cheese can be classified into several types based on several criteria;
g.
h.
i.
j.
k.
l.
Based on the firmness of cheese. [Moisture]
Source of milk. [Cow, buffalo]
Ripening. [Fungi/bacteria]
Country of origin. [eg: cheddar English, Roquefort Southeast France]
Content of fat. [Skim milk, full cream milk]
Manufacturing process.
The basic procedure of manufacturing is same for all types of cheese. There are 4
major steps in the
Production of cheese.
5. Control of the properties of milk.
6. Coagulation
7. Separation of whey & curd
8. Cheese ripening
I. Control of the properties of milk:Good quality milk is more important for cheese making because it is not possible to
pasteurize
Cheese milk intensively. The bacterial content of milk used for cheese making should be low
because microorganisms growing in raw milk may develop unwanted flavour & enzyme. Some
organisms survive pasteurization & cause fault in cheese. The number of psychrotrophs &
thermoduric organism should be low. The physical, chemical & biological properties of the milk
should be controlled.
Basic stages involved in cheese making:*Standardization:Standardization of milk is done to adjust for fat or to have a balance rate of fat & casein
(1: 0.7).
*clarification:The clarifier is an effective alternative for filtration for the removal of extraneous matter,
leucocytes & Some bacteria. It is carried out at 32- 380 c Centrifugally.
Bactofugation:If centrifuged milk is passed through the unit the 2nd time about 90% of the remaining
10% bacteria
is removed. The sludge can be sterilized & reincorporated into the milk.
Homogenization:Milk is homogenized at low pressure the purpose is to reduce the whey exudation from
the coagulum
to make cheese whiter & make promote fat hydrolysis.
Thermization:-
When raw milk must be stored for a few days using for cheese it is subjected to heat
treatment 630 c
for 10-15 sec & cool to 50c prior to storing.
II. Coagulation:It is carried out by the use of any of the following methods:
Use of lactic acid.
Addition of bacteria like lactobacillus sp. Or addition of milk clotting enzyme rennet.
Application of heat.
By the addition of salt.
Alteration of pH.
Among these only a few methods are applicable. The commonly used method is by the
adjustment
of pH.
Coagulation by pH adjustment or Ripening of milk:This is achieved by heating the milk at around 30-33 0 C & adding the starter bacteria.
The organisms grow using lactose as an energy source & converting it into lactic acid by a
complex series of reaction by involving many different enzymes. Selected strains of lactic acid
organisms are used which increase the acidity.
Functions of the starter:
Ensures consistent acid development.
Aids rennet reaction & subsequent coagulation by the developed acidity.
Helps expulsion of whey from the curds.
Contributes to flavor & texture of cheese during ripening.
Suppresses the growth of undesirable organisms.
Microorganisms used for cheese making are;
Type
Function
1. Strep. lactis
Acid formation
2. Strep. cremoris
Acid formation
3. Strep. diacetylactis
Acid, gas & flavor production.
4. Strep. thermohiles
Acid production in high scald cheese.
5. L. bulgaricus
Acid production.
6. Strep. faecalis
Acid & flavor in high scald cheese.
7. Propionibacterium shermanii
Gas & flavor production.
Starters are used at concentration ranging from 0.5 to 2% of milk. The organism multiply
during cheese making from about 10 7 CFU/ml in milk to around 10 9 cfu/gm of the curd. The
growth gets checked at the salting cheese stage. All additives are added & mixed separately
before rennet addition. To provide uniform colour to cheese annatto colour [alkaline extract
from seeds of Bixa orelana] is added to get yellow tint. Calcium chloride at 0.01 to 0.03% of the
milk is used to improve the firmness of the coagulation by rennet. The addition of 15gms of salt
per 100kg of cheese milk prevents blowing (development of too much of gas in the cheese)
caused by coliform bacteria or butyric acid or propionic acid bacteria.
Rennetting:After a mild increase in acidity of milk created by starter rennet extract is added to milk
& uniformly distributed to effect coagulation of milk. The coagulation enzymes are,
Type
Source of Enzymes
* Animal
Calf (Chymosin or pepsin )
Pig (Pepsin)
* Bacteria
B. Subtilis
B. Polymyra
B. mesenteroides
* Fungi
Mucor meihei
M. pusilus
Endothica parasitica.
The enzymes act in 3 phases;
1. Primary / Enzymatic phase:It results in the conversion of one of the milk protein from a colloidal suspension to a
fibrous network. This is done in the presence of calcium.
3. Secondary/Clotting phase:The coagulation of the other function of enzymatic activity & coagulation can be achieved by
an increase
in temperature or decrease in pH.
4. Tertiary/ Proteolytic phase:Chymosin hydrolyze the milk protein to polypeptides. A part of polypeptides are broken
down to
peptides & amino acids.
III. Separation of curd & whey:Separation can be done by mechanical means. Whey separation depends on temperature,
pH & physical characteristics of the curd. Increased temperature enhances whey separation.
Whey separating is carried out by the following methods:
By cutting the curd & allowing the whey to flow.
By placing the curd in perforated containers & allowing the whey to drain through the
perforations.
The curd can also be collected on a clean cloth & whey can be filtered out.
For cutting the curd, special knives are used for different sizes of cubes.
Scalding:High scald cheese the temperature may be 52-58 0 C, in medium scald 30-42 0 C & in low
scald around 30-35 0 C. During combined action of stirring & heat, lactic acid with the curd
particle is formed by the starter organisms, embedded in cheese particles & curd cubes shrinks in
size. When the desired development in the curd has reached whey is drained for texturing the
curd
Draining the whey:The curd is allowed to settle, acidity measured, when it has reached desired level, the
whey is run off until the compact mass of curd is formed in the vat.
Milling:It helps in uniform distribution of salt (1-2%) salt acts as a preservative & flavor
enhancer.
Pressing:The curd is filled in moulds & pressed. The degree of pressing & length of time various
with the type of cheese.
Packaging & storing:Packaging protects
flavor contamination
Entry to external molecules.
Loss of moisture.
Enhances appearance.
Wax coating /plastic film for hard cheese.
Aluminium / plastic film for semi-hard cheese.
Maturing period is 2-24 months. The cheese is stored in increased T 0 in fermentation room
& shifted to ripening room having lower temperature for the development of proteolysis,
lipolysis, aroma & texture.
IV . Cheese ripening:It refers to the changes in the body to texture accompanied by the development of
characteristic flavor typical to that of cheese. Flavor & aroma is produced by the action of
microorganisms & enzymes which breakdown,
Carbohydrate producing lactic acid, acetic acid, Co2 & diacetyl.
H2O insoluble proteins to protease, peptons, peptides, amino acids, organic acids, NH3.
Fat to lower fatty acids, their esters & Ketones.
These changes are brought about by enzymes from,
-> Lactic acid bacteria in starter culture.
-> Miscellaneous non-starter bacteria in milk.
->Rennet & its substitutions used to coagulate the milk.
->Other microorganisms growing within or surface of cheese.
The cheesy flavor is mainly due to carboxyl, nitrogenous compound, fatty acids, sulphur
compounds etc.
Manufacture of Cheddar cheese.
Raw milk
Pasteurize at 71 – 750C – 15 secs [pasteurization reduces the number of spoilage organisms & lactic
acid bacteria & kills most pathogens]
Cool & incubate in cheese vat at 300c [add starter culture Lactococcus lactics ssp cremoris 1 – 1.5%]
[lactic acid fermentation develops]
Milk with 0.19 to 0.21 % lactic acid [rennet added].
[curd’s formation]
Cutting of curds.
[ whey released]
Scalding 38 – 400c & stirring [acid production continues without starter culture].
Cheddaring – Squeezing & Stretching the curd [acid production continues without starter growth
giving a final lactic acid concentration of 0.6 – 0.8 % - primary metabolism].
Milling and salting [ salting prevents further starter activity, assists in preservation & adds flavor &
further release of whey]
Moulding & pressing [further release of whey]
Ripening
[secondary metabolism- Proteinase enzyme released from starter organism produce aminoacid , indole,
sulphur compounds and phenol to enhance flavor. H2O2 and bacteriocin to inhibit pathogen and
spoilage organisms]
[moisture content]
Soft cheese
Semi-soft cheese
[50-80 %]
[39-50%]
Eg: unripened cottage cheese
Ripened camembert cheese
Hard cheese
[34 – 39%]
Very hard cheese [ Very low
moisture].
Salt cured feta cheese
Eg: Ripened by moulds Roquefort cheese
Ripened by bacteria Brick, Gowda, Limburger
SPOILAGE OF CHEESE:
1.DURING MANUFACTURING:
Eg: cheddar cheese
RAW MILK:
Eg: Grana, Parmesan, Asiago old.
Off flavor is produced by gas forming organisms. Eg: Clostridium, coliforms, yeasts.
Gassiness is produced by Clostridium, Bacillus polymyxa [produces gas and defects in ripening
cheese].
Bitter flavor is produced by coliforms, Micrococci, Yeasts [acid proteolytic bacteria].
Leuconostoc produces Holes/openness in cheddar cheese.
Proteolysis, gas production is by undesirable microbes.
Sliminess/Off flavor is produced by Pseudomonas fragi, Alcaligenes metaalcaligenes.
2.DURING RIPENING:
Physical changes [hole formation, change nature of texture]
Chemical changes [undesirable end product, metal discoloration]
Gas holes/eyes/cracks/splitting [Clostridium-butyric acid+gas]
Undesirable acid [Propionibacterium sp.]
Bitterness [Streptococci]
Acid + proteolytic [coliforms, Micrococci]
Yeast flavor/sweet fruity flavor [yeast]
Putrefaction [Clostridium tyrobutyricum, Cl.lentoputrescens, Cl.sporogenes]
Discoloration ;
Eg: rusty spots
Lactobacillus plantarum, L.brewis
Yellow/pink/brown Propionibacterium
Reddish brown to grayish brown due to oxidation of tyrosine by bacteria.
3.FINISHED CHEESE:
OOSPORA [GEOTRICHUM]
Dairy mold G.lactis
Red colour G.rubrum/G.crustacea
Red spot G.aurianticum
Cheese cancer G.caseocorans
4.BLACK SPOT/OFF FLAVOR Monilia sp.,/M.nigra
5. DISCOLOURATION
6.Yellow /red growth
Aspergillus/Mucor/
Alternaria/ Scopulariopsis
Brevibacterium linens
CLADOSPORIUM [DARK/SMOKY COLOUR]
Dark green to black colour C.herbarum
PENICILLIUM [GROWS IN CRACKS]
Green sporesP.puberulum
Yellowish brown spot P.casei
Camembert discolouration P.aurantiovirens
Yoghurt [Bulgarian milk].
Yoghurt is the fermented milk product characterized by its viscous consistency, a strong
acidulous taste due to high acidity [pH 4.6] and a distinct aroma caused mainly by acetaldehyde.
Large-scale manufacture only started in the UK in the 1960s but since then yoghurt has become
an increasingly important dairy product with many different varieties now available in
supermarkets and other retail outlets.
Spoilage:
1. Bloom cartons/frothy consistency and yeasty off flavor, odour yeast ferments sugar into CO2 and
ethanol.
2. Mould growth is less but spoils the surface of yoghurt particularly in under filled cartons.
Prevention:
11. Sterilization of filling equipment.
12. Careful storage of packaging.
13. Installation of filtered air laminar and airflow facilities in filling rooms.
14. Use of UV in filling areas.
15. Periodic fumigation of filling rooms.
16. Control of spillages.
17. Use of sulphate in fruit.
18. Heat treatment of final product.
19. Use of preservative in the final product.
20. Proper use of fruit and fruit syrups to prevent contamination.
Whole milk, Skim milk + water, Whole milk + cream
Pasteurization [850c – 30 mins batch process,90 - 950 c – 10minutes continuous ] inhibits Salmonella,
Listeria, Camphylobacter.
Homogenize [60 – 650c] – smooth texture
Emulsifier’s addition [agar, gums, alginate to increase the viscosity]
Sweeteners addition [5% sugar inhibit lactic acid production].
Heat [90 – 950c] & cool
Inoculate with starter [Strep. salivarius ssp thermophilus, Lactobacillus delbreukii ssp bulgaricus]
Incubate [4 – 16 hrs at 30 – 450c] & Cool [ 10 – 150c]
Add fruit and flavor
Package [Maintain at chill temperature at 4.50c – 2 wks].
Recently, a different type of yoghurt has been produced that uses a mixture of;
L.acidophilus+Bifidobacterium bifidum AB yoghurt
L.acidophilus+Bifidobacterium bifidum+S.salivarius thermophilus ABT yoghurt
These bio or therapeutic yoghurt are said to have health promoting properties. Manufacture of
this type of yoghurt involves direct vat inoculation with the starter followed by incubation at 370 c for
about 16 hrs giving a final product with a pH of 4.2 to 4.4 and a milder creamier flavor.
Nutritive value of yoghurt:
During fermentation of milk the composition of minerals remain unchanged while proteins,
carbohydrates, vitamins and fats to some extent are subjected to changes. The substances formed are
lactic acid, alcohol, CO2 ,antibiotics and vitamins. The following processes make yoghurt
1.Proteolysis:
Proteolysis in milk takes place by exopeptidases and endopeptidases of lactic acid bacteria.
So biological value increases 85.4 to 90%. This increases due to breakdown of proteins into
peptides,
amino acids. The contents of essential amino acid such as leucine, isoleucine, methionine, phenyl
alanine, tyrosine, tryptophan and valine increases which offers special advantage.
2.Hydrolysis of lactose:
Lactose in milk is hydrolysed by metabolic activity of bacteria. Lactic acid inhibits the
growth of putrifactants. It is important for organolectic properties and calcium absorption.
3.Lipolysis:
The homogenization process reduces the size of globules which become digestible, as a result of
lipolytic activity the free fatty acid increases, which have some physiological effect.
4.Changes in vitamins:
There is more than 2 fold increase in vitamins of B group especially thiamine, riboflavin and
nicotinamide.
5. Antibacterial activities:
The antibiotic properties are associated with Lactobacilli in yoghurt and materials responsible are
lactic acid, H2O2 and lactobacilline.
6.Therapeutic properties:
7. Easy absorption and better assimilation. Eg; milk [32% in 1 hr], yoghurt [91% in 1 hr].
8. Improves appetite due to its pleasant refreshing and pungent taste. It is highly nourishing
invigorating.
9. Gastric juice secreted by the action of yoghurt and desirable ratio of calcium and phosphorous
induced by it leads to a high digestive capacity.
10. Removes excessive fat from liver and enhances bile secretion. It has therapeutic importance in GI
disturbances hepatitis, nephritis, diarrhea, colitis, anemia, and anorexia.
11. It provides relief to chronic diarrhea in spruce and ulcerative colitis. Fat free yoghurt is
importance to those who suffer from heart diseases.
12. Yoghurt possesses potent anti-tumour activity. Pathogenic bacteria are not able to survive due to
low pH.
24. Write a brief note onTarhana Production.
Tarhana (Turkish), tarkhina, tarkhana, tarkhwana trachanas/trahanas (Greek
τραχανάς) or (xino)chondros, трахана/тархана (Bulgarian), kishk (Egypt), or kushuk (Iraq)
are dried foods based on a fermented mixture of grain and yoghurt or fermented milk, usually
consumed as soup. As it is both acid and low-moisture, it preserves milk proteins effectively for
long periods. Tarhana is very similar to some kinds of kishk.
The Turkish tarhana consists of cracked wheat (or flour), yoghurt, and vegetables
fermented then dried. The Greek cuisine trahana contains only cracked wheat or a cous cous-like
pasta and fermented milk. In Cyprus, it is considered a national specialty, and is often flavored
with bay leaf, wild thyme, and fennel seed. They are cooked as soup by adding them to stock or
water - or to milk (giving them similarity to breakfast cereals).Trahana may be stored as small
cakes or as coarse lumps.
History
Hill and Bryer argue that tarhana is akin to τρακτον/tractum, a thickener Apicius wrote about in
the first century, which most other authors consider to be a sort of cracker crumb. Dalby (1996)
connects it to the described (and condemned) in Galen's Geoponica 3.8. Weaver (2002) also
considers it of Western origin.
Perry, on the other hand, argues that the phonetic evolution of τραγανός to tarhana is unlikely,
and that it probably comes from Persian tarkhâne. He considers the resemblance to τραγανός and
to 'coarse' coincidental, though he speculates that may have influenced the word by folk
etymology.
In Persian language sources the name of this food is mentioned in the form of Tarkhana by alZamakhshari in his dictionary, in 11th century, and in the form of Tarkhina in Jahangiri
encyclopedia (named after Jahangir the Mughal emperor of India), in 13th centruy CE. Tar in
Persian means wet or soaked and khan or khwan (both spelled the same and W is not
pronounced) means dining place/table, or food, or large wooden bowl. Therefore, in Persian it
would mean the watered or soaked food that quite matches the way the soup is made; Tarhana
must be soaked in water and other possible ingredients are then added and cooked for some time.
Preparation
Tarhana is prepared by mixing flour, yoghurt or sour milk, and possibly cooked vegetables, salt,
and spices (notably tarhana herb); letting the mixture ferment; then drying, grinding, and sieving
the result. The fermentation produces lactic acid and other compounds giving tarhana its
characteristic taste and keeping properties: the pH is lowered to 3.4-4.2, and the drying step
reduces the moisture content to 6-10%, resulting in a medium inhospitable to pathogens and
spoilage organisms, while preserving the milk proteins.wadays, tarhana soup is available as a
convenience food in the form of dehydrated soup in packets.
25. Write a brief note on Taette Production.
Taette:
The taette is a fermented milk product and it is commonly used in scandivania. This taette
is much different from kefir and kumiss. In kefir and kumiss the combination of cultures is used
for the fermentation process. That is Streptococcus lactis and Lactobacillus bulgaricus and a
lactose fermenting yest is inoculated. But in the taette, the yeast and rope forming strains
Streptococcus lactis is inoculated in the milk. The combination of cultures is not added here.
UNIT-III
1.Explain the house committee for quality assurance.
In accordance with clause 2(d)(1) of Rule X of the House of Representatives, the
Committee on Veterans’ Affairs on February 11, 2003, adopted its oversight plan for the
108th Congress.
This oversight plan is directed at those matters most in need of oversight within the
next two years. The Committee is cognizant of the requirement that it conduct oversight
on all significant laws, programs, or agencies within its jurisdiction at least every ten
years. To ensure coordination and cooperation with the other House committees having
jurisdiction over the same or related laws affecting veterans, the Committee will consult
as necessary with the Committee on Armed Services, the Committee on Education and
the Workforce, and the Committee on Government Reform.
Oversight will be accomplished through committee and subcommittee hearings, field
and site visits by Members and staff, and meetings and correspondence with interested
parties. Methods of oversight will include existing and requested reports, studies,
estimates, investigations and audits by the Congressional Research Service, the
Congressional Budget Office, the General Accounting Office, and the Offices of the
Inspectors General of the Departments of Veterans Affairs and Labor.
The Committee will seek the views of veterans’ service organizations, military
associations, other interest groups and private citizens. The Committee also welcomes
communications from any individuals and organizations desiring to bring matters to its
attention. A series of joint hearings is scheduled with the Senate Committee on
Veterans Affairs at which veterans’ service organizations and military associations will
present to the committees their national resolutions and agendas for veterans.
While this oversight plan describes the foreseeable areas in which the Committee
expects to conduct oversight during the 108th Congress, the Committee and its
subcommittees will undertake additional oversight activities as the need arises.
1. VA-administered Insurance Program. The Department of Veterans Affairs (VA)
administers six life insurance programs under which two million policies with a value of
$20 billion remained in force at the end of fiscal year 2002. The committee will examine
policy and operational issues VA faces in operating the seventh largest insurance
program in the United States.
2. Non-Service-Connected Pension Program. The non-service-connected disability
pension program provides financial assistance to more than 348,000 low-income
veterans. Veterans must have at least 90 days of military service, including at least one
day of wartime service, and be totally and permanently disabled for employment
purposes as a result of disability not related to their military service, or over age 65.
The committee will examine the administration of this program.
3. Improvements in Timeliness of Claims Processing. VA provides over $22 billion a year
in disability compensation and pension benefits to more than 2.4 million veterans. The
Veterans Benefits Administration (VBA) has made many improvements to its operations,
including realigning its field offices to improve control of claims and shifting its focus
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from resource management to workload management. The committee will focus on the
General Accounting Office’s December 2002 report, Veterans Benefits: Claims
Processing Timeliness Performance Measure Could be Improved (GAO-03-282).
4. State of Veterans’ Employment and Training. From May 1997 to June 2001, the
General Accounting Office (GAO) issued eight reports criticizing the Veterans’
Employment and Training Service, Department of Labor, for deficiencies in performance,
management, and strategic planning. Public Law 107-288, the Jobs for Veterans Act,
reformed the nationwide veterans’ employment and training delivery system, focusing
on accountability, flexibility, incentives, and results. Further, Public Law 106-50, the
Veterans Entrepreneurship and Small Business Development Act of 1999, increased
small business opportunities for veterans and disabled veterans by improving their
access to capital, information, and markets. The committee will examine implementation
of these two laws.
5. Troops-To-Teachers. The Troops-To-Teachers program services as an alternative
route to teacher certification for military servicemembers and retirees who seek a
second career as a public school teacher. The program is funded by the Department of
Education. The committee plans a joint hearing with the Committee on Education and
the Workforce. The committees expect to examine the skills and experience that
veterans bring to teaching, as well as the administration of the program.
6. Role of the Board of Veterans’ Appeals in the 21st Century. The Board of Veterans’
Appeals (BVA) is the component of the VA responsible for making the final Departmental
decision on behalf of the Secretary in appeals of veterans’ benefits claims. Since the
advent of judicial review of appeals of veterans’ claims in 1988, the essential mission of
BVA has remained relatively unchanged. The committee will examine how to most
effectively use the Board’s expertise and resources in serving veterans.
7. Quality Assurance for Disability Claims at the Board of Veterans’ Appeals. Veterans
who are dissatisfied with a decision made by a VA regional office may appeal that
decision to BVA. During fiscal years 1999 and 2000, BVA decided an average of 35,000
appeals per year. GAO reviewed the quality assurance program at the Board and the
Board’s collection of data to improve the quality and consistency of its decisions on
veterans’ claims. The committee will focus on the GAO’s August 2002 report, Veterans’
Benefits: Quality Assurance for Disability Claims and Appeals Processing Can Be Further
Improved. (GAO-02-806).
8. Vocational Rehabilitation and Employment. VA’s Vocational Rehabilitation and
Employment (VR&E) program provides services and assistance to enable veterans with
service-connected disabilities to obtain and maintain suitable employment, and to
enable certain other disabled veterans to achieve independence in daily living. The
committee will examine VR&E’s focus on suitable employment, assistance to the most
seriously disabled veterans, succession planning, contracted services, claims processing,
employer outreach and quality assurance.
9. Office of Federal Contract Compliance Programs. The Office of Federal Contract
Compliance Programs (OFCCP) is an enforcement agency within the Department of
Labor. In addition to other equal employment laws, OFCCP enforces the Vietnam Era
Veterans’ Readjustment Assistance Act of 1974 (VEVRAA). The law requires that
employers with Federal contracts of $100,000 or more provide equal opportunity and
affirmative action for certain veterans. The Federal government awards prime contracts
worth approximately $200 billion per year. The committee will examine OFCCP’s recent
investigatory and enforcement actions related to VEVRAA, staffing matters, and the
general complaint process.
10. Fiduciary Activities. When a probate court or VA rating board determines an adult
VA beneficiary is incompetent, VBA personnel assess the need for a fiduciary, appoint an
appropriate person or entity to manage the beneficiary’s funds, and monitor the
management of those funds. As of December 31, 2002, VBA personnel supervised the
management of funds for more than 100,000 incompetent beneficiaries. VA’s Inspector
General has begun conducting Combined Assessment Program reviews at VBA regional
offices. The most recent summary report (Report No. 02-01811-38) indicates that
improvement with regard to Fiduciary and Field Examination activities is needed at more
than 50 percent of the regional offices reviewed between June 2000 and September
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2002. The committee will determine the extent of problems with VBA’s fiduciary
program and recommendations for improvements.
11. Meeting the Health Care Needs of Veterans. Despite record budget increases, the
growing demand for health care is outpacing the resources allotted to VA for veterans’
health care. The committee will evaluate factors that contribute to the loss of current
services, long waiting times and delayed or denied care. The committee will also review
the recommendations of the President’s Task Force to Improve Health Care Delivery for
Our Nation’s Veterans and any plans to implement the Task Force’s recommendations.
12. Infrastructure Maintenance in VA Health Care and CARES. The VA health care
system capital asset planning process, known as Capital Assets Realignment for
Enhanced Services (CARES) II, is underway, with a scheduled date of completion during
the 108th Congress. The committee is concerned about the cumulative effects of years
of insufficient resources to adequately maintain VA’s aging health care facilities. Many
need significant maintenance, repair and modernization. The committee will review
these needs and the implementation of CARES and its next phases.
13. Veterans Equitable Resource Allocation System. The Veterans Health Administration
(VHA) adopted this system of allocating funds to its field health activities in April 1997.
During the past year, the allocation model was revised. The committee will review the
implementation, operation and effectiveness of the new Veterans Equitable Resource
Allocation (VERA) model and its impact on veterans.
14. Management Improvements. The VA’s plans in fiscal year 2003 included saving
$298 million by making management improvements, with an additional $800 million in
savings proposed for fiscal year 2004. The committee will review the business practices,
scope and success of VA management improvements.
15. VA and DOD Health Resources Sharing. Sections 721 through 726 of Public Law
107-314 provided the most significant changes to VA-DOD sharing authority in its 20year history. With new opportunities and incentives in place to conserve scarce federal
health care resources and improve the delivery of services to the military-veteran
community, the committee intends to continue its close oversight of VA-DOD resource
sharing, especially implementation of the new legislation.
16. Status of VA Medical, Biological, Chemical and Radiological Research. VA medical
research, in affiliation with the nation’s leading schools of medicine, has been
remarkably successful in curing human disease and advancing biomedicine. The
committee has monitored VA research for a number of years and will continue to review
it. Public Law 107-287 expanded the VA’s role in homeland security and created new
research centers to counter biological, chemical, and radiological terrorism and threats
against active duty service members, veterans and the general public. Implementation
of the new law will be carefully monitored.
17. Mental Health and Substance-Use Disorder Programs. Reported reductions in
capacity of VA programs to care for the most seriously mentally ill veterans, especially
those with psychoses and with substance-use disorders, continue to be a matter of
concern. The committee will explore the state of VA’s mental health programs and the
effectiveness of chronic mental illness treatment programs in VA’s institutional, contract,
community-based, case-management and aftercare programs.
18. Follow-up on Millennium Act. Public Law 106-117, the Veterans Millennium Health
Care and Benefits Act, was the most significant health care legislation Congress has
enacted for veterans in a number of years. Since the law was enacted, VA has
implemented many of its provisions. The committee will continue to give attention to
the remaining steps VA must take to comply fully with its mandates and will provide
oversight to those programs already implemented, including the effectiveness of pilot
programs and the maintenance of capacity in VA’s long-term care programs.
2.Explain thePersons involved in internal microbial quality control policy.
Air- and surface-cleaning technologies
The technologies needed to create healthy buildings already exist, but they are not implemented
widely enough to interdict epidemics. Optimized combinations of filtration and ultraviolet
germicidal irradiation (UVGI) can be used to remove airborne microbes with high efficiencies.
Combining and optimizing these technologies is the most cost effective means of disinfecting
indoor air.1
Filtration removes airborne particles including mold spores, many bacteria, and allergens.
UVGI eliminates many harmful bacteria and viruses.
Disinfection systems can control bioaerosols.
Existing buildings can be retrofitted with air disinfection systems, but the most economic longterm solution is to construct new buildings that maintain aerobiological cleanliness by design.
Air circulation is often poor in older buildings, and there are limits to what retrofitted aircleaning systems can do for them. New buildings can be built in which the airflow is more
evenly distributed and in which effectiveness of air cleaning can be maximized.2 A variety of
other technologies, including photocatalytic oxidation (PCO), ozone, pulsed light, and
antimicrobial materials, are also available options for air and surface biocontamination problems.
Criteria for rating healthy buildings
Modern air disinfection systems can achieve high levels of air cleaning, but limited budgets often
require us to ask exactly how much air cleaning is needed to protect health. This question
ultimately hinges on how buildings rate:
aerobiologically — the indoor levels of airborne microbes
epidemiologically — the infection risk of the building
Airborne levels of microbes
We can measure airborne levels of microbes.
Indoor air contains a great variety of bioaerosols, most of which are relatively harmless to
healthy humans. The concentration of airborne microbes in indoor environments, treated
collectively without regard to species, provides a reasonable indication of overall aerobiological
air quality. Levels of bacteria and fungi vary by season, with lows in winter, and increase with
occupancy, as people are the primary source of contagious pathogens. Airborne levels are
measured in terms of colony-forming units (cfu) of bacteria or fungi per cubic meter. Some
hospital operating rooms are designed to maintain levels as low as 10 cfu/m3, although this level
often proves difficult to achieve. Levels in homes and offices need not be this low, making
solutions there less cost-prohibitive.
Infection risk
We can also estimate infection risk.
The infection risk (IR) of any building might be estimated by collecting data on infection rates
and symptoms or through methods of risk analysis.3 Another approach is to estimate the risk
using computer models of building airflow to calculate daily doses of inhaled contaminants.
Airborne levels can be easily, if not always accurately, assessed with air samplers. The IR to an
occupant in a particular building can be evaluated from epidemiological data. The IR can also be
inversely viewed as the percentage of occupants protected from infection, a parameter called the
building protection factor (BPF).
The BPF is the complement of the IR— a low IR implies a high BPF— and it can be used to rate
and compare buildings under a common design basis. The BPF is primarily a function of the
volume, airflow, outside air fraction, and removal efficiency of the air disinfection system. Being
an intrinsic property of the building, it applies generically to all microbial species.4
Buildings differ according to their operating parameters. A completely unprotected building may
have a BPF of 0% to 1%, whereas a building that maximizes protection of occupants may have a
BPF of up to 99%. BPF can be considerably improved in existing buildings through the addition
of air cleaning or other ventilation system improvements.
These measures offer guidelines to buildings.
At least four general categories of buildings have been suggested:1,5
1. Problem buildings foster aerobiological problems or act as amplifiers. Their airborne
levels may exceed 10,000 cfu/m3. IR can approach 99% or more and BPF 1% or less.
2. Normal buildings have average airborne levels, about 500 to 5000 cfu/m3. Typically, IR
is about 50% to 75% and BPF about 25% to 50%.
3. Healthy buildings promote good air quality and health or are above average. Airborne
levels are 100 to 1000 cfu/m3. Typically, IR is less than 50% and BPF 50% or higher.
4. Immune buildings are designed to actively prevent airborne disease transmission.
Airborne levels are as low as 10 cfu/m3. IR is less than 10% and BPF 90% or higher.
Disease-free buildings
Buildings concentrate allergens due mainly to the protective effects of shade, warmth, substrate
materials, and moisture. For the same basic reasons, they act as vectors (carriers) for contagious
airborne diseases. Humans have been building enclosed habitats for perhaps half a million years,
and in this course of time airborne pathogens evolved the ability to survive indoors just long
enough to transmit to new hosts. They have adapted to our enclosed habitats so completely that
they cannot survive outdoors. This evolutionary process accelerated when man began
husbanding animals, from which almost all human pathogens seem to have jumped species. The
evolutionary process continues today as emerging pathogens adapt to indoor transmission, and
the number of new disease species has increased exponentially over time, in concert with the size
and density of the human population.4
Can we immunize buildings?
