超临界体系脂肪酶膜催化合成甘油二酯的研究

Study on the Preparation of Diacylglycerol by Lipase Membrane Catalyzed in Supercritical System

以醋酸纤维素和聚四氟乙烯为材料制备醋酸纤维素/聚四氟乙烯复合膜,采用吸附-交联相结合的固定化方法,用该复合膜固定化脂肪酶。并研究了在超临界CO2状态下,采用该固定化脂肪酶膜催化一级大豆油与甘油反应合成甘油二酯的工艺,以反应产物中甘油二酯的含量为指标,通过单因素与响应面法进行分析,确定最佳的工艺条件为:一级大豆油与甘油的物质的量比为2∶1,反应温度为64℃,时间为7 h,加酶量为3.2%,甘油含水量为1%。在此条件下,得到反应产物中甘油二酯的质量分数为66.3%。

CA-PTFE composite membranes were prepared by cellulose acetate（CA）and polytetrafluoroethylene（PTFE）with absorbing-crosslinking method.The CA-PTFE composite membrane was used for immobilizing lipase.The preparation of diacylglycerol by lipase Immobilized on membrane was catalyzed in Supercritical CO2 system,this response was synthesized from first grade soybean oil and glycerin.According to the percentage composition of diacylglycerol,though the single factor and response surface,the optimum conditions were determine as follows：first grade soybean oil and glycerin molar ratio 2∶1,reaction temperature 64 ℃,time 7 h,the quantity of enzyme 3.2%,water content of glycerol 1%.Under these conditions,the content of diacylglycerol was 66.3% in the products.