酶促乙酯化和分子蒸馏联用制备高DHA乙酯的工艺

Preparation of ethyl esters highly enriched in DHA via enzymatic ethylation and molecular distillation

摘要: 利用固定化脂肪酶催化乙酯化反应将裂殖壶菌总脂转化为乙酯,并借助分子蒸馏手段制备得到了高DHA含量的乙酯产品。实验考察了反应温度、时间、底物质量配比和脂肪酶添加量等参数对酶促乙酯化反应的影响。在较优条件下(反应温度40℃,反应时间24h,底物质量比10∶2,Lipozyme 435添加量为油脂质量的6%),固定化脂肪酶的操作稳定性良好。采用分子蒸馏技术富集酶促醇解所得裂殖壶菌乙酯中的DHA,可得到DHA含量高于80%的乙酯产品,通过多级分子蒸馏和将轻相组分回流的方式可以显著提高DHA含量乙酯的得率。

Abstract: In the present study, the total lipids from Schizochytrium sp. were ethylated by immobilized lipase and ethyl esters highly enriched in C22∶6 n-3 (DHA) was obtained through molecular distillation. The effect of temperature, reaction time, substrate ratio, and enzyme dosage on enzymatic ethylation was investigated. Under optimum reaction conditions (reaction temperature 40℃, reaction time 24 h, substrate ratio 10∶2, Lipozyme 435 dosage 6%) , immobilized lipase had good operational stability. Ethyl esters with no less than 80% DHA was obtained via molecular distillation, and the yield of DHA ethyl esters could be significantly improved by multistage molecular distillation and recycle of light fractions.