A STUDY OF THE DISTRIBUTION OF EICOSAPENTAENOIC ACID AND DOCOSAHEXAENOIC ACID BETWEEN THE ALPHA AND BETA GLYCEROL CHAINS IN FISH OILS BY C-13-NMR SPECTROSCOPY

Using the C-13-NMR signals for the C1 and C2 carbon atoms it is possib le to determine the proportion of EPA and of DHA in the alpha and beta chains of triacylglycerols. This has been applied to seven fish oils and to EPA/DHA enriched fractions obtained from four of these. The res ults show that these two important n-3 polyene acids are distributed d ifferently in fish oil triacylglycerols. DHA is concentrated in the be ta position (59-87%), but EPA is more randomly distributed between the alpha and beta chains. These results accord with those obtained for o ther fish oils by stereospecific gas chromatographic procedures.