无溶剂体系磷脂酶Lecitase~ Ultra催化棕榈油甘油解制备甘油二酯研究

Synthesis of diacylglycerol through glycerolysis of palm oil catalyzed by phospholipase Lecitase~ Ultra in a solvent-free system

采用磷脂酶LecitaseUltra在无溶剂体系中催化棕榈油甘油解反应制备甘油二酯(DAG)。采用单因素试验研究了DAG的酶促甘油解反应条件,通过分子蒸馏对DAG进行纯化,并采用GC-MS测定了其脂肪酸组成。结果表明,最佳甘油解工艺参数为:甘油与棕榈油摩尔比7.5∶1,反应温度40℃,初始水分含量4%(占底物总质量),加酶量2%(占底物总质量),反应时间8 h;在最佳条件下,产品中DAG含量为59.2%。经两级分子蒸馏,DAG含量可达88.1%。其中,1,3-DAG含量为1,2-DAG的1.6倍。同原料棕榈油相比,DAG中的饱和脂肪酸得到了显著富集。

The diacylglycerol（ DAG） was prepared through glycerolysis of palm oil catalyzed by phospholipase LecitaseUltra in a solvent- free system. The enzyme catalyzed glycerolysis conditions of DAG were studied by single factor experiment and it was purified by molecular distillation,then its fatty acid composition was analyzed by GC- MS. The results showed that the optimal glycerolysis conditions were obtained as follows： molar ratio of glycerol to palm oil 7. 5 ∶ 1,reaction temperature 40 ℃,initial water content 4%（ based on the total mass of substrates）,enzyme dosage 2%（ based on the total mass of substrates）,and reaction time 8 h. Under the optimal conditions,the content of DAG in the product was59. 2%. While the content of DAG could achieve 88. 1% through two- step molecular distillation,in which the content of 1,3- DAG was 1. 6 times as high as 1,2- DAG. Compared with palm oil,the saturated fatty acids of DAG were enriched largly.