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.
Adulterant – 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 & Sugar
Adulterant – 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
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.
Adulterant – 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.
Adulterant – 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.
Adulterant – 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.