date:Sep 07, 2012
ttage cheese, condensed milk, khoa, milk powder, etc.
About 5ml of diluted H2SO4 or concentrated HCl is added to one teaspoon full of the melted milk sample in a test tube and shaken well. If it turns pink (in case of H2SO4) or crimson (in case of HCl) it indicates the presence of coal tar dyes. If HCl does not give a colour, it can be obtained by diluting it with water.
Dairy products
Sweet curd
A tablespoonful of curd is taken in a test tube and about ten drops of hydrochloric acid are added