Monitoring of lipase-catalyzed transesterification between eicosapentaenoic acid ethyl ester and tricaprylin by silver ion high-performance liquid chromatography and high-temperature gas chromatography

A high-resolution method based on silver ion high-performance liquid chroma tography (HPLC) and high-temperature gas chromatography (HTGC) with on-colu mn injection was established for the separation of triacylglycerols (TAG) w hich contained eicosapentaenoic acid (EPA). A solvent system based on n-hex ane, 2-propanol, and acetonitrile in HPLC for the separation of EPA-contain ing TAG was developed. It was dependent upon the number of EPA molecules an d their isomeric distribution or! the glycerol backbone. This technique was used to monitor the incorporation of EPA onto specific positions on the gl ycerol backbone. For quantitative monitoring of the synthesis reaction, of the TAG containing EPA, an HTGC analysis was developed. For monitoring of t he synthesis of structured TAG containing EPA, transesterification of trica prylin with EPA ethyl ester in a solvent-free system was performed. The tra nsesterification reaction using various lipases was studied at a different molar ratios of substrates, several initial water activities (a(w)), and va rious reaction temperatures.