food adulteration and hygiene

Class project on Food adulteration and Hygiene By Sandesh Paudel M. Tech. 1 st Year

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Page 1: Food Adulteration and Hygiene

Class project on

Food adulteration and Hygiene

BySandesh PaudelM. Tech. 1st Year

Page 2: Food Adulteration and Hygiene


The meaning of food adulteration

How foods are adulterated?

Some examples of food adulteration

How serious is it?

Detection of adulteration

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Food adulteration Food adulteration Adulteration is defined as the process by which the quality or the nature of the given substance is reduced through the addition of inferior substances or inedible substances or removal of vital components. The good example is the addition of water to milk and removal of fat from milk.

Addition of water to milk

Removal of fat from milk

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In order to protect the health of consumer, Nepal government promulgated the prevention

of food adulteration Act in 2027. According to this act, any ingredient which then present in

food is injurious to health is an adulterant & the article of food that shall be deemed to be


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a. If the article sold by a vendor is not of the same nature, substance or quality demanded by the purchaser and to his prejudice, or not of the same nature, substance or quality which it purports or represented to be. b. If the article contains any other substance which affects, or if the article is so processed as to affect, injuriously the nature, substance or quality thereof. c. If any inferior or cheaper substances has been substituted wholly or in part for the article, so as to affect injuriously the nature, substance or quality thereof. d. If any constituent of the article has been wholly or in in part abstracted so as to affect injuriously the nature, substance or quality thereof.

A food is said to be adulterated under the following conditions:

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e. If the article has been prepared, packed or kept under the insanitary condition where by it has become contaminated or injurious to health. f. If the article consists wholly or in part of any filthy, putrid, disgusting, rotten, decomposed or diseased animal or vegetable substance or is insect infested or otherwise unfit for human consumption. g. If the article is obtained from a diseased animal.

h. If the article contains any coloring or preservative in excess of the prescribed limits.

i. If the article contains any poisonous or other ingredients, rendering it injurious to health. j. If the quality or purity of the article falls below the prescribed standard or its constituents are present in quantities which are excess of the limits of acceptability.

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How foods are adulterated?How foods are adulterated?

a. Intentional adulteration, done for willful profit, which includes addition, substitution or abstraction of substances which adversely affect the quality of foods

b. Incidental adulteration, with deleterious constituents such as toxins, insecticides, pathogenic bacteria and fungi, etc., due to ignorance, negligence or lack of proper food preparation, processing and storage facilities.

c. Contamination of the food, with harmful microorganisms during production, storage and handling.

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Intentional adulteration Intentional adulteration Pulses are important component of our diet.

Pulses like Mansoor, black gram, gram, mung, etc. either as grams, split dahls or dahl flour (besan) are mixed with the corresponding form of Kesari. Consumption of Kesari for long time produces lathyrism, which results in lower limb paralysis.

Sand, marble, mud, stone, chip, sand and other filth materials are mostly found in grain, pulses, oilseeds, nuts and spices. Addition of excessive common salt to spice powder and curry powder is common practice. Water is added to milk and milk products like curd. Addition of contaminate water to milk could result in gastrointestinal disturbances.

Mineral oil: Mineral oil can be added to edible oils, thus adulterating it. This could be a health hazard as some mineral oils are toxic. Oils and fats are also adulterated with petroleum products causing gastrointestinal disturbances.

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Other common adulterants are animal fats and vegetable ghee in dairy ghee. Orthotricresyl phosphate is a colorless industrial chemical freely soluble in oils but insoluble in water and is used to adulterate some oils. This chemical can cause the permanent damage to the nervous cells.

Argemone seeds: Argemone seeds look very much like mustard seed and are mixed with them as an adulterant. When such mixture is extracted for oil, it becomes dangerously toxic, because consumption of Argemone oil can lead to loss of eyesight, heart disease, epidemic dropsy.

One of the most frequently used adulterants is the coloring matter. Color is used in many foods such as milk products, bakery products, confectionary, soft-drinks, alcoholic beverages, tea and spices. More than 2% of the colors containing marketed samples of food are found to contain non-permitted colorants like coal tar dyes, rhodamine, lead chromate, metanil yellow, malachite green, congo red, yellow earth, etc. All these dyes are toxic and intake of them in excess could lead to abnormalities of eye, bone, skin, lungs, ovaries and testes.

