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Basic Quality Criteria in Food Control Lecture 1 • Food Quality Quality can be defined as combinations of attributes or characteristics of a product that have significance in determining the degree of acceptability of that product to the consumer. Food Quality It can also be said as measure of purity, strength, physicochemical & oregano-leptic characteristic of food products but the classical definition of quality is composite of these characters that differentiate between individual units of the products & have significance in determining the degree of acceptability of that unit by the user Definition Quality is a measure of the degree of excellence or degree of acceptability by the consumer. It can be defined as “summary of features and characteristics of a product or service that bear on its ability to satisfy stated or implied needs”. In simple words the product should have attributes to “satisfy the wants/ needs of the consumer or conformance with the user’s requirements”. It also covers the safety and value for money. Food quality can be considered as a complex characteristic of food that determines its value or acceptability to consumers. Thus it may be defined as “the composite of those characteristics which have significance in determining the degree of acceptability by the buyer. These characteristics should also have the ability to differentiate individual unit of the product.” Every food product has characteristics and indices measurable by sensory, physicalchemical, or microbiological methods. Some characteristics are easily perceived; others are unseen. Understanding these quality characteristics and being familiar with the appropriate measuring tools are vital to quality control and the quality assurance of food products. Components The important components of food quality are: food safety, sensory characteristics and nutritional value. Safety of food is a basic requirement of food quality. “Food safety” implies absence or acceptable and safe levels of contaminants,adulterants, naturally occurring toxins or any other substance that may make food injurious to health on an acute or chronic basis. Besides safety, quality attributes include: nutritional value; organoleptic properties such as appearance, colour, texture, taste; and functional properties. Components: The quality attributes are outlined in Table and includes primarily sensory attributes and hidden attributes. The sensory attributes include characteristics such as colour and appearance, viscosity and consistency, smell, taste, touch etc. The hidden characteristics are those which cannot be evaluated with human senses and yet are of real importance to human health and welfare. Nutritive value is one of the hidden characteristics, which is now considered by the consumers as a quality attribute. Adulterants and toxicants are the other hidden characteristics. Toxic substances may be of microbial origin, veterinary drugs residues, pesticide residues or heavy metals. Table1. The quality attributes The quality attributes are outlined in Table and includes primarily sensory attributes and hidden attributes i) Food safety: In order to understand “food safety” we must first know the terms safe and hazard. “Safe” means that nothing harmful happens when we consume a food. A “hazard” is the capacity of a thing to cause harm. The objective of the food safety is to protect the food supply from microbial, chemical and physical hazards or contamination that may occur during all stages of production and handling-management of animals at farm, transportation,storage of raw milk, processing, production of value added products, distribution and storage of end products. It aims for keeping food wholesome and free from food borne illness. The important associated definitions and factors are described for better understanding of the food safety. a) Food borne illness: Food borne illness or food poisoning is caused by consuming food contaminated with pathogenic bacteria, toxins, viruses or parasites. The contamination may or may not alter a food’s organoleptic properties but cause illness and disease to human beings after consumption and usually arises from improper handling, preparation or storage of food. Food-borne diseases are classified as food infections or food intoxications. Food infections involve microorganisms present in the food at the time of consumption which then grow in the host and cause illness and disease.Food intoxications involve toxic substances produced in foods by microorganisms prior to consumption and cause disease upon ingestion.The toxin producing microorganisms need not to grow in the host to produce a disease or even be present in the food. So we must acknowledge that intoxication can occur even if no viable microorganisms are ingested. (b) Food hazards: Food becomes hazardous by contamination. Contamination is the unintended presence of harmful substances or microorganisms in food. Food hazards can be defined as a biological, chemical or physical agent in a food, with the potential to cause an adverse health effect (Table). Physical hazards are foreign particles, like glass/wood or metal pieces, stone, bone fragments, feathers, fibre, hair, etc. Chemical hazards include substances such as cleaning solutions and sanitizers, non permitted adulterants, pesticide and heavy metal residues. Biological hazards come mainly from microorganisms Quality ,Ministry of Health is pursuing a broad and long-term sciencebased strategy to improve the food safety and to better protect the public health. Part of this strategy is a farm-to-table approach to improve the safety of food at each step in the food production, distribution, and marketing chain Table2. Types of Food Hazards (d) The Food Safety and Standards Act, 2006: The chapter six of the Act titled as “Special Responsibilities as to Food Safety” deals with responsibilities of the food business operator, liability of manufacturers, packers, wholesalers, distributors and sellers and recall procedures (e) Safety concerns: We know that the goal of food safety is to reduce the size of risks to the lowest reasonable level without severe disruption of the food supply. For this we should first identify hazards related to foods or food components and then estimate the size of the risk that the hazard will cause. It is important to note that all foods have some degree of risk and that no food is absolutely “safe.” The important consideration becomes “the size of the risk and how the size of the risk can be reduced” without eliminating the food source. Specific food safety concerns differ markedly and include • • • • • • • • • • • Additives, colours and flavours. Antibiotics and other food additives. Fertilizers and other growing aids. Irradiation. Microbiological contamination. Naturally occurring food toxicants. Nutrition. Pesticides. Pollutants. Processing, packaging and labelling. Tampering. (f) Adhering to Safety Standards: The advantages associated with adhering to food safety standards are: • Ensures safety of food products. • Greater health protection. • Increased international acceptance of food products. • Helps to meet applicable food safety related statuary & regulatory requirements. • Demonstrate conformance to international standards and applicable regulatory requirements. • Reduces risk of product/service liability claims. (g) Recent Concerns of Food Safety: Prions, genetically modified foods, the incidence of bovine spongiform encephalopathy (BSE), and dioxincontaminated foods are some of the new food safety concerns. Prions are one of the new sources of food borne diseases. A prion is the short form of proteinaceous infectious particle. Dr. Stanely Prusiner coined the word “prion” as a name for the infectious agent, by combining the first two syllables of the words “proteinaceous” and “infectious.” While the infectious agent was named a prion, the specific protein that the prion was made of was named PrP, an abbreviation for “protease-resistant protein”.The normal form of the protein is called PrPC, while the infectious form is called PrPSc, which stands for prion protein