Detecting Food Adulteration at Home

By admin

May 10, 2017

Protect your food. By Dr Kalpana Sarkar According to the food and safety standard authority of India (FSSAI), adulteration is defined as addition or subtraction of any substance to and from food, so that its natural composition and quality is affected.

Adulteration of food is prevalent everywhere. Tea, coffee, spices, salt, sugar, grains and milk are affected. Even fruits and vegetables are not spared. Sawdust, stone bites, husk, dung etc are used to increase the weight of the product, while certain dyes like Metanil yellow and Sudan red which are used for colouring, increase the visual appeal. These dyes are carcinogenic i.e. causing cancer. Other adulterants cause stomach upsets, liver problems and also affect the other organs of the body.

You cannot see these adulterants with the naked eye (except in some cases), but you can detect them at home. A few of these tests may require the use of acid, but you can instead use lemon juice or orange juice as suggested by some people. Outlined below are tests on some common kitchen items.

MilkAdulterant – water, which can cause water-borne diseases. Test – Put a drop of milk on a smooth slanting surface. Pure milk will flow down slowly and leave a white trail behind. Watered milk will run down fast and leave no such trail.Adulterant – Synthetic milk. Test – This has a bitter after-taste and turned yellow on heating.Adulterant – Starch, which can cause nausea and vomiting. Test – Take a small sample in a test tube. Add 20ml water. Boil and cool. Add a few drops of iodine. A blue colour indicates starch.Adulterant – Urea. Test – Take 1 tsp milk in a glass Add 1 tsp soya bean powder Mix and leave for 5mts. Dip a red litmus paper. If it turns blue, the test is positive.Adulterant – Detergent. Test – Shake a small sample of the milk. It will froth.Adulterant – Vanaspati. Test – Take 5ml each of milk and water in a test tube. Add 1 ml hydrochloric acid. A red colour after 5mts indicates the presence of vanaspati.Adulterant – Formalin, which is used as a preservative. Test – Take 10ml of milk in a test tube and add 2-3 drops of sulphuric acid. A blue ring at the top indicates the presence of formalin.

Salt & SugarAdulterant – chalk powder Test – Dissolve a teaspoon of salt / Sugar in a glass of water. If it is pure, it will dissolve. If chalk is present, it will sink to the bottom

Iodised salt Test – Add some salt on the cut surface of a raw potato. After 1 minute add some lemon juice. Lodized salt will turn blue whereas normal salt will not change colour.

Ice-creamAdulterant – Wash powder, which adds a sheen to the product and also causes stomach upsets. Test- Add a few drops of lemon juice to the ice-cream if it froths and bubbles, washing powder is present.

Coffee powderAdulterant – Powdered tamarind seeds and chicory. This can lead to joint pains, loose stools and giddiness. Test – Sprinkle some coffee powder on a glass of water. The pure coffee will float, but chicory sinks down and leaves a trail of colour in the water.

Tea leavesAdulterant – Iron filings and colour added to used and dried tea leaves. Test – Iron filings can be removed by a magnet. Put some tea leaves on a damp blotting paper. The presence of colour on the paper shows that the leaves have been dyed.

GheeAdulterant – Mashed potato and vanaspati. Test – Potato has starch. Conduct the starch test and vanaspati text mentioned as for milk.

Butter & curdAdulterant – Vanaspati.Test – Conduct the vanaspati test as for milk.

Coconut oilAdulterant – Other vegetable oils. Test – Put a small sample in the fridge. Coconut oil will freeze, while the other oils will from a separate layer.

Edible oilAdulterant – Argemone oil.Test – Take a little oil in a test tube, add a little nitric acid shake. A red colour is positive of argemone oil.

Arhar dalAdulterant – Kesari dal, which can cause paralysis. Test – Kesari dal is wedge-shaped and can be seen and removed manually.

Haldi, besan & some pulsesAdulterant – Metanil yellow and yellow aniline dye which can cause cancer and stomach upsets. Test – In a test tube, mix 1 tsp of the product in lukewarm water. Add a few drops hydrochloric acid. A pink, violet or purple colour indicates the presence of Metanil yellow.

Mustard seedsAdulterant – Argemone seeds which can cause dropsy and glaucoma.Test – Mustard seeds are smooth from outside and when crushed are yellow inside. Argemone seeds are outwardly rough and when crushed are white from inside.

Red chilly powderAdulterant – Brick powder, coloured sawdust and Sudan red. Test – Sprinkle a little powder on a glass of water. The brick powder will settle to the bottom. The water soluble colour in the sawdust will produce streaks of colour in the water.

Cumin seedsAdulterant – Grass seeds coloured with charcoal. Test – Rub a little jeera between your fingers. A black residue indicates charcoal.

AsfoetidaAdulterant – Soapstone and starch. Test – Shake a little hing in water. The adulterants will settle down. Pure hing dissolves in water to from a milky solution. To detect starch, conduct the test as mentioned for milk.

Coriander powderAdulterant – Saw dust and dung. Test – Sprinkle some powder on a glass of water. Both adulterants will float on the water. Dung will emit a foul odour.

SagoAdulterant – Marble pieces. Test – Soak some sago in water. Genuine sago globules will swell up, whereas marble will not.

HoneyAdulterant – Sugar, gur and water. Test – Dip a cotton wick in honey and burn it. unadulterated honey will burn with a flame. If adulterated, the water content will not allow it do burn. Moreover, pure honey crystallises at the bottom of the jar after many days.

PeppercornsAdulterant – Dried papaya seeds which can cause liver and stomach problems, mineral oil. Test – Put a few pepper corns in a glass of water. The mature corns will sink to the bottom. The papaya seeds will float. Pepper corns coated with mineral oil will smell of kerosene.Big ElaichiAdulterant – small elaichi seeds Test – Big elaichi seeds have a smooth surface while small elaichi seeds have a crinkled surface.ClovesAdulterant – Exhausted cloves and mineral oil. Test – Exhausted cloves are small, shrunken in size and not pungent. A sheen on the clove indicates the presence of mineral oil.CinnamonAdulterant – Cassia bark. Test – Cinnamon is thin and because of its curvature, can be fitted around a pencil. It has a distinctive taste and flavour. Cassia bark has several layers between the outer rough layer and the inner smooth layer which can be seen.

SaffronAdulterant – Dyed maize filaments. Test –Saffron is water soluble. Put a saffron strand in a bowl of water. It will keep on giving colour continually, till it fully dissolves. Even if you take out of the strand midway, it will look like the original dry strand. This means it is genuine. The colour of artificial saffron will wash out, leaving the colorless strand behind. Moreover a genuine saffron strand will not break as the artificial one.Sweet potatoes & red chilliesAdulterant – Rhodamine B colour. Test – Dip a small ball of cotton in liquid paraffin. Swipe it on the outer surface of the potato or chilly. If positive, colour will be seen.Green vegetablesAdulterant – Malachite green which is carcinogenic. Test – Take a small sample and put on moist blotting paper. A green colour on the paper is positive for malachite green.

ApplesAdulterant –A thin layer of wax on the outside to prevent dehydration and to keep the fruit fresh for a long time. Test – Gently scrape the surface with the blunt edge of a knife. A thin layer of wax will come out.Silver foilAdulterant – Aluminium foil. Test – Silver foil burns completely where as aluminium foil turns into ashes.What you can do Buy ISI or Agmark certified products or from a reputed brands. Raw spices can be purchased from a trusted source and ground at home. If adulteration is suspected, approach a consumer group who will test sample and file a complaint on your behalf. You can also go to public health institute where your samples will be analyzed. Or you can file a complaint with the health office giving details about your sample.