ABSTRACT
The lipid fraction of foods containing the fat-soluble vitamins is composed mainly of triglycerides, with much smaller amounts of sterols, carotenoids, phospholipids, and minor lipoidal constituents. All of these substances exhibit solubility properties similar to those of the fat-soluble vitamins, and therefore they constitute a potential source of interference. A proportion of the indigenous fat-soluble vitamin content of a food is bound up with a lipoprotein complex, and hence the fat22protein bonds must be broken to release the vitamin. The protective gelatine coating used in certain proprietary vitamin premixes will need to be dissolved before commencing the analysis of supplemented foods.