of scrapie. Prions are generally quite resistant to denaturation by protease, heat, radiation, and formalin treatments, although potency or infectivity can be reduced. Prions enter cells and apparently believed to infect and propagate by refolding abnormally into a structure which is able to convert normal The diseases associated by prisons are: Creutzfeldt-Jakob Disease (CJD), Bovine spongiform encephalopathy (BSE- commonly known as “mad cow disease”), fatal familial insomnia and kuru (translated as “to tremble with fear”). Dioxin–Contaminated Foods: Dioxin is the popular name for the family of halogenated organic compounds, the most common consisting of polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzopdioxins (PCDDs). PCDD/PCDFs are industrial pollutants that persist in the environment. They have been shown to bio accumulate in humans and wildlife due to their lipophilic (fat loving) properties. Dioxins are a carcinogen in higher amounts, and cause developmental and reproductive problems. They are absorbed primarily through dietary intake of fat, as this is where they accumulate in animals, including humans Genetically Modified (GM) Foods: The GM foods are produced from genetically modified organisms (GMO). A GMO means: an organism that has been modified (manipulation of DNA) by gene technology. Genetically modified (GM) crops and food are being grown and consumed by the public. The advantages associated are: increased yields from agriculture,more powerful control of pests and weeds, reduced use of some agrochemicals and enhancement of nutritional value or other characteristics of crops, etc. There are many things which people hold up as possible dangers of genetic modification: risk of transferring crop traits to wild species, negative impacts on wildlife from more powerful control of pests and weeds, increased use of some agrochemicals, increased corporate control of seed supply and; limited studies on food safety concerns on human health in form of toxins/ allergenic reactions/ reduction in good micro flora of duct, etc. ii) Nutritional Value: Nutritional value of the product has grown in importance as consumers have become better informed about foods. The consumers demand for nutritional labelling in addition to food safety. Nutritional changes occur in foods during handling, processing and storage due to microbiological, enzymatic and chemical reactions. One of the principal responsibilities of the dairy technologists is to preserve nutrients through all phases of food acquisition,processing, preparation and storage. ii) Nutritional Value: As a food processor, we should have good knowledge of the stability of nutrients under different conditions. Vitamin A is highly sensitive (i.e., unstable) to acid, air, light, and heat; on the other hand,vitamin C is stable in acid but is sensitive to alkalinity, air, light, and heat. Because of the instability of nutrients under various conditions and their water solubility, cooking losses of some essential nutrients may be greater than 75%. In modern food processing operations, however, losses seldom exceed 25%. The food should not contain any toxic/ anti- nutritional substances. iii) Sensory Characteristics: The sensory characteristics of foods and materials are based on perception of human senses i.e. senses of sight, smell, taste, touch and hearing. QUALITY EVALUATION • Three methods; 1 Subjective method 2. Objective method 3.microscopic method • 1. Subjective Method; Evaluating quality are based on opinion of the investigators. it includes sense organs. It is usually a physiological reaction which is a result of past training, experience of the individual influence of personal preference & power of perception. It is also referred as subjective or sensory method e.g. flavor, color, touch, odour and taste. • 2. Objective method; objective methods of quality are based on observations from which the human perception is excluded. They are based on scientific tests. • Physical methods of Measurement; This is perhaps the quickest method s are generally. They are concerned with such attributes of product quality as size, texture, color, consistency imperfections or they may be concerned with process variables like headspace, fill, drained weight, or vacuum • • Chemical methods of measurement. Standard analysis methods are generally used for quantitative chemical evaluation in most cases , but these chemical analysis are often too long & tedious as a result industries have developed method termed as quick test for such as those for ; enzymes, moisture, fiber, pH or acidity • 3. Microscopic method • They have excellent application in a quality control programme because they help in determination of microbial count, spoilage protection in fresh and processed products and can differentiate between cell types and organisms. These methods can be divided into two categories • Adulteration & contamination Examination will indicate the presence of molds, insects, excreta or foreign material. Each test is specific. Differentiation between cell type , tissue type,& m/o of various stored foods Lecture 2 Food Quality (Cont) Food Quality Quality can be defined as combinations of attributes or characteristics of a product that have significance in determining the degree of acceptability of that product to the consumer Factors contributing towards quality of food • • • • • • • Nutritional value Appearance Color Taste Odor Adulterants Contaminants (Physical, Microbiological Chemical & • Nutrient means any substance normally consumed as a constituent of food: • Which provides energy; or • Which is needed for growth and development and maintenance of healthy life; or • A deficit of which will cause characteristic biochemical or physiological changes to occur Proximate analysis of foods refers to determining the major components of foods • Moisture (db or wb) • Ash (total minerals) - AIA, Sulphated ash, Water soluble Ash, Water Insoluble Ash • Fats/lipids - Saturated fats MUFA PUFA PUFA • Protein • Carbohydrates - Reducing sugar/ Non reducing sugar • Crude Fibre • Energy (Calories) Benefits of Nutritional analysis- Food quality parameters • • • • • • • • • Better quality check Increasing Product consistency Easy Processing & Formulations Better Preservation Easing marketing and distribution tasks Increases yearly availability of many foods Enables transportation of foods across long distances reduces the incidence of food borne disease. Improve the quality of life for people with allergies, diabetics, and other people who cannot consume some common food elements • Enables better food fortification Moisture Analysis • Moisture is an important factor in food quality, preservation, and resistance to deterioration Moisture is a quality factor: -Dehydrated vegetables and fruits -Dried milks -Powdered eggs -Dehydrated potatoes -Spices and herbs -Jams and jellies to prevent sugar crystallization Sugar syrups -Prepared cereals – conventional and instant mixes -Concentrated milks -Liquid cane sugar (67% solids) and liquid corn sweetener (80% solids) • Dehydrated products (these are difficult to package if too high in moisture) • Concentrated fruit juices • Moisture (or solids) content is often specified in compositional standards (i.e., Standards of Identity) • The percentage of added water in processed foods is commonly specified. Total Ash/ Minerals Ash refers to the inorganic residue remaining after either ignition or complete oxidation of organic matter in a foodstuff. • • • • • • • • • • Ash content represents the total mineral content in foods. The ash content of most fresh foods rarely is greater than 5%. Pure oils and fats generally contain little or no ash Fats, oils, and shortenings : 0.0 to 4.1% ash Dairy products : 0.5 to 5.1% Fruits- Fruit juice: 0.2–0.6% Dried fruits : 2.4–3.5% Flours and meals: 0.3 to 1.4% Pure starch contains : 0.3% Nuts and nut products : 0.8–3.4% Fat Analysis Fat analysis is important for: • Quantitative and qualitative analysis of lipids in foods is important for accurate nutritional labeling • Determination of whether the food meets the standard of identity • To ensure that the product meets manufacturing specifications • Lipids in food are subjected to many chemical reactions during processing and storage • To ensure product flow and consistency Fatty acid composition of different oils Edible oils Olive Oil Canola Oil Mustard Oil Lard Sesame Oil Rice bran Oil Palm Oil Ghee / Butterfat Corn Oil Soyabean Oil Grapeseed Oil Sunflower Oil Cottonseed Oil Safflower Oil Coconut Oil Saturated Fat MonoUnsaturated Fat 10 07 11 43 14 22 48 68 13 15 11 12 27 10 89 82 61 56 47 42 42 38 28 27 23 20 19 19 14 7 Poly-Unsaturated Fat Omega-3 Fatty Omega- 6 Fatty Acid Acid * 11 15 1 * * * 1 * 8 * * * * * 8 21 18 9 44 36 14 3 60 54 69 69 54 76 4 Protein • Protein analysis is important for: 1. Nutrition labeling 2. Pricing: The cost of certain commodities is based on the protein content as measured by nitrogen content (e.g., cereal grains; milk for making certain dairy products, e.g., cheese). 