THE STRUCTURE OF THE TRIACYLGLYCEROLS OF MEADOWFOAM OIL

The triacylglycerols of meadowfoam oil have been resolved by HPLC in the silver ion and reversed-phase modes, and by the two techniques used in a complementary fashion. The fractions obtained were collected and quantified by gas chromatography of their methyl esters in the presence of an internal standard. Silver ion chromatography gave a distinctive resolution in which fractions differing solely in the position and chain-length of a single monoenoic fatty acyl group were resolved, the order of elution being 11-20:1, 5-20:1, 13-22:1, 5-18:1 and 9-18:1. Reversed-phase chromatography also gave fractions containing single positional isomers, (11-20:1<5-20:1<13-22:1<5-22:1), but the pattern was more difficult to discern since fractions containing 22:2 tended to overlap with those containing 20:1. The species (5-20:1)(5-20:1)(22:2), (5-20:1)(5-20:1)(5-20:1) and (5-20:1)(5-20:1)(13-20:1) were found to be the most abundant, and together comprised 67% of the total. A small but significant trilinolein fraction was detected and its presence may have biosynthetic implications. © 1990 AOCS Press.