By designing our habitats strictly for human comfort, we have unwittingly fostered the
adaptation and proliferation of dangerous pathogens. It is only by re-engineering our buildings to
eliminate, rather than foster, airborne disease transmission that we can reverse this evolutionary
trend. By immunizing enough buildings against disease, it is theoretically possible to develop
herd immunity in a community or city. The percentage of buildings that would need to be
immunized to block an airborne epidemic is similar to the percentage of a population vaccinated
to achieve herd immunity, and depending on the contagiousness of the species, this may be as
low as 30%.4
In addition to air disinfection and improved delivery of clean air, there are other factors that can
aid in the development of healthy buildings. Rugs, carpets, furniture, draperies, and the like can
absorb mold spores and regenerate new ones if they become wet. Material selectivity can be one
beneficial approach, and other alternatives include the use of self-disinfecting materials,
pressurization, and isolation of zones within buildings, including the provision of buffer zones
between the inside and outdoor air and the creation of clean inner zones safe from airborne
health threats.
3.Explain the Quality check at every step from collection of raw materials till
it reaches the customer.
The trade of spices has been an integral part of our business, since our inception. We began our business
in Kerala as suppliers of spices from Kerala to West Bengal. Our expertise in the spices trade, ages back
to the 1970’s. It is one of the primary business ventures of the group.Since then, the company has been
setting
foot
into
diversified
business.
Navin Trading Company is a subsidiary of Jaihind Traders, which has a tradition of over 30 years into
various business fields like Spices, Iron and Steel, Aluminium, Composite Panels, Commodity Trading,
etc. We started our operations in Cochin, with our office at Mattanchery, which has been the hub of spices
trade in Kerala. Navin Trading Company has won the Export Award for 1999 – 2000. We are pioneers in
the
trade
of
black
pepper.
Today, an ISO 22000: 2005, HACCP , FSMS certified company, Navin Trading is one of the key players
in the spices export from Kerala. With over thirty years into the spices trade, are pioneers in the trade of
black pepper. All our processing operations are strictly in conformity with the International Quality norms
laid by HACCP Hazard Analysis at Critical Control Points. Our modern processing facilities for the
products include a full line of drying, cleaning, grinding, sizing, sieving, blending and storage facility, in
order to cater to all the specific requirements of our customers. The cleaning process includes, precleaning, classifying, drying, de-stoning, magnetic separation, spirals sortex, etc. Products are controlled
by in-house state of the art approved laboratory by qualified staff. Our quality assurance programme
emphasizes product safety through FSMS Food Safety Management System.
Zest for knowledge and the ability to go the extra mile has always been our plus points, giving us the
cutting edge in this highly global and dynamic business environment.
Quality Policy / Processes
Quality
Policy:
Quality control is a process that is respected in the company and every employee is made to understand
that no product we manufacture can be less than the best. Authorities and quality control agencies are
convinced
about
our
quest
for
quality
and
employee
satisfaction.
Navin Trading is an ISO 22000: 2005, HACCP , FSMS certified company into the spices industry. All
our processing operations are strictly in conformity with the International Quality norms laid by HACCP
(Hazard Analysis at Critical Control Points). This ensures a perfect machinery of checks at every step
right from the raw material procurement stage till the product reaches the warehouse of the consumer. we
reach
for
new
horizons
only
to
initiate
the
journey
towards
the
next.
We have a state of the art factory at Aluva, with a fully functional Quality control laboratory. All
incoming raw materials are thouroughly inspected before it enters the processing line. The products are
then passed through numerous quality control processes, strictly moniterd at each stage. The end product
is finally released only after the approval of a team of trained quality control personel, inorder to ensure
that we deliver the finest products.
Infrastructure
Navin Trading is an ISO 22000: 2005, HACCP , FSMS certified company into the spices
industry. All our processing operations are strictly in conformity with the International Quality
norms laid by HACCP (Hazard Analysis at Critical Control Points). This ensures a perfect
machinery of checks at every step right from the raw material procurement stage till the product
reaches the warehouse of the consumer. we reach for new horizons only to initiate the journey
towards the next.
Our modern processing facilities for the products include a full line of drying, cleaning, grinding,
sizing, sieving, blending and storage facility, in order to cater to all the specific requirements of
our customers. The cleaning process includes, pre-cleaning, classifying, drying, de-stoning,
magnetic seperation, spirals (sortex), etc. Products are controlled by in-house state of the art
approved laboratory by qualified staff. Our quality assurance programme emphasizes product
safety through FSMS.
We have a state of the art factory at Aluva, with a fully functional Quality control laboratory. All
incoming raw materials are thouroughly inspected before it enters the processing line. The
products are then passed through numerous quality control processes, strictly moniterd at each
stage. The end product is finally released only after the approval of a team of trained quality
control personel, inorder to ensure that we deliver the finest products.
Raw Materials
Milk containers are made from paperboard coated with a waterproof plastic, generally
polyethylene. The wood pulp that is used to make paperboard for milk cartons is a blend of
softwood and hardwood. Softwood is usually a type of pine, though the actual trees used vary
depending on the location of the paper mill. Softwood produces long wood fibers that provide
strength to the paperboard. Hardwood comes from deciduous trees such as oaks. Hardwood has
shorter fibers that make for a better printing surface. Pulp for milk carton board is usually 60%
hardwood and 40% soft.
Several other chemicals are used to make milk cartons. One is oxygenated chlorine, which
bleaches the wood pulp. Other chemicals specific to each manufacturer are added to the paper to
add strength. Chemical pigments in the ink are used for the printing process as well.
The Manufacturing
Process
Making the paperboard
1 The heavy paper used for milk cartons is categorized as a type of paperboard. It is typically
made on a Fourdrinier machine, one of the oldest and most common types of papermaking
equipment. The process begins with wood chips. The chips are heated and bathed in chemicals
that soften them and break them into small bits of wood fiber. The pulp is bleached in a bath of
oxygenated chlorine. The pulp is then washed and passed through several screens, to remove
debris. Next, the pulp is fed through a machine called a refiner, which grinds the wood fibers
between rotating disks.
The refined pulp flows into the headbox of the Fourdrinier machine. In the headbox, a
mixture of water and pulp is spread across a continually moving screen. The water drains
away below through the openings in the screen, leaving a mat of damp wood fiber. The
mat is drawn through huge rollers that squeeze out additional water. Next, the paperboard
is dried, by passing it over steam-heated cylinders.
Applying waterproof coating
2 The dried paperboard next moves through the rollers of an extruder. As the paperboard is pulled
through the rollers, the machine extrudes a small amount of molten polyethylene. The
polyethylene clings to both sides of the paperboard in a thin film. Several grades of polyethylene
may be combined in the extruder, and the machine actually lays down multiple layers of film in
one pass. The different layers accomplish different tasks, such as reducing moisture penetration,
reducing oxygen penetration, and aiding in essential oil retention. As the paperboard comes
through the extruder, it passes over a chilled roller, which cools both surfaces. The paper now has
an extremely glossy, waterproof finish. It is wound into a large roll, to be transported to the
printing area. The roll is typically 120 in (3.05 m) wide, too big to fit onto the printing and cutting
machine. The large roll is slit into narrower rolls, the width determined by the desired dimensions
of the finished carton.
Printing and cutting the blank
3 Printing is usually done by the flexo-graphic method, which uses rubber printing plates attached
to steel shells. Workers load the roll of polyethylene-coated paperboard into the press. The press
prints the words and images of the milk carton onto the paperboard. A typical milk carton might
be printed in anything from one to seven colors. All of the colors are printed at one pass through
the machine. Next, the same machine scores the paperboard along what will be the edges of the
carton, where the box will fold later. A die lowers, and stamps out the carton. If you cut open an
empty milk carton down one side and across the bottom and unfold it, you can see the shape of
the cut piece. This flat, scored, and printed piece is called a blank. The high-speed printing and
cutting equipment turns out hundreds of blanks per minute.
Sealing the blanks
4 Workers at the carton plant next load the blanks into a sealing machine. The machine takes the
flat blank and folds it laterally, creating an overlapping side seam. The seam is then heated and
squeezed together. The heated polyethylene bonds and the seam are strong and watertight without
any additional glue. Thousands of blanks per minute shoot through the sealing machine. This is
the final step at the carton manufacturer. The rest of the process is completed at the dairy. The
sealed and folded blanks are loaded into corrugated cartons, and they are shipped.
4.Explain theImplementation of ISO Standards and history.
ISO 22000 is a standard developed by the International Organization for Standardization dealing
with food safety. This is a general derivative of ISO 9000.
..
Food safety
Food safety is linked to the presence of food-borne hazards in food at the point of consumption.
Since food safety hazards can occur at any stage in the food chain it is essential that adequate
control be in place. Therefore, a combined effort of all parties through the food chain is required.
ISO 22000 standard
The ISO 22000 international standard specifies the requirements for a food safety management
system that involves the following elements:
interactive communication
system management
prerequisite programs
HACCP principles
Critical reviews of the above elements have been conducted by many scientists [1], [2], [3], [4].
Communication along the food chain is essential to ensure that all relevant food safety hazards
are identified and adequately controlled at each step within the food chain. This implies
communication between organizations both upstream and downstream in the food chain.
Communication with customers and supplies about identified hazards and control measures will
assist in clarifying customer and supplier requirements.
Recognition of the organization's role and position within the food chain is essential to ensure
effective interactive communication throughout the chain in order to deliver safe food products
to the final consumer.
The most effective food safety systems are established, operated and updated within the
framework of a structured management system and incorporated into the overall management
activities of the organization. This provides maximum benefit for the organization and interested
parties. ISO 22000 has been aligned with ISO 9001 in order to enhance the compatibility of the
two standards.
ISO 22000 can be applied independently of other management system standards or integrated
with existing management system requirements.
ISO 22000 integrates the principles of the Hazard Analysis and Critical Control Point (HACCP)
system and application steps developed by the Codex Alimentarius Commission. By means of
auditable requirements, it combines the HACCP plan with prerequisite programmes. Hazard
analysis is the key to an effective food safety management system, since conducting a hazard
analysis assists in organizing the knowledge required to establish an effective combination of
control measures. ISO 22000 requires that all hazards that may be reasonably expected to occur
in the food chain, including hazards that may be associated with the type of process and facilities
used, are identified and assessed. Thus it provides the means to determine and document why
certain identified hazards need to be controlled by a particular organization and why others need
not.
During hazard analysis, the organization determines the strategy to be used to ensure hazard
control by combining the prerequisite programmes and the HACCP plan.
ISO is developing additional standards that are related to ISO 22000. These standards will be
known as the ISO 22000 family of standards. At the present time, the following standards will
make up the ISO 22000 family of standards:
ISO 22000 - Food safety management systems - Requirements for any organization in the food
chain.
ISO 22001 - Guidelines on the application of ISO 9001:2000 for the food and drink industry
(replaces: ISO 15161:2001).
ISO/TS 22002- Prerequisite programmes on food safety -- Part 1: Food manufacturing
ISO TS 22003 - Food safety management systems for bodies providing audit and certification of
food safety management systems.
ISO TS 22004 - Food safety management systems - Guidance on the application of ISO
22000:2005.
ISO 22005 - Traceability in the feed and food chain - General principles and basic requirements
for system design and implementation.
ISO 22006 - Quality management systems - Guidance on the application of ISO 9002:2000 for
crop production.
ISO 22000 is also used in the Food Safety Systems Certification (FSSC) Scheme FS22000.
FS22000 is a Global Food Safety Initiative (GFSI) approved scheme.
ISO 9001 vs ISO 22000
In comparison with ISO 9001, the standard is a more procedural orientated guidance than a
principle based one. Apart from that, ISO 22000 is an industrial-specific risk management
system for any type of food processing and marketing, which can be closely incorporated with
the quality management system of ISO 9001. The detailed similarities and differences of the two
standards can be found elsewhere
Potential justification
In 2004, European Office of Crafts, Trades and Small and Medium-sized Enterprises for
Standardisation addressed that the standard is only suitable for large sized companies and small
food businesses will not be able to seek such a high standard due to the lack of resources to
pursue the certification. The agency suggests to create an alternative for small food business to
achieve the same objective [9]. EFSA is now making their efforts on the food legislations that are
adaptable for the SMEs in food supply chains [10]. A few critics also proposed that organizations
which seek the standard certification should also do the same to the ISO 14001 along with the
ISO 9001, as they consider that large amounts of risks are mainly from the primary production in
the supply chains rather than the later stages of food processing .
ISO14000 - Introduction
After the success of the ISO9000 series of quality standards, the International Standards
Organization published a comprehensive set of standards for environmental management. This
series of standards is designed to cover the whole area of environmental issues for organizations
in the global marketplace.
History of Development
The ISO 14000 series emerged primarily as a result of the Uruguay round of the GATT negotiations and
the Rio Summit on the Environment held in 1992. While GATT concentrates on the need to reduce nontariff barriers to trade, the Rio Summit generated a commitment to protection of the environment across
the world. The environmental field has seen a steady growth of national and regional standards. The
British Standards Institution has BS 7750, the Canadian Standards Association has environmental
management, auditing, eco-labeling and other standards, the European Union has all of these plus the ecomanagement and audit regulations, and many other countries (e.g. USA, Germany and Japan) have
introduced eco-labeling programs.
After the rapid acceptance of ISO 9000, and the increase of environmental standards around the
world, ISO assessed the need for international environmental management standards. They
formed the Strategic Advisory Group on the Environment (SAGE) in 1991, to consider whether
such standards could serve to:
Promote a common approach to environmental management similar to quality management;
Enhance organizations' ability to attain and measure improvements in environmental performance; and
Facilitate trade and remove trade barriers.
In 1992, SAGE's recommendations created a new committee, TC 207, for international
environmental management standards. The committee, and its sub-committees include
representatives from industry, standards organizations, government and environmental
organizations from many countries. The new series of ISO14000 standards are designed to cover:
environmental management systems
environmental auditing
environmental performance evaluation
environmental labeling
life-cycle assessment
environmental aspects in product standards
Why have these standards ?
A set of international standards brings a world-wide focus to the environment, encouraging a
cleaner, safer, healthier world for us all. The existence of the standards allows organizations to
focus environmental efforts against an internationally accepted criteria.
At present many countries and regional groupings are generating their own requirements for
environmentla issues, and these vary between the groups. A single standard will ensure that there
are no conflicts between regional interpretations of good environmental pactice.
The fact that companies may need environmental management certification to compete in the
global marketplace could easily overshadow all ethical reasons for environmental management.
Within Europe, many organizations gained ISO9000 Registration primarily to meet growing
demands from customers. ISO 9000 quality registration has become necessary to do business in
many areas of commerce. Similarly, the ISO 14000 management system registration may
become the primary requirement for doing business in many regions or industries.
Who do the standards apply to ?
The standards apply to all types and sizes of organizations and are designed to encompass
diverse geographical, cultural and social conditions. For ISO14001, except for committing to
continual improvement and compliance with applicable legislation and regulations, the standard
does not establish absolute requirements for environmental performance. Many organizations,
engaged in similar activities, may have widely different environmental management systems and
performance, and may all comply with ISO14001.
What do the standards apply to ?
This is primarily for the company to decide, and to clearly document the extent of coverage.
However, limiting coverage to a small [inconsequential] area may provide competitors with an
ideal marketing opportunity!.
There does not appear to be a limit to the coverage of the environmental management system in
that it can include the organization's products, services, activities, operations, facilities,
transportation, etc.
From a slightly different viewpoint, all of the elements in the previous sentence should be
considered for environmental impact resulting from current practices, past practices and future
practices, ......and should further be reviewed for their impact under normal, abnormal and
emergency conditions.
What does the ISO 14000 Series cover ?
The best way to answer this question is to provide a list of the proposed standards:
Standard
Title / Description
14000
Guide to Environmental Management Principles, Systems and
Supporting Techniques
14001
Environmental Management Systems - Specification with Guidance for
Use
14010
Guidelines for Environmental Auditing - General Principles of
Environmental Auditing
14011
Guidelines for Environmental Auditing - Audit Procedures-Part 1:
Auditing of Environmental Management Systems
14012
Guidelines for Environmental Auditing - Qualification Criteria for
Environmental Auditors
14013/15
Guidelines for Environmental Auditing - Audit Programmes, Reviews
& Assessments
14020/23
Environmental Labeling
14024
Environmental Labeling - Practitioner Programs - Guiding Principles,
Practices and Certification Procedures of Multiple Criteria Programs
14031/32
Guidelines on Environmental Performance Evaluation
14040/43
Life Cycle Assessment General Principles and Practices
14050
Glossary
14060
Guide for the Inclusion of Environmental Aspects in Product Standards
General Description of ISO14001
ISO14001 requires an Environmental Policy to be in existence within the organisation, fully
supported by senior management, and outlining the policies of the company, not only to the staff
but to the public. The policy needs to clarify compliance with Environmental Legislation that
may effect the organization and stress a commitment to continuous improvement. Emphasis has
been placed on policy as this provides the direction for the remainder of the Management
System.
Those companies who have witnessed ISO9000 Assessments will know that the policy is
frequently discussed during the assessment, many staff are asked if they understand or are aware
of the policy, and any problems associated with the policy are seldom serious. The
Environmental Policy is different, this provides the initial foundation and direction for the
Management System and will be more stringently reviewed than a similar ISO9000 policy. The
statement must be publicised in non-technical language so that it can be understood by the
majority of readers. It should relate to the sites within the organisation encompassed by the
Management System, it should provide an overview of the company’s activities on the site and a
description of those activities. A clear picture of the company’s operations.
The preparatory review and definition of the organization's environmental effects is not part of a
ISO14001 Assessment, however examination of this data will provide an external audit with a
wealth of information on the methods adopted by the company. The preparatory review itself
should be comprehensive in consideration of input processes and output at the site. This review
should be designed to identify all relevant environmental aspects that may arise from existence
on the site. These may relate to current operations, they may relate to future, perhaps even
unplanned future activities, and they will certainly relate to the activities performed on site in the
past (i.e. contamination of land).
The initial or preparatory review will also include a wide-ranging consideration of the legislation
which may effect the site, whether it is currently being complied with, and perhaps even whether
copies of the legislation are available. Many of the environmental assessments undertaken
already have highlighted that companies are often unaware of ALL of the legislation that affects
them, and being unaware, are often not meeting the requirements of that legislation.
The company will declare its primary environmental objectives, those that can have most
environmental impact. In order to gain most benefit these will become the primary areas of
consideration within the improvement process, and the company’s environmental program. The
program will be the plan to achieve specific goals or targets along the route to a specific goal and
describe the means to reach those objectives such that they are real and achievable. The
Environmental Management System provides further detail on the environmental program. The
EMS establishes procedures, work instructions and controls to ensure that implementation of the
policy and achievement of the targets can become a reality. Communication is a vital factor,
enabling people in the organisation to be aware of their responsibilities, aware of the objectives
of the scheme, and able to contribute to its success.
As with ISO9000 the Environmental Management System requires a planned comprehensive
periodic audit of the Environmental Management System to ensure that it is effective in
operation, is meeting specified goals, and the system continues to perform in accordance with
relevant regulations and standards. The audits are designed to provide additional information in
order to exercise effective management of the system, providing information on practices which
differ to the current procedures or offer an opportunity for improvement.
In addition to audit, there is a requirement for Management Review of the system to ensure that
it is suitable (for the organization and the objectives) and effective in operation. The
management review is the ideal forum to make decisions on howe to improve for the future.
5.Explain thePrinciples and use of HACCP in Food industry.
Basic principles of HACCP
There are seven discrete activities that are necessary to establish, implement and maintain a HACCP
plan, and these are referred to as the 'seven principles' in the Codex Guideline (1997).
The seven principles are[1]:
Principle 1
Conduct a hazard analysis.
Identify hazards and assess the risks associated with them at each step in the commodity system.
Describe possible control measures.
Principle 2
Determine the Critical Control Points (CCPs)
A critical control point is a step at which control can be applied and is essential to prevent or
eliminate a food safety hazard, or reduce it to an acceptable level. The determination of a CCP can be
facilitated by the application of a decision tree, such as the one given in Appendix IV.
Principle 3
Establish critical limits.
Each control measure associated with a CCP must have an associated critical limit which separates
the acceptable from the unacceptable control parameter.
Principle 4
Establish a monitoring system
Monitoring is the scheduled measurement or observation at a CCP to assess whether the step is under
control, i.e. within the critical limit(s) specified in Principle 3.
Principle 5
Establish a procedure for corrective action, when monitoring at a CCP indicates a deviation
from an established critical limit.
Principle 6
Establish procedures for verification to confirm the effectiveness of the HACCP plan.
Such procedures include auditing of the HACCP plan to review deviations and product dispositions,
and random sampling and checking to validate the whole plan.
Principle 7
Establish documentation concerning all procedures and records appropriate to these principles
and their application
Application of HACCP to mycotoxin control
Once tasks 1 to 5 have been completed the following will be in place: a HACCP team, a Description
and Intended Use table, and a verified Commodity Flow Diagram. This will provide information on a
specific commodity from a unique source, and this information is required to complete the hazard
analysis. See the case studies in Chapter 3 for examples of implementation, including that of stages 1
to 5.
Task 6 - Mycotoxin hazard analysis and identification of possible control measures
Hazard Analysis
a) Identification of mycotoxin hazard
For a given commodity system in a particular location, the HACCP team need to first consider
which, if any, of the mycotoxins known to constitute a food safety hazard are likely to be present.
Over 300 mycotoxins are known, but only a relatively few of these are widely accepted as presenting
a significant food or animal feed safety risk. These hazardous mycotoxins are listed in Tables 1 and 2
in Chapter 1. Of these only the following mycotoxins have regulatory limits set by one or more
countries: the aflatoxins (including aflatoxin M1), ochratoxin A, zearalenone, patulin, ergot alkaloids,
and deoxynivalenol. Guideline limits exist for fumonisin B1 and regulatory limits are likely to be set
in the near future. The regulatory limits are taken as the target levels and should be included in the
Product Description table. Mycotoxin limits can also be set by the customer in specific contracts and
it is possible that these may include mycotoxins not subject to regulatory limits.
The risk of a particular mycotoxin hazard should be estimated using well established data on the
relative susceptibilities of commodities to given mycotoxins and the climatic conditions required for
the mycotoxins to be produced. The EU has identified the following animal feed ingredients, and
their products, as being highly susceptible to aflatoxin contamination: maize, groundnut cake,
cottonseed cake, babassu, palm kernel cake and copra cake. The EU has also identified the following
foodstuffs as highly susceptible to aflatoxin contamination: dried figs and other dried fruit,
groundnuts, pistachios and other edible nuts and cereals. These commodities are specified in the
respective EC regulations (1525/98 amending regulation 194/97). Maize grown in temperate climates
would be less likely to be contaminated with aflatoxin, but could be contaminated with trichothecene
mycotoxins or fumonisin B1. Although published mycotoxin survey data exists for many
commodities, it is important that surveillance studies are performed if mycotoxin data is lacking for a
particular commodity, or for production in a particular climatic zone.
b) Identification of steps in the Commodity Flow Diagram (CFD) where mycotoxin
contamination is most likely to occur
Once the mycotoxin hazard(s) has been identified, each step in the CFD must be considered in turn
and the likelihood of mycotoxin contamination occurring must be assessed. Usually published
scientific data will be available to act as a guide, but it may be necessary to commission a study to
determine, or confirm that the correct steps have been identified. The situation may change from year
to year, and season to season, so there will need to be an element of mycotoxin surveillance in the
HACCP plan.
An important fact to establish is whether pre-harvest contamination with mycotoxins is likely or
whether contamination occurs primarily post-harvest. Mycotoxins produced by Fusarium spp, such
as fumonisin B1 are invariably produced pre-harvest, but climatic conditions effect the degree of
blight and the resultant level of mycotoxin contamination. Aflatoxins can be produced both preharvest and post-harvest and climatic conditions can have a significant bearing: drought stress
favours pre-harvest contamination, whereas post-harvest handling during the rainy season favours
post-harvest aflatoxin contamination.
It is rarely possible to be certain that pre-harvest mycotoxin levels are below regulatory or target
levels in the commodity system, so post-harvest mycotoxin control measures can often only prevent
or reduce ADDITIONAL contamination, rather than prevent the hazard completely. Consequently it
is often necessary to introduce a segregation step to remove any batches containing an unacceptable
level of mycotoxin.
c) Possible Mycotoxin Control Measures
The most effective mycotoxin control measures is to dry the commodity such that the water activity
(aw) is too low to support mould growth and/or prevent mycotoxin production. To prevent the growth
of most moulds the aw needs to be £ 0.70, which translates to a moisture content of approximately
14% for maize and 7.0% for groundnuts at 20°C (the corresponding moisture content decreases as
the temperature increases). Each toxigenic mould has its own minimum water activity for growth and
mycotoxin production and these translate into moisture contents for each commodity. These moisture
contents are termed 'safe' and would be the critical limit for the control measure.
It is important to specify a target 'safe' moisture content with a maximum as well as an average value,
e.g. 14% no part exceeding 15%. If only an average value is specified it may conceal a large range of
moisture contents within the batch and the commodity would not be safe from mould growth and
mycotoxin contamination. A drying process is required which dries evenly and the critical limits
must be set bearing this in mind. Validation of such a CCP must involve moisture determination of
multiple samples.
If the commodity is at an 'unsafe' moisture content for longer than 48 hours, then mould can grow
and mycotoxins be produced. Hence limiting the time that the commodity spends in the 'unsafe'
moisture content window to less than 48 hours is a control measure. This explains why timely sundrying can sometimes be safer than delayed mechanical drying. Two days on a drying floor with
occasional turning can often achieve the target 'safe' moisture content, whereas a back-log at the
mechanical drier can result in the critical limit of 48 hours not being met.
Once produced, it is not usually possible to remove mycotoxins, other than by physical separation
(grading) techniques. To apply this type of control measure, representative samples of batches of
commodity are collected and tested for selected mycotoxins. Only those batches containing less than
the critical limit of mycotoxin, as specified in official regulations, are accepted. For some
commodities, such as blanched groundnuts, colour sorters may be effective in rejecting individual
high-aflatoxin nuts and accumulating low-aflatoxin nuts, and may be classified as a control measure.
There are a few examples where effective chemical detoxification is possible, such as ammoniation
of certain animal feed ingredients and refining of vegetable oils. These are control measures that
would also be suitable for application at a critical control point for aflatoxin, but only for the
specified commodities.
It is essential that GAP, GSP, and GMP pre-requisites are in place, and simply ensuring that this is
the case can significantly reduce the risk of the mycotoxin hazard. Examples of procedures which fall
within the scope of these pre-requisites include: irrigation, insect control, use of resistant varieties,
and use of pallets in store.
Task 7 - Determine Critical Control Points (CCPs)
Determination of CCPs can be achieved using a well designed decision tree, if necessary, to
supplement the knowledge and experience of the HACCP team (see Appendix IV). Each step in the
CFD is considered in turn, and the questions answered in sequence. It should be noted that it is
necessary to be able to answer Yes to Question 1 (Do preventative control measures exist?) before a
CCP can be established. The Codex 1997 definition of a control measure is any action and activity
that can be used to prevent or eliminate a food safety hazard, or reduce it to an acceptable level.
There are commodity systems, such as the production of apple juice (Case study 5), where control
measures are possible at a number of steps, and each is capable of achieving a known percentage
reduction in the level of mycotoxin. It is possible, therefore, to calculate the acceptable level of
patulin at each step and perform validation. If the risk of the acceptable level of mycotoxin being
exceeded is considered to be sufficiently low, then the HACCP team may determine each of the steps
as CCPs.
Task 8 - Establish critical limits for each CCP
When the control measure is segregation based on mycotoxin analysis, then the critical limit will
often be set at the acceptable level, which in turn will be set at, or below, the regulatory mycotoxin
limit. Acceptable levels, and any associated critical limits, can sometimes be set higher than a
regulatory limit, provided that a subsequent step can guarantee to attain the acceptable level of
hazard in the final product.
For control measures that involve drying to a 'safe' moisture content, the parameter that will be
measured, and for which critical limits will be set, will usually be parameters such as the temperature
of the drier and the dwell time, e.g. for a continuous flow drier the critical limit for temperature could
be 80 +/- 2°C and the critical limit for dwell time could be 20 +/- 1 minute.
Critical limits for chemical detoxification could be the temperature and pressure of the reaction
vessel and the dwell time.
Task 9 - Establish a monitoring system for each CCP
The monitoring system must be a scheduled measurement, usually of a basic parameter such as
temperature or time, to detect any deviation from the critical limits.
When segregation of acceptable and unacceptable batches is required in the agricultural system, for
example at a secondary trader, then rapid testing procedures are needed to test incoming batches.
A number of semi-quantitative immunoaffinity rapid test kits are available which work to a stated
target level, eg 5 or 20 µk/kg of the appropriate mycotoxin. Here the critical limit would normally be
the presence or absence of a coloured derivative. More traditional mini-column and TLC dilution to
extinction techniques can still be useful for segregation of batches at the factory gate, and for these
the presence or absence of a blue fluorescent band or spot is the critical limit.
Task 10 - Establish a corrective action
There are two sorts of corrective action. The first is action to regain control. For instance if a critical
limit for a moisture content is not attained, then the corrective action could be to check the
specification of the drier and effect repairs, or perhaps to increase the temperature setting or the dwell
time. The second type of corrective action is to isolate the product produced whilst the CCP was out
of control and amend the product disposition, by either discarding or down-grading it, or reprocessing it if this is appropriate.
Task 11 - Establish verification procedures
At regular, specified, intervals the complete HACCP plan should be verified by checking that the
levels of mycotoxin in the final product are within acceptable levels. If this is found not to be the
case, then immediately trouble-shooting should be carried out to identify the step at which the hazard
has become out of control. Critical limits may need to be amended, or a new control measure may
need to be validated and introduced. Similarly, if a review of deviations and product dispositions
indicated an unacceptable degree of control at a particular CCP, then revisions will need to be made.
Task 12 - Establish documentation and record keeping
Standard HACCP documentation and record keeping is appropriate, but the complexity of the
records should reflect the sophistication of the step in the commodity system.
UNIT-IV
MICROBIOLOGICAL EXAMINATION OF FOOD:Introduction
The stated chief purposes of microbiological criteria for foods are to give assurance:
1. That the foods will be acceptable from the Public health standpoint that is will not be
responsible for the spread of infectious disease or for food poisoning.
2. That the foods will be of satisfactory quality
3. The foods will have keeping qualities that should be expected of the product.
4. Sampling for tests is a problem since the lack of homogeneity in most foods makes
location, size and number of samples significant.
5. Standards usually are based on total numbers of organisms, numbers of organisms,
numbers of indicator organisms or numbers of pathogens.
1.Explain the Indicator organisms in detail.
It may be necessary to carry out a microbiological examination of a food for one or more of a number
of reasons.
Escherichia coli is a natural component of the human gut flora and its presence in the environment, or
on foods, generally implies some history of contamination of faecal origin.
