date:Sep 07, 2012
the sample is adulterated with coal tar dye. If the red colour appears after the sugar is added and the mixture is shaken, then only vanaspati or margarine is present.
Mashed potatoes, sweet potatoes and other starches
A few drops of iodine are added to a ghee sample. Iodine, which is brownish in colour, turns blue if the sample contains mashed potatoes, sweet potatoes or other kinds of starches.
Edible oil
About 5ml of edible oil is taken in a test tube and about 5ml of hydrochloric acid is