3. Functional property investigation: - gliadin and glutenins in wheat flour for breadmaking, - Casein in milk for coagulation into cheese products - egg albumen for foaming 4. Biological activity determination: - The proteolytic enzymes - Pectinases in the ripening of fruits 2. Factors Determining Food Quality 2.1. Sensory Properties 2.1.1. Appearance and Color 2.1.2. Texture 2.1.3. Taste and Flavor 2.2. Physical Properties 2.3. Chemical Composition 2.3.1. Moisture Content 2.3.2. Fat Content 2.3.3. Food Protein 2.3.4. Carbohydrates 2.3.5. Vitamins 2.3.6. Minerals 2.4. Food Additives 2.5. Microbiological Characteristics 2.6. Other Natural or Synthetic Components Influencing Quality and Safety 2.7. Packaging and Labeling Factors Determining Food Quality 2.1. Sensory Properties The measurement of sensory properties and determination of the importance of these properties to consumer product acceptance represent major accomplishments in sensoryn evaluation. These achievements have been possible as a direct result of advances insensory evaluation, in the application of contemporary knowledge about the measurement of human behavior, and in a more systematic and professional approach totesting. 2.1. Sensory Properties Man accepts food on the basis of certain characteristics that he defines and perceiveswith his senses. These attributes are described in terms of sensations and are sometimes referred to as qualitative or sensory qualities. They include perceptions of appearance factors such as color, size, shape, and physical aspects; kinesthetic factors such as texture, viscosity, consistency, finger feel, and mouth feel; and flavor factors or sensations combining odor and taste. 2.2.Appearance and Colour Color and other aspects of apperaance influence food appreciation and quality, especially by the consumer. Man has subjective standards for the acceptable range and preferred optima for these qualities for almost every food.The importance of the color of agricultural commodities and processed foods cannot be overstressed. An important problem is discoloration or the fading of the colors of various raw and processed fruits and vegetables. In some cases, color changes areaccompanied by undesirable changes in texture, taste, or odor. Overaged cheese, beer,meat, and fish all develop off-color, which the consumer recognizes as being associatedwith poor flavor quality. Five functions that should be considered in understanding human reactions to color in foods are • Perception. Food selection or judgment of food quality would be extremely difficultif color discrimination were removed, even though size, texture, shape, and othercues were left intact. • Motivation. Food color and the color of the environment in which the food is seencan significantly increase or decrease our desire or appetite for it. • Emotion. Liking or disliking a food is conditioned by its color; attractive foods aresought out as pleasure-giving, while unattractive foods are avoided. • Learning. By the process of experience, we learn what color to expect and consider“natural,” and we predict rather precisely what properties a food or beverage willhave from our memory of similar materials. • Thinking. Our reaction to unusual properties or to new foods can be changed if theyare explained to us. 2.3. Texture Texture can be described as the properties of a foodstuff apprehended both by the eyes and by the skin and muscle senses in the month, embracing roughness, smoothness, graininess, and so forth. Texture The texture or mouth feel of liquid foods, especially those that behave as Newtonian fluids, is closely related to their viscosity. When the degree of gum solution sliminess was evaluated by a trained panel, mouth feel ratings were correlated with viscosity. The texture of fruits and vegetables has been assessed with instruments that measure compression, resistance to penetration, or force required to shear. The Magness pressure tester, wherein a steel plunger of a specified diameter penetrates the flesh of a fruit, is used widely for determination of the maturity of deciduous fruits. Variouspenetrometers have been developed for objective evaluation of the texture of cooked,canned, and frozen foods. The most important components of food texture are flavor When food is consumed ,the interaction of taste, odor, and textural feeling provides an overall sensation that is best defined by the English word “flavor.” German and some other languages do not have an adequate expression for such a broad and comprehensive term. Flavor results from compounds that are divided into two broadclasses: Those responsible for taste and those responsible for odors, the latter often designated as aroma which provides both sensations. • Odor, the olfactory perception caused by volatile substances released from a product in the mouth via the posterior napes • Taste, gustatory perceptions (salty, sweet, sour, bitter) caused by soluble substances in the mouth • Chemical feeling factors that stimulate nerve ends in the soft membranes of the buccal and nasal cavities (astringency, spice heat/cooling, bite, metallic flavor,umami taste). flavor Flavor is the most important sensory property of many food products. Flavor, as an attribute of foods, beverages, and seasonings, is defined as the sum of perceptions resulting from stimulation of the sense ends that are grouped together at the entrance of the alimentary and respiratory tracts. For the purpose of practical sensory analysis, the term for the impressions perceived via the chemical senses from a product in the mouthis restricted. Defined in this manner, flavor includes flavor The threshold concentrations (values) for aroma compounds are dependent on their vapor pressure, which is affected by both temperature and medium. The values are also influenced by the assay procedure and/or performance of the sensory panel. The frequent discrepancies in threshold values in the literature are basically due to suchdifferences. Particularly important aroma constituents are those compounds that bear the characteristic aroma of the food, the so-called “character impact compound.” With regard to the occurrence of such key compounds, food can be divided into four groups 2.3. Chemical Composition The nature and amount of substances in a given food product determine the nutritive value and other properties. As the development and enforcement of standards of identity and purity, the control of food safety is based on the determination of chemical composition, including chemical contaminants. Analysis of the molecular composition of food substances is known as proximate analysis. It is used to study the protein, fat, carbohydrate, ash, and water content of foods ( 2.3.1. Moisture Content Water (moisture) is the predominant constituent in many food products (Table 4). As amedium, water supports chemical reactions, and it is a direct reactant in hydrolytic processes. Therefore, removal of water from food, or binding it by increasing theconcentration of common salt or sugar retards many reactions and inhibits the growth ofmicroorganisms, thus improving the shelf life of a number of foods. Through physicalinteraction with proteins, polysaccharides, lipids, and salts, water contributes significantly to the texture