Traditional the group chosen has been designated the coliforms- those organisms capable of
fermenting lactose in the presence of bile at 37C.
This will include most strains of E. coli but also includes organisms such as Citrobactor and
Enterobactor.
Indicator organism
Indicator organisms are used to measure potential fecal contamination of environmental
samples. The presence of coliform bacteria, such as E. coli, in surface water is a common
indicator of fecal contamination. Coliform bacteria in water samples may be quantified using the
most probable number (MPN) method, a probabilistic test which assumes cultivable bacteria
meet certain growth and biochemical criteria. If preliminary tests suggest that coliform bacteria
are present at numbers in excess of an established cut-off (the Coliform Index), fecal
contamination is suspected and confirmatory assays such as the Eijckman test are
conducted.[citation needed]
Coliform bacteria selected as indicators of fecal contamination must not persist in the
environment for long periods of time following efflux from the intestine, and their presence must
be closely correlated with contamination by other fecal organisms. Indicator organisms need not
be pathogenic.[1]
Direct-to-Consumer genetic testing
Direct-to-Consumer (DTC) genetic testing is a type of genetic test that is accessible directly to
the consumer without having to go through a health care professional. Usually, to obtain a
genetic test, health care professionals such as doctors acquire the permission of the patient and
order the desired test. DTC genetic tests, however, allow consumers to bypass this process and
order one themselves. There are a variety of DTC tests, ranging from testing for breast cancer
alleles to mutations linked to cystic fibrosis. Benefits of DTC testing are the accessibility of tests
to consumers, promotion of proactive healthcare and the privacy of genetic information. Possible
additional risks of DTC testing are the lack of governmental regulation and the potential
misinterpretation of genetic information.
2.Explain the Immunological methods in detail.
Immunological methods
Indirect immunofluorescence
ELISA
Immunoblotting (Western blot)
Complement fixation test
Immunofluorescence
Microphotograph of a histological section of human skin prepared fordirect
immunofluorescence using an anti-IgA antibody. The skin is from a patient with HenochSchonlein purpura: IgA deposits are found in the walls of small superficial capillaries (yellow
arrows). The pale wavy green area on top is the epidermis, the bottom fibrous area is the dermis.
Microphotograph of a histological section of human skin prepared fordirect immunofluorescence using
an anti-IgG antibody. The skin is from a patient with systemic lupus erythematosus and shows IgG
deposit at two different places: The first is a band-like deposit along the epidermalbasement
membrane ("lupus band test" is positive). The second is within the nuclei of the epidermal cells (antinuclear antibodies).
Immunofluorescence is a technique used for light microscopy with a fluorescence microscope and is
used primarily on biological samples. This technique uses the specificity of antibodies to theirantigen to
target fluorescent dyes to specific biomolecule targets within a cell, and therefore allows visualisation of
the distribution of the target molecule through the sample. Immunofluorescence is a widely used example
of immunostaining and is a specific example of immunohistochemistry that makes use of fluorophores to
visualise the location of the antibodies. [1]
Immunofluorescence can be used on tissue sections, cultured cell lines, or individual cells, and may be
used to analyse the distribution of proteins, glycans, and small biological and non-biological molecules.
Immunofluoresence can be used in combination with other, non-antibody methods of fluorescent staining,
for example, use of DAPI to label DNA. Several microscope designs can be used for analysis of
immunofluorescence samples; the simplest is the epifluorescence microscope, and theconfocal
microscope is also widely used. Various super-resolution microscope designs that are capable of much
higher resolution can also be used.[2]
Types of immunofluorescence
There are two classes of immunofluorescence techniques, primary (or direct) and secondary (or indirect).
Primary (direct)
Primary, or direct, immunofluorescence uses a single antibody that is chemically linked to afluorophore.
The antibody recognises the target molecule and binds to it, and the fluorophore it carries can be detected
via microscope. This technique has several advantages over the secondary (or indirect) protocol below
because of the direct conjugation of the antibody to the fluorophore. This reduces the number of steps in
the staining procedure, is therefore faster, and can avoid some issues with antibody cross-reactivity or
non-specificity, which can lead to increased background signal.
Secondary (indirect)
Secondary, or indirect, immunofluorescence uses two antibodies; the first (the primary antibody)
recognises the target molecule and binds to it, and the second (the secondary antibody), which carries the
fluorophore, recognises the primary antibody and binds to it. This protocol is more complex than the
primary (or direct) protocol above and takes more time but allows more flexibility.
This protocol is possible because an antibody consists of two parts, a variable region (which recognizes
the antigen) and an invariant region (which makes up the structure of the antibody molecule). A
researcher can generate several primary antibodies that recognize various antigens (have different variable
regions), but all share the same invariant region. All these antibodies may therefore be recognized by a
single secondary antibody. This saves the cost of modifying the primary antibodies to directly carry a
fluorophore.
Different primary antibodies with different invariant regions are typically generated by raising the
antibody in different species. For example, a researcher might create primary antibodies in a goat that
recognize several antigens, and then employ dye-coupled rabbit secondary antibodies that recognize the
goat antibody invariant region ("rabbit anti-goat" antibodies). The researcher may then create a second set
of primary antibodies in a mouse that could be recognised by a separate "donkey anti-mouse" secondary
antibody. This allows re-use of the difficult-to-make dye-coupled antibodies in multiple experiments.
Limitations
As with most fluorescence techniques, a significant problem with immunofluorescence is photobleaching.
Loss of activity caused by photobleaching can be controlled by reducing the intensity or time-span of
light exposure, by increasing the concentration of fluorophores, or by employing more robust
fluorophores that are less prone to bleaching (e.g., Alexa Fluors, Seta Fluors, or DyLight Fluors).
In general, immunofluorescence is limited to fixed (i.e., dead) samples. Analysis of structures within live
cells by immunofluorescence is not possible, as antibodies cannot cross the cell membrane. As such some
uses of immunofluorescence have been outmoded by the development of recombinant proteins containing
fluorescent protein domains, e.g., green fluorescent protein (GFP). Use of such "tagged" proteins allows
determination of their localisation in live cells.
ELISA
Enzyme-linked immunosorbent assay (ELISA), also known as an enzyme
immunoassay(EIA), is a biochemical technique used mainly in immunology to detect the
presence of anantibody or an antigen in a sample. The ELISA has been used as a diagnostic tool
in medicine and plant pathology, as well as a quality control check in various industries. In
simple terms, in ELISA, an unknown amount of antigen is affixed to a surface, and then a
specific antibody is applied over the surface so that it can bind to the antigen. This antibody is
linked to an enzyme, and in the final step a substance is added that the enzyme can convert to
some detectable signal, most commonly a colour change in a chemical substrate.
Performing an ELISA involves at least one antibody with specificity for a particular antigen. The
sample with an unknown amount of antigen is immobilized on a solid support (usually
apolystyrene microtiter plate) either non-specifically (via adsorption to the surface) or
specifically (via capture by another antibody specific to the same antigen, in a "sandwich"
ELISA). After the antigen is immobilized the detection antibody is added, forming a complex
with the antigen. The detection antibody can be covalently linked to an enzyme, or can itself be
detected by a secondary antibody which is linked to an enzyme through bioconjugation. Between
each step the plate is typically washed with a mild detergent solution to remove any proteins or
antibodies that are not specifically bound. After the final wash step the plate is developed by
adding an enzymatic substrate to produce a visible signal, which indicates the quantity of antigen
in the sample.
Traditional ELISA typically involves chromogenic reporters and substrates which produce some
kind of observable color change to indicate the presence of antigen or analyte. Newer ELISAlike techniques utilize fluorogenic, electrochemiluminescent, and real-time PCR reporters to
create quantifiable signals. These new reporters can have various advantages including
higher sensitivities and multiplexing[1][2]. Technically, newer assays of this type are not strictly
ELISAs as they are not "enzyme-linked" but are instead linked to some non-enzymatic reporter.
However, given that the general principles in these assays are largely similar, they are often
grouped in the same category as ELISAs.
Applications
ELISA results using S-OIV Aneuraminidase antibody at 1 μg/ml to probe the immunogenic and the
corresponding seasonal influenza A neuraminidasepeptides at 50, 10, 2 and 0 ng/ml.
Because the ELISA can be performed to evaluate either the presence of antigen or the presence of
antibody in a sample, it is a useful tool for determining serum antibody concentrations (such as with
the HIV test[3] or West Nile Virus). It has also found applications in the food industry in detecting
potential food allergens such as milk, peanuts, walnuts, almonds, and eggs.[4] ELISA can also be used in
toxicology as a rapid presumptive screen for certain classes of drugs.
The ELISA was the first screening test widely used for HIV because of its high sensitivity. In an ELISA,
a person's serum is diluted 400-fold and applied to a plate to which HIV antigens are attached. If
antibodies to HIV are present in the serum, they may bind to these HIV antigens. The plate is then washed
to remove all other components of the serum. A specially prepared "secondary antibody" — an antibody
that binds to other antibodies — is then applied to the plate, followed by another wash. This secondary
antibody is chemically linked in advance to an enzyme. Thus, the plate will contain enzyme in proportion
to the amount of secondary antibody bound to the plate. A substrate for the enzyme is applied, and
catalysis by the enzyme leads to a change in color or fluorescence. ELISA results are reported as a
number; the most controversial aspect of this test is determining the "cut-off" point between a positive
and negative result.
A cut-off point may be determined by comparing it with a known standard. If an ELISA test is used for
drug screening at workplace, a cut-off concentration, 50 ng/mL, for example, is established, and a sample
will be prepared which contains the standard concentration of analyte. Unknowns that generate a signal
that is stronger than the known sample are "positive". Those that generate weaker signal are "negative."
History
Before the development of the ELISA, the only option for conducting
an immunoassay was radioimmunoassay, a technique usingradioactively-labeled antigens or antibodies.
In radioimmunoassay, the radioactivity provides the signal which indicates whether a specific antigen or
antibody is present in the sample. Radioimmunoassay was first described in a paper by Rosalyn Sussman
Yalow and Solomon Berson published in 1960[5].
Because radioactivity poses a potential health threat, a safer alternative was sought. A suitable alternative
to radioimmunoassay would substitute a non-radioactive signal in place of the radioactive signal. When
enzymes (such as peroxidase) react with appropriate substrates (such as ABTS or 3,3’,5,5’Tetramethylbenzidine), this causes a change in color, which is used as a signal. However, the signal has to
be associated with the presence of antibody or antigen, which is why the enzyme has to be linked to an
appropriate antibody. This linking process was independently developed by Stratis Avrameas and G.B.
Pierce[6]. Since it is necessary to remove any unbound antibody or antigen by washing, the antibody or
antigen has to be fixed to the surface of the container, i.e. the immunosorbent has to be prepared. A
technique to accomplish this was published by Wide and Jerker Porath in 1966. In 1971, Peter Perlmann
and Eva Engvall at Stockholm University in Sweden, and Anton Schuurs and Bauke van Weemen in The
Netherlands, independently published papers which synthesized this knowledge into methods to perform
EIA/ELISA.
Types
"Indirect" ELISA
The steps of "indirect" ELISA follows the mechanism below:
A buffered solution of the protein antigen to be tested for is added to each well of a microtiter plate,
where it is given time to adhere to the plastic through charge interactions.
A solution of non-reacting protein, such as bovine serum albumin, or casein is added to block any
plastic surface in the well that remains uncoated by the protein antigen.
Next the primary antibody, generally in the form of serum is added, which contains a mixture of the
serum donor's antibodies, of unknown concentration, some of which may bind specifically to the test
antigen that is coating the well.
Afterwards, a secondary antibody is added, which will bind any antibody produced by a member of
the donor's species (for example, an antibody produced in a mouse that will bind any rabbit antibody).
This secondary antibody often has an enzyme attached to it, which has a negligible effect on the
binding properties of the antibody.
A substrate for this enzyme is then added. Often, this substrate changes color upon reaction with the
enzyme. The color change shows that secondary antibody has bound to primary antibody, which
strongly implies that the donor has had an immune reaction to the test antigen. This can be helpful in
a clinical setting, and in R&D.
The higher the concentration of the primary antibody that was present in the serum, the stronger the
color change. Often a spectrometer is used to give quantitative values for color strength.
The enzyme acts as an amplifier; even if only few enzyme-linked antibodies remain bound, the enzyme
molecules will produce many signal molecules. Within common-sense limitations the enzyme can go on
producing color indefinitely, but the more primary antibody is present in the donor serum, the more
secondary antibody + enzyme will bind, and the faster color will develop. A major disadvantage of the
indirect ELISA is that the method of antigen immobilization is non-specific; when serum is used as the
source of test antigen, all proteins in the sample may stick to the microtiter plate well, so small
concentrations of analyte in serum must compete with other serum proteins when binding to the well
surface. The sandwich or direct ELISA provides a solution to this problem, by using a "capture" antibody
specific for the test antigen to pull it out of the serum's molecular mixture.
ELISA may be run in a qualitative or quantitative format. Qualitative results provide a simple positive or
negative result (yes or no) for a sample. The cutoff between positive and negative is determined by the
analyst and may be statistical. Two or three times the standard deviation (error inherent in a test) is often
used to distinguish positive from negative samples. In quantitative ELISA, the optical density (OD) of the
sample is compared to a standard curve, which is typically a serial dilution of a known-concentration
solution of the target molecule. For example if your test sample returns an OD of 1.0, the point on your
standard curve that gave OD = 1.0 must be of the same analyte concentration as your sample.
Sandwich ELISA
A sandwich ELISA. (1) Plate is coated with a capture antibody; (2) sample is added, and any antigen
present binds to capture antibody; (3) detecting antibody is added, and binds to antigen; (4) enzymelinked secondary antibody is added, and binds to detecting antibody; (5) substrate is added, and is
converted by enzyme to detectable form.
A less-common variant of this technique, called "sandwich" ELISA, is used to detect sample antigen. The
steps are as follows:
1. Prepare a surface to which a known quantity of capture antibody is bound.
2. Block any non specific binding sites on the surface.
3. Apply the antigen-containing sample to the plate.
4. Wash the plate, so that unbound antigen is removed.
5. Apply enzyme linked primary antibodies as detection antibodies which also bind specifically to
the antigen.
6. Wash the plate, so that the unbound antibody-enzyme conjugates are removed.
7. Apply a chemical which is converted by the enzyme into a color or fluorescent or electrochemical
signal.
8. Measure the absorbency or fluorescence or electrochemical signal (e.g., current) of the plate wells
to determine the presence and quantity of antigen.
The image to the right includes the use of a secondary antibody conjugated to an enzyme, though
technically this is not necessary if the primary antibody is conjugated to an enzyme. However, use of a
secondary-antibody conjugate avoids the expensive process of creating enzyme-linked antibodies for
every antigen one might want to detect. By using an enzyme-linked antibody that binds the Fc region of
other antibodies, this same enzyme-linked antibody can be used in a variety of situations. Without the first
layer of "capture" antibody, any proteins in the sample (including serum proteins) may competitively
adsorb to the plate surface, lowering the quantity of antigen immobilized.Use of the purified specific
antibody to attach the antigen to the plastic eliminates a need to purify the antigen from complicated
mixtures before the measurement, simplifying the assay, and increasing the specificity and the sensitivity
of the assay.
A descriptive animation of the application of sandwich ELISA to home pregnancy testing can be
found here.
Competitive ELISA
A third use of ELISA is through competitive binding. The steps for this ELISA are somewhat different
than the first two examples:
1. Unlabeled antibody is incubated in the presence of its antigen (Sample)
2. These bound antibody/antigen complexes are then added to an antigen coated well.
3. The plate is washed, so that unbound antibody is removed. (The more antigen in the sample, the
less antibody will be able to bind to the antigen in the well, hence "competition.")
4. The secondary antibody, specific to the primary antibody is added. This second antibody is
coupled to the enzyme.
5. A substrate is added, and remaining enzymes elicit a chromogenic or fluorescent signal.
For competitive ELISA, the higher the sample antigen concentration, the weaker the eventual signal. The
major advantage of a competitive ELISA is the ability to use crude or impure samples and still selectively
bind any antigen that may be present.
(Note that some competitive ELISA kits include enzyme-linked antigen rather than enzyme-linked
antibody. The labeled antigen competes for primary antibody binding sites with your sample antigen
(unlabeled). The more antigen in the sample, the less labeled antigen is retained in the well and the
weaker the signal).
Commonly the antigen is not first positioned in the well.Multiple and Portable ELISA (M&P
ELISA)(ELISA Reverse in published papers)
A new technique (EP 1 499 894 B1 in EPO Bulletin 25.02.209 N. 2009/09; USPTO 7510687 in USPTO
Bulletin 31.03.2009; ZL 03810029.0 in SIPO PRC Bulletin 08.04.2009) uses a solid phase made up of an
immunosorbent polystyrene rod with 8-12 protruding ogives. The entire device is immersed in a test tube
containing the collected sample and the following steps (washing, incubation in conjugate and incubation
in chromogenous) are carried out by dipping the ogives in microwells of standard microplates pre-filled
with reagents.
The advantages of this technique are as follows:
1. The ogives can each be sensitized to a different reagent, allowing the simultaneous detection of
different antibodies and / or different antigens for multi-target assays;
2. The sample volume can be increased to improve the test sensitivity in clinical (saliva, urine), food
(bulk milk, pooled eggs) and environmental (water) samples;
3. One ogive is left unsensitized to measure the non-specific reactions of the sample;
4. The use of laboratory supplies for dispensing sample aliquots, washing solution and reagents in
microwells is not required, facilitating the deveopment of ready-to-use lab-kits and on-site kits.
Complement fixation test
The complement fixation test is an immunological medical test that can be used to detect the presence of
either specific antibody or specific antigen in a patient's serum. It was widely used to diagnose infections,
particularly with microbes that are not easily detected by culture methods, and in rheumatic diseases.
However, in clinical diagnostics labs it has been largely superseded by other serological methods such
as ELISA and by DNA-based methods of pathogen detection, particularly PCR.
Process
The CF test uses sheep red blood cells (sRBC), pre-bound by anti-sRBC antibody, and serum (usually
from guinea pig) as a source ofcomplement, which is a system of serum proteins that react with antigenantibody complexes. If this reaction occurs on a cell surface, it will result in the formation of transmembrane pores and therefore destruction of the cell. Accordingly, if the antibody-sensitized sRBC are
brought into contact with active complement, they will undergo disintegration (hemolysis).
Complement will also react with antigen-antibody complexes in solution. The complement is thereby
expended and can no longer trigger hemolysis; inhibition of complement hemolysis therefore indicates
the presence of antigen-antibody complexes. A patient's serum containing a certain antibody (specific for,
say, rubella virus) will yield antigen-antibody complexes after addition of the corresponding antigen
(inactivated rubella virus in our example). Complement added to the mixture will be consumed, and
sensitized sRBC added subsequently will not undergo hemolysis. Therefore, absence of hemolysis
constitutes a positive CF test (patient's serum contains the antibody of interest).
Testing for antigen
While detection of antibodies is the more common test format, it is equally possible to test for the
presence of antigen. In this case, the patient's serum is supplemented with specific antibody to induce
formation of complexes; addition of complement and indicator sRBC is performed as before.
Quantitative testing
The test can be made quantitative by setting up a series of dilutions of patient serum and determining the
highest dilution factor that will still yield a positive CF test. This dilution factor corresponds to the titer
Western blot
Western blot analysis of proteins separated by SDS-PAGE.[1]
The Western blot (alternatively, protein immunoblot) is an analytical technique used to detect
specific proteins in a given sample of tissue homogenate or extract. It uses gel electrophoresis to separate
native or denatured proteins by the length of the polypeptide (denaturing conditions) or by the 3-D
structure of the protein (native/ non-denaturing conditions). The proteins are then transferred to a
membrane (typically nitrocellulose or PVDF), where they are probed (detected) using antibodies specific
to the target protein.
There are now many reagent companies that specialize in providing antibodies
(both monoclonaland polyclonal antibodies) against tens of thousands of different proteins.[4] Commercial
antibodies can be expensive, although the unbound antibody can be reused between experiments. This
method is used in the fields of molecular biology, biochemistry, immunogenetics and other molecular
biology disciplines.
Other related techniques include using antibodies to detect proteins in tissues and cells
byimmunostaining and enzyme-linked immunosorbent assay (ELISA).
The method originated from the laboratory of George Stark at Stanford. The name Western blotwas given
to the technique by W. Neal Burnette[5] and is a play on the name Southern blot, a technique
for DNA detection developed earlier by Edwin Southern. Detection of RNA is termednorthern
blotting and the detection of post-translational modification of protein is termed eastern blotting.
Steps in a Western blot
Tissue preparation
Samples may be taken from whole tissue or from cell culture. In most cases, solid tissues are first broken
down mechanically using ablender (for larger sample volumes), using a homogenizer (smaller volumes),
or by sonication. Cells may also be broken open by one of the above mechanical methods. However, it
should be noted that bacteria, virus or environmental samples can be the source of protein and thus
Western blotting is not restricted to cellular studies only.
Assorted detergents, salts, and buffers may be employed to encourage lysis of cells and to solubilize
proteins. Protease and phosphataseinhibitors are often added to prevent the digestion of the sample by its
own enzymes. Tissue preparation is often done at cold temperatures to avoid protein denaturing.
A combination of biochemical and mechanical techniques – including various types of filtration
and centrifugation – can be used to separate different cell compartments and organelles.
Gel electrophoresis
The proteins of the sample are separated using gel electrophoresis. Separation of proteins may be
by isoelectric point (pI), molecular weight, electric charge, or a combination of these factors. The nature
of the separation depends on the treatment of the sample and the nature of the gel. This is a very useful
way to determine a protein.
By far the most common type of gel electrophoresis employs polyacrylamide gels and buffers loaded
with sodium dodecyl sulfate (SDS).SDS-PAGE (SDS polyacrylamide gel electrophoresis) maintains
polypeptides in a denatured state once they have been treated with strong reducing agents to remove
secondary and tertiary structure (e.g. disulfide bonds [S-S] to sulfhydryl groups [SH and SH]) and thus
allows separation of proteins by their molecular weight. Sampled proteins become covered in the
negatively charged SDS and move to the positively charged electrode through the acrylamide mesh of the
gel. Smaller proteins migrate faster through this mesh and the proteins are thus separated according to
size (usually measured in kilodaltons, kDa). The concentration of acrylamide determines the resolution of
the gel - the greater the acrylamide concentration the better the resolution of lower molecular weight
proteins. The lower the acrylamide concentration the better the resolution of higher molecular weight
proteins. Proteins travel only in one dimension along the gel for most blots.
Samples are loaded into wells in the gel. One lane is usually reserved for a marker or ladder, a
commercially available mixture of proteins having defined molecular weights, typically stained so as to
form visible, coloured bands. When voltage is applied along the gel, proteins migrate into it at different
speeds. These different rates of advancement (different electrophoretic mobilities) separate
into bands within eachlane.
It is also possible to use a two-dimensional (2-D) gel which spreads the proteins from a single sample out
in two dimensions. Proteins are separated according to isoelectric point (pH at which they have neutral
net charge) in the first dimension, and according to their molecular weight in the second dimension.
Transfer
In order to make the proteins accessible to antibody detection, they are moved from within the gel onto a
membrane made of nitrocellulose orpolyvinylidene difluoride (PVDF). The membrane is placed on top of
the gel, and a stack of filter papers placed on top of that. The entire stack is placed in a buffer solution
which moves up the paper by capillary action, bringing the proteins with it. Another method for
transferring the proteins is called electroblotting and uses an electric current to pull proteins from the gel
into the PVDF or nitrocellulose membrane. The proteins move from within the gel onto the membrane
while maintaining the organization they had within the gel. As a result of this "blotting" process, the
proteins are exposed on a thin surface layer for detection (see below). Both varieties of membrane are
chosen for their non-specific protein binding properties (i.e. binds all proteins equally well). Protein
binding is based upon hydrophobic interactions, as well as charged interactions between the membrane
and protein. Nitrocellulose membranes are cheaper than PVDF, but are far more fragile and do not stand
up well to repeated probings.
The uniformity and overall effectiveness of transfer of protein from the gel to the membrane can be
checked by staining the membrane withCoomassie Brilliant Blue or Ponceau S dyes. Ponceau S is the
more common of the two, due to Ponceau S's higher sensitivity and its water solubility makes it easier to
subsequently destain and probe the membrane as described below.[6]
Blocking
Since the membrane has been chosen for its ability to bind protein and as both antibodies and the target
are proteins, steps must be taken to prevent interactions between the membrane and the antibody used for
detection of the target protein. Blocking of non-specific binding is achieved by placing the membrane in a
dilute solution of protein - typically 3-5% Bovine serum albumin (BSA) or non-fat dry milk (both are
inexpensive) in Tris-Buffered Saline (TBS), with a minute percentage of detergent such as Tween
20 or Triton X-100. The protein in the dilute solution attaches to the membrane in all places where the
target proteins have not attached. Thus, when the antibody is added, there is no room on the membrane
for it to attach other than on the binding sites of the specific target protein. This reduces "noise" in the
final product of the Western blot, leading to clearer results, and eliminates false positives.
Detection
During the detection process the membrane is "probed" for the protein of interest with a modified
antibody which is linked to a reporter enzyme, which when exposed to an appropriate substrate drives a
colourimetric reaction and produces a colour. For a variety of reasons, this traditionally takes place in a
two-step process, although there are now one-step detection methods available for certain applications.
Two steps
Primary antibody
Antibodies are generated when a host species or immune cell culture is exposed to the protein of interest
(or a part thereof). Normally, this is part of the immune response, whereas here they are harvested and
used as sensitive and specific detection tools that bind the protein directly.
After blocking, a dilute solution of primary antibody (generally between 0.5 and 5 micrograms/mL) is
incubated with the membrane under gentle agitation. Typically, the solution is composed of buffered
saline solution with a small percentage of detergent, and sometimes with powdered milk or BSA. The
antibody solution and the membrane can be sealed and incubated together for anywhere from 30 minutes
to overnight. It can also be incubated at different temperatures, with warmer temperatures being
associated with more binding, both specific (to the target protein, the "signal") and non-specific ("noise").
Secondary antibody
After rinsing the membrane to remove unbound primary antibody, the membrane is exposed to another
antibody, directed at a species-specific portion of the primary antibody. Antibodies come from animal
sources (or animal sourced hybridoma cultures); an anti-mouse secondary will bind to almost any mousesourced primary antibody, which allows some cost savings by allowing an entire lab to share a single
source of mass-produced antibody, and provides far more consistent results. This is known as a secondary
antibody, and due to its targeting properties, tends to be referred to as "anti-mouse," "anti-goat," etc. The
secondary antibody is usually linked to biotin or to a reporter enzyme such as alkaline
phosphatase or horseradish peroxidase. This means that several secondary antibodies will bind to one
primary antibody and enhance the signal.
Most commonly, a horseradish peroxidase-linked secondary is used to cleave a chemiluminescent agent,
and the reaction product producesluminescence in proportion to the amount of protein. A sensitive sheet
of photographic film is placed against the membrane, and exposure to the light from the reaction creates
an image of the antibodies bound to the blot. A cheaper but less sensitive approach utilizes a 4chloronaphthol stain with 1% hydrogen peroxide; reaction of peroxide radicals with 4-chloronaphthol
produces a dark brown stain that can be photographed without using specialized photographic film.
As with the ELISPOT and ELISA procedures, the enzyme can be provided with a substrate molecule that
will be converted by the enzyme to a colored reaction product that will be visible on the membrane (see
the figure below with blue bands).
Another method of secondary antibody detection utilizes a near-infrared (NIR) fluorophore-linked
antibody. Light produced from the excitation of a fluorescent dye is static, making fluorescent detection a
more precise and accurate measure of the difference in signal produced by labeled antibodies bound to
proteins on a Western blot. Proteins can be accurately quantified because the signal generated by the
different amounts of proteins on the membranes is measured in a static state, as compared to
chemiluminescence, in which light is measured in a dynamic state.[7]
A third alternative is to use a radioactive label rather than an enzyme coupled to the secondary antibody,
such as labeling an antibody-binding protein like Staphylococcus Protein A or Streptavidin with a
radioactive isotope of iodine. Since other methods are safer, quicker, and cheaper, this method is now
rarely used; however, an advantage of this approach is the sensitivity of auto-radiography based imaging,
which enables highly accurate protein quantification when combined with optical software (e.g.
Optiquant).
One step
Historically, the probing process was performed in two steps because of the relative ease of producing
primary and secondary antibodies in separate processes. This gives researchers and corporations huge
advantages in terms of flexibility, and adds an amplification step to the detection process. Given the
advent of high-throughput protein analysis and lower limits of detection, however, there has been interest
in developing one-step probing systems that would allow the process to occur faster and with less
consumables. This requires a probe antibody which both recognizes the protein of interest and contains a
detectable label, probes which are often available for known protein tags. The primary probe is incubated
with the membrane in a manner similar to that for the primary antibody in a two-step process, and then is ready for
direct detection after a series of wash steps.
Western blot using radioactive detection system
Analysis
After the unbound probes are washed away, the Western blot is ready for detection of the probes that are
labeled and bound to the protein of interest. In practical terms, not all Westerns reveal protein only at one
band in a membrane. Size approximations are taken by comparing the stained bands to that of the marker
or ladder loaded during electrophoresis. The process is repeated for a structural protein, such as actin or
tubulin, that should not change between samples. The amount of target protein is indexed to the structural
protein to control between groups. This practice ensures correction for the amount of total protein on the
membrane in case of errors or incomplete transfers.
Colorimetric detection
The colorimetric detection method depends on incubation of the Western blot with a substrate that reacts
with the reporter enzyme (such asperoxidase) that is bound to the secondary antibody. This converts the
soluble dye into an insoluble form of a different color that precipitates next to the enzyme and thereby
stains the membrane. Development of the blot is then stopped by washing away the soluble dye. Protein
levels are evaluated through densitometry (how intense the stain is) or spectrophotometry.
Chemiluminescent detection
Chemiluminescent detection methods depend on incubation of the Western blot with a substrate that will
luminesce when exposed to the reporter on the secondary antibody. The light is then detected by
photographic film, and more recently by CCD cameras which capture a digital image of the Western blot.
The image is analysed by densitometry, which evaluates the relative amount of protein staining and
quantifies the results in terms of optical density. Newer software allows further data analysis such as
molecular weight analysis if appropriate standards are used.
Radioactive detection
Radioactive labels do not require enzyme substrates, but rather allow the placement of medical X-ray film
directly against the Western blot which develops as it is exposed to the label and creates dark regions
which correspond to the protein bands of interest (see image to the right). The importance of radioactive
detections methods is declining[citation needed], because it is very expensive, health and safety risks are high,
and ECL (enhanced chemiluminescence) provides a useful alternative.
Fluorescent detection
The fluorescently labeled probe is excited by light and the emission of the excitation is then detected by a
photosensor such as CCD camera equipped with appropriate emission filters which captures a digital
image of the Western blot and allows further data analysis such as molecular weight analysis and a
quantitative Western blot analysis. Fluorescence is considered to be among the most sensitive detection
methods for blotting analysis.
Secondary probing
One major difference between nitrocellulose and PVDF membranes relates to the ability of each to
support "stripping" antibodies off and reusing the membrane for subsequent antibody probes. While there
are well-established protocols available for stripping nitrocellulose membranes, the sturdier PVDF allows
for easier stripping, and for more reuse before background noise limits experiments. Another difference is
that, unlike nitrocellulose, PVDF must be soaked in 95% ethanol, isopropanol or methanol before use.
