date:Sep 07, 2012
ed hydrochloric acid are taken in a stoppered test tube and a pinch of sugar is added to it. It is shaken for about a minutes and left for about five minutes. If the acid turns crimson, it indicates the presence of vanaspati or margarine.
The test is specific to sesame oil, which is added to vanaspati and margarine, Some coal tar colours also give a positive test. If the test is positive (i.e. if the acid turns red) only by adding strong hydrochloric acid (without adding crystals of sugar) then