of food Food products with aw values between 0.6 and 0.9 are known as “intermediate moisture foods.” These food products must be protected extensively against microbial spoilage. One of the options to decreasing water activity, and thus improving the shelf life of food, is to use additives with high water-binding capacities ( 2.3.2. Fat Content The majority of lipids are derivatives of fatty acids. In these so-called acyl lipids the fatty acids are present as esters and in some minor lipid groups in amide form. The acyl residue influences strongly the hydrophobicity and the reactivity of the acyl lipids. The nutritive, physiological importance of lipids is based on their role as fuel molecules (39 kJ/g triglycerides), and as a source of essential fatty acids and vitamins. Apart from their roles, some other lipid properties are indispensable in food handling or processing. These include the pleasant creamy or oily mouthful, and the ability to solubilize many taste and aroma constituents of food 2.3. Chemical Composition 2.3.1. Moisture Content 2.3.2. Fat Content 2.3.3. Food Protein 2.3.4. Carbohydrates 2.3.5. Vitamins 2.3.6. Minerals 2.4. Food Additives 2.5. Microbiological Characteristics 2.6. Other Natural or Synthetic Components Influencing Quality and Safety 2.7. Packaging and Labeling 3. Overall Evaluation of Food Quality Why use Additives ? Food produced on the large scale that is needed to supply supermarkets and other food shops has to be transported and stored before it is consumed . It has to stay in top condition over a much longer period of time than home cooked food. Additives are used so that these foods still have a consistently high quality. What are food additives? • They are chemicals ,or ingredients which are added to food products for maintaining their stability. • Additives are artificial or natural chemicals , added to food , for microbial and chemical stability of foods or delay or even stop food rancidity. The Codex Alimentarious Commission has defined “Food Additive” as under: Food Additive means any substance not normally consumed as a food by itself and not normally used as a typical ingredient of the food ,whether or not it has nutritive value, the intentional addition of which to food for a technological purpose in the manufacture, processing, preparation, treatment , packing, or holding of such food results, or may be reasonably expected to result in it or its bye products becoming a component or otherwise affecting the characteristics of such foods. The term does not include contaminants or substances added to food for maintaining or improving its nutritive value. Functions of food additives: • Improve the taste or appearance of a processed food Eg: beeswax –glazing agent is used to coat apples • Improve the keeping quality or stability of a food Eg: sorbitol –added to mixed dried fruit to maintain moisture level and softness of the fruit Functions of food additives: • Improve shelf life or storage time Eg: sulphurdioxide added to sausage meat to avoid microbial growth • Ensure nutritional value • Maintain uniform quality and to enhance quality parameters like flavour,colour etc., in large scale production Types of food additives: Direct or intentional food additives which are added deliberately to improve its sensory quality, stability, ease in processing and retention of quality during handling and retailing . Indirect or unintentional food additives which get included into foods incidentally during handling, processing and packaging. Classes of food additives Preservatives. Food colours. Food flavors and flavor enhancers High intensity / lowcalorie sweeteners. Antioxidants. Emulsifiers. Acidulants Anti-caking agents E-Codes • E-codes are codes sometimes found on food labels in the European Union (Great Britain, France, Germany, Spain, Italy, Portugal etc.) • The codes indicates an ingredient which is some type of food additives • The “E” indicates that is a “European Union Approved” food additive • Other countries have different food labeling laws E-Codes number E-100 E-200 E-300 E-400 E-500 E-600 Groups of Food Ingredients Coloring agents Preservatives Anti-oxidants Thickeners, Stabilizers, Gelling agents, Emulsifiers Agents for physical characteristics Flavor enhancers What are the effects of food additives? Immediate effects: Headache Change in energy level Alterations in mental concentration, behavoiur , or immune response Long term effects: Increase risk of cancer ,cardiovascular disease and other degenerative conditions Preservatives: • They prevent spoilage of food due to fungi , bacteria and other microorganisms • Commonly used in Low fat spreads Cheeses, margarine, mayonnaise Bakery products Dried fruit preparations Eg: sodium benzoate , sodium nitrite, benzoic acid ,BHA(butylated hydroxy anisole ) /BHT(butylated hydroxy toluene) Sodium benzoate- carbonated drinks ,pickles , sauces Side effects: aggravates asthma and suspected to be a neurotoxin and carcinogen , may cause fetal abnormalities . Worsens hyperactivity Food Safey –Natural Toxins Hazards in Food • • • • • • • Physical:glass, stone, metal, wood, etc Chemical: -natural toxins -residues -metals -toxins formed during food processing Microbiological:pathogenic microorganisms (bacteria, viruses, parasites, etc) • Naturally Occuring Toxins in Food • Man Made Toxins Natural Toxins •They are naturally present in plants & animals. •The long term ingestion of natural toxins in commonly eaten foods the risks to human health? •Usually, natural toxins are not acutely toxic, except in a few cases in animals. •Most of the natural toxins, particularly those occurring in plant-derived foods, induce adverse effects only after chronic ingestion or by allergic reactions. An Overview of Natural Toxins in Food What are Natural Toxins in Food? As opposed to man-made chemicals such as pesticides, veterinary drugs or environmental pollutants that get into our food supply, toxins can be present due to their natural occurrence in food. Natural toxins found inherently in foods of plant and animal origins can be harmful when consumed in sufficient quantities. Risks of toxins in food General toxicity (instant death or illness) •Carcinogenic •Mutagenic •Teratogenic •Endocrine disrupters (hormones) •Microbial pathogens Natural Toxins in Foods •Endogenous toxins of plant originToxic phenolic substances: flavonoids, tannins, coumarin, safrole, and myristicin Cyanogenic glycosides Glucosinolates Acetylcholinesterase inhibitors Biogenic amines Central stimulants •Natural contaminants Mixing of edible plants with toxic plants Contamination resulting from intake of toxic substances by animals Microbial toxins Natural Toxins Present in Food of Plant Origin Of over 300 000 different plant species in the world, at least 2 000 species are considered to be poisonous. Cases of poisoning are often reported when wild species of mushrooms, berries or other plants are ingested. Globally, only hundreds of plant species are commonly eaten, yet many of them can become toxic to the body if they are taken in excess or if they are not properly treated before consumption. Depending on the species, the edible parts of plants vary, which may include foliage, buds, stems, roots, fruits and tubers, and so are their poisonous parts. Natural Toxins Present in Food of Plant Origin Plants from the same genera may exhibit similar or vastly different toxicities. The amount and the distribution of the toxins present in a plant vary according to the species as well as the geographical conditions where it is grown. In general, plant organs that are important for survival and reproduction, such as flowers and seeds, will concentrate defense compounds. These compounds may be more rapidly synthesized or stored at certain stages of critical growth, i.e. in buds, young tissue or seedlings as in the case of potato sprouts. Common examples of natural toxins in food plants include glycoalkaloids in potatoes, cyanide-generating compounds in bitter apricot seeds and bamboo shoots, enzyme inhibitors and lectins in soya beans, green beans and other legumes Sprouted potatoes Solanine. Another natural toxin, solanine, is found in some potatoes. Your mother told you not to eat potatoes with a green tinge and to throw away sprouted potatoes, and she was right Mushroom Toxins •Caused by the high content of amatoxins in mushrooms. •Mushrooms identified as containing amatoxin toxins are the species Amanita bisporigera, A. temifolia, A. ocreata, A. suballiacea, Galerina autumnalis, and Lipiota brunneolilacea There are four categories of mushroom toxins: 1.Neurotoxins Cause neurological symptoms such as profuse sweating, hallucinations, depression, spastic colon, excitement, convulsions, and coma. Protoplasmic poisons Cause generalized destruction of cells, which is followed by organ failure. 