PVDF membranes also tend to be thicker and more resistant to damage during use.
2-D gel electrophoresis
2-dimensional SDS-PAGE uses the principles and techniques outlined above. 2-D SDS-PAGE, as the
name suggests, involves the migration of polypeptides in 2 dimensions. For example, in the first
dimension polypeptides are separated according to isoelectric point, while in the second dimension
polypeptides are separated according to their molecular weight. The isoelectric point of a given protein is
determined by the relative number of positively (e.g. lysine and arginine) and negatively (e.g. glutamate
and aspartate) charged amino acids, with negatively charged amino acids contributing to a high isoelectric
point and positively charged amino acids contributing to a low isoelectric point. Samples could also be
separated first under nonreducing conditions using SDS-PAGE and under reducing conditions in the
second dimension, which breaks apart disulfide bonds that hold subunits together. SDS-PAGE might also
be coupled with urea-PAGE for a 2-dimensional gel.
In principle, this method allows for the separation of all cellular proteins on a single large gel. A major
advantage of this method is that it often distinguishes between different isoforms of a particular protein e.g. a protein that has been phosphorylated (by addition of a negatively charged group). Proteins that have
been separated can be cut out of the gel and then analysed by mass spectrometry, which identifies the
protein.
Please refer to reference articles for examples of the application of 2-D SDS PAGE.
[edit]Medical diagnostic applications
The confirmatory HIV test employs a Western blot to detect anti-HIV antibody in a
human serum sample. Proteins from known HIV-infected cells are separated and blotted on a
membrane as above. Then, the serum to be tested is applied in the primary antibody incubation step;
free antibody is washed away, and a secondary anti-human antibody linked to an enzyme signal is
added. The stained bands then indicate the proteins to which the patient's serum contains antibody.
A Western blot is also used as the definitive test for Bovine spongiform encephalopathy (BSE,
commonly referred to as 'mad cow disease').
Some forms of Lyme disease testing employ Western blotting.
Western blot can also be used as a confirmatory test for Hepatitis B infection.
In veterinary medicine, Western blot is sometimes used to confirm FIV+ status in cats.
DIRECT EXAMINATION:. When examining foods, the possibility of detecting the presence of microorganisms by looking at a
sample directly under the microscope should not be missed.
. A small amount of material can be mounted and teased out in a drop of water on a slide, covered with
a cover slip, and examined.
Direct-to-Consumer genetic testing
Direct-to-Consumer (DTC) genetic testing is a type of genetic test that is accessible directly to the
consumer without having to go through a health care professional. Usually, to obtain a genetic test, health
care professionals such as doctors acquire the permission of the patient and order the desired test. DTC
genetic tests, however, allow consumers to bypass this process and order one themselves. There are a
variety of DTC tests, ranging from testing for breast cancer alleles to mutations linked to cystic fibrosis.
Benefits of DTC testing are the accessibility of tests to consumers, promotion of proactive healthcare and
the privacy of genetic information. Possible additional risks of DTC testing are the lack of governmental
regulation and the potential misinterpretation of genetic information.
3.Explain the culture techniques in detail.
cultural tecniques:The full microbiological examination usually requires that individual viable propagules are encouraged to
multiply in liquid media or on the surface, or with in the matrix, of a medium solidified with agar.
Cell culture
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Epithelial cells in culture, stained for keratin (red) and DNA (green)
Cell culture is the complex process by which cells are grown under controlled conditions. In practice, the
term "cell culture" has come to refer to the culturing of cells derived from multicellular eukaryotes,
especially animal cells. However, there are also cultures of plants, fungi and microbes, including viruses,
bacteria and protists. The historical development and methods of cell culture are closely interrelated to
those of tissue culture and organ culture.
Animal cell culture became a common laboratory technique in the mid-1900s,[1] but the concept
of maintaining live cell lines separated from their original tissue source was discovered in the
19th century.
History
The 19th-century English physiologist Sydney Ringer developed salt solutions containing the
chlorides of sodium, potassium, calcium and magnesium suitable for maintaining the beating of
an isolated animal heart outside of the body.[1] In 1885 Wilhelm Roux removed a portion of the
medullary plate of an embryonic chicken and maintained it in a warm saline solution for several
days, establishing the principle of tissue culture.[3] Ross Granville Harrison, working at Johns
Hopkins Medical School and then at Yale University, published results of his experiments from
1907–1910, establishing the methodology of tissue culture.[4]
Cell culture techniques were advanced significantly in the 1940s and 1950s to support research
in virology. Growing viruses in cell cultures allowed preparation of purified viruses for the
manufacture of vaccines. The injectable polio vaccine developed by Jonas Salk was one of the
first products mass-produced using cell culture techniques. This vaccine was made possible by
the cell culture research of John Franklin Enders, Thomas Huckle Weller, and Frederick
Chapman Robbins, who were awarded a Nobel Prize for their discovery of a method of growing
the virus in monkey kidney cell cultures.
Concepts in mammalian cell culture
Isolation of cells
Cells can be isolated from tissues for ex vivo culture in several ways. Cells can be easily purified
from blood, however only the white cells are capable of growth in culture. Mononuclear cells
can be released from soft tissues by enzymatic digestion with enzymes such as collagenase,
trypsin, or pronase, which break down the extracellular matrix. Alternatively, pieces of tissue can
be placed in growth media, and the cells that grow out are available for culture. This method is
known as explant culture.
Cells that are cultured directly from a subject are known as primary cells. With the exception of
some derived from tumors, most primary cell cultures have limited lifespan. After a certain
number of population doublings (called the Hayflick limit) cells undergo the process of
senescence and stop dividing, while generally retaining viability.
An established or immortalised cell line has acquired the ability to proliferate indefinitely either
through random mutation or deliberate modification, such as artificial expression of the
telomerase gene. There are numerous well established cell lines representative of particular cell
types.
Maintaining cells in culture
Cells are grown and maintained at an appropriate temperature and gas mixture (typically, 37°C,
5% CO2 for mammalian cells) in a cell incubator. Culture conditions vary widely for each cell
type, and variation of conditions for a particular cell type can result in different phenotypes being
expressed.
Aside from temperature and gas mixture, the most commonly varied factor in culture systems is
the growth medium. Recipes for growth media can vary in pH, glucose concentration, growth
factors, and the presence of other nutrients. The growth factors used to supplement media are
often derived from animal blood, such as calf serum. One complication of these blood-derived
ingredients is the potential for contamination of the culture with viruses or prions, particularly in
biotechnology medical applications. Current practice is to minimize or eliminate the use of these
ingredients wherever possible, but this cannot always be accomplished. Alternative strategies
involve sourcing the animal blood from countries with minimum BSE/TSE risk such as Australia
and New Zealand, and using purified nutrient concentrates derived from serum in place of whole
animal serum for cell culture.[5]
Plating density (number of cells per volume of culture medium) plays a critical role for some cell
types. For example, a lower plating density makes granulosa cells exhibit estrogen production,
while a higher plating density makes them appear as progesterone producing theca lutein cells.[6]
Cells can be grown in suspension or adherent cultures. Some cells naturally live in suspension,
without being attached to a surface, such as cells that exist in the bloodstream. There are also cell
lines that have been modified to be able to survive in suspension cultures so that they can be
grown to a higher density than adherent conditions would allow. Adherent cells require a surface,
such as tissue culture plastic or microcarrier, which may be coated with extracellular matrix
components to increase adhesion properties and provide other signals needed for growth and
differentiation. Most cells derived from solid tissues are adherent. Another type of adherent
culture is organotypic culture which involves growing cells in a three-dimensional environment
as opposed to two-dimensional culture dishes. This 3D culture system is biochemically and
physiologically more similar to in vivo tissue, but is technically challenging to maintain because
of many factors (e.g. diffusion).
Cell line cross-contamination
Cell line cross-contamination can be a problem for scientists working with cultured cells. Studies
suggest that anywhere from 15–20% of the time, cells used in experiments have been
misidentified or contaminated with another cell line.[7][8][9] Problems with cell line cross
contamination have even been detected in lines from the NCI-60 panel, which are used routinely
for drug-screening studies.[10][11] Major cell line repositories including the American Type
Culture Collection (ATCC) and the German Collection of Microorganisms and Cell Cultures
(DSMZ) have received cell line submissions from researchers that were misidentified by the
researcher.[10][12] Such contamination poses a problem for the quality of research produced using
cell culture lines, and the major repositories are now authenticating all cell line submissions.[13]
ATCC uses short tandem repeat (STR) DNA fingerprinting to authenticate its cell lines.[14]
To address this problem of cell line cross-contamination, researchers are encouraged to
authenticate their cell lines at an early passage to establish the identity of the cell line.
Authentication should be repeated before freezing cell line stocks, every two months during
active culturing and before any publication of research data generated using the cell lines. There
are many methods for identifying cell lines including isoenzyme analysis, human lymphocyte
antigen (HLA) typing, Chromosomal analysis, Karyotyping, Morphology and STR analysis.[14]
One significant cell-line cross contaminant is the immortal HeLa cell line.
Manipulation of cultured cells
As cells generally continue to divide in culture, they generally grow to fill the available area or
volume. This can generate several issues:
Nutrient depletion in the growth media
Accumulation of apoptotic/necrotic (dead) cells.
Cell-to-cell contact can stimulate cell cycle arrest, causing cells to stop dividing known as contact
inhibition or senescence.
Cell-to-cell contact can stimulate cellular differentiation.
Among the common manipulations carried out on culture cells are media changes, passaging
cells, and transfecting cells. These are generally performed using tissue culture methods that rely
on sterile technique. Sterile technique aims to avoid contamination with bacteria, yeast, or other
cell lines. Manipulations are typically carried out in a biosafety hood or laminar flow cabinet to
exclude contaminating micro-organisms. Antibiotics (e.g. penicillin and streptomycin) and
antifungals (e.g. Amphotericin B) can also be added to the growth media.
As cells undergo metabolic processes, acid is produced and the pH decreases. Often, a pH
indicator is added to the medium in order to measure nutrient depletion.
Media changes
In the case of adherent cultures, the media can be removed directly by aspiration and replaced.
Passaging cells
Passaging (also known as subculture or splitting cells) involves transferring a small number of
cells into a new vessel. Cells can be cultured for a longer time if they are split regularly, as it
avoids the senescence associated with prolonged high cell density. Suspension cultures are easily
passaged with a small amount of culture containing a few cells diluted in a larger volume of
fresh media. For adherent cultures, cells first need to be detached; this is commonly done with a
mixture of trypsin-EDTA, however other enzyme mixes are now available for this purpose. A
small number of detached cells can then be used to seed a new culture.
Transfection and transduction
Another common method for manipulating cells involves the introduction of foreign DNA by
transfection. This is often performed to cause cells to express a protein of interest. More recently,
the transfection of RNAi constructs have been realized as a convenient mechanism for
suppressing the expression of a particular gene/protein. DNA can also be inserted into cells using viruses,
in methods referred to as transduction, infection or transformation. Viruses, as parasitic agents, are well
suited to introducing DNA into cells, as this is a part of their normal course of reproduction.
[edit] Established human cell lines
One of the earliest human cell lines, descended from Henrietta Lacks, who died of the cancer that those
cells originated from, the cultured HeLa cells shown here have been stained with Hoechst turning their
nuclei blue.
Cell lines that originate with humans have been somewhat controversial in bioethics, as they may outlive
their parent organism and later be used in the discovery of lucrative medical treatments. In the pioneering
decision in this area, the Supreme Court of California held in Moore v. Regents of the University of
California that human patients have no property rights in cell lines derived from organs removed with
their consent.
A SELECTION OF MEDIA COMMONLY USED IN FOOD MICROBIOLOGY:
MEDIUM
USE
1. Plate count agar
Aerobic mesophilic count
2. Mac Conkey broth
MPN of coliforms in water
3. Brilliant Green/Lactose/ Bile broth
MPN of coliforms in food
4. Violet red/ bile/Glucose agar
Enumeration of Enterobacteriaceae.
5. Crystal violet /Azide / Blood agar
Enumeration of faecal Streptococci.
6. Baird- Parker agar
Enumeration of S. aureus
7. Vassiliadis broth
Selection enrichment of Salmonella.
8. Thiosulfate / bile/ citrate/ Sucrose agar
Isolation of Vibrios
9. Rose Bengal/ Chloramphenicol agar
Enumeration of moulds and yeasts
10. Mac Conkey agar
E. coli .
4.Explain the Enumeration methods in detail.
Enumeration methods:-
Plate counts
It has already been suggested that to count microorganisms in a food sample by direct microscopy
has a limited sensitivity because of the very small sample size in the field of view at the
magnification needed to see microorganisms, especially bacteria.
In a normal routine laboratory the most sensitive methods of detecting the presence of a viable
bacterium is to allow it to amplify itself to form a visible colony.
This forms the basis of the traditional pour plate and spread plate and most probable number
counts.
5.Explain the Alternative methods in detail.
Alternative methods
.Cultural methods are relatively labour intensive and require time for adequate growth to occur.
. Many food microbiologists also consider that the traditional enumeration methods are not only too
slow but lead to an over dependence on the significance of numbers of colony forming units.
. A number of methods have been developed which aim to give answer of redox to as “Rapid
methods”.
Dye- reduction test:
A group of tests which have been used for some time in the dairy industry dependent on the
response of a number of redox dye to the presence of metabolically active microorganisms.
They are relatively simple and rapid to carry out at low cost.
The redox dyes are able to take up electrons from an active biological system and this results in a
change of colour.
Dye Reduction Tests: Methylene Blue and
Resazurin.
Methylene Blue Reduction Test
The methylene blue reduction test is based on the fact that the color imparted to milk by the
addition of a dye such as methylene blue will disappear more or less quickly. The removal of the
oxygen from milk and the formation of reducing substances during bacterial metabolism causes
the color to disappear. The agencies responsible for the oxygen consumption are the bacteria.
Though certain species of bacteria have considerably more influence than others, it is generally
assumed that the greater the number of bacteria in milk, the quicker will the oxygen be
consumed, and in turn the sooner will the color disappear. Thus, the time of reduction is taken as
a measure of the number of organisms in milk although actually it is likely that it is more truly a
measure of the total metabolic reactions proceeding at the cell surface of the bacteria.
The methylene blue reduction test has lost much of its popularity because of its low correlation
with other bacterial procedures. This is true particularly in those samples which show extensive
multiplication of the psychrotropic species.
Apparatus.–The necessary equipment consists of test tubes with rubber stoppers, a pipette or
dipper graduated to deliver 10 ml of milk and a water bath for maintaining the samples at 35o to
37oC. The bath should contain a volume of water sufficient to heat the samples to 35o C within
10 minutes after the tubes enter the water and should have some means of protecting the samples
from light during the incubation period. If a hot-air chamber is used, the samples should be
heated to 35o C in a water bath since warm air would heat the milk too slowly.
The dry tablets contain methylene blue thiocyanate and may be obtained from any of the usual
laboratory supply houses. They should be certified by the Commission on Standardization of
Biological Stains. The solution is prepared by autoclaving or momentarily boiling 200 ml of
distilled water in a light resistant (amber) stoppered flask and then adding one methylene blue
tablet to the flask of hot water. The tablet should be completely dissolved before the solution is
cooled. The solution may be stored in the stoppered, amber flask or an amber bottle in the dark.
Fresh solution should be prepared weekly.
Procedure in Testing.–The following procedures are recommended.
(1) Sterilize all glassware and rubber stoppers either in an autoclave or in boiling water. Be sure
all glassware is chemically clean.
(2) Measure 1 ml of the methylene blue thiocyanate solution into a test tube.
(3) Add 10 ml of milk and stopper.
(4) Tubes may be placed in the water bath immediately or may be stored in the refrigerator at 0o
to 4o C for a more convenient time of incubation. When ready to perform the test, the
temperature of the samples should be brought to 35o C within 10 minutes.
(5) When temperature reaches 36o C, slowly invert tubes a few times to assure uniform
creaming. Do not shake tubes. Record this time as the beginning of the incubation period. Cover
to keep out light.
(6) Check samples for decolorization after 30 minutes of incubation. Make subsequent readings
at hourly intervals thereafter.
(7) After each reading, remove decolorized tubes and then slowly make one complete inversion
of remaining tubes.
(8) Record reduction time in whole hours between last inversion and decolorization. For
example, if the sample were still blue after L 5 hours but was decolorized (white) at the 2.5 hour
reading, the methylene blue reduction time would be recorded as 2 hours. Decolorization is
considered complete when four-fifths of the color has disappeared.
Classification.–The suggested classification is listed.
Class 1. Excellent, not decolorized in 8 hours.
Class 2. Good, decolorized in less than 8 hours but not less than 6 hours.
Class 3. Fair, decolorized in less than 6 hours but not less than 2 hours.
Class 4. Poor, decolorized in less than 2 hours.
Factors Affecting the Test.–Many factors affect the methylene blue reduction test and therefore
the steps of operation should be uniform.
Since the oxygen content must be used up before the color disappears, any manipulation that
increases the oxygen affects the test. Cold milk holds more oxygen than warm milk; pouring
milk back and forth from one container to another increases the amount, and at milking time
much oxygen may be absorbed.
The kind of organisms affect the rate of reduction. The coliforms appear to be the most rapidly
reducing organisms, closely followed by Streptococcus lactis, some of the faecal Streptococci,
and certain micrococci. Thermoduric and psychrotrophic bacteria reduce methylene blue very
slowly if at all. A large number of leucocytes affect the reduction time materially.
Light hastens reduction and therefore the tests should be kept covered. The concentration of the
dye should be uniform as an increased concentration lengthens the time of reduction. Increasing
the incubation temperature augments the activity of the bacteria and therefore shortens the
reduction time.
The creaming of the test samples causes a number of organisms to be removed from the body of
the milk and brought to the surface with the rising fat. This factor causes variations in the
reduction time, since the bacteria are not evenly distributed. The accuracy of the test i s
increased, reduction time shortened and decolorization more uniform if the samples are
periodically inverted during incubation.
The Resazurin Test
The resazurin test is conducted similar to the methylene blue reduction test with the judgement
of quality based either on the color produced after a stated period of incubation or on the time
required to reduce the dye to a given end-point. Numerous modifications have been proposed.
The two most commonly used are the "one-hour test" and the "triple-reading test" taken after
one, two, and three hours of incubation. Other modifications have value in specific applications.
The procedure for making the resazurin test is as follows: Prepare resazurin solution by
dissolving one resazurin tablet (dye content/ tablet, approximately 11 mg, certified by Biological
Stain Commission) in 200 ml of hot distilled water as was done in the methylene blue test. Place
one ml of dye solution in a sterile test tube, then add 10 ml of sample. Stopper the tube, place in
the incubator and, when the temperature reaches 36o C, invert to mix the milk and dye. Incubate
at 36o C. Tubes are examined and classified at the end of an hour in the "one-hour test" or at the
end of three successive hourly intervals in the "triplereading test." The following relationships of
color and quality are generally accepted:
Color of Sample: Quality of Milk
1. Blue (no color change): Excellent
2, Blue to deep mauve: Good
3. Deep mauve to deep pink: Fair
4. Deep pink to whitish pink: Poor
5. White: Bad
The resazurin test may be a valuable time saving tool if properly conducted and intelligently
interpreted, but should be supplemented by microscopic examination.
Results on the reliability of the resazurin tests are conflicting. One study in comparing the
resazurin test with the Breed microscopic method on 235 samples found the test reliable. Other
reports state that the resazurin test is an unreliable index of bacteriological quality in milk. A
major criticism of the method is that the resazurin reduction time of refrigerated bottled milk at
either 20o or 37o C is much too long to be of any value in evaluating bacteriological spoilage of
stored milk.
Standard Methods notes that under no circumstances should results of either methylene blue or
resazurin tests be reported in terms of bacterial numbers. The two dye reduction procedures are
described in more detail in Chapter 15 of the Thirteenth Edition of Standard Methods compiled
by the American Public Health Association.
ELECTRICAL METHODS
Electrical methods employ a variety of measurements of the effects of electrical current flow
within the Earth. The phenomena that can be measured include current flow, electrical potential
(voltages), and electromagnetic fields. A summary of the better-known electrical methods is
given below. In this set of notes we will consider only one of these methods, the DC resistivity
method, in greater detail.
DC Resistivity - This is an active method that employs measurements of electrical
potential associated with subsurface electrical current flow generated by a DC, or slowly
varying AC, source. Factors that affect the measured potential, and thus can be mapped
using this method, include the presence and quality of pore fluids and clays. Our
discussions will focus solely on this method.
Induced Polarization (IP) - This is an active method that is commonly done in
conjunction with DC Resistivity. It employs measurements of the transient (short-term)
variations in potential as the current is initially applied or removed from the ground, or
alternatively the variation in the response as the AC frequency is changed. It has been
observed that when a current is applied to the ground, the ground behaves much like a
capacitor, storing some of the applied current as a charge that is dissipated upon removal
of the current. In this process, both capacitative and electrochemical effects are
responsible. IP is commonly used to detect concentrations of clay, and electrically
conductive metallic mineral grains.
Self Potential (SP) - This is a passive method that employs measurements of naturally
occurring electrical potentials commonly associated with shallow electrical conductors,
such as sulfide ore bodies. Measurable electrical potentials have also been observed in
association with groundwater flow and certain biologic processes. The only equipment
needed for conducting an SP survey is a high-impedance voltmeter and some means of
making good electrical contact to the ground.
Electromagnetic (EM) - This is an active method that employs measurements of a timevarying magnetic field generated by induction through current flow within the earth. In
this technique, a time-varying magnetic field is generated at the surface of the earth that
produces a time-varying electrical current in the earth through induction. A receiver is
deployed that compares the magnetic field produced by the current-flow in the earth to
that generated at the source. EM is used for locating conductive base-metal deposits, for
locating buried pipes and cables, for the detection of unexploded ordnance, and for nearsurface geophysical mapping.
Magnetotelluric (MT) - This is a passive method that employs measurements of naturally
occurring electrical currents, telluric currents, generated by magnetic induction from
electrical currents in the ionosphere. This method can be used to determine electrical
properties of materials at relatively great depths (down to and including the mantle)
inside the Earth. In this technique, a time variation in electrical potential is measured at a
base station and at survey stations. Differences in the recorded signal are used to estimate
subsurface distribution of electrical resistivity.
ATP DETERMINATION
ATP determination
ATP determination using the time stable bioluminescent luciferase assay. This
assay is optimized for applications where ATP concentrations ranging from 10
nM up to 10 µM are determined. The luminescence signal is stable for at least 4
hours.
The luciferase bioluminescent assay includes thermostable firefly luciferase, DLuciferin as substrate and appropriate buffer solutions optimized for sensitive
ATP quantification.
The production of ATP is vital for muscle contraction, chemiosmotic homeostasis, and normal cellular
function. Many studies have measured ATP content or qualitative changes in ATP production, but few
have quantified ATP production in vivo in isolated mitochondria. Because of the importance of
understanding the energy capacity of mitochondria in biology, physiology, cellular dysfunction, and
ultimately, disease pathologies and normal aging, we modified a commercially available bioluminescent
ATP determination assay for quantitatively measuring ATP content and rate of ATP production in isolated
mitochondria. The bioluminescence assay is based on the reaction of ATP with recombinant firefly
luciferase and its substrate luciferin. The stabilities of the reaction mixture as well as relevant ATP
standards were quantified. The luminescent signals of the reaction mixture and a 0.5 µM ATP standard
decreased linearly at rates of 2.16 and 1.39% decay/min, respectively. For a 25 µM ATP standard, the
luminescent signal underwent a logarithmic decay, due to intrinsic deviations from the Beer-Lambert law.
Moreover, to test the functionality of isolated mitochondria, they were incubated with 1 and 5 mM
oligomycin, an inhibitor of oxidative phosphorylation. The rate of ATP production in the mitochondria
declined by 34 and 83%, respectively. Due to the sensitivity and stability of the assay and methodology,
we were able to quantitatively measure in vivo the effects of age and caloric restriction on the ATP
content and production in isolated mitochondria from the brain and liver of young and old Fischer-344
rats. In both tissues, neither age nor caloric restriction had any significant effect on the ATP content or the
rate of ATP production. This study introduces a highly sensitive, reproducible, and quick methodology for
measuring ATP in isolated mitochondria.
DNA/RNA METHODOLOGY
Biological complexity emerges from different organizational levels in a highly regulated space-time
coordination of processes that involves the participation and orchestrated interaction of DNA, RNA, and
proteins between each other and the environment. Fully understanding normal biological processes such
as cell differentiation, development and aging, and pathological conditions requires integrated genomic,
transcriptional, and proteomic studies (1–3), which demand the simultaneous isolation of DNA, RNA,
and proteins from the same sample.
Quick and reliable methods that perform simultaneous extraction of DNA, RNA, and proteins from a
single sample are ideal for the generation of matched samples that can save time and money and allow for
the efficient use of small and precious biological samples. Researchers are increasingly turning away
from classic RNA and protein extraction techniques, such as phenol-chloroform separation (4) or timeconsuming cesium chloride gradient centrifugation, because of the hazardous chemicals used and that the
methods are generally unsuited for routine use in the laboratory. Spin column technology is a simple and
quick approach to extracting nucleic acids from small biological samples. Furthermore, most columnbased procedures do not require the amount of hazardous chemicals that are used in traditional nucleic
acid extraction procedures (5).
Recently, Morse and coworkers (5) discussed the combined extraction of RNA and proteins using RNA
spin column–based technology, and Hummon et al. (6) showed an improved method for isolation and
solubilization of proteins after TRIzol extraction of RNA and DNA from the same sample. However,
none of these authors did a complete analysis of the proteins obtained at the level of two-dimensional (2D) electrophoresis to compare the protein profile obtained with conventional methods used in proteomics
studies. Here we present a methodology to simultaneously extract RNA/proteins and/or DNA, RNA, and
proteins from the same sample using commercially available column-based nucleic acid extraction kits.
We further compared the protein profile obtained with some of the methods dedicated to extracting
proteins using 2-D electrophoresis, and we show that buffer choice is critical in the efficient extraction of
proteins from these kits to allow proteomic studies.
6.Explain the Labotatory accreditation in detail.
Labotatory accreditation
Medical laboratory
A medical laboratory or clinical laboratory is a laboratory where tests are done on clinical specimens in
order to get information about the health of a patient as pertaining to the diagnosis, treatment, and
prevention of diseases.
Departments
Laboratory medicine is generally divided into four sections, and each of which is further divided into a
number of units. These four sections are:
Anatomic Pathology: units are included here, namely histopathology, cytopathology, and electron
microscopy. Academically, each unit is studied alone in one course. Other courses pertaining to this
section include anatomy, physiology, histology, pathology, andpathophysiology.
Clinical Microbiology: This is the largest section in laboratory medicine; it encompasses five
different sciences (units). These includebacteriology, virology, parasitology, immunology,
and mycology.
Clinical Biochemistry: Units under this busy section are instrumental
analysis, enzymology, toxicology and endocrinology.
Hematology: This small, yet busy, section consists of two units, which are coagulation and blood
bank.
Genetics is also studied along with a subspecialty known as cytogenetics.
Distribution of clinical laboratories in health institutions varies greatly from one place to another. Take
for example microbiology, some health facilities have a single laboratory for microbiology, while others
have a separate lab for each unit, with nothing called a "microbiology" lab.
Laboratory equipment for hematology(black analyser) and urinalysis (left of the open centrifuge).
Here's a detailed breakdown of the responsibilities of each unit:
Microbiology receives almost any clinical specimen, including
swabs, feces, urine, blood,sputum, cerebrospinal fluid, synovial fluid, as well as possible infected
tissue. The work here is mainly concerned with cultures, to look for suspected pathogens which, if
found, are further identified based on biochemical tests. Also, sensitivity testing is carried out to
determine whether the pathogen is sensitive or resistant to a suggested medicine. Results are reported
with the identified organism(s) and the type and amount of drug(s) that should be prescribed for the
patient.
Parasitology is a microbiology unit that investigates parasites. The most frequently encountered
specimen here is faeces. However, blood, urine, sputum, and other samples may also contain
parasites.
Virology is concerned with identification of viruses in specimens such as blood, urine,
andcerebrospinal fluid.
Hematology works with whole blood to do full blood counts, and blood films as well as many
other specialised tests.
Coagulation requires citrated blood samples to analyze blood clotting times and coagulation
factors.
Clinical Biochemistry usually receives serum or plasma. They test the serum for chemicals
present in blood. These include a wide array of substances, such as lipids, blood sugar, enzymes,
and hormones.
Toxicology mainly tests for pharmaceutical and recreational drugs. Urine and blood samples are
submitted to this lab.
Immunology/Serology uses the concept of antigen-antibody interaction as a diagnostic tool.
Compatibility of transplanted organs is also determined.
Immunohaematology, or Blood bank determines blood groups, and performs compatibility testing
on donor blood and recipients. It also prepares blood components, derivatives, and products for
transfusion. Regulated by the FDA since giving blood is considered a drug, this unit determines a
patient's blood type and Rh status, checks for antibodies to common antigens found on red blood
cells, and cross matches units that are negative for the antigen.
Urinalysis tests urine for many analytes. Some health care providers have a urinalysis laboratory,
while others don't. Instead, each component of the urinalysis is performed at the corresponding unit.
If measuring urine chemicals is required, the specimen is processed in the clinical biochemistry lab,
but if cell studies are indicated, the specimen should be submitted to the cytopathology lab, and so on.
Histopathology processes solid tissue removed from the body (biopsies) for evaluation at the
microscopic level.
Cytopathology examines smears of cells from all over the body (such as from the cervix) for
evidence of inflammation, cancer, and other conditions.
Electron microscopy prepares specimens and takes micrographs of very fine details by means
of TEM and SEM.
Genetics mainly performs DNA analysis.
Cytogenetics involves using blood and other cells to get a karyotype. This can be helpful in
prenatal diagnosis (e.g. Down's syndrome) as well as in cancer (some cancers have
abnormal chromosomes).
Surgical pathology examines organs, limbs, tumors, fetuses, and other tissues biopsied in surgery
such as breast mastectomys.
Medical laboratory staff
Clinical laboratory in a Hospital setting with two technicians shown.
The following is the hierarchy of the clinical laboratory staff from highest authority to lowest:
Medical Director
Pathologist, Clinical biologist
Resident in Pathology, Anatomical pathology or Clinical biology
Pathologist Assistant,
Laboratory Manager,
Department Supervisor,
Chief/Lead Technologist,
Cytotechnologist, Medical Laboratory Scientist, Histotechnologist,
Medical Laboratory Technician, Histotechnician
Medical Laboratory Assistant (Lab Aide),
Phlebotomist,
Transcriptionist,
Specimen processor, Secretary).
Some of these titles don't exist in some countries. Sometimes technologists and technicians do the same
work. In France, clinical biologistsmay also be Medical director and laboratory manager.
Types of laboratory
In many countries, there are two main types of labs that process the majority of medical
specimens. Hospital laboratories are attached to ahospital, and perform tests on
patients. Private (or community) laboratories receive samples from general practitioners, insurance
companies, and other health clinics for analysis. These can also be called reference laboratories where
more unusual and obscure tests are performed. For extremely specialised tests, samples may go to a
research laboratory. A lot of samples are sent between different labs for uncommon tests. It is more cost
effective if a particular laboratory specializes in a rare test, receiving specimens (and money) from other
labs, while sending away tests it cannot do.
