STRUCTURE OF UNSATURATED VEGETABLE OIL GLYCERIDES - DIRECT CALCULATION FROM FATTY ACID COMPOSITION

Composition and structure of unsaturated glycerides of vegetable oils can be calculated directly from the fatty acid composition of the oil. Fatty acid distribution on the 2 position as normally determined by lipase hydrolysis is calculated from the composition of the whole oil by applying the following three rules in their respective order: Saturated fatty acids and those with chain length greater than 18 carbons are first distributed equally and randomly on the 1 and 3 position of the glycerol moiety; oleic and linolenic acids are treated equally, or as a unit, and distributed equally and randomly on all three glyceride positions with any excess from the 1 and 3 position being added to the 2 position; and all remaining positions are filled by linoleic acid. Remarkably good agreement between the calculated and experimentally determined fatty acid distributions is shown for soybean, linseed, safflower and many other vegetable oils whose compositions are reported in the literature. An association between oleic and linolenic acid within the glyceride structure of some vegetable oils is evident. © 1969 AOCS Press.