Enzymatic Synthesis and Physicochemical Properties of MLM-Type Structured Lipids

Monoglycerides were prepared through alcoholysis and used for the synthesis of MLM-type structured lipids through its esterification with caprylic acid under the catalysis of immobilized 1,3-specific lipase.The optimal esterifcation conditions,as determined using orthogonal array design based on one-factor-at-a-time experiments,were 9% of lipozyme RM IM lipase concentration(on the basis of substrate mass),14 h of reaction time,40 ℃ of reaction temperature,and 1:6 of molar ratio of MAGs to caprylic acid.Under these conditions,the incorporation rate of caprylic acid was 60.48%,and 92.84% caprylic acid was distributed at the 1or 3 position of glycerol.Purified MLM-type structured lipids were obtained after subsequent two-step molecular distillation with an incorporation rate of 73.34% for caprylic acid.The physicochemical properties could comply with the national standards of Grade 4 rapeseed oil at least.