In many countries there are mainly three types of Medical Laboratories as per the types of investigations
carried out. 1. Clinical Pathology 2. Clinical Microbiology & 3. Clinical Biochemistry laboratories. 1.
Clinical Pathology: Haematology, Histopathology, Cytology, Routine Pathology2. Clinical Microbiology:
Bacteriology, Mycobacteriology, Virology, Mycology, Parasitology, Immunology, Serology.3. Clinical
Biochemistry: Biochemical analysis, Hormonal assays etc.Blood Banks:- Blood bank is a separate body.
Its laboratory need Microbiological analysis for infectious diseases that may be found in blood. Pathology
to observe Blood grouping, Haematology & cross matching reactions. It also involves PRO department
for the communication & contact for blood donations etc..
Specimen processing and work flow
Sample processing will usually start with a set of samples and a request form.
Typically a set of vacutainer tubes containing blood, or any other specimen, will arrive to the laboratory
in a small plastic bag, along with the form.
The form and the specimens are given a laboratory number. The specimens will usually all receive the
same number, often as a sticker that can be placed on the tubes and form. This label has a barcode that
can be scanned by automated analyzers and test requests uploaded from the LIS. Entry of requests onto a
laboratory management system involves typing, or scanning (where barcodes are used) in the laboratory
number, and entering the patient identification, as well as any tests requested. This allows laboratory
machines, computers and staff to know what tests are pending, and also gives a place (such as a hospital
department, doctor or other customer) for results to go.
For biochemistry samples, blood is usually centrifuged and serum is separated. If the serum needs to go
on more than one machine, it can be divided into separate tubes.
Many specimens end up in one or more sophisticated automated analysers, that process a fraction of the
sample and return one or more "results". Some laboratories use robotic sample handlers (Laboratory
automation) to optimize the workflow and reduce contamination risk and sample handling of the staff.
The work flow in a lab is usually heavy from 2:00 am to 10:00 am. Nurses and doctors generally have
their patients tested at least once a day with general complete blood counts and chemistry profiles. These
orders are then drawn during a morning run by phlebotomists for results to be available in the patient's
charts for the attending physicians to consult during their morning rounds. Another busy time for the lab
is after 3:00 pm when private practice physician offices are closing. Couriers will pick up specimens that
have been drawn throughout the day and deliver them to the lab. Also, couriers will stop at outpatient
drawing centers and pick up specimens. These specimens will be processed in the evening and overnight
to ensure results will be available the following day.
Laboratory informatics
Laboratories today are held together by a system of software programs and computers that exchange data
about patients, test requests, and test results known as a Laboratory information system or LIS. The LIS is
interfaced with the hospital information system.
This system enables hospitals and labs to order the correct test requests for each patient, keep track of
individual patient or specimen histories, and help guarantee a better quality of results as well as printing
hard copies of the results for patient charts and doctors to check.
Result analysis, validation and interpretation
According to ISO 15189 norm, all pathological results must be verified by a competent professional. In
some countries staff like clinical scientists do the majority of this work inside the laboratory with
abnormal results referred to the relevant pathologist. In others, only medical staff (pathologist or clinical
biologist) is concerned by this phase. It can be assisted by some software in order to validate normal or
non modified results. Medical staff are sometimes also required in order to explain pathology results
to physicians. For a simple result given by phone or for a technical problem it's a medical technologist
explaining it to a registered nurse.
Departments in some countries are exclusively directed by a specialized Pathologist, in others a
consultant, medical or non-medical, may be the Head of Department. Clinical Scientists have the right to
interpret and discuss pathology results in their discipline in many countries, in Europe they are qualified
to at least Masters level, may have a PhD and can have an exit qualification equivalent to medical staff
e.g. FRCPath in the UK. In France only medical staff (Pharm.D. and M.D. specialized in Anatomical
pathology or Clinical biology) can discuss pathological results, clinical scientists are not considered as a
part of medical staff.
Scandal in the clinical lab industry
As medical technology advanced doctors were able to get more and more tests done in shorter and shorter
amounts of time. Where in the past a doctor might order a potassium and glucose and it would take hours
for the results, now a doctor can order a full chemistry panel of 20 or more different analytes and get the
results in under an hour. The results are also much more accurate and reliable now than in the past. Thus,
into the 1970s and 1980s the lab became a source of profit within the hospital structure.
Some commercial labs began taking illegal and nefarious actions to increase their income. These practices
included medicare and medicaid fraud by performing and billing for tests that the ordering physician
never ordered, paying kickbacks to private doctor offices for sending their specimens to these reference
labs, and other complicated criminal activity. These kickbacks included donuts, free computers, fax
machines, and more. These events culminated mostly in the mid-1990s with the SmithKline Beecham
Clinical Laboratory (SBCL) scandal.[2] It is believed SBCL paid at least $325 million in penalties and the
industry as a whole paid over $1 billion to insurance and government agencies that were defrauded. Ever
since this time, the lab has become a source of expense and loss in the hospital budget (commercial labs
have nothing to do with hospitals) and lab medicine's reputation was given a black eye. Now many labs
have a compliance officer with mandatory annual meetings about compliance for all employees.
Medical laboratory accreditation
Credibility of medical laboratories is paramount to the health and safety of the patients relying on the
testing services provided by these labs. The international standard in use today for the accreditation of
medical laboratories is ISO 15189 - Medical laboratories - particular requirements for quality and
competence.
Accreditation is done by the Joint Commission, AABB, and other state and federal agencies. CLIA 88 or
the Clinical Laboratory Improvement Amendments also dictate testing and personnel.
The accrediting body in Australia is NATA, all laboratories must be NATA accredited to receive payment
from Medicare.
In France, where accrediting body is COFRAC, in 2010, modification of legislation established ISO
15189 accreditation as an obligation for all clinical laboratories.
UNIT-V
1.Explain the food laws and regulations in detail.
To meet a country’s sanitary and phytosanitary requirements, food must comply with the local laws and
regulations to gain market access. These laws ensure the safety and suitability of food for consumers, in
some countries; also govern food quality and composition standards.
The requirement of food regulation may be based on several factors such as whether a country adopts
international norms developed by the Codex Alimentarius Commission of the Food and Agriculture
Organization of the United Nations and the World Health Organization; good agricultural and
manufacturing practices; or a country may also has its own suite of food regulations. Each country
regulates food differently and has its own food regulatory framework. Usually more than one agency is
involved in food regulations e.g. health and agriculture, they may have centralized or regionally
controlled food regulations, and different agencies may be involved in enforcement activities.
Types of food safety and quality standards that apply in most countries:
Food Safety and Standards Act
The Indian Parliament has recently passed the Food Safety and Standards Act, 2006that overrides all
other food related laws. It will specifically repeal eight laws:
The Prevention of Food Adulteration Act, 1954
The Fruit Products Order, 1955
The Meat Food Products Order, 1973
The Vegetable Oil Products (Control) Order, 1947
The Edible Oils Packaging (Regulation) Order, 1998
The Solvent Extracted Oil, De oiled Meal, and Edible Flour (Control) Order, 1967
The Milk and Milk Products Order, 1992
Essential Commodities Act, 1955 relating to food
The Act establishes a new national regulatory body, the Food Safety and Standards Authority of India, to
develop science based standards for food and to regulate and monitor the manufacture, processing,
storage, distribution, sale and import of food so as to ensure the availability of safe and wholesome food
for human consumption. All food imports will therefore be subject to the provisions of the Act and any
rules and regulations made under the Act.
As a temporary measure, the standards, safety requirements and other provisions of the repealed Acts and
Orders and any rules and regulations made under them will continue to be in force until new rules and
regulations are put in place under the Food Safety and Standards Act, 2006. For that reason, importers
will for some time have to continue to take into account the provisions of those repealed Acts and Orders.
Prevention of Food Adulteration Act
A basic statute (Prevention of Food Adulteration Act (PFA) of 1954 and the PFA Rules of 1955, as
amended) protects India against impure, unsafe, and fraudulently labelled foods. The PFA standards and
regulations apply equally to domestic and imported products and cover various aspects of food processing
and distribution. These include food colour, preservatives, pesticide residues, packaging and labelling,
and regulation of sales. Further details are available from the Ministry of Health and Family Welfare. All
imported products must adhere to the rules specified in the Act and its regulations, including those
covering labelling and marketing requirements. The PFA focuses primarily on the establishment of
regulatory standards for primary food products, which constitute the bulk of the Indian diet.
PFA rules sometimes appear to be drafted in a manner that goes beyond the mere establishment of
minimum product quality specifications, by prescribing recipes for how food products are to be
manufactured.
There is an appeals process for amending rules, although this is time-consuming. The Central Committee
for Food Standards, chaired by the Director General of Health Services, is the decision-making entity
Syrups.
Weights and measures
Standards for weights and measures are administered by the Ministry of Consumer Affairs, Food and
Public Distribution under the Standards of Weights and Measures Act, 1976 and related rules and
notifications. All weights or measures must be recorded in metric units and certain commodities can only
be packed in specified quantities (weight, measure or number). These include baby and weaning food,
biscuits, bread, butter, coffee, tea, vegetable oils, milk powder, and wheat and rice flour.
Shelf life
At the time of importation food products are required to have a valid shelf life, or residual shelf life, of
not less than 60 per cent of their original shelf life. For more information, see the relevant notification at
the Government of India Ministry of Commerce and Industry website.
Fruit Products Order
The fruit and vegetable processing sector is regulated by the Fruit Products Order, (FPO), which is
administered by the Department of Food Processing Industries.
The FPO contains specifications and quality control requirements regarding the production and marketing
of processed fruits and vegetables, sweetened aerated water, vinegar, and synthetic syrups.
All such processing units are required to obtain a license under the FPO, and periodic inspections are
carried out. Processed fruit and vegetable products imported into the country must meet the FPO
standards.
Meat Food Products Order
Regulations for the production of meat products are covered by the Meat Food Products Order, .
The Order:
Specifies sanitation and hygiene requirements for slaughterhouses and manufacturers of meat
products.
Contains packing, marking and labeling provisions for containers of meat products.
Defines the permissible quantity of heavy metals, preservatives, and insecticide residues in meat
products.
The Directorate of Marketing and Inspection at the Ministry of Agriculture is the regulatory authority for
the order, which is equally applicable to domestic processors and importers of meat products.
Livestock Importation Act
India has established procedures for the importation of livestock and associated products under
the Livestock Importation Act, 1898.
Under the regulations, the import of meat products, eggs and egg powder and milk products require a
sanitary import permit from the Department of Animal Husbandry, Dairying and Fisheries at the Ministry
of Agriculture.
A detailed import risk analysis is carried out, taking into account the disease situation prevailing in the
exporting country compared with the disease situation in India.
Milk and Milk Products Order
The production, distribution and supply of milk products is controlled by the Milk and Milk Products
Order, 1992. The order sets sanitary requirements for dairies, machinery, and premises, and includes
quality control, certification, packing, marking and labeling standards for milk and milk products.
Standards specified in the order also apply to imported products. The Department of Animal Husbandry,
Dairying and Fisheries at the Ministry of Agriculture is the regulatory authority.
Essential Commodities Act, 1955: The main objective of the Act is to regulate the manufacture,
commerce, and distribution of essential commodities, including food. A number of Control Orders have
been promulgated under the provisions of this Act. These are:
Standards of Weights and Measures Act, 1976 and the Standards of Weights and Measures (Packaged
Commodities) Rules, 1977: The Act governs sale of packaged commodities and provides for mandatory
registration of all packaged products in the country.
Consumer Protection Act, 1986: The Act provides for constitution of District Forum/State/National
Commission for settlement of disputes between the seller/service provider and the consumer.
The Infant Milk Substitutes, Feeding Bottles and Infant Foods (Regulation of Production, Supply and
Distribution) Act, 1992 and Rules 1993: This Act aims at promoting breast feeding and ensuring proper
use of infant milk substitutes and infant food.
The Insecticide Act, 1968: The Act envisages safe use of insecticides so as to ensure that the leftover
chemical residues do not pose any health hazard.
Export (Quality Control and Inspection) Act, 1963: The Act aims at facilitating export trade through
quality control and inspection before the products are sold to international buyers.
Environment Protection Act, 1986: This Act incorporates rules for the manufacture, use, import and
storage of hazardous microorganisms / substances / cells used as foodstuff.
Pollution Control (Ministry of Environment and Forests): A no-objection certificate from the respective
State Pollution Control Board is essential for all dairy plants.
(i) Industrial Licences: No licence is required for setting up a dairy plant in India. Only a memorandum
has to be submitted to the Secretariat for Industrial Approvals (SIA) and an acknowledgement obtained.
However, a certificate of registration is required under the Milk and Milk Products Order (MMPO), 1992.
Voluntary Standards
There are two organizations that deal with voluntary standardization and certification systems in the food
sector. The Bureau of Indian Standards looks after standardization of processed foods and standardization
of raw agricultural produce is under the purview of the Directorate of Marketing and Inspection.
Bureau of Indian Standards (BIS)
The activities of BIS are two fold the formulation of Indian standards in the processed foods sector and
the implementation of standards through promotion and through voluntary and third party certification
systems. BIS has on record, standards for most of processed foods. In general, these standards cover raw
materials permitted and their quality parameters; hygienic conditions under which products are
manufactured and packaging and labelling requirements. Manufacturers complying with standards laid
down by the BIS can obtain and "ISI" mark that can be exhibited on product packages. BIS has identified
certain items like food colours/additives, vanaspati, and containers for packing, milk powder and
condensed milk, for compulsory certification.
Directorate of Marketing and Inspection (DMI)
The DMI enforces the Agricultural Products (Grading and Marketing) Act, 1937. Under this Act, Grade
Standards are prescribed for agricultural and allied commodities. These are known as "Agmark"
Standards. Grading under the provisions of this Act is voluntary. Manufacturers who comply with
standard laid down by DMI are allowed to use "Agmark" labels on their products.
Management Systems for Quality and Food Safety
ISO 9000 Quality Management Systems
The ISO 9000 system is looked at as a system with minimum quality requirements. It builds a baseline
system for managing quality. The focus, therefore, is on designing a total quality management system,
one that complies with external standards, but includes the specific requirement of industry and integrates
elements of competitiveness.The millennium standard (ISO 9000:2000) has changed the focus from
procedure to process. The main features of the ISO 9000:2000 standards are:
Refinement in the presentation to make reading easy and elimination of general inauditable statements
such as "consideration shall be given”
The present standard gave an impression that it was applicable to manufacturing situation though it was
applied in organizations of different types and sizes, including the service sector. The new standard is a
broad-based standard applicable to all sectors.
In the new standards, approach has changed from continuous improvement to continual improvement.
Continuous improvement remained an implied approach to quality improvement in ISO 9000.
Plant Quarantine Order
India introduced the Plant Quarantine (Regulation of Import into India) Order in 2003 to prohibit and
regulate the import of agricultural articles. Orders include:
A ban on the import of certain plants and planting materials from designated countries (eg sugarcane from
Australia)
A restriction on the import of other plants and plant materials to authorized institutions, with additional
declarations and special conditions attached.
A requirement for additional declarations (such as a phytosanitary certificate issued by the exporting
country) and special conditions for a further positive list of plants and plant materials. The Order, with
amendments, is available at the Department of Agriculture and Cooperation and Plant Quarantine
Organization of India websites. The implementing agency is the Directorate of Plant Protection,
Quarantine, and Storage, under the Department of Agriculture and Cooperation, Ministry of Agriculture.
Export (Quality Control and Inspection) Act, 1963
The Export Inspection Council is responsible for the operation of this Act. Under the Act, a large number
of exportable commodities have been notified for compulsory pre-shipment inspection. The quality
control and inspection of various export products is administered through a network of more than fifty
offices located around major production centres and ports of shipment. In addition, organizations may be
recognized as agencies for inspection and /or quality control. Recently, the government has exempted
agriculture and food products, fruit products and fish and fishery products from compulsory pre-shipment
inspections; provided that the exporter has a firm letter from the overseas buyer stating that the overseas
buyer does not require pre-shipment inspection from official Indian inspection agencies.
Other Government Regulations
Industrial Licence:
No licence is required for setting up a Dairy Project in India. Only a Memorandum has to be submitted to
the Secretariat for Industrial Approvals (SIA) and an acknowledgment is to be obtained.
However Certificate of Registration is required under the Milk and Milk Products Control Order
(MMPO) 1992.
Foreign Investment:
Foreign Investment in dairying requires prior approval from the Secretariat of Industrial Approvals,
Ministry of Industry, as dairying has not been included in the list of High Priority Industries.
Automatic approval will be given upto 51% Foreign Investment in High Priority Industries.
In case of other Industries, proposals will be cleared on case to case basis. Government may allow 51%
without enforcing the old limit of 40% applicable under Foreign Exchange Regulations Act at its
discretion.
Foreign Technology Agreements:
Foreign Technology Agreements are freely allowed in high priority industries under the following
terms:Lump sum payment of Rs 10 million
Royalty payment of 5% on domestic sales and 8% as exports subject to total payment of 8% on sales
turnover, over a 10 year period from the date of agreement or 7 years from commencement of production.
Foreign Technology Agreements in dairying also need prior approval. Foreign Exchange required for
payment of Royalty will have to be purchased at market rates.
Foreign Technicians can be freely hired.
Import of Capital Goods
Import of capital goods is automatically allowed if it is financed through Foreign Equity. Alternatively,
approval is needed from the Secretariat of Industrial Approvals. The approval depends on the availability
of Foreign Exchange Resources.
Import of Second Hand Capital Goods
Import of Second hand goods is allowed subject to the following conditions:
Minimum Residual life of 5 years
The equipment should not be more than 7 years old
A certificate from the Chartered Engineers of the country of origin certifying the age and the Residual life
is to be produced.
Import will be allowed only for actual users.
Dividend Balancing
Remittances of dividend should be covered by earnings from exports recorded in the years prior to the
payment of dividend or in the years of the payment of the dividend.
2.Explain the Prevention of Food Adulteration Programme
2.Prevention of Food Adulteration Programme in detail.
The Ministry of Health and Family Welfare is responsible for ensuring safe food to the consumers.
Keeping this in view, a legislation called "Prevention of Food Adulteration Act, 1954" was enacted. The
objective envisaged in this legislation was to ensure pure and wholesome food to the consumers and also
to prevent fraud or deception. The Act has been amended thrice in 1964, 1976 and in 1986 with the
objective of plugging the loopholes and making the punishments more stringent and empowering
Consumers and Voluntary Organisations to play a more effective role in its implementation.
The subject of the Prevention of Food Adulteration is in the concurrent list of the constitution. However,
in general, the enforcement of the Act is done by the State/U.T Governments. The Central Government
primarily plays an advisory role in its implementation besides carrying out various statutory
functions/duties assigned to it under the various provisions of the Act.
The laws regulating the quality of food have been in force in the country since 1899. Until 1954, several
States formulated their own food laws. But there was a considerable variance in the rules and
specifications of the food, which interfered with inter-provincial trade. The Central Advisory Board
appointed by the Government of India in 1937 and the Food Adulteration Committee appointed in 1943,
reviewed the subject of Food Adulteration and recommended for Central legislation. The Constitution of
India provided the powers to Central Government for making such legislation as the subjects of Food and
Drugs Adulteration are included in the concurrent list. The Government of India, therefore, enacted a
Central Legislation called the Prevention of Food adulteration Act (PFA) in the year 1954 which came
into effect from 15 June, 1955. The Act repealed all laws, existing at that time in States concerning food
adulteration.
In India, a three-tier system is in vogue for ensuring food quality and food safety. They are:
Government of India;
State/UT Governments;
Local Bodies.
The Prevention of Food Adulteration Act is a Central legislation. Rules and Standards framed under the
Act are uniformly applicable throughout the country. Besides, framing of rules and standards, the
following activities are undertaken by the Ministry of Health and Family Welfare.
Keeping close liaison with State/local bodies for uniform implementation of food laws.
Monitoring of activities of the States by collecting periodical reports on working of food laws,
getting the reports of food poisoning cases and visiting the States from time to time.
Arranging periodical training programme for Senior Officer/Inspector/Analysts.
Creating consumer awareness about the programme by holding exhibitions/seminars/training
programmes and publishing pamphlet'.
Approving labels of Infant Milk Substitute and Infant food, so as to safeguard the health of
infants.
Coordinating with international bodies like ISO/FAO/WHO and Codex.
Carrying out survey-cum-monitoring activities on food contaminants like colours.
Giving administrative/financial/technical support to four Central Food Laboratories situated in
Kolkata, Ghaziabad, Mysore and Pune and providing technical guidance to the food laboratories
set up by the States/Local Bodies.
Holding activities connected with National Monitoring Agency vested with powers to decide
policy issues on food irradiation.
Formulation of Manual on food analysis method.
The Ministry of Health and Family Welfare is designated as the National Codex Contact Point in India to
examine and formulate India's views on the agenda for the various meeting of Codex Alimentarius
Commission, a joint venture of FAO/WHO dealing with International Food Standards and its subsidiary
committees. The Ministry of Health and Family Welfare constituted a National Codex Committee (NCC)
and an Assistant Director General (PFA) has been working as Liaison Officer for NCC. The NCC has
further constituted 24 Shadow Committees corresponding to various Codex commodities committees for
preparation and finalization of India's stand.
India has been regularly atending the various sessions of the Codex Alimentarius Commission and
various Codex Commodity Committees to put forward her views and defend these views.
Harmonisation of PFA with Codex
After signing the Sanitary and Phytosanitary (SPS) and Technical Barrier to Trade (TBT) agreements by
India and removal of quantitative restrictions on import of food products into India, the exercise of
harmonization of standards for food products, use of food additives, microbiological requirements,
harmonization of regulations, in line with international standards prescribed by Codex Alimentarius
Commission and International Standards Organisation (ISO) had been initiated.
Prevention of Food Adulteration Programme
Role of State/UT Governments
Enforcement of the food laws primarily rests with the State/UTs. There are 28 States and 7 Union
Territories in the country. The implementation of the Act in most of the States is under the administrative
control of the Directorate of Health Services, whereas, in a few States, the implementation is being
combined with Drugs Administration under the Joint Food and Drug Administration. The implementation
has been left to the administrative setup of the States, but it has been stressed on the States that whatever
the structure be, there should be a whole-time Senior Officer duly qualified and experienced in Food
Science, Food Technology, Food Analysis with other supporting officers and inspectors. State
Governments are also empowered to make rules laying down details of licensing conditions of food, the
establishments of food industries and prescribing licence fees.
The provisions under PFA Rules have been amended nearly 360 times and standards of around 250
articles of food which are of mass consumption have been prescribed. While making amendments,
standards formulated by Codex/technological development in the food industry sector/dietary
habits/nutritional status of our population, social/cultural practices are taken into consideration.
By and large, in most of the States, implementation in corporation/municipal area rests with the Local
Bodies which employ their own food inspectors. Licensing of food industries/establishments is also left to
them.
There are 72 food laboratories in the country at District/Regional or State level in addition to four Central
Food Laboratories set-up by the Central Government. Almost every State has got one or more laboratory
depending upon its need. About 12 of these laboratories are under the administrative control of the local
bodies whereas the remaining ones are under the administrative control of the State Government.
Following constraints have been noticed in the programme:
Shortage of Food Inspectors with the States/Local Bodies,
Deficiency in the testing laboratories on the following counts:
Inadequate trained manpower,
Inadequate testing facilities,
Non-availability of sophisticated equipment,
Inadequate budgetary provision,
Non-availability of reference standard material,
Non-availability of programme officer for PFA with the State/Local Bodies at State and District
levels,
Non-availability of separate legal cell for trial of PFA cases with the State/Local Bodies,
Non-availability of regular refresher training programme for all the functionaries.
Efforts of Central Government for Solving the Constraints
Refresher training programmes are being arranged for all the functionaries namely: (a) Food
Inspectors, (b) Local (Health) Authorities, (c) Food (Health) Authorities, (d) Public Analyst and
Chemist. Training for Analysts and Chemists are being organized in their own laboratories by
trainer deputed by the Central Government. These trainers stay in one lab for six working days
and first of all they setup the laboratory as per Good Laboratory Practices and thereafter, the
specific training is organized.
Sophisticated equipments are being supplied to State Food Testing Laboratories so that at least
one laboratory in each State is appropriately strengthened. Efforts are being made to ensure that
warranty of the equipment so supplied are for minimum 3 years along with consumables and
proper trainings is provided to the analysts/chemists by the supplier for handling and running the
equipment.
Efforts are also being made to ensure that each State is linked electronically with its District
Headquarters. The expenditure for this is proposed to be provided from the World Bank Assisted
Capacity Building Project for food and drugs being implemented by the Central Government.
This will facilitate smooth sharing of information and networking.
Efforts are being made to provide at least one analyst from the Central Budget through the World
Bank Assisted Project in each Food Testing Lab for a period of 5 years.
Standard reference material for pesticides, listed under Rule 65 of PFA Rules, all the metals listed
under Rule 57 of the PFA Rules and aflatoxin are being supplied to one lab in each State.
Books on methods of analysis like AOAC, Pearson, Food Chemical Codex, have already been
supplied to a majority of the laboratories.
Training programme for consumers, traders, vendors and street food hawkers have been
organized and will be organized in future as a consumer education programme on food safety.
Sensitisation training programmes have been organized for Port (Health) Officers/Customs
Officers/Customs House Clearing Agents and importers on various provisions of PFA Act/Rules
and other provisions namely packaged Commodity Order and Customs Act, so that these officers
may appropriately handle the imported food product.
The Food Safety and Standards Act, 2006: With the coming into effect of the Food Safety and
Standards Act, 2006 (FSSA) enacted by Parliament in August 2006, the Prevention of Food Adulteration
Act, 1954 stands repealed from the date on which Food Safety and Standards Act comes into force on
such date as the Central Government may, by notification in the Gazette.
Notwithstanding the repeal of the enactment and Orders specified in the Second Schedule, the standards,
safety requirements and other provisions of the Act and the rules and regulations made there under and
Orders listed in that Schedule shall continue to be in force and operate till new standards are specified
under this Act or rules and regulations made there under.
Provided that anything done or any action taken under the enactment and Orders under repeal shall be
deemed to have been done or taken under the corresponding provisions of this Act and shall continue in
force accordingly unless and until superseded by anything done or by any action taken under this Act.
World Bank Assisted-Capacity Building Project on Food Safety
As trade in food commodities expands globally, food safety can no longer be considered a mere domestic
issue. The agreements under the WTO require the development of modern food control and safety
programs by national Governments. The issue does not relate only to end product parameters but also to
process control.
In order to strengthen the food safety infrastructure in the country, a 5 year World Bank Aided Capacity
Building Project for Food Safety and Quality Control of Drugs has been launched by the Central
Government.
The Project Objectives/Components are as below:
To enhance the capacities of laboratories at the State and Central levels through infrastructure
strengthening and training of personnel to upgrade their existing skills. It is separately proposed
that only those labs be allowed to do statutory testing which are accredited to NABL (National
Accrediation Board for Testing and Calibration Laboratories).
To introduce GMP (Good Manufcturing Practice) and HACCP (Hazard Analysis and Critical
Control Points) in the medium and small-scale food processing operations and upgrade facilities
in the laboratories including testing for microbiological contamination.
To create greater awareness of food safety and hygiene in the small, cottage and unorganised
sectors including the street food sector through training,
To develop a system of continuous surveys of households to get client perceptions which will
provide substantive inputs for policy development and program improvements.
Setting up of Management Information System and electronic linkages between Central and State
Offices and Central and State Labs in the area of food to ensure better monitoring and data
collection.
FRUIT PRODUCTS ORDER (FPO), 1955
Fruit Products Order - 1955, promulgated under section 3 of the Essential Commodities Act — 1955,
aims at regulating sanitary and hygienic conditions in manufacture of fruit, vegetable products. It is
mandatory for all manufacturers of fruit & vegetable products to obtain license under this Order to ensure
good quality products, manufactured under hygienic conditions. The Fruit Product Order lays down tie
minimum requirements for:
1. Sanitary and hygienic conditions of premises, surroundings and personnel.
2. Water to be used for processing.
3. Machinery and equipment.
4. Product standards.
Besides this, maximum limits of preservatives, additives and contaminants have also been specified for
various
products.
This order is implemented by Department of Food Processing Industries through the Directorate of Fruit
& Vegetable Preservation at New Delhi. The Directorate bas four regional offices located at Delhi,
Mumbai, Calcutta and Chennai, as well as sub-offices at Lucknow and Guwahati. The officials of the
Directorate undertake frequent inspections of the manufacturing units and draw random
samples of products from the manufacturers and markets which are analyzed in the laboratories to test
their
conformity
with
the
specifications
laid
under
FPO.
The Central Fruit Products Advisory Committee comprising of the officials of concerned Government
Departments, technical experts, representatives of Central Food Technology Research Institute, Bureau of
Indian Standards, Fruit and vegetable Producers and Processing Industry, is responsible for
recommending amendments in the Fruit Product Order. In view of the demands of the industry,-and the
liberalized economic scenario, major amendments were made in FPO during 1997. It bas been amended
further in the year 2000 in consumer interest.
CODEX ALIMENTARIUS COMMISSION
Codex Alimentarius Commission is an International Commission constituted by Food and Agriculture
Organization (FAO) and World Healtb Organisation (WHO) of United Nations whose objective is to
protect the health of consumers and to ensure fair practices in tine food trade. The term Codex
Alimentarius" is taken from Latin Language and means food code'. The Codex Alimentarius is a
collection of International Standards for the safety and quality of food as well as codes of good
manufacturing practice and other guidelines to protect the health of consumers and remove unfair
practices in International Trade. These standards, guidelines and recommendations are recognized
worldwide for international trade negotiations and also for settlings of disputes by WTO.
The Codex Contact Point in India is the Directorate General of Health Services (DGHS) in the M/o
Health & Family Welfare. However, the D/o Food Processing Industries is closely associated with me
activities of Codex Alimientarius in their country. The Department has made provision of Rs.100 lakhs in
the budget of 2000-2001 for creating the data base, technical examination of various standards in
association with experts and coordination as well as participation in international Codex meetings.
A Delegation led by senior officer of this Department participated in the 28th Session of the Codex
Committee on Food Labelling held during 5-9 May 2000 at Ottawa, Canada.
Another delegation comprising of representatives of Mineral Water and Chocolate industries attended
meetings of Codex Committee on Natural Mineral Waters and Cocoa Products and Chocolates held at
Fribourg, Switzerland from 30th October to 4th November. India's view points on different agenda items
were
well
taken
in
these
meetings.
The D/o Food Processing Industries intends to set up a dedicated information cell in association with
CIFTI to work solely on collecting, analyzing, documenting and then disseminating the information on
different food laws responses on Codex agendas and reports, WTO issues including case studies or any
other issue related to food processing.
FOOD QUALITY
During the year, the Department has provided grant of Rs.100.00 lakhs to the Central Food Technological
Research Institute (CFTRI), Mysore for the on-going Nodal Codex Food Laboratory at CFTRI.