3.Gastrointestinal irritants Produce rapid, transient nausea, abdominal cramping, vomiting, and diarrhea. Disulfram-like toxins 4.Disulfram-like toxins are usually nontoxic and produce no symptoms. However, if alcohol is consumed within 72 hours after eating them, they may produce vomiting, nausea, headache, flushing, and cardiovascular disturbances. *The first symptoms of mushroom poisoning occur within 6– 24 hours after ingestion of the mushrooms (phase one). *Phase two, also called the gastrointestinal phase, involves severe vomiting and abdominal cramps, nausea, and watery diarrhea. *Phase three lasts about 12–24 hours and is characterized by improved clinical symptoms; however, it is also the beginning of liver necrosis. *Phase four (the last phase), results in hepatic failure, encephalopathy, internal bleeding, and, often, acute renal failure. Internal bleeding is usually observed and may cause complications and death. •Patients usually die within 5–20 days after ingestion of the mushrooms Natural toxins in aquatic organisms poisoning symptoms include tingling and burning in face, lips, tongue, and ultimately the whole body, and parathesia followed by numbness, general motor incoordination, confusion, and headache. Microbial Toxin: Mycotoxin Mycotoxin contamination of food and feed highly depends on the environmental conditions that lead to mold growth and toxin production. •The detectable presence of live molds in food, therefore, does not automatically indicate that mycotoxins have been formed. •On the other hand, the absence of viable molds in foods does not necessarily mean there are no mycotoxins. The latter could have been formed at an earlier stage prior to food processing. •Because of their chemical stability, several mycotoxins persist during food processing, while the molds are killed. DEFINITION-Mycotoxin Myco: fungus. Toxin: naturally-produced poison. Mycotoxins are secondary metabolites of fungi that are recognized as toxic to other life forms. Can be heat stable, not destroyed by canning or other processes. Types of mycotoxins Aflatoxins Fumonisin Ochratoxins Patulin Citrinin Trichothecenes Zearalenone Aflatoxin Aflatoxin is the name for a group of toxins (poisonous chemical compounds) that are produced by two fungi called Aspergillus flavus and Aspergillus parasiticus. Aflatoxins • Aflatoxins are the most important mycotoxins, which is produced by certain species of Aspergillus (A. flavus and A. parasiticus), which develop at high temperatures and humidity levels. • •Aflatoxins are carcinogenic substances and may be present in a large number of foods. This toxin can cause cancer, cirrhosis of the liver. • •For substances of this type there is no threshold below which no harmful effect is observed. • The aflatoxins B1, B2 fluoresce blue and G1, G2 fluoresce green when viewed under a microscope. • •A major metabolic product of aflatoxin B1 is aflatoxin M (usually excreted in the milk of dairy cattle that have consumed aflatoxincontaminated feed). • •LD50 ranges from 0.5 to 10 mg/kg body weight (any species of animals) • The most common commodities contaminated are tree nuts, peanuts, and corn and cottonseed oil. • The major aflatoxins of concern are B1, B2, G1, and G2 usually found together in various proportions. Aflatoxin B is usually predominant, and it is the most toxic and carcinogenic. Ochratoxin Aspergillus ochraceus and several other species including Penicillium produce seven structurally related secondary metabolites called ochratoxin. Ochratoxin is found in a large variety of foods including wheat, corn, soybeans, barley, coffee beans, meats and cheese. Barley is thought to be the predominant source. Fumonsins Fumosins are produced by Fusarium verticillioides, F. proliferatum, and F. nygamai. Patulin Patulin is produced by Penicillium clariform, P. expansum, P. patulum. Mycotoxins can cause Death. Respiratory problems. Reproductive problems. Liver, kidney or other organ damage. Cancer. Bleeding. Birth defects. Mycotoxin Treatment Mycotoxin poisoning is known as mycotoxicosis. There is no cure for mycotoxicosis. Antibiotics and drugs have little effect. The best treatment is to stop the exposure to mycotoxins. Natural Toxins Present in Food of Animal Origin Natural toxin of animal origin may be a product of metabolism or a chemical that is passed along the food chain. While poisoning after eating terrestrial animals is relatively uncommon, poisoning due to marine toxins occurs in many parts of the world. Marine toxins produced by toxic microalgae are accumulated in shellfish, crustacean and finfish following their consumption. Tetrodotoxin, a potent marine neurotoxin, is thought to be produced by certain bacteria. It is found in over 90 species of puffer fish and may cause lethality after ingested even a small amount. Seafood poisoning commonly reported in coral reef fish is due to the presence of ciguatoxin that may be found in more than 300 species of fish. Histamine produced by bacterial spoilage of scombroid fish causes another kind of seafood poisoning. There are approximately 1 200 species of poisonous and venomous animals in the world. While most of them are not used as food, care must be taken to avoid the poisonous glands or tissue containing the toxins when these animals are used as food. Glands of some animals that are not considered poisonous or venomous when ingested can also cause food poisoning such as gall-bladder of grass carp which contains the cyprinol related chemicals. Toxic Effects and Food Poisoning Natural toxins in food can cause both acute and chronic health effects with a range of clinical symptoms. Acute symptoms range from mild gastrointestinal upset, neurological symptoms, respiratory paralysis to fatality. This is more likely among the susceptible groups of the population such as children and the elderly. Within hours if not shorter, acute symptoms are seen following ingestion of various marine toxins in shellfish and other seafood. Acute poisoning is also seen in the consumption of wild mushrooms or inadequately treated plants such as ginkgo seeds and bitter apricot seeds. Toxic Effects and Food Poisoning Chronic toxicity is seen more often in poisoning caused by plants toxins such as many alkaloids. Pyrrolizidine alkaloids that are present in weeds in crops and in certain plants may cause toxicity to the liver over prolonged consumption. The amount of food that would cause toxic effects depends on the toxin level present as well as individual susceptibility. Risk Reduction Measures In some cases, appropriate methods of food processing and thorough cooking can be employed to destroy or reduce the level of toxin. In other cases where the toxin cannot be reduced or removed, intake should be limited. Thorough cooking destroys enzyme inhibitors and lectins of beans. Soaking in water, and boiling also remove some cyanide-generating compounds in the foods concerned. Removal of gonads, skin, and parts of certain fish eliminates toxins concentrated in these tissues. In general, whether a substance poses harm depends on its concentration, amount of intake and the health status of individual since the body can detoxify low levels of many potentially dangerous substances. As a rule of thumb, the public should follow the conventional ways of food processing that are known to be safe, and maintain a balanced and varied diet so that exposures to certain types of natural toxins can be kept to a safe level. Hydrazines. Mushrooms, when eaten raw, are