Distribution in Triacylglycerols of Vegetable Oils with “High - Low Oleic Acid” and “High Linolenic Acid”

Carbon-13 nuc lear m agnetic re sonance (C N MR) spe ctroscopy w as applied t o de termine the fa tty ac id positional composition of triacylglycerols in vegetable oils with oleic acid percentages “higher and lower than 50%” and with linolenic acid percentages higher than 5%. In particular, conventional C NMR spectroscopy which applies the basic one-pulse sequence for signal averaging, was used to determine on the basis of carboxy and unsaturated carbon resonances, the compositions of two different pools of fatty acids at the 1,3and 2-positions of triacylglycerols. The results confirmed that the chains at 1,3and 2triacylglycerol positions deviated from the 1,3-random-2-random distribution pattern at variable extents depending on the chain concentration in the total triglyceride of oil samples. However, two factors were likely to regulate the chain distribution between 1,3and 2-glycerol positions, namely the concentration of fatty acids in the total triglyceride and their positional specificity.