Check Your Food

Simple Screening test for Detecting Adulteration in Common Food :

1	Vegetable oil	Castor oil	Take 1 ml. of oil in a clean dry test tube. Add 10 ml. Of acidified petroleum ether. Shake vigorously for 2 minutes. Add 1 drop of Ammonium Molybdate reagent. The formation of turbidity indicates presence of Castor oil in the sample.
		Argemone oil	Add 5 ml, conc. HNO3 ­­to 5 ml.sample. Shake carefully. Allow to separate yellow, orange yellow, crimson colour in the lower acid layer indicates adulteration.
2	Ghee	Mashed Potato Sweet Potato, etc.	Boil 5 ml. Of the sample in a test tube. Cool and a drop of iodine solution. Blue colour indicates presence of Starch.  colour disappears on boiling &  reappears on cooling.
		Vanaspati	Take 5 ml. Of the sample in a test tube. Add 5 ml. Of Hydrochloric acid and 0.4 ml of 2% furfural solution or sugar crystals. Insert the glass stopper and shake for 2 minutes. Development of a pink or red colour indicates presence of Vanaspati in Ghee.
		Rancid stuff (old ghee)	Take one teaspoon of melted sample and 5 ml. Of HCl in a stoppered glass tube. Shake vigorously for 30 seconds. Add 5 ml. Of 0.1% of ether solution of Phloroglucinol. Restopper & shake for 30 seconds and allow to stand for 10 minutes. A pink or red colour in the lower(acid layer) indicates rancidity.
		Synthetic Colouring Matter	Pour 2 gms. Of filtered fat dissolved in ether. Divide into 2 portions. Add 1 ml. Of HCl to one tube. Add 1 ml. Of 10% NaOH to the other tube. Shake well and allow to stand. Presence of pink colour in acidic solution or yellow colour in alkaline solution indicates added colouring matter.
3	Honey	Invert sugar/jaggery	1.      Fiehe’s Test: Add 5 ml. Of solvent ether to 5 ml. Of honey. Shake well and decant the ether layer in a petri dish. Evaporate completely by blowing the ether layer. Add 2 to 3 ml. Of resorcinol (1 gm. Of resorcinol resublimed in 5 ml. Of conc. HCl.) Appearance of cherry red colour indicates presence of sugar/jaggery.
			2.      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.
4.	Pulses/Besan	Kesari dal(Lathyrus sativus)	Add 50 ml. Of dil.HCl to a small quantity of dal and keep on simmering water for about 15 minutes. The pink colour, if developed indicates the presence of Kesari dal.
5	Pulses	Metanil Yellow(dye)	Add conc.HCl to a small quantity of dal in a little amount of water. Immediate development of pink colour indicates the presence of metanil yellow and similar colour dyes.
		Lead Chromate	Shake 5 gm. Of pulse with 5 ml. Of water and add a few drops of HCl. Pink colour indicates Lead Chromate.
6	Bajra	Ergot infested Bajra	Swollen and black Ergot infested grains will turn light in weight and will float also in water
7	Wheat flour	Excessive sand & dirt	Shake a little quantity of sample with about 10 ml. Of Carbon tetra chloride and allow to stand. Grit and sandy matter will collect at the bottom.
		Excessive bran	Sprinkle on water surface. Bran will float on the surface.
		Chalk powder	Shake sample with dil.HCl Effervescence indicates chalk.
8	Common spices like Turmeric, chilly, curry powder,etc.	Colour	Extract the sample with Petroleum ether and add 13N H2SO4 to the extract. Appearance of red colour (which persists even upon adding  little distilled water) indicates the presence of added colours. However, if the colour disappears upon adding distilled water the sample is not adulterated.
9	Black Pepper	Papaya seeds/light berries, etc.	Pour the seeds in a beaker containing Carbon tetra-chloride. Black papaya seeds float on the top while the pure black pepper seeds settle down.
10	Spices(Ground)	Powdered bran and saw dust	Sprinkle on water surface. Powdered bran and sawdust float on the surface.
11	Coriander powder	Dung powder	Soak in water. Dung will float and can be easily detected by its foul smell.