a source of potentially cancer-causing hydrazines. Because they're inactivated when cooked, this is a case where cooked is better than raw. • Psoralens. Produced in moldy celery, this relatively mild natural toxin can give you a skin rash when you're in the sun -- a reaction called photosensitivity Residue Problems in Food Lecture 4 • FOOD SAFETY :A suitable edible product which when consumed orally either by a human or an animal does not cause any health risks (to consumer • RESIDUES:These substances having a pharmacological actions of their metabolites and of other substances transmitted to animal products and which are likely to be harmful to human health. RESIDUES Pesticide residues Heavy metal residues Antibotic residues Pest: “ includes vectors of human or animal disease, unwanted species of plants or animals causing harm during or otherwise interfering with the production, processing, storage, transport or marketing of food, agricultural commodities, wood and wood products or animal feedstuffs”. Introduction When crops are treated with pesticides very small amounts may remain in or on the crop after harvesting or storage. In order to determine any pesticide residues present in foodstuffs analytical methods capable of accurately measuring extremely small amounts of pesticides are required. Gas chromatography is the most used equipment in pesticide analysis others include High performance liquid chromatography (HPLC) . 116 A pesticide is any substance or mixture of substances intended for preventing, destroying, repelling, or mitigating any pest. Pests include insects, plant pathogens, weeds, molluscs, birds, mammals, fish, nematodes (roundworms), microbes and people that destroy property, spread or a vector for disease or cause a nuisance PESTICIDES A pesticide is a substance or mixture of substance intended for preventing, destroying, repelling or lessening the damage caused by the pest. A pesticide can be a insect, plant pathogen, weed, bacteria, bird etc. That compete with the human for food, destroy property, spread disease. A pesticide can be a chemical, biological agent, antimicrobial, disinfectant etc. Many chemical pesticides are poisonous to human and animals. Classification of pesticides 1. Herbicide-These are the chemicals used to kill weeds (i.e., unwanted plants) e.g. Borax, Nitrofen. 2. Insecticide-These are used to kill insect. E.g. DDT, BHC. 3. Rodenticide-These are used to kill rodents. e.g. Warfarin, Zinc phosphide. 4. Nematicide-These are used to kill namatodes e.g. DBCP, Phorate 5. Molluscicide-These ar used to kill molluscs e.g Sodium pentachloridephenate. 6.Fungicides-These are used to kill fungus e.g. Bordeaux mixture 7.Algaecides-These are used to kill algae e.g. Copper sulphate, Endothal 8.Bactericide-These are used to kill bacteria e.g. Dichlorophen,Oxolinic acid 9.Piscicides-These are used to kill fishes e.g. Trifloro methyl nitrophenol(TFM) Chemical or Synthetic Pesticides Organochlorenes-These are non-biodegradable and persist in soil for long time e.g., DDT, BHC, Endosulfan, Aldrin. Organophosphate-These are esters of alcohols with phosphoric acid or with some other acids. These are very toxic acetyl-cholinesterase inhibitors as a result of which the breakdown of acetyl choline stops.The accumulation of acetyl choline resulting in convulsion paralysis and death e.g.,Malathion. Carbamates-They are derived from carbamic acid. Mode of action of carbamates is almost similar to organo- phosphates e.g.,Carbaryl, Dimetilan. Working of Pesticides Pesticides work in the following ways By blocking the cellular processes of the target organisms in a purely mechanical way e.g., Spray oils, petroleum oils. By destroying or altering the pest’s metabolism e.g., Rotenone and cyanide which disrupt respiratory function in pests. By disrupting enzyme processes or denature proteins e.g. Inorganic Copper compounds By simulating or interfering with hormones e.g., Phenoxy herbicides. By disrupting photosynthesis and preventing the weed plant from producing or storing energy e.g., Triazine. Benefits of pesticides • They are used in public health programmes to control vector born diseases • They are used to protect the stored food grains. • They protect the standing crop in the field. They do not increase the crop yield like fertilizer but by protecting the crop from pests. • They can be used to control household pests. Hazards of pesticides 1. The pesticide industries cause pollution of soil, water and air.The pesticidal residue washed along with rain water, is added to the nearby water resources making it unfit for drinking. 2. They enter the food chain and cause problem of bioaccumulation or biomagnification. 3. They are not target specific hence also kills non-pest insects. It adversely affect the mechanism of entomophily. 4.Continuous and indiscriminate use of pesticides may develop resistance in insect pest like superpest and superbugs. Pesticides are often referred to according to the: 1) Type of pest they control 2) Derived from a common source or production method - chemical pesticides - biopesticides - antimicrobials - pest control devices Chemical pesticides: • Organophosphate Pesticides - These pesticides affect the nervous system by disrupting the enzyme that regulates acetylcholine, a neurotransmitter. Most organophosphates are insecticides. However, they usually are not persistent in the environment. (e.g. parathion, malathion, and methyl parathion) • Carbamate Pesticides affect the nervous system by disupting an enzyme that regulates acetylcholine, a neurotransmitter. The enzyme effects are usually reversible. There are several subgroups within the carbamates. (e.g. Bendiocarb, Carbaryl, Methomyl, and Propoxur) • Organochlorine Insecticides were commonly used in the past, but many have been removed from the market due to their health and environmental effects and their persistence (e.g. DDT and chlordane). • Pyrethroid Pesticides were developed as a synthetic version of the naturally occurring pesticide pyrethrin, which is found in chrysanthemums. They have been modified to increase their stability in the environment. Some synthetic pyrethroids are toxic to the nervous system. (e.g. permethrin, resmethrin, and sumithrin ) • Biopesticides: – Pesticides derived from such natural materials as animals, plants, bacteria, and certain minerals. 1. Microbial pesticides consist of a microorganism (e.g. a bacterium, fungus, virus or protozoan) as the active ingredient. For example, there are fungi that control certain weeds, and kill specific insects. 2. Plant-Incorporated-Protectants (PIPs) are pesticidal substances that plants produce from genetic material that has been added to the plant. 3. Biochemical pesticides are naturally occurring substances that control pests by non-toxic mechanisms (e.g. insect sex pheromones that interfere with mating, and various scented plant extracts that attract insect pests to traps). Pesticide & Residues- Definitions • Biocide by definition is any substance used with the intention of killing living organisms whether these are pests or not. • Pesticides are compounds that man uses to control, meaning to reduce in number or to eradicate, organisms that interact negatively with his activities such as crop production and gardening, or to control disease in people, animals, etc. • Pesticide Residues Any substance or mixture of substances in food for man or animals resulting from the use of a pesticide including any specified derivatives, such as degradation and conversion products, metabolites, reaction products and impurities considered to be of toxicological significance. Toxicity Labelling Label Name Level of toxicity Oral lethal dose mg per kg body weight of test animal Red label Extremely toxic Yellow label Highly toxic 51-500 Endosulfan, carbaryl,quinalp hos, and others. Blue label Moderately toxic 501-5000 Malathion, thiram,glyphosat e, and others. Green label Slightly toxic More than 5000 Mancozeb, oxyfluorfen, mosquito repellant oils and liquids, and most other Wikipedia household insecticides. 