A simple and cost effective method to detect adulteration in ghee with vegetable oils through microscopic examination of sterols

Abstract

Plant sterols together called as phytosterols, and animal sterols mainly cholesterol differ from each other in their crystal shapes, apart from other differences in terms of chemical structure, melting points, etc. When viewed under the microscope, after their isolation from the samples in purified state, phytosterols crystals appear hexagonal in shape while those of cholesterol acquire parallelogram shape. But the mixture of phytosterols and cholesterol shows the crystal structure with re-entry angle (Swallow’s tail).On the basis of this characteristic crystal shape, detection of vegetable oils in milk fat up to a level of 15 percent could be confirmed with this simple cost effective method . However, this approach cannot be applied for the detection of body fats in milk fat because of the existence ofcommon sterol (cholesterol) in them