How to check if milk and milk products are adulterated

Food is basis of our existence and none of us think twice or compromise on the quality of food. What if the milk which you make your child forcefully drink is adulterated? What if the paneer that has numerous health benefits, which your husband lovingly eats is full of unhealthy starch? There are certain tests you can easily perform in your kitchen with the help of easily available ingredients to assess the purity of these products which help you distinguish between adulterated and pure food.

The Food Safety and Standards Authority of India (FSSAI) defines food adulteration as an act of intentionally debasing the quality of food offered for sale either by admixture or substitution of inferior substances or by removal of some valuable ingredient.

Food adulteration also takes into account unintentional contamination of food during their period of growth, harvesting, storage, processing, transport and processing, for example- pesticide residue in grains.

It also defines a food adulterant as any substance which is or can be employed for making the food unsafe or sub standard or mis-branded or containing extraneous matter. Food products can be adulterated by using various food additives like artificial colours which are very harmful to your health.

Here are a few things you should know about food adulterants and how to check if your food is adulterated:

Food product	Adulterant	Test to check adulteration
Milk	Water	Place a drop of milk on a shiny, polished slanting surface. Milk leaves no trail behind but if water is added to it you will find a white trail behind the drop.
	Starch	Add a drop of iodine solution (easily available in medical stores or the one from your first-aid box). Formation of blue colour indicates adulteration.
	Vanaspati	Take around 3 ml milk in a test tube and an ml of hydrochloric acid to it. Appearance of red colour after 5 minutes indicates presence of vanaspati in milk.
	Detergent	Add 5 ml water to approximately same amount of milk. Shake for 5 minutes. Appearance of lather indicates presence of detergent.
	Formalin	Take 10 ml milk in a test tube and add concentrated sulphuric acid to it from the sides of the test tube. Avoid shaking the tube. Appearance of violet ring at the intersection indicates presence of formalin.
Ghee/ Cottage cheese or paneer/condensed milk, khoa, milk powder	Coal tar dyes	To a melted sample of the product add approximately 5 ml of dilute sulphuric acid or concentrated hydrochloric acid. Appearance of pink colour in case of sulphuric acid and red incase of hydrochloric acid indicates presence of coal tar dyes.
	Starch	Add a few drops of iodine to the sample, if the brown colour becomes blue, it indicates presence of mashed potatoes.
Ghee / Butter	Vanaspati	To a little melted ghee add equal amounts of hydrochloric acid and add a pinch of sugar to it. Shake well and let it set for 5 minutes. If crimson colour appears in lower layer indicates presence of vanaspati.
	Mashed potatoes/sweet potatoes	Add a few drops of iodine to the sample, if the brown colour becomes blue, it indicates presence of mashed potatoes.

All these tests are easy to perform. A word of precaution would be to wear hand gloves while handling acids.