1-50 Listed chemicals Monocrotophos, zinc phosphide, ethyl mercury acetate, and others. Insectide • Classification by chemical group – – – – Organo Chlorine Organo Phosphate Carbamates Pyrethroids Organochlorine • Organic compound containing at least one covalently bonded atom of chlorine (the diphenylethanes, the cyclodienes and the Cyclohexanes)Highly Effective against various Insects • High persistence and Highly lipophilic DDT Dicolfol Methoxychlor X-Cl X=Cl X=OCH3 Y=H Y=OH Y=H Aldrin Dialdrin & Endrin Endosulfan Lindane Organophosphate • • • acetylcholinesterase (AChE) in ganglia and in the parasympathetic nervous system. [SLUD Syndrome] Highly Toxic , Less lipophilicity, Fast degradation Parathion (parathion-ethyl) introduced in 1944 -higher environmental stability LD 50:3–13 mg kg−1BW Ref, Mello et al., 2003 : Food Safety: Comtaminants and toxins Common name Rat oral LD50 Rabbit dermal LD50 Chlorpyrifos 96–270 2,000 Diazinon 1,250 2,020 Dimethoate 235 400 Ethoprop 61.5 2.4 Fenamiphos 10.6–24.8 71.5–75.7 Malathion 5,500 >2,000 Methamidopho 13 (female s only) 122 Methyl 45 6 Carbamates • Low toxicity/ Low Lipophilic • Acetylcholineesterase Inhibitor (Reversable) • Common name Rat oral LD50 Rabbit dermal LD50 Aldicarb 1 20 Carbaryl 500–850 >2,000 Carbofuran 8 >3,000 Fenoxycarb 16,800 >2,000 Methiocarb 60–1,000 depending on product >2,000 (rat) Methomyl 30–34 >2,000 Oxamyl 5.4 2,960 Thiodicarb 66 >2,000 Pyrethroids • Pyrethroids~ Pyrethrin (Tanacetum cinerariaefolium) Common name DeltametrinLD50 for the fly is 0.0003 µg Rat oral LD50 Rabbit dermal LD50 Allethrin 860 11,332 Bifenthrin 375 >2,000 Cyfluthrin 869–1271 >5,000 (rat) Cyhalothrin 79 632 (rat) Cypermethrin 250 >2,000 Deltamethrin 31–139 (female) >2,000 Esfenvalerate 451 2,500 Fenpropathrin 70.6–164 >2,000 Fluvalinate 261–282 >20,000 Permethrin 430–4,000 >2,000 Benzoylureas • Synthesized between dichlobenil derivatives and fenuron • Act on the formation of chitin,hindering the development of larvae during moult (by causing the imperfect formationof the new cuticle) and causing their death. • They are not selective , affect CNS of mammals. • Eg., Diflubenzuron, Flufenoxuron, Hexaflumuron Fungicides • Inorganic FungicidesCopper Salts • Organic Fungicides in Table • DithiocarbomatesEthyle ne thio urea • Benzimidazoles- Systemic Fungicide • Dicarboximides- Resistant • Triazoles - biosynthesis of ergosterol • Anilinopyrimidines- Act on biosynthesis of AA Ref, Mello et al., 2003 : Food Safety: Comtaminants and toxins Herbicides • mechanism of action of herbicides is an interaction with the biochemical processes of vegetables, they have no toxicity for animals, But • Dermitis • Paraquat- Toxic to lungs • Percolate into soil Ref, Mello et al., 2003 : Food Safety: Comtaminants and toxins Maximum residue levels (MRLS) • Mrl is the highest level of a pesticide residue that is legally tolerated in or on food or feed when pesticides are applied correctly (Good Agricultural Practice). • Mrl covers the safety of all the consumers i.e children to adults • The maximum residue levels information is provided by the chemical produce during chemical registration. • Any food or non-food should meet the levels of pesticide mrl of the different pesticides 138 Example of MRL analysis on grapes 139 Extraction process • This is a fundamental process in pesticide residue analysis because no in-situ technique has yet been invented. • There are several extraction approaches employed such as: Pressurized liquid extraction(PLE) Supercritical fluid extraction (SFE) Aqueous extraction Microwave-assisted extraction(MAE) Solid-phase extraction (SPE) Solid-phase microextraction (SPME) Matrix solid-phase dispersion (MSPD) 140 Clean-up Clean-up is done to obtain uncontaminated products for analysis. The clean-up process is vital especially in analysis of fatty foods. Liquid-liquid and liquid-solid partitioning in which separation is based on polarity is the primary mean of clean-up in residue analysis. Separations based on molecular weight, gelpermeation or size-exclusion chromatography is common clean-up technique. Other techniques used include precipitation, centrifugation, ultrafiltration, dialysis and 141 immunochemical. Gel permeation chromatography • Also known as size-exclusion chromatography (SEC) separates compounds with large molecular weight such as lipids and proteins from smaller analytes such as pesticides using a porous stationary phase material. 142 Analysis • Capillary electrophoresis Small amount of sample is typically sucked or forced into the capillary by pneumatic pressure, then the voltage is applied. Separation of ions occurs based on the mobility of ions, which is a function of size and charge. Smaller cations in the buffer have higher mobility and force overall flow toward the anode. Neutral molecules are carried with this flow in the electro-osmotic front while charged molecules migrate faster or slower through the capillary based on their charge and mobility. 143 Gas-liquid chromatography GC-MS GC-MS is usually used in the analysis of mid- polar to non-polar compounds whereas HPLC technique used for polar compounds. Organophosphate and carbamate pesticides are mid polar in nature thus gas chromatography is well suited for their analysis. GC-MS systems are equipped with extensive mass spectral “libraries”that can be extremely useful for identification and characterization of unknown compounds. 144 Example of final GC data obtained Source : www.restek.com 145 Pesticides detected using GC Pesticides analysed using GC Organochlorines e.g. dieldrine, DDT, Lindane. Organophosphorus e.g. diazinon, dichlorvos, malathion Pyrethroids e.g. cypermethrin, deltamethrin Aromatic fungicides eg chlorothalonil, quintozene Dicarboximide fungicides eg folpet • Other pesticides also analyzed using GC but showing low or no response include: Carbamates, imidazoles, benzoylureas, sulfonylureas 146 Pesticides analysed using LC Carbamates e.g. carbendazim Conazoles e.g. fenamidone Sulfonylureas e.g. triasulfuron Triazines e.g. simazine Phenylureas e.g. linuron Strobilurins e.g. azoxystrobin Neonicotinoids e.g. acetamiprid All the above plus their metabolites can be analysed by Liquid chromatography 147 Mass spectrometry • Ideally suited for multiresidue analysis • Features of MS Universal and selective Screening and confirmation Compatible with GC and LC 148 Food Adulteration Lecture 5 • • • • Definition of adulteration Types of adulteration Common foods adulterated How to detect adulteration Introduction Food adulteration consists of a large number of practices, e.g., mixing, substitution, concealing the quality, putting up decomposed food for sale, misbranding or giving false labels and addition of toxicants. The ignorance of people being not able to recognize food that is wholesome versus adulterated has made such adulteration possible. Food adulteration can be: • Economic adulteration implies that food is adulterated by dilution (adding water to milk), removal (removing 11% fat from food and using 2% fat), or using substitutes (using Equal for sugar). • Adulteration also results from addition of foreign material to food, such as stones in rice to compensate for weight. This addition increases the volume of trade. • Adulteration can also occur because of the type of package used for holding food. Labeling should disclose the integrity of the food, and if adulterated food is labeled as one that is not, then unaware consumers are injured or harmed by consuming such food. Packaging and labeling are more recent developments, and newer laws have been instituted to discourage food adulteration. ADULTERATION Simple definition: Reducing the purity of an article by the addition of a foreign or inferior substance Act of intentionally debasing the quality of food offered for sale either by admixture or substitution of inferior substances or by the removal of some valuable ingredient. What is Adulteration? • An adulterant is a chemical substance which should not be contained within other substances (e.g. food, beverages, and fuels) for legal or other reasons. • The addition of adulterants is called adulteration. • The word is appropriate only when the additions are unwanted by the recipient. Otherwise the expression would be food