Take a teaspoon of powdered dung, a pinch of brick powder. Add a dash of saw dust and rat droppings. Mix well and heat in rancid ghee. For extra zing, add chalk powder and washing soda. Serve with steaming rice. Well, not really. This is not an exotic dish out of a sorceress’ recipe book. But these ingredients do make their way into our food, without our knowledge.

Yes, we are talking about food adulteration. While many nations have initiated measures to keep their citizens safe from food adulterants in the wake of reports of milk products from China being contaminated with harmful substances like melamine, Indian health authorities are content with their bureaucratic chalta hai attitude.

The problem of adulteration in India is two-fold. First, there’s deliberate adulteration for financial gain, and secondly there’s contamination by harmful substances without the know-ledge of the manufacturer or trader — the result of carelessness and lack of hygiene in processing, storing or transportation.
“Authorities seem to believe that Indians are more resistant to diseases and thus a little high level of adulterants will not affect their health,” says consumer activist M.V. Subbaiah.

There have been cases of an MNC mixing sodium hydroxide or washing soda with infant milk formula. Imagine feeding a newborn washing powder! Nickel in chocolates is another cause of concern. “If there is a problem with a food product that means it should not be sold. Food alerts are quite common elsewhere, but not in India. We have the Prevention of Food Adulteration Act, but lack of strong legal will often makes the cases weak and unscrupulous elements escape punishment,” says senior consumer activist P.V.S. Ramamurthy.

In a Delhi case, adulterated suji was analysed after six days. The trader escaped punishment on the possibility that insects may have developed in suji after the sample was taken. In Himachal Pradesh, after rat droppings were found in sabut moong (green dal) it was ruled that the presence of rat droppings was due to natural causes and beyond the control of the trader.  Common adulterants include powdered dung, methanol or industrial alcohol, fine sand particles, harmful chemicals, synthetic colours used for fabric dyeing, insects, insect eggs and rat droppings.

Colour-coded investigation

Adulterants, both harmful and simple, can be detected easily through tests that can be done at home. Here are a few such tests as suggested by the union ministry of health and Family Welfare:

Vegetable oils are generally mixed with castrol or argemone oil to make quick profits. In case of castrol oil take 1 ml of vegetable oil in a clean dry test tube and add 10 ml. of acidified petroleum ether. Shake for 2 minutes and add a drop of ammonium molybdate reagent. The formation of turbidity indicates presence of castor oil.

In case of argemone oil add 5 ml concentrated HNO3 to 5 ml sample. Shake carefully and then allow to separate. Yellow, orange or crimson colour in the lower acid layer indicates adulteration. Ghee is generally mixed with mashed potato or sweet potato to make it weighty and creamy. Often vanaspati is also added to ghee. In case of mashed potato or sweet potato, boil 5 ml sample in a test tube, cool and put a drop of iodine solution. Blue colour indicates presence of starch. Colour disappears on boiling and reappears on cooling.

In case of vanaspati take 5 ml of the sample in a test tube and add 5 ml of hydrochloric acid and 0.4 ml of 2 per cent furfural solution or sugar crystals. Insert the glass stopper and shake for 2 minutes. Pink or red colour indicates presence of vanaspati.

Often old ghee (rancid stuff) is added. To detect this, take one teaspoon of melted sample and 5 ml of Hydrochloric acid in a glass tube. Shake vigorously for 30 seconds. Add 5 ml of 0.1 per cent of ether solution of phloroglucinol. Shake for 30 seconds and allow to stand for 10 minutes. A pink or red colour in the lower acid layer indicates rancidity.

Synthetic colours in food items can be detected by pouring 2 gm of filtered fat dissolved in ether. Divide this into 2 portions. Add 1 ml of HCl to one tube and 1 ml of 10 per cent NaOH Nitric acid to the other tube. Shake well and allow to stand. Pink colour in acidic solution and yellow colour in alkaline solution indicates added colouring matter.

Honey is generally adulterated with invert sugar or jaggery. Take 5 ml. of honey in a porcelain dish. Add aniline chloride solution and stir well. Orange-red colour indicates presence of sugar.

Besan atta is adulterated with Kesari dal (Lathyrus sativus). Add 50 ml of diluted HCL to a small quantity of dal and keep on simmering water for about 15 minutes. Pink colour indicates the presence of kesari dal.

Pulses are also adulterated with metanil yellow dye. To find this add concentrated HCl to a small quantity of dal in a little water. Immediate development of pink colour indicates the presence of metanil yellow and other colour dyes.
Atta is generally contaminated with excessive sand and dirt. Shake a little quantity of sample with 10 ml of carbon tetrachloride and allow to stand. Grit and sandy matter will collect at the bottom. Chalk powder is used in atta. To find out, shake sample with diluted HCL. Effervescence indicates chalk.

Spices (ground) are adulterated by red bran and saw dust. Sprinkle on water surface. Powdered bran and sawdust float on the surface. Coriander powder is adulterated with dung powder. To find out, soak in water. Dung will float and can be easily detected by its foul smell.

Chillies are adulterated with brick powder, grit, sand, dirt etc.  Pour the sample in a beaker containing a mixture of chloroform and carbon tetrachloride. Brick powder and grit will settle at the bottom. Turmeric  is often mixed with lead chromate to give a deep yellow colour. Ash the sample. Dissolve it in 1:7 sulphuric acid (H2SO4) and filter. Add 1 or 2 drops of 0.1 per cent dipenylcarbazide. A pink colour indicates presence of lead chromate.

Cumin seeds are mixed with grass seeds coloured with charcoal dust. Rub the cumin seeds on palms. If palms turn black adulteration in indicated. Asafoetida heeng is adulterated with soap stone. Shake a small powdered sample with water. Soap stone or other earthy matter will settle at the bottom.

Foodgrains contain hidden insect infestations. To test, take a filter paper impregnated with ninhydrin (1 per cent 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 insect infestation.