Check impurities in ghee

Objective:
To test the presence of most common impurities in Ghee
Theory:
Ghee can be easily admixture with cheap adulteration. This common adulterants are the (i) Vanaspati (hydrogenated fat and (ii) starch from sweet potato.
Procedure:
• Vegetable oil/ margarine: Take about one teaspoonful of melted ghee in the test tube or bottle. Add a pinch of sugar. Close test tube or bottle and shake to mix. Let it stand for five minutes. After five minutes, if a red colour appears in the bottom of the ghee then the sample contains vegetable oil.
• Sweet potato/ starch: Melt a small quantity of ghee in a vessel. Add a few drops of the iodine solution to the melted ghee. If the iodine solution, which is brown in colour, turns purple, then the ghee is adulterated with a starch like mashed potato or sweet potato.