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Common adulterants in different foodsCommon adulterants in different foods

In milk and milk products

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In vegetable fats and oils

In spices and condiments

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In cereals

In pulses

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In sweetening agents and soft drinks

In beverages

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Incidental adulteration Incidental adulteration

Foods can become contaminated with toxic metals or chemicals, such as compounds of lead, mercury, arsenic, antimony, DDT, BHC, etc. due to the following causes: a. Accidental mixing of the food with toxic

chemicals used as rat poison such as arsenic oxides, barium carbonate, lead arsenate and others.

b. Accidental contamination with pesticides and insecticides.

c. The presence of some toxic chemicals or minerals in certain marine foods, e.g. mercury.

d. Presence of excessive amounts of certain food additives.

e. Use of improper kind of tin plate and lacquer for canning of food resulting in metallic contamination of food, and indiscrimination of all plastic packaging materials.

Pests like rodents and pesticide residue could also render food unfit for human consumption.

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PesticidesPesticides like DDT could leave residue on the plant

product much more than that is considered safe.

The maximum permissible residue allowed for DDT and Malathion is 3 ppm. For Pyrethru, it is 10 ppm. But pesticide residue in most of the fruits and vegetables has been found much higher than permissible limits.

Precautions should be taken before the consumption of such produce. Fruits/vegetables must be washed repeatedly with potable water before consumption.

Use of pesticide has increased the possibility of metallic contamination of food. If proper care is not taken in using the right kind of tin plate & lacquer for food canning, metallic contamination of food could be a problem.

Some metallic residues are highly toxic when they get entrance to human body, which include arsenic, mercury, lead and tin.

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Arsenic Arsenic pesticides are main source of arsenic

contamination of foods. For e.g. fruits as apples and grapes are sprayed with lead arsenates, if eaten without washing could be harmful. The quantity of arsenic allowed in food products vary from 0.1 ppm (milk) to 5.0 ppm (spices) depending upon the food.

When arsenic contamination is higher than the prescribed limit, it can cause dizziness, chills, cramps and paralysis.

Lead Lead could get into food through the lead pipes

carrying water and from food colors containing lead salts.

The quantity of lead allowed in food products varies from 0.5 ppm (concentrated soft drinks) to 10.0 ppm (liquid pectin and chemicals not otherwise specified) depending on the food products.

If the buildup of lead in body increases beyond the critical level of 40-80 mcg per 100ml of blood, mental disturbances and behavior disorders may be produced followed by muscular paralysis, convulsions and permanent brain damage.

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Mercury It is present in the form of its

compounds in water and food. The effluents from many chemical

industries have high concentration of mercury and human beings and animals consuming crops grown with such water of fish from such areas could develop mercury poisoning.

Intake of above 0.033 mg of mercury per person is harmful. Such intakes of mercury could affect the brain with the patient becoming blind or deaf. Convulsion with intense pain is also one of the symptoms of mercury poisoning.

Tin Canned foods & beverages usually contain

small quantities of tin. Contents in foods may cause severe

headache, vomiting, vertigo, photophobia, abdominal pain, dehydration and retention of urine.

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Packaging hazards Polythene, polyvinyl chloride and all lead

compounds are used to produce flexible packaging materials.

Packaging material must not contain any toxic thermal breakdown product which would be injurious to health.

Temperatures used for heat sealing or sterilization should not result in formation of toxic residues.

Plastic packaging materials mostly create health hazard. To avoid such incidences, it is essential that food grade plastic packaging material is used for packaging foods.

Food additives Safe maximum limits have been prescribed for

food additives such as benzoic acid, sorbic acid and metabisulfite in processed foods.

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Solvent residues

Hexane is the solvent permitted for solvent extraction of oil from oilseed cakes.

A safe limit of 170 ppm has been prescribed for hexane in solvent extracted edible oilseed flour.

Animal feed additives

Special additives such as diethyl stilbestrol and antibiotics are added to animal and poultry feeds. These are present in the meat of animals fed on feeds containing these chemicals.

Stilbestrol even in small doses can cause leukemia and cancer. Antibiotics can cause drug resistance and hardening of arteries.

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Insects and rodents contamination of stored foods

Insect infestation: It causes heavy losses & damage to the quality of grains in storage. Taste, flavor, hygienic quality and acceptability of food grains are affected due to the presence of the excreta (rich in uric acid), insect fragments and dead insects. The contents of B-vitamins & the nutritive value of the proteins are lowered.

Rodents: Rodents cause damages to stored foods as follows: (i) They consume large quantities of food grains, and (ii) The hygienic quality of the grain is affected by the excreta of the rodents and also by some disease producing microorganisms present in them.

Molds (Fungi): Contamination of molds (pathogenic fungi) have harmful effects on the stored foods.

Losses of food grains due to these factors are high and may range from 10-30% depending on the commodity, place and mode of storage.

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Contamination of food with harmful microorganisms

Raw foods such as meat, fish, poultry, milk and vegetables grown on sewage purchased from the market are likely to be contaminated with harmful microorganisms. These are generally destroyed during cooking or processing of the food.