HAZARD ANALYSIS AND CRITICAL CONTROL POINT (HACCP)
The Food Industry plays an important role in the national economy. In today's global market, quality and
food
safety
have
become
competitive
edge
for
the
enterprises
producing
foods and providing services. Therefore, the installation of ISO: 9000 Quality Management Systems and
Hazard Analysis Critical Control Points (HACCP) based food safety system is extremely desirable in
view of the changing scenario in the international trade. The D/o Food Processing Industries is operating
a Plan Scheme for Generic Advertisement on Processed Food and Marketing Assistance. Under this
Scheme, assistance in the form of grant-in-aid is provided to all agencies to the extent of 50% subject to a
limit of Rs.10 lakhs towards the cost of implementing Total Quality Management including obtaining
ISO:9000
Certification,
HACCP
etc.
The D/o Food Processing Industries in association with CIFTI organized series of seminars/workshops on
quality and safety in different parts of the country to create awareness among the food industries as well
as
consumers.
In addition to this, D/o Food Processing Industries in association with ILSI-INDIA organized a South
Asian Conference on food safety from 11-13 December 2000 to discuss the issues relating to food safety
and
food
trade
in
South
Asian
Countries.
Agri-Tech'2000 held in Chandigarh during 1-5 December, 2000, devoted half a day session on 5.12-2000
towards presentation and discussion on food safety, hygiene and compliance to food standards and food
laws which inter-alia include HACCP issues.
MPO
The role and function
of the MPO
Main objective
The main objective of the MPO to render supportive and related services to the milk producers of
South Africa.
Objective
To supply supportive and related services to the milk producers of Southern Africa, including
research, training and advice with regard to economical, financial, statistical, secretarial, administrative, inspective, accounting, public relations, industrial relations, health and educational
services, regulation and legal services in relation to the primary dairy industry.
Functions
Promoting milk producers’ interests is cardinal to the activities of the MPO. The MPO ensures that
milk producers’ voices are heard on all levels – from regional to national – and that negative
presumptions are addressed and positive results pursued. The organisation aims to improve relations
between the primary and secondary industries.
Filial companies
The policy to establish filial companies that are transformed to viable entities ensures that the MPO
is able to give R6 back in value to the producer for every R1 paid in membership fees.
MPOSA Holdings
MPOSA Holdings was established in 2001 to serve as a holding company, rendering services
through the affiliates to the MPO. Mposa has six filials namely AgriBonus, Agri Connect, Agri
Travel and Tours, the Intervet MPO Institute for Dairy Technology, Cendel and Mposa Investigation
Services.
Liaison
The MPO is involved with Mbisi, the organisation that is responsible for the management of the
National Milk Recording Scheme. The MPO also organises and has shareholding in the important biannual South African Large Herds Conference, and organising the biggest dairy expo in Africa, the
All Africa Dairy Expo. Statistics and industry information are made available to the producers, the
industry and the government. This information equips the producer to make informed decisions and
is also used in high-level negotiations, even at international level.
The MPO is a member of the International Dairy Federation (IDF). The MPO is also a member of the
Dairy Standard Agency and thus contributes to the promotion of milk quality.
As the mouthpiece of the producer, the MPO liaises with government departments such as Sars, Itac,
the Agricultural Trade Forum, Sacu task teams and the National Agricultural Marketing Council
concerning the Codex Alimentarius, traceability, tariffs, HACCP, black economic empowerment,
school milk schemes as well as animal diseases. The MPO also liaises with suppliers and the
secondary industry.
3.Explain the ISO 9001: 2008.
ISO 9001: 2008
Primary
ISO 9001: 2008 (updated from the original ISO 9001: 2000) is the best known of the ISO 9000 family of
International Standards for quality management. The standard gives the requirements for a quality
management system and is one of more than 15,000 voluntary international standards published by the
International Organisation for Standardisation (ISO).1ISO 9001: 2008 does not give requirements for
specific products or services; rather, it provides a set of generic requirements relating to the processes of
development and production, and how they will be managed, reviewed and improved in order achieve
customer satisfaction.
The requirements call for the processes to be comprehensively documented as procedures to which staff
are expected to consistently conform. This is with the aim of meeting the needs and expectations of the
customer and helping organisations to comply with applicable regulations. Implementation involves
making production procedures explicit (say what you do), documenting them, ensuring they are followed
and checking they are effective. A quality management system can be audited by an independent
certification body as conforming to the standard (leading to anISO 9001: 2008 certificate), although this is
not compulsory unless it is a market or regulatory requirement.
Summary
Assessments for certification are carried out against the ISO 9001: 2008 standard, which is the only
certification standard in the ISO 9000 family. To comply with ISO 9001: 2008 an organisation needs to
review its processes in accordance with the standard’s requirements in order to meet the needs and
expectations of the ‘customer base’. The ISO requirements cover a wide range of topics:
• Management commitment to quality.
• ‘Customer’ focus.
• Adequacy of an organisation’s resources.
• Employee competence.
• Process management (for production, service delivery
and relevant administrative and support processes).
• Quality planning.
• Design, purchasing, monitoring and measurement of
its processes and products.
• Processes to resolve customer complaints.
• Corrective/preventive actions.
• A requirement to drive continual improvement of the
organisation.
• A requirement to monitor ‘customer’ perceptions
about the quality of the goods and services it provides.
The organisation compiles a Quality Manual, outlining the implementation of quality management
procedures and how the ISO 9001: 2008 requirements are being met.
When the quality system and requirements are in place and established, organisations like the British
Standards Institution recommend a pre-assessment by a third party to identify areas where an organisation
may not be operating according the standard’s requirements and to help make effective change towards
that goal.
Organisations then seek an independent auditing by a certification body to check conformity with the
requirements of the standard and to ensure that they are working in practice. However, an organisation
can implement ISO 9001: 2008 without having its management system audited and certified. ISO does
not itself certify organisations. Most countries have formed accreditation bodies that in turn approve
individuals and organisations to audit and certify organisations applying for ISO 9001: 2008 compliance
certification.
In the UK, such accreditation is conducted by the United Kingdom Accreditation Service (UKAS), the
only UK accreditation body recognised by the Government. Organisations that seek certification to ISO
9001: 2008 are encouraged by the Government to use the services of those individual organisations that
UKAS has authorised in order to receive the National Accreditation Mark. An ISO 9001: 2008 certificate
is temporary and must be renewed at regular intervals recommended by the certification body – usually
between one and three years.
Potential benefits
• ISO 9001: 2008 covers an extensive range of
requirements and seeks to improve the quality of all of
the organisation’s management activities, which has
the potential to result in some substantial overall
organisational improvement.
• ISO 9001: 2008 is one of the most nationally and
internationally known quality standards that affirms
the independent approval of a management system
designed specifically to deliver high levels of customer
satisfaction.
• It has the potential to improve internal and external
accountability and communication of management and
production procedures.
• ISO 9001 certification can help an organisation qualify
for a tender or to achieve preferred supplier status,
typically for a Local Authority.
Potential limitations
• Pursuing the standard has the potential to be
expensive in terms of start-up and running costs
and has the potential be time consuming to
implement.
• There is less flexibility than other tools and it is much
more difficult to use in smaller parts of for single
issues.
• Its origins are in the industrial sector and whilst the
latest version, has been made more user friendly for
service organisations it may be less suitable for
socially enterprising organisations.
• As a quality management standard, it was not designed
to evaluate an organisation’s broader impacts on
society or the environment. ISO14001:2004, however,
provides a separate environmental management system
standard.
A note on the ISO 14000 Series
ISO has also developed a family of environmental management standards called ISO 14000. ISO
14001:2004 is the certification standard similar to ISO 9001:2000 in concept and structure. They both
require organisations that implement them to continually improve their performance. Both standards
concern processes and not products directly. Both will share some similar benefits and limitations due to
these similarities.
ISO 14001:2004 (the latest version) is primarily concerned with ‘environmental management’ or what the
organisation does to minimise harmful effects on the environment caused by its activities. The ISO 14000
family consists of standards relating to Environmental Management Systems (EMS), which are tools to
help the organisation develop its environmental policy, objectives and targets, and classify them by when
they apply to:
• The organisational level (implementing EMS,
conducting environmental auditing and related
investigations, and evaluating environmental
performance).
• Products and services (using environmental
declarations and claims, conducting life cycle
assessment), addressing environmental aspects in
product standards, and understanding terms and
definitions).
ISO 14001:2004 ensures that organisations are aware of environmental aspects of their work in order to
minimise negative impacts and improve environmental performance. ISO suggests that the standard can
provide significant tangible benefits, including:
• Reduced raw material/resource use.
• Reduced energy consumption.
• Improved process efficiency.
• Reduced waste generation and disposal costs.
• Utilisation of recoverable resources.
The standard can be implemented by a wide variety of organisations, whatever their current level of
environmental maturity. However, a commitment to compliance with applicable environmental legislation
and regulations is required, along with a commitment to continuous improvement.
Who can use ISO 9001: 2008?
The vast majority of ISO standards are highly specific to a particular product, material, or process.
However, ISO 9001 (quality) and ISO 14001 (environment) are ‘generic management system standards’.
‘Generic’ means that the same standard can be applied to any organisation, large or small, whatever its
product or service, in any sector of activity, and whether it is a business enterprise, a public
administration, or a government department. ISO 9001 contains a generic set of requirements for
implementing a quality management system and ISO 14001 for an environmental management system.
What resources are needed?
Leadership
Senior individuals in an organisation will need to be fully committed.
Proficiencies or skills
Training in understanding the standards may be required. Actions taken to meet implementation to the
requirements are left to the organisation itself. The organisation then needs to address the issues needed to
comply with the standards.
Staff time
Whilst this may vary depending on the size of the organisation and the change that has to be
implemented, estimates from organisations the Charities Evaluation Services and the Scottish Executive
indicate that it can take from between 6 and18 months to implement.
Courses, support, and information
The ISO website contains information on all aspects of the ISO 9000 family as well as hardcopies, a
Magical Demystifying Tour of ISO 9000 and ISO 14000 and the ISO magazine, ISO Management
Systems, and other publications.2 ISO publications include the handbook, ISO 9001 for small businesses.
Top
Development, ownership and support
The ISO is responsible for developing, maintaining and publishing the ISO 9000 family. The ISO is a
non-governmental organisation (NGO) network of the national standards institutes of 150 countries with
one member per country, with a Central Secretariat in Geneva, Switzerland, that co-ordinates the system.
It was created in 1947 and has a strategic partnership with the World Trade Organisation (WTO).3
The ISO does not itself audit or assess the management systems of organisations. The Scottish Executive
estimates that a typical organisation of between 60 and 70 people would expect to pay £2,000–£3,000 for
the initial assessment and £1,000–£1,600 each year for the audits, in addition to the cost of publications.
Top
Third sector examples
• Co-operatives UK
• Age Concern
• National Childminding Association
• Triodos Bank
• Disability Homes Network (DHN)
• Typetalk, a joint venture between BT and The Royal
National Institute for the Deaf
Examples from other sectors
There are thousands of companies throughout the world that have implemented ISO standards. Articles
giving examples can be found on the ISO website.
ISO 22000
[edit]Food safety
Food safety is linked to the presence of food-borne hazards in food at the point of consumption. Since
food safety hazards can occur at any stage in the food chain it is essential that adequate control be in
place. Therefore, a combined effort of all parties through the food chain is required.
.ISO 22000 standard
The ISO 22000 international standard specifies the requirements for a food safety management system
that involves the following elements:
interactive communication
system management
prerequisite programs
HACCP principles
Critical reviews of the above elements have been conducted by many scientists [1], [2], [3], [4].
Communication along the food chain is essential to ensure that all relevant food safety hazards are
identified and adequately controlled at each step within the food chain. This implies communication
between organizations both upstream and downstream in the food chain. Communication with customers
and supplies about identified hazards and control measures will assist in clarifying customer and supplier
requirements.
Recognition of the organization's role and position within the food chain is essential to ensure effective
interactive communication throughout the chain in order to deliver safe food products to the final
consumer.
The most effective food safety systems are established, operated and updated within the framework of a
structured management system and incorporated into the overall management activities of the
organization. This provides maximum benefit for the organization and interested parties. ISO 22000 has
been aligned with ISO 9001 in order to enhance the compatibility of the two standards.
ISO 22000 can be applied independently of other management system standards or integrated with
existing management system requirements.
ISO 22000 integrates the principles of the Hazard Analysis and Critical Control Point (HACCP) system
and application steps developed by the Codex Alimentarius Commission. By means of auditable
requirements, it combines the HACCP plan with prerequisite programmes. Hazard analysis is the key to
an effective food safety management system, since conducting a hazard analysis assists in organizing the
knowledge required to establish an effective combination of control measures. ISO 22000 requires that all
hazards that may be reasonably expected to occur in the food chain, including hazards that may be
associated with the type of process and facilities used, are identified and assessed. Thus it provides the
means to determine and document why certain identified hazards need to be controlled by a particular
organization and why others need not.
During hazard analysis, the organization determines the strategy to be used to ensure hazard control by
combining the prerequisite programmes and the HACCP plan.
ISO is developing additional standards that are related to ISO 22000. These standards will be known as
the ISO 22000 family of standards. At the present time, the following standards will make up the ISO
22000 family of standards:
ISO 22000 - Food safety management systems - Requirements for any organization in the food chain.
ISO 22001 - Guidelines on the application of ISO 9001:2000 for the food and drink industry (replaces:
ISO 15161:2001).
ISO/TS 22002- Prerequisite programmes on food safety -- Part 1: Food manufacturing
ISO TS 22003 - Food safety management systems for bodies providing audit and certification of food
safety management systems.
ISO TS 22004 - Food safety management systems - Guidance on the application of ISO 22000:2005.
ISO 22005 - Traceability in the feed and food chain - General principles and basic requirements for
system design and implementation.
ISO 22006 - Quality management systems - Guidance on the application of ISO 9002:2000 for crop
production.
ISO 22000 is also used in the Food Safety Systems Certification (FSSC) Scheme FS22000. FS22000 is a
Global Food Safety Initiative (GFSI) approved scheme.
ISO 9001 vs ISO 22000
In comparison with ISO 9001, the standard is a more procedural orientated guidance than a principle
based one. Apart from that, ISO 22000 is an industrial-specific risk management system for any type of
food processing and marketing, which can be closely incorporated with the quality management system
of ISO 9001. The detailed similarities and differences of the two standards can be found elsewhere
Potential justification
In 2004, European Office of Crafts, Trades and Small and Medium-sized Enterprises for Standardisation
addressed that the standard is only suitable for large sized companies and small food businesses will not
be able to seek such a high standard due to the lack of resources to pursue the certification. The agency
suggests to create an alternative for small food business to achieve the same objective [9]. EFSA is now
making their efforts on the food legislations that are adaptable for the SMEs in food supply chains [10]. A
few critics also proposed that organizations which seek the standard certification should also do the same
to the ISO 14001 along with the ISO 9001, as they consider that large amounts of risks are mainly from
the primary production in the supply chains rather than the later stages of food processing [11], [12]
4.Explain the World Trade Organization in detail.
World Trade Organization
The World Trade Organization (WTO) is an organization that intends to supervise
andliberalize international trade. The organization officially commenced on January 1, 1995 under
the Marrakech Agreement, replacing the General Agreement on Tariffs and Trade (GATT), which
commenced in 1948. The organization deals with regulation of trade between participating countries; it
provides a framework for negotiating and formalizing trade agreements, and a dispute resolution process
aimed at enforcing participants' adherence to WTO agreements which are signed by representatives of
member governments and ratified by their parliaments.[4][5] Most of the issues that the WTO focuses on
derive from previous trade negotiations, especially from the Uruguay Round (1986-1994).
The organization is currently endeavoring to persist with a trade negotiation called the Doha Development
Agenda (or Doha Round), which was launched in 2001 to enhance equitable participation of poorer
countries which represent a majority of the world's population. However, the negotiation has been dogged
by "disagreement between exporters of agricultural bulk commodities and countries with large numbers
of subsistence farmers on the precise terms of a 'special safeguard measure' to protect farmers from surges
in imports. At this time, the future of the Doha Round is uncertain."[6]
The WTO has 153 members,[7] representing more than 97% of total world trade[8] and 30 observers, most
seeking membership. The WTO is governed by a ministerial conference, meeting every two years; a
general council, which implements the conference's policy decisions and is responsible for day-to-day
administration; and a director-general, who is appointed by the ministerial conference. The WTO's
headquarters is at the Centre Willi
5. Explain the consumer protection act in detail.
The consumer protection act, 1986
Though consumer is the purpose and most powerful motivating force of production, yet at the
same time consumer is equally vulnerable segment of the whole marketing system. Attempts have
been made to guard the interest of the consumer in a sporadic way till 1986, when Government of
India enacted a comprehensive legislation-Consumer Protection Act, to safe guard the interest of the
consumer then ever before. The Consumer Protection Act, 1986, applies to all goods and services,
excluding goods for resale or for commercial purpose and services rendered free of charge and under a
contract for personal service. The provisions of the Act are compensatory in nature. It covers public,
private, joint and cooperative sectors.
The Act enshrines the rights of the consumer such as right to safety, right to be informed, right
to be heard, and right to choose, right to seek redressal and right to consumer education.
Consumer: A consumer is any person who buys any goods for a consideration and user of such
goods where the use is with the approval of buyer, any person who hires/avails of any service for a
consideration and any beneficiary of such services, where such services are availed of with the
approval of the person hiring the service. The consumer need not have made full payment.
Goods: Goods mean any movable property and also include shares, but do not include any
auctionable claims.
Service: Service of any description such as banking, insurance, transport, processing, housing
construction, supply of electrical energy, entertainment, board or lodging.
Nature of complaint:
a)
Any unfair trade practice or restrictive trade practice adopted ;by the trader
b) Defective goods
b)
Deficiency in service
c)
Excess price charged ;by the trader
d) Unlawful goods sale, which is hazardous to life and safety when used
Consumer Courts: A three-tier-system
a)
National Consumer Dispute Redressal Commission: claims above Rs. 20 lakh
(a) Consumer Dispute Redressal Commission or State Commission: Claims from Rs 5 to
20 lakh.
(a)
Consumer Dispute Redressal Forum or District Forum: Claims upto Rs 5 Lakh
Complaint: A complaint, hand written or typed, can be filed by a consumer, a registered consumer
organisation, central or state Government and one or more consumers, where there are numerous
consumers having the same interest.No stamp or court fee is needed. The nature of complaint
must be clearly mentioned as well as the relief sought by the consumer. It must be in quadruplicate
in district forum or state commission. Else, additional copies are required to be filed.
Grant of relief:
(a) Repair of defective goods
(b) Replacement of defective goods
(c) Refund of the price paid for the defective goods or service
(d) Removal of deficiency in service
(e) Refund of extra money charged
(f)
Withdrawal of goods hazardous to life and safety
(g)
Compensation for the loss or injury suffered by the consumer due to negligence of the
opposite party
(h)
Adequate cost of filing and pursuing the complaint
Normally, complaints should be decided within 90 days from the date of notice issued to the
opposite party. Where a sample of any goods is required to be tested, a complaint is required to be
disposed of within 150 days; it may take more time due to practical problems.
Consumer Protection Councils: Councils have been setup in all states and at the center to
promote and protect the rights and interest of consumers. These councils are advisory in nature and
can play important role in recommending consumer oriented policies to the state and central
Government.
British Standards
British Standards are the standards produced by BSI Group which is incorporated under a Royal
Charter (and which is formally designated as the National Standards Body (NSB) for the UK).[1] The BSI
Group produces British Standards under the authority of the Charter, which lays down as one of the BSI's
objectives to:
(2) Set up standards of quality for goods and services, and prepare and promote the general adoption of
British Standards and schedules in connection therewith and from time to time to revise, alter and amend
such standards and schedules as experience and circumstances require
—BSI Royal Charter, Faller and Graham
Formally, as per the 2002 Memorandum of Understanding between the BSI and the United Kingdom
Government, British Standards are defined as:
"British Standards" means formal consensus standards as set out in BS 0-1 paragraph 3.2 and based upon
the principles of standardisation recognised inter alia in European standardisation policy.
—MEMORANDUM OF UNDERSTANDING BETWEEN THE UNITED KINGDOM
GOVERNMENT AND THE BRITISH STANDARDS INSTITUTION IN RESPECT OF ITS
ACTIVITIES AS THE UNITED KINGDOM'S NATIONAL STANDARDS BODY, United
Kingdom Department for Business, Innovation, and Skills[3]
Products and services which BSI certifies as having met the requirements of specific standards within
designated schemes are awarded theKitemark.[4]
British Standards are one of the formal exceptions made to the Restrictive Trade Practices Act. §18(5) of
the Act specifies that agreements to comply with British Standards should be disregarded when deciding
whether an agreement is a restriction upon trade.
6.Explain the hygiene and sanitation in food sectors.
How British Standards are made
The BSI Group as a whole does not produce British Standards, as standards work within the BSI is decentralized. The
governing Board of BSI establishes a Standards Board. The Standards Board does little apart from setting up Sector
Boards (a Sector in BSI parlance being a field of standardization such as ICT, Quality, Agriculture,
Manufacturing, or Fire). Each Sector Board in turn constitutes several Technical Committees. It is the
Technical Committees that, formally, approve a British Standard, which is then presented to the Secretary
of the supervisory Sector Board for endorsement of the fact that the Technical Committee has indeed
completed a task for which it was constituted.[6]
The standards
The standards produced are titled British Standard XXXX[-P]:YYYY where XXXX is the number of
the standard, P is the number of the part of the standard (where the standard is split into multiple parts)
and YYYY is the year in which the standard came into effect. BSI Groupcurrently has over 27,000 active
standards. Products are commonly specified as meeting a particular British Standard, and in general this
can be done without any certification or independent testing. The standard simply provides a shorthand
way of claiming that certain specifications are met, while encouraging manufacturers to adhere to a
common method for such a specification.
The Kitemark can be used to indicate certification by BSI, but only where a Kitemark scheme has been
set up around a particular standard. It is mainly applicable to safety and quality management standards.
There is a common misunderstanding that Kitemarks are necessary to prove compliance with any BS
standard, but in general it is neither desirable nor possible that every standard be 'policed' in this way.
Following the move on harmonisation of the standard in Europe, some British Standards are gradually
superseded or replaced by the relevantEuropean Standards (EN).
History
BSI Group began in 1901 as the Engineering Standards Committee, led by James Mansergh, to
standardise the number and type of steelsections, in order to make British manufacturers more efficient
and competitive.
Over time the standards developed to cover many aspects of tangible engineering, and then engineering
methodologies including quality systems, safety and security.
Examples of British Standards
BS 0 A standard for standards specifies Development, Structure and Drafting of British
Standards themselves.
BS 9 - for bullhead steel rail sections in various weights.
BS 11 - for flat bottom steel rail sections in various weights
BS 31 for steel conduit and fittings for electrical wiring
BS 88 a specification for cartridge fuses for voltages up to and including 1000 V a.c. and 1500 V d.c.
BS 196 for protected-type non-reversible plugs, socket-outlets cable-couplers and appliance-couplers
with earthing contacts for single phase a.c. circuits up to 250 volts
BS 308 a now deleted standard for engineering drawing conventions, having been absorbed into BS
8888.
BS 336 for fire hose couplings and ancillary equipment
BS 381 for colours used in identification, coding and other special purposes
BS 476 for fire resistance of building materials / elements
BS 499-1 welding terms and symbols. Glossary for welding, brazing and thermal cutting
BS 546 for mains power plugs and sockets (older standard)
BS 857 for safety glass for land transport
BS 1088 for marine plywood
BS 1192 for Construction Drawing Practice. Part 5 (BS1192-5:1998) concerns Guide for structuring
and exchange of CAD data.
BS 1361 for cartridge fuses for a.c. circuits in domestic and similar premises
BS 1363 for mains power plugs and sockets
BS 1377-9:1990 The standard penetration test (SPT) is an in-situ dynamic penetration test designed to
provide information on the geotechnical engineering properties of soil.
BS 1881:201 Methods of Testing Concrete Part 201: Guide to the Use of Non-Destructive Methods
of Test for Hardened Concrete
BS 1881:204 Testing concrete. Recommendations on the use of electromagnetic covermeters.
BS 1852 resistor and capacitor value coding
BS 2660 for colours for building and decorative paints[7]
BS 3506 for unplasticized PVC pipe for industrial uses
BS 3621 for thief resistant lock assembly. Key egress.
BS 3943 for plastic waste traps
BS 4293 for residual current-operated circuit-breakers
BS 4343 for industrial electrical power connectors
BS 4573 a specification for 2-pin reversible plugs and shaver socket-outlets
BS 4800 for paint colours used in building construction
BS 4900 for vitreous enamel colours used in building construction
BS 4901 for plastic colours used in building construction
BS 4902 for sheet / tile floor covering colours used in building construction
BS 4960 for weighing instruments for domestic cookery
BS 4962 for plastics pipes and fittings for use as subsoil field drains
BS 5252 for colour-coordination in building construction
BS 5400 for steel, concrete and composite bridges.
BS 5499 for graphical symbols and signs in building construction; including shape, colour and layout
BS 5544 for anti-bandit glazing (glazing resistant to manual attack)
BS 5750 for quality management, the source for ISO 9000
BS 5759 Specification for webbing load restraint assemblies for use in surface transport
BS 5837 for protection of trees during construction work
BS 5930 for site investigations
BS 5950 for structural steel
BS 6312 for telephone plugs and sockets
BS 6651 code of practice for protection of structures against lightning
BS 6701 installation, operation and maintenance of telecommunications equipment and
telecommunications cabling
BS 6879 for British geocodes, a superset of ISO 3166-2:GB
BS 7430 code of practice for earthing
BS 7671 Requirements for Electrical Installations, The IEE Wiring Regulations, produced by
the IET.
BS 7799 for information security, the source for ISO/IEC 27001, 27002 (former 17799), and 27005
BS 7901 for recovery vehicles and vehicle recovery equipment
BS 7925-1 vocabulary of terms in software testing
BS 7925-2 software component testing
BS 8110 for structural concrete
BS 8485 for the characterization and remediation from ground gas in affected developments
BS 8494 for detecting and measuring carbon dioxide in ambient air or extraction systems
BS 15000 for IT Service Management, (ITIL), now ISO/IEC 20000
BS 3G 101 for general requirements for mechanical and electromechanical aircraft indicators
BSEN12195-2-2001 Load restraint assemblies on road vehicles. Safety. Web lashing made from
man-made fibres
BS EN 60204-1:2009 Safety of machinery - Electrical equipment of machines
Publicly Available Specifications
BSI also publishes a series of Publicly Available Specification (PAS) documents.
Publicly Available Specifications (PAS) are a flexible and rapid standards development model that is
open to all organizations. A PAS is a sponsored piece of work allowing organizations flexibility in the
rapid creation of a standard while also allowing for a greater degree of control over the document's
development. A typical development time frame for a PAS is around 6–9 months. Once published by BSI
a PAS has all the functionality of a British Standard for the purposes of creating schemes such as
management systems and product benchmarks as well as codes of practice. A PAS is a living document
and after two years the document will be reviewed and a decision made with the client as to whether or
not this should be taken forward to become a formal British standard.
Examples
PAS 78: Guide to good practice in commissioning accessible websites
PAS 55- 1: Asset management - Specification for the optimized management of physical
infrastructure assests
PAS 72: Responsible Fishing - Specification of good practice for fishing vessels
PAS 911: Fire strategies - guidance and framework for their formulation
PAS 82: Shopfitting - Management system specification
PAS 77: IT Service continuity Management - Code of Practice
BSI PAS 100 Composting specification
BSI PAS 101 Specification for recovered container glass
BSI PAS 102 Specification for processed glass for selected secondary end markets
BSI PAS 103 Specification for quality and guidance for good practice in collection and
preparation for recycling
BSI PAS 104 Specification for quality and guidance for good practice for the supply of post
consumer wood for consumption in the manufacture of panel board products
BSI PAS 105 Specification for paper waste
Availability
Copies of British Standards are sold at the BSI Online Shop[8] or can be accessed via subscription to
British Standards Online (BSOL)[9]. They can also be ordered via the publishing units of many other
national standards bodies (ANSI, DIN, etc.) and from several specialized suppliers of technical
specifications.
Many British Standards (BSs) – as well as some of the European and International Standards that were
adopted as British Standards (BS EN, BS ISO) – are also available in public and university libraries in the
United Kingdom. However, BSI makes standards available to these libraries only under licence
restrictions which forbid loan, inter-library loan, open-shelf access, and copying of more than 10% of a
document by library users[10]. The BSI Knowledge Centre in Chiswick charges visiting members of the
public a fee of £20 per hour. This service is free to BSI members, students and accredited journalists[11].
Sanitation is the hygienic means of promoting health through prevention of human contact with
the hazards of wastes. Hazards can be either physical, microbiological, biological or chemical agents of
disease. Wastes that can cause health problems are human and animal feces, solid wastes, domestic
wastewater (sewage, sullage, greywater), industrial wastes, and agricultural wastes. Hygienic means of
prevention can be by using engineering solutions (e.g. sewerage andwastewater treatment), simple
technologies (e.g. latrines, septic tanks), or even by personal hygiene practices (e.g.
simple handwashing with soap). Sanitation as defined by the WHO (World Health Organisation);
Sanitation generally refers to the provision of facilities and services for the safe disposal of human urine
and faeces. Inadequate sanitation is a major cause of disease world-wide and improving sanitation is
known to have a significant beneficial impact on health both in households and across communities. The
word 'sanitation' also refers to the maintenance of hygienic conditions, through services such as garbage
collection and wastewater disposal. [1]
The term "sanitation" can be applied to a specific aspect, concept, location, or strategy, such as:
Basic sanitation - refers to the management of human feces at the household level. This
terminology is the indicator used to describe the target of the Millennium Development Goal on
sanitation.
On-site sanitation - the collection and treatment of waste is done where it is deposited. Examples
are the use of pit latrines, septic tanks, and imhoff tanks.
Food sanitation - refers to the hygienic measures for ensuring food safety.
Environmental sanitation - the control of environmental factors that form links in disease
transmission. Subsets of this category are solid waste management, water and wastewater treatment,
industrial waste treatment and noise and pollution control.
Ecological sanitation - a concept and an approach of recycling to nature the nutrients from
human and animal wastes
Hygiene
Washing one's hands, a form ofhygiene, is the most effective overall way to prevent the spread
of infectious disease.
Astronaut taking a hot bath in the crew quarters of the Orbital Workshop (OWS) of the Skylab space
station cluster in Earth orbit. In deploying the shower facility the shower curtain is pulled up from the
floor and attached to the ceiling. The water comes through a push-button shower head attached to a
flexible hose. Water is drawn off by a vacuum system.
Hygiene refers to the set of practices associated with the preservation of health and healthy living.
Etymology
First attested in English in 1670s, the word hygiene comes from the French hygiène, theromanization of
the Greek "ὑγιεινή (τέχνη)" - hugieinē technē, meaning "(art) of health", from ὑγιεινός (hugieinos), "good
for the health, healthy",[1] in turn from ὑγιής (hugiēs), "healthful, sound, salutary,
wholesome".[2] In ancient Greek religion, Hygeia (Ὑγίεια) was the personification of health.[3]
Concept of hygiene
well as to personal and professional care practices related to most aspects of living. In medicine and in
home (domestic) and everyday life settings, hygiene practices are employed as preventative measures to
reduce the incidence and spreading of disease. In the manufacture of food, pharmaceutical, cosmetic and
other products, good hygiene is a key part ofquality assurance i.e. ensuring that the product complies with
microbial specifications appropriate to its use. The terms cleanliness (or cleaning) and hygiene are often
used interchangeably, which can cause confusion. In general, hygiene mostly means practices that prevent
spread of disease-causing organisms. Since cleaning processes (e.g., hand washing) remove infectious
microbes as well as dirt and soil, they are often the means to achieve hygiene. Other uses of the term
appear in phrases including: body hygiene, personal hygiene, sleep hygiene, mental hygiene, dental
hygiene, and occupational hygiene, used in connection with public health. Hygiene is also the name of a
branch of science that deals with the promotion and preservation of health, also called hygienics. Hygiene
practices vary widely, and what is considered acceptable in one culture might not be acceptable in
another.
