Synthesis of EPA- and DHA-Enriched Structured Acylglycerols at the -2 Position Starting from Commercial Salmon Oil by Enzymatic Lipase Catalysis under Supercritical Conditions.

There is consistent evidence that long-chain polyunsaturated fatty acids (LCPUFA) belonging to the -3 series, i.e., eicosapentaenoic (20:5-3, EPA) and docosahexaenoic (22:6-3, DHA) acids, decrease the risk of heart, circulatory and inflammatory diseases. Furthermore, the bioavailability of such fatty acids has been shown to depend on their location in triacylglycerol (TG) molecules at the -2 position. Consequently, great attention has been accorded to the synthesis of structured acylglycerols (sAG), which include EPA or DHA at the -2 position. The aim of this work was to synthesize sAG starting from deodorized refined commercial salmon oil. For this, immobilized lipase B from  (nonspecific) was used as a catalyst for the intra-interesterification process under CO supercritical conditions (COSC). According to the COSC reaction time, three different fractions including sAG compounds were obtained. The location of EPA and DHA at the -2 position in the resulting glycerol backbone was identified by mass spectrometry (MALDI-TOF) analysis. In all fractions obtained, a marked decrease in the starting TG content was observed, while an increase in the DHA content at the -2 position was detected. The fraction obtained after the longest reaction time period (2 h) led to the highest yield of -2 position DHA in the resulting sAG molecule.