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Detection of food adulteration

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Simple physical tests for detection of food adulterants Simple physical tests for detection of food adulterants

Many forms of adulteration are easily determined by simple tests that anyone, without the training of the professional chemist, may practice, using the ordinary apparatus found in the household and reagents which are constantly at hand or may be readily obtained at the drug-store. A few are given below: Organic and inorganic matter (like sand, gravel,

dirt, pebbles, stones) may be present in rice, sugar, pulses, mustards, cumin seeds, wheat, etc. Such matter can be observed simply or by simple magnification and removed.

Artificial color: It can be detected easily by visual observations. For e.g. coal tar dye is used in roasted gram and tea leaves. Depositing the tea on a moistened blotting paper will show coal tar dye presence by the color spreading on the blotting paper. Similarly, artificial color in chilies can be detected by rubbing the outer side of the chili with cotton cloth. If the cotton extracts the color and becomes red, it is an indication that the sample has added color.

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Kesari dahl in rahar, masoor, gram dahls: Kesari dahl has a characteristic wedge shape. There are two varieties: one small resembling masoor dahl, and other large resembling rahar dahl. The husked Kesari dahl is mixed with rahar. The unhusked one is mixed with black masoor or Bengal gram.

Ergots seeds in bajara: Ergots are lighter than bajara seeds and if small quantities are placed in glass of water, the ergots seeds will float.

Argemone seeds mixed with mustard seeds: Argemone seeds are small and black in color resembling mustard but not uniformly smooth and round. They can be identified under magnifying glass.

Girts in sugar and salts: Dissolve a little of the sample in hot water, sugar and salt will dissolve whereas girts will not.

Iron fillings in suji or tea leaves: By drawing a magnet over the sample, iron fillings will cling to the magnet, thus revealing their presence.

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Simple laboratory chemical testsSimple laboratory chemical tests

Beside the visual tests, certain laboratory tests could be devised to detect the adulteration in foods. However, these tests are very elementary and one should not jump to conclusion about the food being adulterated unless it is confirmed by the tests carried out in recognized laboratory. Some tests are given below:

Metanil yellow in haldi powders and sweets: Take 2 gm of ground sample in a test tube, add 5 ml of alcohol. Shake and add a few drops of conc. HCl, a pink coloration indicates the presence of metanil yellow.

Addition of starch to milk, dairy sweets, butter, coffee powder, etc.: Add a drop of iodine solution to small quantity of sample, formation of blue color indicates adulteration with starch. In case of coffee powder, make a decoction of coffee; decolorize it by adding potassium permanganate solution. Then add drop of iodine solution. Blue color formation will indicate adulteration with starch.

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Argemone oil with mustard oil: Heat 5 ml of test sample with 5 ml of nitric acid for 2-3 minutes. A red color will appear if Argemone oil is present.

Rancidity in oils: To the 5 ml of sample in test tube, add 5 ml of 0.1% phosphoglucinol solution in ether. Shake for 30 minutes and then allow to stand for 30 min. A pink or red color in the acid indicates that the oil sample is rancid.

Mineral acid in aerated water: Prepare metanil yellow paper by soaking filter paper strips in 0.1% aqueous solution of metanil yellow. The paper is soaked in aerated beverages. Mineral acid would color the paper violet. This is retained even in drying the paper.

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Notable incidents of adulterationNotable incidents of adulteration In 1987, Beech-Nut paid $2.2 million in fines for

violating the Federal Food, Drug, & Cosmetic Act by selling artificially flavored sugar water as apple juice.

In 1997, ConAgra Foods pled guilty to federal criminal charges that one of its units illegally sprayed water on stored grain to increase its weight and value.

In 2007, samples of wheat gluten mixed with melamine, presumably to produce artificially inflated results from common tests for protein content, were discovered in many U.S. pet food brands, as well as in human food supply. The adulterated gluten was found to have come from China, and U.S. authorities concluded that its origin was the Xuzhou Anying Biologic Technology Development Company, a Xuzhou, China-based company.

In 2008, significant portions of China's milk supply were found to have been contaminated with melamine. Infant formula produced from melamine-tainted milk killed at least six children and were believed to have harmed thousands of others.

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Adulteration of food was practiced even in ancient times. It was not a serious problem then because, business was on a small scale and transaction involved a large measure of personal accountability.

Later with the increased centralization of food processing and distribution, and corresponding decline in personal accountability, intentional adulteration of food increased. In recent years, adulteration of food has become a serious problem over the world.

The percentage of adulterated food in our country is increasing day by day, and it accounts to 30-35%. Unfortunately, in our country, there are still no stronger consumer associations to give proper education to the public at large about the various methods of food adulteration and ways to detect them.

Apart from cheating the consumer, results of adulteration is disorder or disease.

At LastAt Last

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very much!

Thank You