Alteration of Sterols and Steryl Esters in Vegetable Oils during Industrial Refining

Abstract

Steryl esters of fatty acids have been isolated from vegetable oils by rapid chromatography on a short column of silica gel and quantitatively determined by HPLC on RP-18 columns using an evaporative light scattering detector that was calibrated with β-sitosteryl oleate as external standard. The steryl esters isolated according to the above technique from corn, soybean, and rapeseed oils at different stages of industrial refining have been analyzed for their constituent sterols and fatty acids by GC. Moreover, the total sterols were analyzed by GC. In all three oils a substantial part of the sterols occurred as steryl esters. Some alterations in the composition of the constituent sterols and fatty acids of the steryl esters were observed during industrial processing. Keywords: Industrial fat refining; HPLC; sterols; steryl esters; vegetable oils