Lipase-catalyzed transesterification of medium-long-medium structured lipid (MLM-SL) using palm olein and tricaprylin in packed-bed reactor (PBR)

Abstract

Lipase-catalyzed transesterification between refined bleached deodorized palm olein (RBDO) and tricaprylin to produce medium-long-medium structured lipid (MLM-SL) in a packed bed reactor (PBR) has been investigated. A specific sn-1,3 commercial Lipozyme TL IM was used as biocatalyst.  Within this study, the progress of transesterification was monitored especially for triacylglycerol (TAG) formation with equivalent carbon number (ECN) of 32, presumably 1,3-dicapryoyl-2-oleoyl-sn-glycerol (COC). Transesterification conditions investigated were residence times (i.e., 15, 30, and 60 min) and enzyme loadings (2.0 and 4.5 g).  The highest yield of ECN 32 (13%) and transesterification degree (71%) were obtained at residence time of 15 mins for both enzyme loadings. Longer residence time seemed to facilitate lipid hydrolysis over transesterification. This was indicated by the number of peaks appearing in the high-performance liquid chromatography (HPLC) chromatograms and the reduction of fat slip melting point (SMP). Additionally, the highest productivity was obtained at 2.0 g enzyme loading. Conclusively, this study has demonstrated the potential use of packed-bed reactor with immobilized Lipozyme TL IM for continuous synthesis of MLM-SLs especially TAG with ECN32.