固定化脂肪酶催化酱油糟油脂合成甘油二酯的研究

Synthesis of Diacylglycerol in Soy Sauce Residue Oil Catalyzed by Immobilized Lipase

本文以酱油糟为研究对象,利用实验室自主研发的低温连续相变萃取技术提取其中的油脂,并对提取出来的油脂主要理化指标进行分析,选用自制的具有Sn-1,3位专一性固定化脂肪酶HM IM对其油脂中丰富的游离脂肪酸(含量为61.50%)酯化合成甘油二酯。通过酶的添加量、甘油添加量、反应温度、搅拌速度、金属离子和不同辅助脱酸处理这几个因素进行优化,得到最佳的酯化合成甘油二酯条件为:自制固定化脂肪酶00S添加量1%、甘油添加量为理论所需量的1.2倍、反应温度65℃、真空度0.098 MPa+氮吹,2 mmol K+处理固定化酶、搅拌速度120 r/min下反应10 h,酱油糟油脂的游离脂肪酸酯化率达96.36%,甘油二酯含量达48.65%(43.65%的1,3-DG、5.00%的1,2-DG)、2.24%FFA、9.31%的MG,39.80%的TG,而且酯化反应不会改变油脂的脂肪酸组成。酶法酯化处理既降低了酱油糟油脂的酸值、又富含功能性甘油二酯,对其开发再利用提供新的途径。

Soy sauce residue oil was was extracted with free fatty acids content of 61.50% by a novel continuous phase transition extraction method at low temperature, and the self-made immobilized lipase HMIM with Sn-1, 3 specificity was used to catalyze the synthesis of diacylglycerol. The enzyme dosage the content of glycerin, reaction temperature, mefal ions and auxiliary acid treatment methods were optimized, and the optimal conditions were determined as follows： immobilized lipase dosage 1%, content of glycerol 1.2 times of the required, reaction temperature： 65 ~C, vacuum degree; 0.098 MPa, K＋ concentration 2 mmoL, stirring speed 20 r/min and reaction time 10 h. Under these conditions, the free fatty acid esterification rate was 96.36% and the content of diglyceride was 48.65% （43.65% of 1,3-DG 5.00% of 1,2-DG）. The contents of FFA, MG and TG were 2.24%, 9.31% and 39.80%, respectively. Results showed that esterification reaction would not change the fatty acid composition of soy sauce residue oil. Process of Enzymatic esterification not only reduced the acid value of soy sauce residue oil but also increased the contents of functional diacylglycerol, which provided a new method for the development and utilization of soy sauce residue.