Detection of Milk Fat Adulteration by Molecular Distillation

Abstract

Summary An apparatus and a method are described for the molecular distillation at 250C for 1 hr of food fats and oils without decomposition or polymerization. Seasonal variations in milk fat composition were shown to influence the distillate yield. Distillate yields from mixtures of milk fat, produced in different seasons of the year, and domestic food fats or oils, indicated that molecular distillation can detect additions of these fats or oils but not of coconut oil. If the production season of the milk fat were unknown, a minimum addition of 18-20% domestic food fat or oil could be detected; the detectable amount could well be less than 5% with milk fat produced at certain seasons of the year. Deviations in the refractive indices of the distillates, obtained from milk fat-edible fat and oil mixtures, from those considered normal for milk fat, indicated a possibility of detecting additions of coconut oil but not of domestic food fats or oils. If the production season of the milk fat were unknown, a minimum addition of 30% coconut oil could be detected; the detectable amount could be less than 5% with milk fat produced at certain seasons of the year.