additive. Adulterants when used in illicit drugs are called cutting agents, while deliberate addition of toxic adulterants to food or other products for human consumption is known as poisoning. What is Adulteration?? • Adulteration usually refers to mixing other matter of an inferior and sometimes harmful quality with food or drink intended to be sold. As a result of adulteration, food or drink becomes impure and unfit for human consumption. • "Adulteration" is a legal term meaning that a food product fails to meet federal or state standards. Food adulteration is defined as ‘the intentional addition of non-permitted foreign matter’. Reasons for food adulteration are To get more profit To increase the weight, adulterant is added. To increase volume of trade by showing lower prices. Food is said to be adulterated if… • the article sold by a vendor is not of the nature, substance or quality demanded by the purchaser; • the article contains any other substance which affects the nature, substance or quality; • any inferior or cheaper substance has been substituted; • the article had been prepared, packed or kept under insanitary conditions whereby it has become contaminated or injurious to health; • the article consists wholly or in part of any filthy, putrid, , rotten, decomposed or diseased animal or vegetable substance or is insect-infested or is otherwise unfit for human consumption; • the article is obtained from a diseased animal; • the article contains any poisonous or other ingredient which renders it injurious to health; • the container of the article is composed of any poisonous or deleterious substance which renders its contents injurious to health; • any coloring matter other than that prescribed is present in the article; • the article contains any prohibited preservative or permitted preservative in excess of the prescribed limits; Different Types of Food Adulteration Intentional: Sand, marble chips, stones, mud, other filth, talc, chalk powder, water, mineral oil Incidental: Pesticide residues tin from can, droppings of rodents, larvae in foods. Metallic contamination: Arsenic from pesticides, lead from water, mercury from effluent, from chemical industries, tins from cans. Packaging Hazards: Polyethylene, polyvinyl chloride and allied compounds are used to produce flexible packaging material. Some Adulterated Foods in market Turmeric, dals and pulses • Adulterant: Metanil Yellow and Kesari Dal • Health hazard: highly carcinogenic, stomach disorders. Green chillies, green peas&other vegetables • Adulterant : Malachite Green, Argemone seeds • Health hazard: carcinogenic if consumed over a long period of time Mustard seeds and mustard oil • Adulterant : Argemone seeds, Papaya seeds • Health hazard: epidemic dropsy and severe glaucoma Some other adulterants… Cream is adulterated with gelatin, and formaldehyde is employed as a preservative for it. Butter is adulterated to an enormous extent with oleomargarine, a product of beef fat. Brick dust in chilli powder, colored chalk powder in turmeric. In confectionery, dangerous colors, such as chrome yellow, prussian blue, copper and arsenic compounds are employed. Pickles and canned vegetables are sometimes colored green with copper salts. Common adulterants present in food: Milk - Addition of water/removal of fat. Skim milk - soluble starch. Cream -foreign fats. Vegetable oils -Cheap/non edible oil like linseed, mineral oils. Wheat and rice -stones Chilli powder- Starch colored red by tar dye. Black pepper- Dried papaya seeds Honey -colored sugar syrup. Tea - exhausted tea leaves. 055 ADULTERATED MILK Milk is generally adulterated with either water or by starch MATERIALS REQUIRED Milk samples Dropper Black paper Tincture iodine (available in Pharmacy) milk NORMAL ADULTERANT TO MILK IS WATER PURE MILK WILL FLOW SLOWLY AND LEAVE A WHITE TRAIL. ADULTERATED MILK WILL FLOW FAST AND NOT LEAVE A WHITE TRAIL If milk is contaminated by starch then add a drop of tincture iodine to warm milk milk adulterated milk no change in colour changes in colour to blue Foods Commonly Involved Honey • Invert sugar/jaggery Test • Aniline Chloride Test : Take 5 ml. Of honey in a porcelain dish. Add Aniline Chloride solution (3 ml of Aniline and 7 ml. Of 1:3 HCl) and stir well. Orange red colour indicates presence of sugar. Foods Commonly Involved Wheat flour Adulterants in food Diseases or Health Effects • Chalk powder Test • Shake sample with dil.HCl Effervescence indicates chalk. Some adulterated food products and there adverse effects • Turmeric, dals and pulses such as moong or channa: Here adulterant is Metanil Yellow and Kesari Dal (Added to enhance the yellow colour of a food substance).It's harmful effect is that it is highly carcinogenic and if consumed over a continuous period of time it can also cause stomach disorders. • Green chillies, green peas and other vegetables: Here adulterant is Malachite Green (To accentuate the bright, glowing green colour of the vegetable).Argemone seeds (used to add bulk and weight)that it is a coloured dye that has proven to be carcinogenic for humans if consumed over a long period of time. Some Examples Adulteration in olive oil Contd… • Mustard seeds and mustard oil: Here adulterant is Argemone seeds (used to add bulk and weight).Papaya seeds (used to add bulk)that the consumption of these could cause epidemic dropsy and severe glaucoma. Young children and senior citizens with poor immunity are more susceptible this. • Paneer, khoya, condensed milk and milk: Here adulterant is starch (used to give itthick, rich texture).It 's harmful effect is that it is unhygienic, unprocessed water and starch can cause stomach disorders. Starch greatly reduces the nutritional value of the ingredient. Contd… • Ice cream: Here adulterant is pepperonil, ethylacetate, butraldehyde, ethyl acetate, nitrate, washing powder etc which are not less than poison. Pepper oil is used as a pesticide and ethyl acetate causes terrible diseases affecting lungs, kidneys and heart. • Black pepper: Here adulterant is Papaya seeds (used to add bulk).It 's harmful effect is that Papaya seeds can cause serious liver problems and stomach disorders. • Coffee powder: Here adulterant is Tamarind seeds, chicory powder It 's harmful effect is that it can cause diarrhea, stomach disorders, giddiness and severe joint pains How to Detect Adulteration • Ingredient : Coffee powder, Adulterant: Cereal starch Take a small quantity (one-fourth of a tea-spoon) of the sample in a test tube and add 3 ml of distilled water in it. Light a spirit lamp and heat the contents to colourize. Add 33 ml of a solution of potassium permanganate and muratic acid (1:1) to decolourize the mixture. The formation of blue colour in mixture by addition of a drop of 1% aqueous solution of iodine indicates adulteration with starch. Images showing Detection of Adulteration Contd… • Ingredient : Black Pepper, Adulterant: Papaya Seeds Papaya seeds do not have any smell and are relatively smaller in size. Adulteration of papaya seed with Black Pepper may be detected by way of visual examination as also by way of smelling. Ingredient : Coriander powder , Adulterant: Saw Dust Take a little amount (a half of tea-spoon) of the sample. Sprinkle it on water in a bowl. Spice powder gets sedimented at the bottom and saw-dust floats on the surface. An Article on Food Adulteration Contd… • Ingredient : Green vegetables like Bitter Gourd, Green Chilly and others, Adulterant: Malachite Green Green vegetables like Bitter Gourd, Green Chilly and others Malachite Green Take a small part of the sample and place it on a piece of moistened white blotting paper. The impression of color on the paper indicates the use of malachite green, or any other low priced artificial color. Ingredient : Rice, Adulterant: Earth, sand, grit, unhusked paddy, rice bran, talc, etc. These adulterants may be detected visually and removed by way of sorting, picking, and washing. COMMON ADULTERATES Addition of chalk to flour Added water can be an adulterant Addition of colors to disguise poor quality Addition of sand to brown sugar and rice to make heavier Addition of sand to brown sugar and brown rice