Check adulteration in Milk at home

Check adulteration in Milk at home with simple measures as below :

       
Milk- Water
The presence of water can be by putting a drop of milk on a polished slanting surface. The drop of pure milk either or flows lowly leaving a white trail behind it, whereas milk adulterated water will flow        immediately without leaving a mark 

Milk-Starch
Add a few drops of tincture of Iodine or Iodine solution. Formation of blue colour indicates the presence of starch. Iodine solution is easily available in the medical stores.
            
Milk-Urea
Take a teaspoon of milk in a test tube. Add ½ teaspoon of soybean or arhar powder. Mix up the contents thoroughly by shaking the test tube. After 5 minutes, dip a red litmus paper in it. Remove the paper after ½ a        minute. A change in colour from red to blue indicates the presence of        urea in the milk
 
Milk-Vanaspati
Take 3 ml of milk in a test tube. Add 10 drops of hydrochloric acid. Mix up one teaspoonful of sugar. After 5 minutes, examine the mixture. The red colouration indicates the presence of vanaspati in the milk 

Milk- Formalin
Take 10 ml of milk in a tests tube and add 5 ml of con sulphuric acid from the sides of the wall without shaking. If a violet or blue ring appears at the intersection of two layers then it shows presence of formalin. Formalin enhances the life of milk and thus is added for   preservation purpose.
            
Milk-Synthetic milk
Synthetic milk has a bitter after taste, gives a soapy feeling on rubbing between the fingers and turns yellowish on heating