		Common salt	To 5 ml. Of sample add a few drops of silver nitrate. White precipitate indicates adulteration.
12	Chillies	Brick powder grit, sand, dirt, filth, etc.	Pour the sample in a beaker containing a mixture of chloroform and carbon tetrachloride. Brick powder and grit will settle at the bottom.
13	Badi Elaichi seeds	Choti Elaichi seeds	Separate out the seeds by physical examination. The seeds of Badi Elaichi have nearly plain surface without wrinkles or streaks while seeds of cardamom have pitted or wrinkled ends.
14	Turmeric Powder	Starch of maize, wheat, tapioca, rice	A microscopic study reveals that only pure turmeric is yellow coloured, big in size and has an angular structure. While foreign/added starches are colourless and small in size as compared to pure turmeric starch.
15	Turmeric	Lead Chromate	Ash the sample. Dissolve it in 1:7 Sulphuric acid (H2SO4) and filter. Add 1 or 2 drops of 0.1% dipenylcarbazide. A pink colour indicates presence of Lead Chromate.
		Metanil Yellow	Add few drops of conc.Hydrochloric acid (HCl) to sample. Instant appearance of violet colour, which disappears on dilution with water, indicates pure turmeric. If colour persists Metanil yellow is present.
16	Cumin seeds (Black jeera)	Grass seeds coloured with charcoal dust	Rub the cumin seeds on palms. If palms turn black adulteration in indicated.
17	Asafoetida(Heeng)	Soap stone, other earthy matter	Shake a little quantity of powdered sample with water. Soap stone or other earthy matter will settle at the bottom.
		Chalk	Shake sample with Carbon tetrachloride (CCl4). Asafoetida will settle down. Decant the top layer and add dil.HCl to the residue. Effervescence shows presence of  chalk.
18	Food grains	Hidden insect infestation	Take a filter paper impregnated with Ninhydrin (1% in alcohol.) Put some grains on it and then fold the filter paper and crush the grains with hammer. Spots of bluish purple colour indicate presence of hidden insects infestation
19	Milk	Water Urea	Put a drop of milk on polished vertical surface. The drop of pure milk either stops or flows slowly leaving a white trail behind it. Whereas milk adulterated with water will flow immediately without leaving a mark. Take 5 ml of milk in a test tube and add 2 drops of bromothymol blue soln. Development of blue colour after 10 minutes indicates presence of urea.
20	Ice Cream	Washing Powder	Put some lemon juice, bubbles are observed on the presence of washing powder
21	Sugar	Chalk	Dissolve sugar in a glass of water, chalk will settle down at the bottom, similarly for salt
22	Silver Foil	Aluminum Foil	On ignition genuine silver foil burns away completely leaving glistening white spherical ball of the same mass while aluminum foil is reduced to ashes of black Grey colour.
23	Coffee	Chicory	Gently sprinkle the coffee powder on surface of water in a glass.  The coffee floats over the water but chicory begins to sink down within few seconds.  The falling chicory powder particles leave behind them a trail of colour, due to large amount of caramel they contain
24	Tea	Coloured leaves  Used tea Iron fillings	Rub leaves on white paper, artificial colour comes out on paper. Tea leaves sprinkled on wet filter paper. Pink or red spots on paper show colour Move a magnet through the sample. Iron will stick to the magnet.
25	Red Chilli powder	Rodemine Culture Brick Powder	Take 2gms sample in a test tube, add 5ml of acetone. Immediate appearance of red colour indicates presence. of Rodamine  Brick powder settles fast chilli powder settles slowly when put in water.
26	Saffron	Coloured dried tendrils of maize cob	Pure saffron will not break easily like artificial. Pure saffron when allowed to dissolved in water will continue to give its colour so long as it lasts.