Medical hygiene
Medical hygiene pertains to the hygiene practices related to the administration of medicine, and medical
care, that prevents or minimizes disease and the spreading of disease.
Medical hygiene practices include:
Isolation or quarantine of infectious persons or materials to prevent spread of infection.
Sterilization of instruments used in surgical procedures.
Use of protective clothing and barriers, such as masks, gowns, caps, eyewear and gloves.
Proper bandaging and dressing of injuries.
Safe disposal of medical waste.
Disinfection of reusables (i.e. linen, pads, uniforms)
Scrubbing up, hand-washing, especially in an operating room, but in more general health-care
settings as well, where diseases can be transmitted[4]
Most of these practices were developed in the 19th century and were well established by the mid-20th
century. Some procedures (such as disposal of medical waste) were tightened up as a result of late-20th
century disease outbreaks, notably AIDS and Ebola.
[edit]Home and everyday life hygiene
Home hygiene pertains to the hygiene practices that prevent or minimize disease and the spreading of
disease in home (domestic) and in everyday life settings such as social settings, public transport, the work
place, public places etc.
Hygiene in home and everyday life settings plays an important part in preventing spread of infectious
diseases.[5] It includes procedures used in a variety of domestic situations such as hand hygiene,
respiratory hygiene, food and water hygiene, general home hygiene (hygiene of environmental sites and
surfaces), care of domestic animals, and home healthcare (the care of those who are at greater risk of
infection).
At present, these components of hygiene tend to be regarded as separate issues, although all are based on
the same underlying microbiological principles. Preventing the spread of infectious diseases means
breaking the chain of infection transmission. The simple principle is that, if the chain of infection is
broken, infection cannot spread. In response to the need for effective codes of hygiene in home and
everyday life settings the International Scientific Forum on Home Hygiene has developed a risk-based
approach (based on Hazard Analysis Critical Control Point (HACCP), which has come to be known as
“targeted hygiene”. Targeted hygiene is based on identifying the routes of spread of pathogens in the
home, and applying hygiene procedures at critical points at appropriate times to break the chain of
infection.
The main sources of infection in the home[6] are people (who are carriers or are infected), foods
(particularly raw foods) and water, and domestic animals (in western countries more than 50% of homes
have one or more pets). Additionally, sites that accumulate stagnant water—such as sinks, toilets, waste
pipes, cleaning tools, face cloths—readily support microbial growth, and can become secondary
reservoirs of infection, though species are mostly those that threaten “at risk” groups. Germs (potentially
infectious bacteria, viruses etc.) are constantly shed from these sources via mucous, faeces, vomit, skin
scales, etc. Thus, when circumstances combine, people become exposed, either directly or via food or
water, and can develop an infection. The main “highways” for spread of germs[6] in the home are the
hands, hand and food contact surfaces, and cleaning cloths and utensils. Germs can also spread via
clothing and household linens such as towels. Utilities such as toilets and wash basins, for example, were
invented for dealing safely with human waste, but still have risks associated with them, which may
become critical at certain times, e.g., when someone has sickness or diarrhea. Safe disposal of human
waste is a fundamental need; poor sanitation is a primary cause of diarrhoeal disease in low income
communities. Respiratory viruses and fungal spores are also spread via the air.
Good home hygiene means targeting hygiene procedures at critical points, at appropriate times, to break
the chain of infection i.e. to eliminate germs before they can spread further.[6] Because the “infectious
dose” for some pathogens can be very small (10-100 viable units, or even less for some viruses), and
infection can result from direct transfer from surfaces via hands or food to the mouth, nasal mucosa or the
eye, 'hygienic cleaning' procedures should be sufficient to eliminate pathogens from critical surfaces.
Hygienic cleaning can be done by:
Mechanical removal (i.e. cleaning) using a soap or detergent. To be effective as a hygiene
measure, this process must be followed by thorough rinsing under running water to remove germs
from the surface.
Using a process or product that inactivates the pathogens in situ. Germ kill is achieved using a
“micro-biocidal” product i.e. a disinfectantor antibacterial product or waterless hand sanitizer, or by
application of heat.
In some cases combined germ removal with kill is used, e.g. laundering of clothing and
household linens such as towels and bedlinen.
Hand hygiene
Defined as hand washing or washing hands with soap and water or using a waterless hand sanitizer.
Hand hygiene is central to preventing spread of infectious diseases in home and everyday life settings. [7]
In situations where hand washing with soap is not an option (e.g. when in a public place with no access to
wash facilities), a waterless hand sanitizer such as an alcohol hand gel can be used. They can also be used
in addition to hand washing, to minimise risks when caring for “at risk” groups. To be effective, alcohol
hand gels should contain not less than 60%v/v alcohol. Hand sanitizers are non-options in most
developing country settings; in situations where availability of water is a problem, there are appropriate
solutions such as tippy-taps, which use much less water and are very low-cost to make, with local
materials. In low income communities mud or ash is sometimes used as an alternative to soap.
Respiratory hygiene
Correct respiratory and hand hygiene when coughing and sneezing reduces the spread of germs
particularly during the cold and flu season.
Carry tissues and use them to catch coughs and sneezes
Dispose of tissues as soon as possible
Clean your hands by hand washing or using an alcohol hand sanitizer.
Food hygiene at home
Food hygiene pertains to the hygiene practices that prevent food poisoning . The five key principles of
food hygiene, according to WHO, are:
Prevent contaminating food with pathogens spreading from people, pets, and pests.
1. Separate raw and cooked foods to prevent contaminating the cooked foods.
2. Cook foods for the appropriate length of time and at the appropriate temperature to kill
pathogens.
3. Store food at the proper temperature.
4. Use safe water and raw materials
Household water treatment and safe storage
Household water treatment and safe storage are practices which can be used by the family at home and in
the community to ensure that drinking water is safe for consumption.
Drinking water quality remains a significant problem, not only in developing countries[9] but also in
developed countries[10]; even in the European region it is estimated that 120 million people do not have
access to safe drinking water. Point-of-use water quality interventions can reduce diarrhoeal disease in
communities where water quality is poor, or in emergency situations where there is a breakdown in water
supply. Since water can become contaminated during storage at home (e.g. by contact with contaminated
hands or using dirty storage vessels), safe storage of water in the home is also important.
Methods for treatment of drinking water [13],[12] include:
1. Chemical disinfection using chlorine or iodine
2. Boiling
3. Filtration using ceramic filters[14][15]
4. Solar disinfection - Solar disinfection is an effective method, especially when no chemical
disinfectants are available.[16][17]
5. UV irradiation - community or household UV systems may be batch or flow-though. The lamps
can be suspended above the water channel or submerged in the water flow.
6. Combined flocculation/disinfection systems – available as sachets of powder which act by
coagulating and flocculating sediments in water followed by release of chlorine.
7. Multibarrier methods – Some systems use two or more of the above treatments in combination or
Hygiene in the kitchen, bathroom and toilet
Routine cleaning of “contact” (hand, food and drinking water) sites and surfaces (such as toilet seats and
flush handles, door and tap handles, work surfaces, bath and basin surfaces) in the kitchen, bathroom and
toilet reduces the risk of spread of germs.[13] The infection risk from the toilet itself is not high, provided it
is properly maintained, although some splashing and aerosol formation can occur during flushing,
particularly where someone in the family has diarrhoea. Germs can survive in the scum or scale left
behind on baths and wash basins after washing and bathing.
Water left stagnant in the pipes of showers can be contaminated with germs that become airborne when
the shower is turned on. If a shower has not been used for some time, it should be left to run at a hot
temperature for a few minutes before use.
Thorough cleaning is important in preventing the spread of fungal infections.[19] Moulds can live on wall
and floor tiles and on shower curtains. Mould can be responsible for infections, cause allergic responses,
deteriorate/damage surfaces and cause unpleasant odours. Primary sites of fungal growth are inanimate
surfaces, including carpets and soft furnishings.[20] Air-borne fungi are usually associated with damp
conditions, poor ventilation or closed air systems.
Cleaning of toilets and hand wash facilities is important to prevent odours and make them socially
acceptable. Social acceptability is an important part of encouraging people to use toilets and wash their
hands, particularly in low income communities.
Laundry hygiene
Laundry hygiene pertains to the practices that prevent or minimize disease and the spreading of disease
via soiled clothing and household linens such as towels.[13] Items that are most likely to be contaminated
with pathogens are those which come into direct contact with the body e.g. underwear, personal towels,
facecloths, nappies. Micro-organisms can also be transferred between contaminated and uncontaminated
items of clothing and linen during laundering. Of concern are the new “community” strains
of MRSA.[21] Experience in the USA suggests that these strains are transmissible within families, but also
in community settings such as prisons, schools and sport teams. Skin-to-skin contact (including
unabraided skin) and indirect contact with contaminated objects such as towels, sheets and sports
equipment seem to represent the mode of transmission.[21]
Two processes are considered suitable for hygienic cleaning of clothing and linen:[13]
Washing or laundering at 60°C or above
Washing or laundering at 30-40°C using a bleach-based product: This produces decontamination
of fabrics by a combination of physical removal and chemical inactivation. However, some types of
fungi and viruses that are harder to inactivate, may not be removed.
Washing at temperatures of 40°C or below with a non-bleach product is considered to carry a risk of
inadequate decontamination.
Medical hygiene at home
Medical hygiene pertains to the hygiene practices that prevents or minimizes disease and the spreading of
disease in relation to administering medical care to those who are infected or who are more “at risk” of
infection in the home. Across the world, governments are increasingly under pressure to fund the level of
healthcare that people expect. Care of increasing numbers of patients in the community, including at
home is one answer, but can be fatally undermined by inadequate infection control in the home.
Increasingly, all of these “at-risk” groups are cared for at home by a carer who may be a household
member who thus requires a good knowledge of hygiene. People with reduced immunity to infection,
who are looked after at home, make up an increasing proportion of the population (currently up to
20%).[5] The largest proportion are the elderly who have co-morbidities, which reduce their immunity to
infection. It also includes the very young, patients discharged from hospital, taking immuno-suppressive
drugs or using invasive systems, etc. For patients discharged from hospital, or being treated at home
special “medical hygiene” (see above) procedures may need to be performed for them e.g. catheter or
dressing replacement, which puts them at higher risk of infection.
Antiseptics may be applied to cuts, wounds abrasions of the skin to prevent the entry of harmful bacteria
which can cause sepsis.
Day-to-day hygiene practices, other than special medical hygiene procedures[22] are no different for those
at increased risk of infection than for other family members. The difference is that, if hygiene practices
are not correctly carried out, the risk of infection is much greater.
Home Hygiene in low income communities
In the developing world, for decades, universal access to water and sanitation has been seen as the
essential step in reducing the preventable ID burden, but it is now clear that this is best achieved by
programmes that integrate hygiene promotion with improvements in water quality and availability,
and sanitation. About 2 million people die every year due to diarrhoeal diseases, most of them are
children less than 5 years of age.[23] The most affected are the populations in developing countries, living
in extreme conditions of poverty, normally peri-urban dwellers or rural inhabitants. Providing access to
sufficient quantities of safe water, the provision of facilities for a sanitary disposal of excreta, and
introducing sound hygiene behaviours are of capital importance to reduce the burden of disease caused by
these risk factors.
Research shows that, if widely practiced, hand washing with soap could reduce diarrhoea by almost fifty
percent[24][25][26] and respiratory infections by nearly twenty-five percent[27][28] Hand washing with soap
also reduces the incidence of skin diseases[29][30], eye infections like trachoma and intestinal worms,
especially ascariasis and trichuriasis.[31]
Other hygiene practices such as safe disposal of waste, surface hygiene, care of domestic animals are also
important in low income communities in order to break the chain of infection transmission.[32]
Disinfectants and antibacterials in home hygiene
Chemical disinfectants are products that kill germs (harmful bacteria, viruses and fungi). If the product is
a disinfectant, the label on the product should say “disinfectant” and/or “kills” germs or bacteria etc.
Some commercial products, e.g. bleaches, even though they are technically disinfectants, say that they
“kill germs”, but are not actually labelled as “disinfectants”. Not all disinfectants kill all types of germs.
All disinfectants kill bacteria (called bactericidal). Some will also kill fungi (fungicidal), bacterial spores
(sporicidal) and/or viruses (virucidal).
An antibacterial product is a product that acts against bacteria in some unspecified way. Some products
labelled “antibacterial” will kill bacteria whilst others may contain a concentration of active ingredient
which will only prevent them multiplying. It is therefore important to check whether the product label
states that it “kills” bacteria” An antibacterial is not necessarily anti-fungal or anti-viral unless this is
stated on the label.
The term sanitizer has been used to define substances which both clean and disinfect. More recently this
term has been applied to alcohol-based products which are used to disinfect the hands (alcohol hand
sanitizers). Alcohol hand sanitizers however are not considered to be effective on soiled hands.
The term biocide is a broad term for a substance that kills, inactivates or otherwise controls living
organisms. It includes antiseptics and disinfectants, which combat micro-organisms, and also
includes pesticides.
[edit]Body hygiene
See also: Body hygiene kit
Body hygiene pertains to hygiene practices performed by an individual to care for one's bodily health and
well being, through cleanliness. Motivations for personal hygiene practice include reduction of personal
illness, healing from personal illness, optimal health and sense of well being, social acceptance and
prevention of spread of illness to others.
Personal hygiene practices include: seeing a doctor, seeing a dentist, regular washing/bathing, and healthy
eating. Personal groomingextends personal hygiene as it pertains to the maintenance of a good personal
and public appearance, which need not necessarily be hygienic.
Body hygiene is achieved by using personal body hygiene products including: soap, hair
shampoo, toothbrushes, tooth paste, cotton swabs, antiperspirant, facial tissue, mouthwash, nail files, skin
cleansers, toilet paper, and other such products.
Excessive body hygiene
The benefits of body hygiene can be diminished by the risks of excessive body hygiene, which is
hypothesized to cause allergic disease and bodily irritation.
Excessive body hygiene and allergies
The hygiene hypothesis was first formulated in 1989 by Strachan who observed that there was an inverse
relationship between family size and development of atopic allergic disorders – the more children in a
family, the less likely they were to develop these allergies.[33] From this, he hypothesised that lack of
exposure to “infections” in early childhood transmitted by contact with older siblings could be a cause of
the rapid rise in atopic disorders over the last thirty to forty years. Strachan further proposed that the
reason why this exposure no longer occurs is, not only because of the trend towards smaller families, but
also “improved household amenities and higher standards of personal cleanliness”.
Although there is substantial evidence that some microbial exposures in early childhood can in some way
protect against allergies, there is no evidence that we need exposure to harmful microbes (infection) or
that we need to suffer a clinical infection.[34][35][36] Nor is there evidence that hygiene measures such as
hand washing, food hygiene etc. are linked to increased susceptibility to atopic disease [31][32] If this is the
case, there is no conflict between the goals of preventing infection and minimising allergies. A consensus
is now developing among experts that the answer lies in more fundamental changes in lifestyle etc. that
have led to decreased exposure to certain microbial or other species, such as helminths, that are important
for development of immuno-regulatory mechanisms.[37] There is still much uncertainty as to which
lifestyle factors are involved.
Although media coverage of the hygiene hypothesis has declined, a strong ‘collective mindset’ has
become established that dirt is ‘healthy’ and hygiene somehow ‘unnatural’. This has caused concern
among health professionals that everyday life hygiene behaviours, which are the foundation of public
health, are being undermined. In response to the need for effective hygiene in home and everyday life
settings, the International Scientific Forum on Home Hygiene has developed a “risk-based” or targeted
approach to home hygiene which seeks to ensure that hygiene measures are focussed on the places, and at
the times which are most critical for infection transmission.[6] Whilst targeted hygiene was originally
developed as an effective approach to hygiene practice, it also seeks, as far as possible, to sustain
“normal” levels of exposure to the microbial flora of our environment to the extent that is important to
build a balanced immune system.
Excessive body hygiene of external ear canals
Excessive body hygiene of the ear canals can result in infection or irritation. The ear canals require less
body hygiene care than other parts of the body, because they are sensitive, and the body system
adequately cares for these parts. Most of the time the ear canals are self-cleaning; that is, there is a slow
and orderly migration of the skin lining the ear canal from the eardrum to the outer opening of the ear.
Old earwax is constantly being transported from the deeper areas of the ear canal out to the opening
where it usually dries, flakes, and falls out.[38] Attempts to clean the ear canals through the removal
of earwax can actually reduce ear canal cleanliness by pushing debris and foreign material into the ear
that the natural movement of ear wax out of the ear would have removed.
Excessive body hygiene of skin
Excessive body hygiene of the skin can result in skin irritation. The skin has a natural layer of oil, which
promotes elasticity, and protects the skin from drying. When washing, unless using aqueous creams with
compensatory mechanisms, this layer is removed leaving the skin unprotected.
Excessive application of soaps, creams, and ointments can also adversely affect certain of the natural
processes of the skin. For examples, soaps and ointments can deplete the skin of natural protective oils
and fat-soluble content such as cholecalciferol (vitamin D3), and external substances can be absorbed, to
disturb natural hormonal balances.
Culinary (food) hygiene
Culinary hygiene pertains to the practices related to food management and cooking to prevent food
contamination, prevent food poisoning and minimize the transmission of disease to other foods, humans
or animals. Culinary hygiene practices specify safe ways to handle, store, prepare, serve and eat food.
Culinary practices include:
Cleaning and disinfection of food-preparation areas and equipment (for example using designated
cutting boards for preparing raw meats and vegetables). Cleaning may involve use of chlorine
bleach, ethanol, ultraviolet light, etc. for disinfection.
Careful avoidance of meats contaminated by trichina worms, salmonella, and other pathogens; or
thorough cooking of questionable meats.
Extreme care in preparing raw foods, such as sushi and sashimi.
Institutional dish sanitizing by washing with soap and clean water.
Washing of hands thoroughly before touching any food.
Washing of hands after touching uncooked food when preparing meals.
Not using the same utensils to prepare different foods.
Not sharing cutlery when eating.
Not licking fingers or hands while or after eating.
Not reusing serving utensils that have been licked.
Proper storage of food so as to prevent contamination by vermin.
Refrigeration of foods (and avoidance of specific foods in environments where refrigeration is or
was not feasible).
Labeling food to indicate when it was produced (or, as food manufacturers prefer, to indicate
its "best before" date).
Proper disposal of uneaten food and packaging.
Personal service hygiene
Personal service hygiene pertains to the practices related to the care and use of instruments used in the
administration of personal care services to people:
Personal hygiene practices include:
Sterilization of instruments used by service providers including hairdressers, aestheticians, and other
service providers.
Sterilization by [autoclave] of instruments used in body piercing and tattoo marking.
Cleaning hands.
History of hygienic practices
Elaborate codes of hygiene can be found in several Hindu texts, such as the Manusmriti and the Vishnu
Purana.[39] Bathing is one of the fiveNitya karmas (daily duties) in Hinduism, and not performing it leads
to sin, according to some scriptures. These codes were based on the notion of ritual purity and were not
informed by an understanding of the causes of diseases and their means of transmission. However, some
of the ritual-purity codes did improve hygiene, from an epidemiological point of view, perhaps by
accident, or because certain practices acquired ritual status on account of an empirical correlation with
good health.
Regular bathing was a hallmark of Roman civilization.[40] Elaborate baths were constructed in urban areas
to serve the public, who typically demanded the infrastructure to maintain personal cleanliness. The
complexes usually consisted of large, swimming pool-like baths, smaller cold and hot pools, saunas, and
spa-like facilities where individuals could be depilated, oiled, and massaged. Water was constantly
changed by an aqueduct-fed flow. Bathing outside of urban centers involved smaller, less elaborate
bathing facilities, or simply the use of clean bodies of water. Roman cities also had large sewers, such as
Rome's Cloaca Maxima, into which public and private latrines drained. Romans didn't have demand-flush
toilets but did have some toilets with a continuous flow of water under them. (Similar toilets are seen
in Acre Prison in the film Exodus.)
Until the late 19th Century, only the elite in Western cities typically possessed indoor facilities for
relieving bodily functions. The poorer majority used communal facilities built above cesspools in
backyards and courtyards. This changed after Dr. John Snow discovered thatcholera was transmitted by
the fecal contamination of water. Though it took decades for his findings to gain wide acceptance,
governments and sanitary reformers were eventually convinced of the health benefits of using sewers to
keep human waste from contaminating water. This encouraged the widespread adoption of both the
flush toilet and the moral imperative that bathrooms should be indoors and as private as possible.[41]
Islamic hygienical jurisprudence
Since the 7th century, Islam has always placed a strong emphasis on hygiene. Other than the need to be
ritually clean in time for the daily prayer (Arabic: Salat) through Wudu and Ghusl, there are a large
number of other hygiene-related rules governing the lives of Muslims. Other issues include the Islamic
dietary laws. In general, the Qur'an advises Muslims to uphold high standards of physical hygiene and to
be ritually clean whenever possible.
Hygiene in Ancient Europe
Contrary to popular belief[42] and although the Early Christian leaders condemned bathing as
unspiritual,[43] bathing and sanitation were not lost in Europe with the collapse of the Roman
Empire.[44][45] Soapmaking first became an established trade during the so-called "Dark Ages".
The Romans used scented oils (mostly from Egypt), among other alternatives.
Bathing did not fall out of fashion in Europe until shortly after the Renaissance, replaced by the heavy use
of sweat-bathing and perfume, as it was thought in Europe that water could carry disease into the body
through the skin. (Water, in fact, does carry disease, but more often if it is drunk than if one bathes in it;
and water only carries disease if it is contaminated by pathogens.) Medieval church authorities believed
thatpublic bathing created an environment open to immorality and disease. Roman Catholic
Church officials even banned public bathing in an unsuccessful effort to halt syphilis epidemics from
sweeping Europe.[46] Modern sanitation was not widely adopted until the 19th and 20th centuries.
According to medieval historian Lynn Thorndike, people in Medieval Europe probably bathed more than
people did in the 19th century.
7.Explain the GHP for Commodities in detail.
GHP for commodities
DFID commissioned a substantial, evidence-based assessment of the impact of the
Global Health Partnerships (GHPs) with which DFID engages at both global and
country level, drawing out best practice principles to guide DFID’s future
engagement. This synthesis report summarises key findings from a series of
component studies which in practice covered a wider range of GHPs.
GHPs are a moving target in a changing environment, and the evidence to assess
them is sometimes limited. Nonetheless, some broad conclusions can be drawn.
First, despite some concerns, individual GHPs are seen overall as having a
positive impact in terms both of achieving their own objectives and of being
welcomed by countries studied. This is true even of GHPs where evaluation has
found organisational or relationship shortcomings. The general theme of findings
from most evaluations is one of GHP success, but with clear scope for yet further
achievement if challenges are resolved.
Key areas of success have been raising the profile of the disease, mobilising
commitment and funding, accelerating progress (though it is unclear whether some
GHP targets will be delivered on time), and in some cases leading innovation. Most
current and planned interventions funded by GHPs are potentially highly costeffective.
Neglected diseases are mostly being addressed by at least one GHP.
GHP-led R&D for new tools to address neglected diseases is intensifying and
focused on those diseases in greatest need. The R&D GHPs generally appear to be
seen as a particularly fruitful way to foster research and development for new
diagnostics, drugs and vaccines. Some GHPs - such as GAVI, the TB Global Drug
Facility and the Green Light Committee for multidrug-resistant TB - have successfully
secured commodity price reductions, and fostered both competition and research,
though ARV price reductions may stem more from increased competition from
generic manufacturers and global pressure than the Accelerating Access Initiative.
GHPs are bringing additional funding for communicable diseases and other global
public goods. They have been successful in leveraging significant additional funds
from Foundations, though not from other new sources. 97% of pledges for GFATM are
from traditional donor countries. They appear to be relatively well targeted towards
diseases which present the largest burden of ill health, towards countries in greatest
need in terms of socio economic status and in relation to recent trends in
development assistance for health and population. However, GHPs alone will be
insufficient to provide countries with the financial means required to deliver a
reasonable package of basic health services.
The limited literature on GHPs in difficult policy environments suggests that it is
possible for GHPs to operate there and perhaps to deliver wider benefits beyond
their specific programme. Country work in this study concluded that the situation
presented by fragile states necessitates even more concerted effort on the part of
multilaterals and bilaterals to provide direct support to the health system. It may
make sense for financing and access/donation GHPs to adopt a slower, more hands
on approach with fragile states, identifying strong national partners (either state or
non-state) through whom they can work.
Second, there are at the same time some critical concerns and challenges. The
more taxing concerns relate to GHP operations at country level.
Some GHPs operate above country level and are aimed at development and
provision of important new public goods and technologies. Many are more aimed at
acceleration of country progress towards the MDGs and other targets. These latter
Assessing the Impact of Global Health Partnerships 5
DFID Health Resource Centre
GHPs are generally seen to fit well with national priorities and programmes, though
there may be issues about the priority given to polio NIDs and HIV/AIDs. Evidence
suggests that low resource countries are likely to need partnership or donor
contribution of three elements to support a successful disease control programme:
some contribution to providing the necessary drugs (through funding, donation or
discounted price); funding for some operational costs, and technical assistance.
Without all three, impact can be limited.
8.Explain the Basic principles of HACCPin detail.
Basic principles of HACCP
There are seven discrete activities that are necessary to establish, implement and maintain a HACCP plan,
and these are referred to as the 'seven principles' in the Codex Guideline (1997).
The seven principles are[1]:
Principle 1
Conduct a hazard analysis.
Identify hazards and assess the risks associated with them at each step in the commodity system. Describe
possible control measures.
Principle 2
Determine the Critical Control Points (CCPs)
A critical control point is a step at which control can be applied and is essential to prevent or eliminate a
food safety hazard, or reduce it to an acceptable level. The determination of a CCP can be facilitated by
the application of a decision tree, such as the one given in Appendix IV.
Principle 3
Establish critical limits.
Each control measure associated with a CCP must have an associated critical limit which separates the
acceptable from the unacceptable control parameter.
Principle 4
Establish a monitoring system
Monitoring is the scheduled measurement or observation at a CCP to assess whether the step is under
control, i.e. within the critical limit(s) specified in Principle 3.
Principle 5
Establish a procedure for corrective action, when monitoring at a CCP indicates a deviation from
an established critical limit.
Principle 6
Establish procedures for verification to confirm the effectiveness of the HACCP plan.
Such procedures include auditing of the HACCP plan to review deviations and product dispositions, and
random sampling and checking to validate the whole plan.
Principle 7
Establish documentation concerning all procedures and records appropriate to these principles and
their application
Application of HACCP to mycotoxin control
Once tasks 1 to 5 have been completed the following will be in place: a HACCP team, a Description and
Intended Use table, and a verified Commodity Flow Diagram. This will provide information on a specific
commodity from a unique source, and this information is required to complete the hazard analysis. See
the case studies in Chapter 3 for examples of implementation, including that of stages 1 to 5.
Task 6 - Mycotoxin hazard analysis and identification of possible control measures
Hazard Analysis
a) Identification of mycotoxin hazard
For a given commodity system in a particular location, the HACCP team need to first consider which, if
any, of the mycotoxins known to constitute a food safety hazard are likely to be present.
Over 300 mycotoxins are known, but only a relatively few of these are widely accepted as presenting
a significant food or animal feed safety risk. These hazardous mycotoxins are listed in Tables 1 and 2
in Chapter 1. Of these only the following mycotoxins have regulatory limits set by one or more
countries: the aflatoxins (including aflatoxin M1), ochratoxin A, zearalenone, patulin, ergot alkaloids,
and deoxynivalenol. Guideline limits exist for fumonisin B1 and regulatory limits are likely to be set
in the near future. The regulatory limits are taken as the target levels and should be included in the
Product Description table. Mycotoxin limits can also be set by the customer in specific contracts and
it is possible that these may include mycotoxins not subject to regulatory limits.
The risk of a particular mycotoxin hazard should be estimated using well established data on the
relative susceptibilities of commodities to given mycotoxins and the climatic conditions required for
the mycotoxins to be produced. The EU has identified the following animal feed ingredients, and
their products, as being highly susceptible to aflatoxin contamination: maize, groundnut cake,
cottonseed cake, babassu, palm kernel cake and copra cake. The EU has also identified the following
foodstuffs as highly susceptible to aflatoxin contamination: dried figs and other dried fruit,
groundnuts, pistachios and other edible nuts and cereals. These commodities are specified in the
respective EC regulations (1525/98 amending regulation 194/97). Maize grown in temperate climates
would be less likely to be contaminated with aflatoxin, but could be contaminated with trichothecene
mycotoxins or fumonisin B1. Although published mycotoxin survey data exists for many
commodities, it is important that surveillance studies are performed if mycotoxin data is lacking for a
particular commodity, or for production in a particular climatic zone.
b) Identification of steps in the Commodity Flow Diagram (CFD) where mycotoxin
contamination is most likely to occur
Once the mycotoxin hazard(s) has been identified, each step in the CFD must be considered in turn
and the likelihood of mycotoxin contamination occurring must be assessed. Usually published
scientific data will be available to act as a guide, but it may be necessary to commission a study to
determine, or confirm that the correct steps have been identified. The situation may change from year
to year, and season to season, so there will need to be an element of mycotoxin surveillance in the
HACCP plan.
An important fact to establish is whether pre-harvest contamination with mycotoxins is likely or
whether contamination occurs primarily post-harvest. Mycotoxins produced by Fusarium spp, such
as fumonisin B1 are invariably produced pre-harvest, but climatic conditions effect the degree of
blight and the resultant level of mycotoxin contamination. Aflatoxins can be produced both preharvest and post-harvest and climatic conditions can have a significant bearing: drought stress
favours pre-harvest contamination, whereas post-harvest handling during the rainy season favours
post-harvest aflatoxin contamination.
It is rarely possible to be certain that pre-harvest mycotoxin levels are below regulatory or target
levels in the commodity system, so post-harvest mycotoxin control measures can often only prevent
or reduce ADDITIONAL contamination, rather than prevent the hazard completely. Consequently it
is often necessary to introduce a segregation step to remove any batches containing an unacceptable
level of mycotoxin.
c) Possible Mycotoxin Control Measures
The most effective mycotoxin control measures is to dry the commodity such that the water activity
(aw) is too low to support mould growth and/or prevent mycotoxin production. To prevent the growth
of most moulds the aw needs to be £ 0.70, which translates to a moisture content of approximately
14% for maize and 7.0% for groundnuts at 20°C (the corresponding moisture content decreases as
the temperature increases). Each toxigenic mould has its own minimum water activity for growth and
mycotoxin production and these translate into moisture contents for each commodity. These moisture
contents are termed 'safe' and would be the critical limit for the control measure.
