Identification of triacylglycerols in the enzymatic transesterification of rapeseed and butter oil

Abstract

AbstractA blend of rapeseed and butter oil was transesterified using immobilized Thermomyces lanuginosus lipase (Lipozyme® TL IM) as catalyst. The reaction was followed by reversed‐phase HPLC and the triacylglycerol peaks were tentatively identified from their elution times by calculating equivalent carbon numbers. Further identification was made using HPLC‐electrospray tandem mass spectrometry. A few of the triacylglycerols detected were typical combinations of fatty acids originating from rapeseed oil, such as α‐linolenic acid, and short‐chain fatty acids from butter oil. Due to the regioselectivity of the lipase, the transesterification reaction involved mainly fatty acids in the sn‐1 and sn‐3 positions. However, significant changes in the fatty acid composition in the sn‐2 position were detected after 6 h.