Milk

Milk is a white liquid produced by the mammary glands of mammals. Milk is an emulsion or colloid of butterfat globules within a water-based fluid that contains dissolved carbohydrates and protein aggregates with minerals.

Because it is produced as a food source for a neonate, all of its contents provide benefits to the growing baby mammal. It is the primary source of nutrition for young mammals before they are able to digest other types of food.

Early-lactation milk contains colostrum, which carries the mother's antibodies to the baby and can reduce the risk of many diseases in the baby.

Milk contains:

Enzymes : The enzymes of cow's milk are reported as proteinases, lactase, diastase, lipase, salolase, catalase, peroxidase, and aldehydrase.

Vitamins : All the vitamins recognized at the present time are contained in milk. Some are present in comparatively large and others in smaller amounts.

Pigments : The appearance of milk is white. This is due to light rays reflected by the colloidally dispersed constituents of the milk, the calcium caseinate, and calcium phosphate.

Salts : Milk contains salts of potassium, sodium, magnesium, calcium, phosphates, chlorides, and citrates. Traces of sulfates and carbonates are found. Iron is present in small amount. Iodides are also found in small amounts. The salts of milk are found in milk in solution, in the colloidal state, and in combination with the proteins. Calcium and magnesium are in combination with the casein to form calcium and magnesium caseinates. Zoller states that there may be traces of sodium and potassium caseinates.

Lactose : Sugar

Fat : Butter fat is composed of glycerol and fatty acids. Fatty acids of both the saturated and unsaturated series are present. The relative percentage of the unsaturated fatty acids varies with the feed, averaging higher in summer than in winter.

Apart from above milk also contains : 

• Niflumic acid -  anti-inflammatory painkiller
• Mefenamic acid – anti-inflammatory
• Flunixin -  anti-inflammatory
• Ibuprofen – painkiller
• Diclofenac – anti-inflammatory
• Ketoprofen -  anti-inflammatory
• Florfenicol –  antibiotic
• 17B-estradiol – sex hormone
• Triclosan – anti-fungal drug
• Pryimethamine – anti-malaria drug
• 17a-ethinylestradiol – steroid hormon

SO how the milk contamination occurs?

Read Carefully…

Sources of Microbial Contamination :

ÖBefore the cow is even milked, pathogens in the surrounding environment can    get into the cow's feed or water. Bacteria on the inside or outside of     the cow's udder can get into the milk. If the milking device (human or mechanical) hasn't been properly sanitized it may contaminate the raw milk

ÖStorage and Transfer of Raw Milk: Any time the milk is transferred or stored; all equipment and containers must be sterile to prevent contamination. The storage temperature must be low enough (usually 4 degrees Celsius) to keep any bacteria remaining in the milk from growing.

ÖPasteurization: We know that pasteurization doesn't kill all the bacteria in milk, but it won't even kill the ones it's supposed to if the guidelines for time and temperature aren't met. One way the dairy industry checks milk to make sure it has been properly pasteurized is by testing for alkaline phosphates. This enzyme has the same D-value as the tuberculosis bacterium, so if it's found in pasteurized milk, that means that time and temperature requirements were not met.

ÖEquipment: Postpasteurization contamination (PPC) because of flaws in equipment or poor sanitation practices is the most common reason for pasteurization failures.Equipment has to be properly maintained and tested, and cleaned and sterilized between uses.

ÖThe plate heat exchanger is one potential source of PPC, since cold raw milk and hot pasteurized milk pass each other on opposite sides of the heat exchange plates. If the plates have leaks or cracks, the raw milk can contaminate the pasteurized milk.

ÖStorage and Transfer After Pasteurization: Milk is vulnerable to what the industry calls time-temperature abuse whenever the milk is transferred or stored. This includes all points at or between the processing plant, the warehouse, the store and your home. The weak link in the overall cold chain is usually that indeterminate period after the milk leaves the retail outlet and reaches the consumer's refrigerator.

ÖNow that it's been brought to your attention, the pressure is on to get the milk home and into the fridge as quickly as possible. Check the temperature of your refrigerator regularly, too. It should always be less than 10 degrees Celsius.

Sources of Chemical Contaminants :

The sources of chemical contaminants in raw materials of animal origin, mainly milk, are to a large extent comparable to those of raw materials originating from plants. The most of chemical contaminants in milk and dairy products are veterinary drugs such as antimicrobials (antibiotics and sulfonamides), hormones, anthelminthitic drugs, pesticides and etc.

ANTIBIOTIC DRUGS

Much of the veterinary treatment of dairy cattle involves intra mammary infusion of antibiotics to control mastitis. Drugs apply to control several illnesses and to increase milk production. The most commonly used antimicrobials in dairy cattle can group into five major classes. These include the beta-lactams (e.g, penicillins and cephalosporins), tetracyclines (e.g., Oxytetracycline, tetracycline and chlortetracycline), amino glycosides (e.g., streptomycine, neomycin and gentamycin), macrolides (e.g., erythromycin) and sulfanomides (e.g., sulfamethazines). These drugs are administered to animals by many routes such as injection routs, orally in the food and water, topically on the skin and by intra mammary and intrauterine infusions. Whenever any route with an antibiotic treats a lactating cow, measurable levels of the antibiotic are usually detectable in the milk for a few days after the last.

