T1 CH3 Matter Around Us — Science STD 6 — Question

Food is the basic requirement for life. It should be pure, nutritious, and free from any type of adulteration.

1. Adulteration
   Sometimes, things that we buy in the market are mixed with harmful and unwanted substances. Food can also get adulterated due to carelessness or lack of proper handling. It will not possible to check for adulteration on visual examination. Following tests will help even a layman or non-technical person to detect adulterants in some of the products.
2. Detection:
   a. Milk: Adulterants used can be water, starch, urea, sucrose, detergents, neutralizer, formalin, etc. These adulterants are used to increase the thickness, viscosity, and shelf life of milk.
   b. Test: Put a drop of milk on a 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. We can also use Lactometer for measuring the specific density of milk.
   c. Sugar: Adulterant: Chalk
   d. Test: Dissolve sugar in a glass of water, chalk will settle down at the bottom
   e. Ice Cream: Adulterant: washing Powder
   f. Test: Put some lemon juice on ice cream, bubbles come out in the presence of washing powder
   g. Test: Take one teaspoonful of melted ghee or butter with an equal quantity of cone. Hydrochloric acid in a test tube and add to it a pinch of cane sugar. Shake well for one minute and let it stand for five minutes. The appearance of crimson colour in the lower layer shows the presence of vanaspati.

We must be careful about the common adulterants in our food. We might be eating a dangerous dye, sawdust, industrial starch or other contaminated foods which are a major source of diseases. And thus, we invite diseases rather than good health. Food adulteration is basically lowering the quality of food. So, we must be aware of such adulteration.