It is important to specify a target 'safe' moisture content with a maximum as well as an average value,
e.g. 14% no part exceeding 15%. If only an average value is specified it may conceal a large range of
moisture contents within the batch and the commodity would not be safe from mould growth and
mycotoxin contamination. A drying process is required which dries evenly and the critical limits
must be set bearing this in mind. Validation of such a CCP must involve moisture determination of
multiple samples.
If the commodity is at an 'unsafe' moisture content for longer than 48 hours, then mould can grow
and mycotoxins be produced. Hence limiting the time that the commodity spends in the 'unsafe'
moisture content window to less than 48 hours is a control measure. This explains why timely sundrying can sometimes be safer than delayed mechanical drying. Two days on a drying floor with
occasional turning can often achieve the target 'safe' moisture content, whereas a back-log at the
mechanical drier can result in the critical limit of 48 hours not being met.
Once produced, it is not usually possible to remove mycotoxins, other than by physical separation
(grading) techniques. To apply this type of control measure, representative samples of batches of
commodity are collected and tested for selected mycotoxins. Only those batches containing less than
the critical limit of mycotoxin, as specified in official regulations, are accepted. For some
commodities, such as blanched groundnuts, colour sorters may be effective in rejecting individual
high-aflatoxin nuts and accumulating low-aflatoxin nuts, and may be classified as a control measure.
There are a few examples where effective chemical detoxification is possible, such as ammoniation
of certain animal feed ingredients and refining of vegetable oils. These are control measures that
would also be suitable for application at a critical control point for aflatoxin, but only for the
specified commodities.
It is essential that GAP, GSP, and GMP pre-requisites are in place, and simply ensuring that this is
the case can significantly reduce the risk of the mycotoxin hazard. Examples of procedures which fall
within the scope of these pre-requisites include: irrigation, insect control, use of resistant varieties,
and use of pallets in store.
Task 7 - Determine Critical Control Points (CCPs)
Determination of CCPs can be achieved using a well designed decision tree, if necessary, to
supplement the knowledge and experience of the HACCP team (see Appendix IV). Each step in the
CFD is considered in turn, and the questions answered in sequence. It should be noted that it is
necessary to be able to answer Yes to Question 1 (Do preventative control measures exist?) before a
CCP can be established. The Codex 1997 definition of a control measure is any action and activity
that can be used to prevent or eliminate a food safety hazard, or reduce it to an acceptable level.
There are commodity systems, such as the production of apple juice (Case study 5), where control
measures are possible at a number of steps, and each is capable of achieving a known percentage
reduction in the level of mycotoxin. It is possible, therefore, to calculate the acceptable level of
patulin at each step and perform validation. If the risk of the acceptable level of mycotoxin being
exceeded is considered to be sufficiently low, then the HACCP team may determine each of the steps
as CCPs.
Task 8 - Establish critical limits for each CCP
When the control measure is segregation based on mycotoxin analysis, then the critical limit will
often be set at the acceptable level, which in turn will be set at, or below, the regulatory mycotoxin
limit. Acceptable levels, and any associated critical limits, can sometimes be set higher than a
regulatory limit, provided that a subsequent step can guarantee to attain the acceptable level of
hazard in the final product.
For control measures that involve drying to a 'safe' moisture content, the parameter that will be
measured, and for which critical limits will be set, will usually be parameters such as the temperature
of the drier and the dwell time, e.g. for a continuous flow drier the critical limit for temperature could
be 80 +/- 2°C and the critical limit for dwell time could be 20 +/- 1 minute.
Critical limits for chemical detoxification could be the temperature and pressure of the reaction
vessel and the dwell time.
Task 9 - Establish a monitoring system for each CCP
The monitoring system must be a scheduled measurement, usually of a basic parameter such as
temperature or time, to detect any deviation from the critical limits.
When segregation of acceptable and unacceptable batches is required in the agricultural system, for
example at a secondary trader, then rapid testing procedures are needed to test incoming batches.
A number of semi-quantitative immunoaffinity rapid test kits are available which work to a stated
target level, eg 5 or 20 µk/kg of the appropriate mycotoxin. Here the critical limit would normally be
the presence or absence of a coloured derivative. More traditional mini-column and TLC dilution to
extinction techniques can still be useful for segregation of batches at the factory gate, and for these
the presence or absence of a blue fluorescent band or spot is the critical limit.
Task 10 - Establish a corrective action
There are two sorts of corrective action. The first is action to regain control. For instance if a critical
limit for a moisture content is not attained, then the corrective action could be to check the
specification of the drier and effect repairs, or perhaps to increase the temperature setting or the dwell
time. The second type of corrective action is to isolate the product produced whilst the CCP was out
of control and amend the product disposition, by either discarding or down-grading it, or reprocessing it if this is appropriate.
Task 11 - Establish verification procedures
At regular, specified, intervals the complete HACCP plan should be verified by checking that the
levels of mycotoxin in the final product are within acceptable levels. If this is found not to be the
case, then immediately trouble-shooting should be carried out to identify the step at which the hazard
has become out of control. Critical limits may need to be amended, or a new control measure may
need to be validated and introduced. Similarly, if a review of deviations and product dispositions
indicated an unacceptable degree of control at a particular CCP, then revisions will need to be made.
Task 12 - Establish documentation and record keeping
Standard HACCP documentation and record keeping is appropriate, but the complexity of the
records should reflect the sophistication of the step in the commodity system.
9.Explain the Cleaning and Disinfection in detail.
Cleaning and Disinfection
What is the difference between cleaning and disinfecting?
Cleaning and disinfecting are not the same thing. In most cases, cleaning with soap and water is adequate.
It removes dirt and most of the germs. However, in other situations disinfecting provides an extra margin
of safety.
You should disinfect areas where there are both high concentrations of dangerous germs and a possibility
that they will be spread to others. That is because disinfectants, including solutions of household bleach,
have ingredients that destroy bacteria and other germs. While surfaces may look clean, many infectious
germs may be lurking around. Given the right conditions some germs can live on surfaces for hours and
even for days.
Do you know where the "hot zones", or the contaminated areas, are in your home?
The kitchen is one of the most dangerous places in the house because of the infectious bacteria that are
sometimes found in raw food such as chicken. Also, there is a potential for germs to be spread to other
people because that is where food is prepared. You cannot always tell where or when germs are hiding.
When you touch a contaminated object you can contaminate other surfaces that you touch afterwards and
spread the germs to others.
Another potential hot zone is the bathroom. Routinely cleaning and disinfecting the bathroom reduces
odors and may help prevent the spread of germs when someone in the house has a diarrheal illness. And
do not forget your child's changing table and diaper pail.
What is the best way to routinely clean and disinfect surfaces?
You should follow the directions on the cleaning product labels. And be sure to read safety
precautions as well.
If you are cleaning up body fluids such as blood, vomit, or feces, you should wear rubber gloves,
particularly if you have cuts or scratches on your hands or if a family member has AIDS, Hepatitis B,
or another bloodborne disease. And it is also a good idea to clean and disinfect surfaces when someone
in the home is sick.
To begin, clean the surface thoroughly with soap and water or another cleaner
After cleaning, if you need to use a disinfectant, apply it to the area, and let it stand for a few
minutes or longer, depending on the manufacturers recommendations. This keeps the germs in contact
with the disinfectant longer.
Wipe the surface with paper towels that can be thrown away or cloth towels that can be washed
afterwards.
Store cleaners and disinfectants out of the reach of children.
And remember, even if you use gloves, wash your hands after cleaning or disinfecting surfaces.
Handwashing
10. Explain the Wastewater and waste disposal in detail.
Wastewater and waste disposal
Wastewater is any water that has been adversely affected in quality by anthropogenic influence. It
comprises liquid waste discharged by domestic residences, commercial properties, industry, and/or
agriculture and can encompass a wide range of potential contaminants and concentrations. In the most
common usage, it refers to the municipal wastewater that contains a broad spectrum of contaminants
resulting from the mixing of wastewaters from different sources.
Sewage is correctly the subset of wastewater that is contaminated with feces or urine, but is often used to
mean any waste water. "Sewage" includes domestic, municipal, or industrial liquid waste
products disposed of, usually via a pipe or sewer or similar structure, sometimes in a cesspool emptier.
The physical infrastructure, including pipes, pumps, screens, channels etc. used to convey sewage from its
origin to the point of eventual treatment or disposal is termed sewerage.
Origin
Wastewater or sewage can come from (text in brackets indicates likely inclusions or contaminants):
Human waste (fæces, used toilet paper or wipes, urine, or other bodily fluids), also known
as blackwater, usually from lavatories;
Cesspit leakage;
Septic tank discharge;
Sewage treatment plant discharge;
Washing water (personal, clothes, floors, dishes, etc.), also known as greywater or sullage;
Rainfall collected on roofs, yards, hard-standings, etc. (generally clean with traces
of oils and fuel);
Groundwater infiltrated into sewage;
Surplus manufactured liquids from domestic sources (drinks, cooking oil, pesticides, lubricating
oil, paint, cleaning liquids, etc.);
Urban rainfall runoff from roads, carparks, roofs, sidewalks, or pavements (contains oils, animal
fæces, litter, fuel or rubber residues,metals from vehicle exhausts, etc.);
Seawater ingress (high volumes of salt and micro-biota);
Direct ingress of river water (high volumes of micro-biota);
Direct ingress of manmade liquids (illegal disposal of pesticides, used oils, etc.);
Highway drainage (oil, de-icing agents, rubber residues);
Storm drains (almost anything, including cars, shopping trolleys, trees, cattle, etc.);
Blackwater (surface water contaminated by sewage);
Industrial waste
industrial site drainage (silt, sand, alkali, oil, chemical residues);
Industrial cooling waters (biocides, heat, slimes, silt);
Industrial process waters;
Organic or bio-degradable waste, including waste from abattoirs, creameries, and ice
cream manufacture;
Organic or non bio-degradable/difficult-to-treat waste
(pharmaceutical or pesticide manufacturing);
extreme pH waste (from acid/alkali manufacturing, metal plating);
Toxic waste (metal plating, cyanide production, pesticide manufacturing, etc.);
Solids and Emulsions (paper manufacturing, foodstuffs, lubricating and
hydraulic oil manufacturing, etc.);
agricultural drainage, direct and diffuse.
Wastewater constituents
The composition of wastewater varies widely. This is a partial list of what it may contain:
Water ( > 95%) which is often added during flushing to carry waste down a drain;
Pathogens such as bacteria, viruses, prions and parasitic worms;
Non-pathogenic bacteria;
Organic particles such as faeces, hairs, food, vomit, paper fibers, plant material, humus, etc.;
Soluble organic material such as urea, fruit sugars, soluble proteins, drugs, pharmaceuticals, etc.;
Inorganic particles such as sand, grit, metal particles, ceramics, etc.;
Soluble inorganic material such as ammonia, road-salt, sea-salt, cyanide, hydrogen
sulfide, thiocyanates, thiosulfates, etc.;
Animals such as protozoa, insects, arthropods, small fish, etc.;
Macro-solids such as sanitary napkins, nappies/diapers, condoms, needles, children's toys, dead
animals or plants, etc.;
Gases such as hydrogen sulfide, carbon dioxide, methane, etc.;
Emulsions such as paints, adhesives, mayonnaise, hair colorants, emulsified oils, etc.;
Toxins such as pesticides, poisons, herbicides, etc.
Wastewater quality indicators
Any oxidizable material present in a natural waterway or in an industrial wastewater will be oxidized both
by biochemical (bacterial) or chemical processes. The result is that the oxygen content of the water will
be decreased. Basically, the reaction for biochemical oxidation may be written as:
Oxidizable material + bacteria + nutrient + O2 → CO2 + H2O + oxidized inorganics such as
NO3 or SO4
Oxygen consumption by reducing chemicals such as sulfides and nitrites is typified as follows:
S-- + 2 O2 → SO4-NO2- + ½ O2 → NO3Since all natural waterways contain bacteria and nutrients, almost any waste compounds
introduced into such waterways will initiate biochemical reactions (such as shown
above). Those biochemical reactions create what is measured in the laboratory as
the Biochemical oxygen demand (BOD). Such chemicals are also liable to be broken
down using strong oxidising agents and these chemical reactions create what is measured
in the laboratory as the Chemical oxygen demand (COD).
Both the BOD and COD tests are a measure of the relative oxygen-depletion effect of a
waste contaminant. Both have been widely adopted as a measure of pollution effect. The
BOD test measures the oxygen demand of biodegradable pollutants whereas the COD test
measures the oxygen demand of oxidizable pollutants.
The so-called 5-day BOD measures the amount of oxygen consumed by biochemical
oxidation of waste contaminants in a 5-day period. The total amount of oxygen consumed
when the biochemical reaction is allowed to proceed to completion is called the Ultimate
BOD. The Ultimate BOD is too time consuming, so the 5-day BOD has almost
universally been adopted as a measure of relative pollution effect.
There are also many different COD tests of which the 4-hour COD is probably the most
common.
There is no generalized correlation between the 5-day BOD and the ultimate BOD.
Similarly there is no generalized correlation between BOD and COD. It is possible to
develop such correlations for a specific waste contaminants in a specific waste water
stream but such correlations cannot be generalized for use with any other waste
contaminants or waste water streams. This is because the composition of any waste water
stream is different. As an example and effluent consisting of a solution of
simple sugars that might discharge from a confectioneryfactory is likely to have organic
components that degrade very quickly. In such a case the 5 day BOD and the ultimate
BOD would be very similar . I.e there would be very little organic material left after 5
days. . However a final effluent of a sewage treatment works serving a large
industrialised area might have a discharge where the ultimate BOD was much greater
than the 5 day BOD because much of the easily degraded material would have been
removed in the sewage treatment process and many industrial processes discharge
difficult to degrade organic molecules.
The laboratory test procedures for the determining the above oxygen demands are
detailed in many standard texts. American versions include the "Standard Methods For
the Examination Of Water and Wastewater" .
Sewage disposal
Industrial wastewater effluent with neutralized pH from tailing runoff. Taken in Peru.
In some urban areas, sewage is carried separately in sanitary sewers and runoff from
streets is carried in storm drains. Access to either of these is typically through a manhole.
During high precipitation periods a sanitary sewer overflow can occur, causing
potential public health and ecological damage.
Sewage may drain directly into major watersheds with minimal or no treatment. When
untreated, sewage can have serious impacts on the quality of an environment and on the
health of people. Pathogens can cause a variety of illnesses. Some chemicals pose risks
even at very low concentrations and can remain a threat for long periods of time because
of bioaccumulation in animal or human tissue.
Treatment
There are numerous processes that can be used to clean up waste waters depending on the
type and extent of contamination. Most wastewater is treated in industrialscale wastewater treatment plants (WWTPs) which may include physical, chemical and
biological treatment processes. However, the use of septic tanks and other On-Site
Sewage Facilities (OSSF) is widespread in rural areas, serving up to one quarter of the
homes in the U.S. The most important aerobic treatment system is the activated sludge
process, based on the maintenance and recirculation of a complex biomass composed by
micro-organisms able to absorb and adsorb the organic matter carried in the wastewater.
Anaerobic processes are widely applied in the treatment of industrial wastewaters and
biological sludge. Some wastewater may be highly treated and reused as reclaimed water.
For some waste waters ecological approaches using reed bed systems such as constructed
wetlands may be appropriate. Modern systems include tertiary treatment by micro
filtration or synthetic membranes. After membrane filtration, the treated wastewater is
indistinguishable from waters of natural origin of drinking quality. Nitrates can be
removed from wastewater by microbialdenitrification, for which a small amount
of methanol is typically added to provide the bacteria with a source of carbon. Ozone
Waste Water Treatment is also growing in popularity, and requires the use of an ozone
generator, which decontaminates the water as Ozone bubbles percolate through the tank.
Disposal of wastewaters from an industrial plant is a difficult and costly problem. Most
petroleum refineries, chemical and petrochemical plants[2][3] have onsite facilities to treat
their wastewaters so that the pollutant concentrations in the treated wastewater comply
with the local and/or national regulations regarding disposal of wastewaters into
community treatment plants or into rivers, lakes or oceans. Other Industrial processes that
produce a lot of waste-waters such as paper and pulp production has created
environmental concern leading to development of processes to recycle water use within
plants before they have to be cleaned and disposed of.
Reuse
Treated wastewater can be reused as drinking water, in industry (cooling towers), in
artificial recharge of aquifers, in agriculture (70% of Israel's irrigated agriculture is based
on highly purified wastewater)[citation needed] and in the rehabilitation of natural ecosystems
(Florida'sEverglades).
Algal fuel
Woods Hole Oceanographic Institution and Harbor Branch Oceanographic Institution,
following the conclusions of the USDOE´s Aquatic Species Program, use wastewater for
breeding algae. The wastewater from domestic and industrial sources contain rich organic
compounds, which accelerate the growth of algae. This algae can be used to
produce algal fuels[5]
Algaewheel, based in Indianapolis, Indiana, presented a proposal to build a new
wastewater treatment facility in Cedar Lake, Indiana that uses algae to treat municipal
wastewater and uses the sludge byproduct to produce biofuel[6][7].
Etymology
The words "sewage" and "sewer" came from Old French essouier = "to drain", which
came from Latin exaquāre. Their formal Latin antecedents
are exaquāticum and exaquārium.
Waste management
.
A blue wheelie bin in Berkshire, England
Waste management in Kathmandu (Nepal)
Waste management is the collection, transport, processing, recycling or disposal, and monitoring
of waste materials.[1] The term usually relates to materials produced by human activity, and is generally
undertaken to reduce their effect on health, the environment or aesthetics. Waste management is also
carried out to recover resources from it. Waste management can
involvesolid, liquid, gaseous or radioactive substances, with different methods and fields of expertise for
each.
Waste management practices differ for developed and developing nations, for urban and rural areas, and
for residential and industrial producers. Management for non-hazardous residential and institutional waste
in metropolitan areas is usually the responsibility of local governmentauthorities, while management for
non-hazardous commercial and industrial waste is usually the responsibility of the generator.
Methods of disposal
Integrated waste management
Integrated waste management using LCA (life cycle analysis) attempts to offer the most benign options
for waste management. For mixed MSW (Municipal Solid Waste) a number of broad studies have
indicated that waste administration, then source separation and collection followed by reuse and recycling
of the non-organic fraction and energy and compost/fertilizer production of the organic waste fraction via
anaerobic digestion to be the favoured path. Non-metallic waste resources are not destroyed as with
incineration, and can be reused/ recycled in a future resource depleted society.
Plasma gasification
Plasma is a highly ionized or electrically charged gas. An example in nature is lightning, capable of
producing temperatures exceeding 12,600 °F (6,980 °C). A gasifier vessel utilizes proprietary plasma
torches operating at +10,000 °F (5,540 °C) (the surface temperature of the Sun) in order to create a
gasification zone of up to 3,000 °F (1,650 °C) to convert solid or liquid wastes into a syngas. When
municipal solid waste is subjected to this intense heat within the vessel, the waste’s molecular bonds
break down into elemental components. The process results in elemental destruction of waste and
hazardous materials.[2]
According to the U.S. Environmental Protection Agency, the U.S. generated 250 million tons of waste in
2008 alone, and this number continues to rise. About 54% of this trash (135,000,000 short tons
(122,000,000 t)) ends up in landfills and is consuming land at a rate of nearly 3,500 acres (1,400 ha) per
year. In fact, landfilling is currently the number one method of waste disposal in the US. Some states no
longer have capacity at permitted landfills and export their waste to other states. Plasma gasification
offers states new opportunities for waste disposal, and more importantly for renewable power generation
in an environmentally sustainable manner.[3]
Landfill
Disposing of waste in a landfill involves burying the waste, and this remains a common practice in most
countries. Landfills were often established in abandoned or unused quarries, mining voids orborrow pits.
A properly designed and well-managed landfill can be a hygienic and relatively inexpensive method of
disposing of waste materials. Older, poorly designed or poorly managed landfills can create a number of
adverse environmental impacts such as wind-blown litter, attraction of vermin, and generation of
liquid leachate. Another common byproduct of landfills is gas (mostly composed of methane and carbon
dioxide), which is produced as organic waste breaks down anaerobically. This gas can create odour
problems, kill surface vegetation, and is agreenhouse gas.
A landfill compaction vehicle in action.
Design characteristics of a modern landfill include methods to contain leachate such as clay or plastic
lining material. Deposited waste is normally compacted to increase its density and stability, and covered
to prevent attracting vermin (such as mice or rats). Many landfills also have landfill gas extraction
systems installed to extract the landfill gas. Gas is pumped out of the landfill using perforated pipes and
flared off or burnt in a gas engine to generate electricity.
Incineration
Spittelau incineration plant inVienna.
Incineration is a disposal method that involves combustion of waste material. Incineration and other high
temperature waste treatment systems are sometimes described as "thermal treatment". Incinerators
convert waste materials into heat, gas, steam and ash.
Incineration is carried out both on a small scale by individuals and on a large scale by industry. It is used
to dispose of solid, liquid and gaseous waste. It is recognized as a practical method of disposing of
certain hazardous waste materials (such as biological medical waste). Incineration is a controversial
method of waste disposal, due to issues such as emission of gaseous pollutants.
Incineration is common in countries such as Japan where land is more scarce, as these facilities generally
do not require as much area as landfills. Waste-to-energy (WtE) or energy-from-waste (EfW) are broad
terms for facilities that burn waste in a furnace or boiler to generate heat, steam and/or electricity.
Combustion in an incinerator is not always perfect and there have been concerns about micro-pollutants
in gaseous emissions from incinerator stacks. Particular concern has focused on some very persistent
organics such as dioxins, furans, PAHs,... which may be created within the incinerator and afterwards in
the incinerator plume which may have serious environmental consequences in the area immediately
around the incinerator. On the other hand this method or the more benign anaerobic digestion produces
heat that can be used as energy.
.Recycling
.
Steel scrap, sorted and baled for recycling.
The popular meaning of ‘recycling’ in most developed countries refers to the widespread collection and
reuse of everyday waste materials such as empty beverage containers. These are collected and sorted into
common types so that the raw materials from which the items are made can be reprocessed into new
products. Material for recycling may be collected separately from general waste using dedicated bins and
collection vehicles, or sorted directly from mixed waste streams.
The most common consumer products recycled include aluminum beverage cans, steel food and aerosol
cans, HDPE and PET bottles, glass bottles and jars, paperboard cartons, newspapers, magazines,
and corrugated fiberboard boxes.
PVC, LDPE, PP, and PS (see resin identification code) are also recyclable, although these are not
commonly collected. These items are usually composed of a single type of material, making them
relatively easy to recycle into new products. The recycling of complex products (such as computers and
electronic equipment) is more difficult, due to the additional dismantling and separation required.
Sustainability
The management of waste is a key component in a business' ability to maintaining ISO14001
accreditations. Companies are encouraged to improve their environmental efficiencies each year. One
way to do this is by improving a company’s waste management with a new recycling service. (such as
recycling: glass, food waste, paper and cardboard, plastic bottles etc.)
Biological reprocessing
Composting, Home composting, and Anaerobic digestion
An active compost heap.
Waste materials that are organic in nature, such as plant material, food scraps, and paper products, can be
recycled using biological composting and digestion processes to decompose the organic matter. The
resulting organic material is then recycled as mulch or compost for agricultural or landscaping purposes.
In addition, waste gas from the process (such as methane) can be captured and used for generating
electricity and heat (CHP/cogeneration) maximising efficiencies. The intention of biological processing in
waste management is to control and accelerate the natural process of decomposition of organic matter.
There are a large variety of composting and digestion methods and technologies varying in complexity
from simple home compost heaps, to small town scale batch digesters, industrial-scale enclosed-vessel
digestion of mixed domestic waste (see Mechanical biological treatment). Methods of biological
decomposition are differentiated as being aerobic or anaerobic methods, though hybrids of the two
methods also exist.
Anaerobic digestion of the organic fraction of MSW Municipal Solid Waste has been found to be in a
number of LCA analysis studies[4][5] to be more environmentally effective, than landfill, incineration or
pyrolisis. The resulting biogas (methane) though must be used for cogeneration (electricity and heat
preferably on or close to the site of production) and can be used with a little upgrading in gas combustion
engines or turbines. With further upgrading to synthetic natural gas it can be injected into the natural gas
network or further refined to hydrogen for use in stationary cogeneration fuel cells. Its use in fuel cells
eliminates the pollution from products of combustion (SOx, NOx, pariculates, dioxin, furans, PAHs...).
An example of waste management through composting is the Green Bin Program in Toronto, Canada,
where household organic waste (such as kitchen scraps and plant cuttings) are collected in a dedicated
container and then composted.
Energy recovery
Anaerobic digestion component of Lübeck mechanical biological treatment plant in Germany, 2007
The energy content of waste products can be harnessed directly by using them as a direct combustion fuel,
or indirectly by processing them into another type of fuel. Recycling through thermal treatment ranges
from using waste as a fuel source for cooking or heating, to anaerobic digestion and the use of the gas fuel
(see above), to fuel for boilers to generate steam and electricity in a turbine. Pyrolysis andgasification are
two related forms of thermal treatment where waste materials are heated to high temperatures with
limited oxygen availability. The process usually occurs in a sealed vessel under highpressure. Pyrolysis of
solid waste converts the material into solid, liquid and gas products. The liquid and gas can be burnt to
produce energy or refined into other chenmical products (chemical refinery). The solid residue (char) can
be further refined into products such as activated carbon. Gasification and advancedPlasma arc
gasification are used to convert organic materials directly into a synthetic gas (syngas) composed
of carbon monoxide andhydrogen. The gas is then burnt to produce electricity and steam. An alternative
to pyrolisis is high temperature and pressure supercritical water decomposition (hydrothermal
monophasic oxidation).
Avoidance and reduction methods
An important method of waste management is the prevention of waste material being created, also known
as waste reduction. Methods of avoidance include reuse of second-hand products, repairing broken items
instead of buying new, designing products to be refillable or reusable (such as cotton instead of plastic
shopping bags), encouraging consumers to avoid using disposable products (such as disposablecutlery),
removing any food/liquid remains from cans, packaging, ...[6] and designing products that use less
material to achieve the same purpose (for example, lightweighting of beverage cans).
Waste handling and transport
A front-loading garbage truck in North America.
Waste collection methods vary widely among different countries and regions. Domestic waste collection
services are often provided by local government authorities, or by private companies in the industry.
Some areas, especially those in less developed countries, do not have a formal waste-collection system.
Examples of waste handling systems include:
In Australia, curbside collection is the method of disposal of waste. Every urban domestic
household is provided with three bins: one for recyclables, another for general waste and another for
garden materials - this bin is provided by the municipality if requested. Also, many households have
compost bins; but this is not provided by the municipality. To encourage recycling, municipalities
provide large recycle bins, which are larger than general waste bins. Municipal, commercial and
industrial, construction and demolition waste is dumped at landfills and some is recycled. Household
waste is segregated: recyclables sorted and made into new products, and general waste is dumped in
landfill areas. According to the ABS, the recycling rate is high and is 'increasing, with 99% of
households reporting that they had recycled or reused some of their waste within the past year (2003
survey), up from 85% in 1992'. This suggests that Australians are in favour of reduced or no
landfilling and the recycling of waste. Of the total waste produced in 2002–03, '30% of municipal
waste, 45% of commercial and industrial waste and 57% of construction and demolition waste' was
recycled. Energy is produced from waste as well: some landfill gas is captured for fuel or electricity
generation. Households and industries are not charged for the volume of waste they produce.
In Europe and a few other places around the world, a few communities use a proprietary
collection system known as Envac, which conveys refuse via underground conduits using a vacuum
system. Other vacuum-based solutions include the MetroTaifun single-line and ring-line systems.
In Canadian urban centres curbside collection is the most common method of disposal, whereby
the city collects waste and/or recyclables and/or organics on a scheduled basis. In rural areas people
often dispose of their waste by hauling it to a transfer station. Waste collected is then transported to a
regional landfill.
In Taipei, the city government charges its households and industries for the volume of rubbish
they produce. Waste will only be collected by the city council if waste is disposed in government
issued rubbish bags. This policy has successfully reduced the amount of waste the city produces and
increased the recycling rate.
In Israel, the Arrow Ecology company has developed the ArrowBio system, which takes trash
directly from collection trucks and separates organic and inorganic materials through gravitational
settling, screening, and hydro-mechanical shredding. The system is capable of sorting huge volumes
of solid waste, salvaging recyclables, and turning the rest into biogas and rich agricultural compost.
The system is used in California, Australia, Greece, Mexico, the United Kingdom and in Israel. For
example, an ArrowBio plant that has been operational at the Hiriya landfill site since December 2003
serves the Tel Aviv area, and processes up to 150 tons of garbage a day.[7]
Technologies
Traditionally the waste management industry has been slow to adopt new technologies such as RFID
(Radio Frequency Identification) tags, GPS and integrated software packages which enable better quality
data to be collected without the use of estimation or manual data entry.
Technologies like RFID tags are now being used to collect data on presentation rates for curbside pick-ups which is useful when examining the usage of recycling bins or similar.
Benefits of GPS tracking is particularly evident when considering the efficiency of ad hoc pickups (like skip bins or dumpsters) where the collection is done on a consumer request basis.
Integrated software packages are useful in aggregating this data for use in optimisation of
operations for waste collection operations.
Rear vision cameras are commonly used for OH&S reasons and video recording devices are
becoming more widely used, particularly concerning residential services and contaminations of the
waste stream.
Waste management concepts
There are a number of concepts about waste management which vary in their usage between countries or
regions. Some of the most general, widely used concepts include:
Diagram of the waste hierarchy.
Waste hierarchy - The waste hierarchy refers to the "3 Rs" reduce, reuse and recycle, which
classify waste management strategies according to their desirability in terms of waste minimization.
The waste hierarchy remains the cornerstone of most waste minimization strategies. The aim of the
waste hierarchy is to extract the maximum practical benefits from products and to generate the
minimum amount of waste.
Extended producer responsibility - Extended Producer Responsibility (EPR) is a strategy
designed to promote the integration of all costs associated with products throughout their life cycle
(including end-of-life disposal costs) into the market price of the product. Extended producer
responsibility is meant to impose accountability over the entire lifecycle of products and packaging
introduced to the market. This means that firms which manufacture, import and/or sell products are
required to be responsible for the products after their useful life as well as during manufacture.
Polluter pays principle - the Polluter Pays Principle is a principle where the polluting party pays
for the impact caused to the environment. With respect to waste management, this generally refers to
the requirement for a waste generator to pay for appropriate disposal of the waste.
Education and awareness
Education and awareness in the area of waste and waste management is increasingly important from a
global perspective of resource management. The Talloires Declaration is a declaration
for sustainability concerned about the unprecedented scale and speed of
environmental pollution and degradation, and the depletion of natural resources. Local, regional, and
global air pollution; accumulation and distribution of toxic wastes; destruction and depletion of
forests, soil, and water; depletion of the ozone layer and emission of "green house" gases threaten the
survival of humans and thousands of other living species, the integrity of the earth and its biodiversity, the
security of nations, and the heritage of future generations. Several universities have implemented the
Talloires Declaration by establishing environmental management and waste management programs, e.g.
the waste management university project. University and vocational education are promoted by various
organizations, e.g. WAMITAB and Chartered Institution of Wastes Management. Many supermarkets
encourage customers to use their reverse vending machines to deposit used purchased containers and
receive a refund from the recycling fees. Brands that manufacture such machines
include Tomra and Envipco.