BOVINE GROWTH HORMONE

Bovine Growth Hormone (BGH) or Bovine Somatotropin (BST) is a genetically engineered protein hormone either identical or similar to the natural bovine pituitary product. Its primary function is to increase milk production dairy lactating cattle. Therefore, BST is a protein hormone that increases milk production in cows between 10 and 15% An increase in milk yield typically occurs with 5 days after beginning of treatment. BGH increases activity and/or longevity of mammary secretary cells, probably via Insulin-like Growth Factor (IGF)-I produced by the liver and/or the mammary gland.

 PARASITICIDE DRUGS

Parasiticide drugs also use to remove internal parasites such as flukes, tapeworms (helminths) and nematodes (round worms) are important in animal production systems. These metabolites can account for all residues found in milk and dairy products at any time point that are both bioavailable and of toxicological significance.  Residues of benzimidazole compounds can occur in milk and dairy products and it is necessary to observe withdrawal periods for milk after therapy. Toxicological studies of animals have shown albendazole and its metabolites to be mutagenic.

PESTICIDES AND INSECTICIDES

Contamination of feeds arises in the field or store where treatment with pesticides occurs. Chlorinated pesticides and related compounds such as DDT, Polychlorinated biphenyls (PCBs) and Dioxins can enter milk and dairy products. The chlorinated hydrocarbons are extremely durable, persistent, endocrine-disrupting activities, bio-accumulating and widely distributed toxic compounds that find their way into the food chain usually through use in controlling environmental or animal pests As much as 20% of an ingested chlorinated hydrocarbon excretes in milk. Chlorinated hydrocarbons adhere to milk fat and butter contains a much higher proportion of these insecticides.  DDT can accumulate in fatty tissues and can transfer into milk and dairy products. Organochlorine pesticides such as DDT and Hexachlorocyclohexane (HCH) have banned in most countries since 1983. Residues of such compounds may persist in the environment and cause contamination through the food chain . Presented organochlorine pesticide residues (owing to their use in sanitary actions) indicating a human exposure through milk and dairy products.

MYCOTOXINS

Some of the moulds produce various toxic metabolites under appropriate temperature and moisture conditions. These metabolites, which may be hazardous for human health, are called mycotoxins  Aflatoxin M1 (AFM1) may be found in the milk of animals that are fed with Aflatoxin B1 (AFB1) containing feed. It can produce by moulds of feeds that have been harvested damp, have not adequately dried, or are improperly stored. These substances through the feedstuff can infect dairy cattle. The content of AFM1 in milk is entirely dependent on the presence of the precursor AFB1 in the ration of dairy cattle and it can numerically express as feed to milk ratio. The forming of AFM1, metabolite of AFB1, occurs in liver and it secrets into milk in the mammary gland of dairy cows.  

HEAVY METALS

Heavy metals can enter to milk and dairy products and affect the health of people who have consumed contaminate milk and dairy products. There are various levels of heavy metals in produced milk samples of different country.

Recombinant Bovine Growth Hormone and Cancer

According to the American Cancer Society recombinant bovine growth hormone (RBGH) is just one of the synthetic (man-made) hormones that are marketed to dairy farmers to increase milk production in cows. Think about this for a moment. If this particular growth hormone increases milk production in cows than what will it do to the human body over time?

• RBGH contains amplified levels of the hormone IGF-1, which promotes cancer tumors in the breast, colon, and prostate.
• It contains increased somatic cell counts (SCC’s), which means the milk has more pus, which makes it turn sour more. quickly.
• Hormone use makes the cows produce low quality milk during times when they should not be giving milk, in other words, during a cows rest period.

· a new study which concludes that milk from cows injected with recombinant Bovine Growth Hormone (rBGH) increases risks of breast and colon cancers in humans. This study is published in the January issue of the International Journal of Health Services, a peer-reviewed, leading international public health journal.

· The study summarizes evidence that rBGH increases levels of insulin-like growth factor (IGF-1) in milk. IGF-1 is a powerful stimulator and regulator of cell-growth and division in humans and cows. The study concludes that increased IGF-1 levels are risk factors for breast and colon cancer.