Lipase-Catalyzed Synthesis Of Monoglycerides

The Monoglyceride is a kind of important polyol non-ionic surface active agent. Highly pure monoglycerides was prepared by immobilized 1,3-specific lipase (Lipozyme IM) from methyl stearate in non-solvent system. It was proved that the proper conditions of synthesis reaction: pH was 7.0, the water was 8% based on glycerin, lipase was 20% based on methyl stearate, the ratio of glycerin to methyl stearate was 1.5, the reaction temperature was 55 D, and the reaction time was 34 hours. Under the conditions, the fractional conversion of methyl stearate was 92.3% and the monoglycerides yield was 90.8% in synthesize reaction. By reclamation, the amount of consumed immobilized lipase was 1.0% to methyl stearate .The monoglycerides products were separated and purified by crystallization. The crystallization temperatures was 20 , the ratio of ethanol to the mixtures was 1.5. The yield of products was 84.1% and the content of monoglycerides was 87.7% in the final products.The kinetics of lipase-catalyzed interesterification of glycerol and methyl stearate was also studied. It was proved that this reaction mechanism is Ping Pong between two reactants. The equation is as follows.The vm , KmB and KmA are 0.154 umol/(g.s), 0.593 mmol/g and 0.367 mmol/g, respectively.The investigation showed that the sum yield of monoglyceride under the studied conditions was 84.1%, and content of monoglyceride was 87.7% in final product. The reaction was processed under mild conditions, and produced high pure of monoglyceride product, and operation was easy. This study provided a new method of preparing high pure monoglycerides by enzymatic intransesterification of methyl stearate.