固定化混合酶系法和纳滤耦联技术制备高纯度低聚果糖的研究-应用化学专业论文.docxVIP

半衰期为36次。固定化过氧化氢酶和固定化葡萄糖氧化酶的最佳配比为2／I 半衰期为36次。固定化过氧化氢酶和固定化葡萄糖氧化酶的最佳配比为2／I (g／g)，固定化混合酶系一固定化果糖基转移酶、过氧化氢酶和葡萄糖氧化 酶配比为1／2／l(g／g／g)，催化蔗糖得至U80％左右高含量的低聚果糖，然后， 再耦联纳滤技术，经过4倍体积的纯化，最终得到90％以上的低聚果糖产品。 关键词：低聚果糖固定化果糖转移酶固定化葡萄糖氧化酶 固定化过氧化氢酶纳滤 II PRODUCTION PRODUCTION OF HIGH．PURITY FOS BY IMMOBILIZED MIXED．ENZYME SYSTEM AND NANOFILTRATION TECHNOLOGY ABSTRACT Fructooligosaccharides(FOS)，a functional sweetener used widely in health food．have lots of favorable biological and functional properties such as low calorie and noncariogenic sweeteners，consecutive improvement ofthe intestinal microbial flora，relief of constipation，decrease of total cholesterol and lipid in the serum．The G—type FOS production converted by immobilized fuctosyltransferase(FTS)or zymogen is not suit for the diabetics because in which the content of glucose and sucrose that have no biological properties is too high and is about 35％and 1 5％，respectively In the course of FOS producing，immobilized glucose oxidase(GOD)and immobilized catalase(CAT)were used for removing glucose which is competitive inhibitor to immobilized FTS．As the result，sucrose Was converted furthest and high-content FOS(more than 80％，FOS／total saccharide)Was get． And then，used the high-content FOS as stuff,P—type FOS(FOS／total Ill saccharide≥90％1 saccharide≥90％1 was obtained by nanofiltration for glucose-removing． The optimal immobilization condition for GOD and CAT were investigated and their enzymatic properties were studied on．The optimal immobilization condition for GOD was as follows：carrier-一D380 positive ion exchange resin， carries／GOD—lg／2mg，gluctarldehyde concentration—O．2％，temperature-一30C， cross-link time·一8h，pH7．0．It was found that free and immobilized GOD have the pH optimum of 5．5 and 6．0，and were stable over a pH range of 5．0-7．0．The optimal temperature and thermostability ofthe immobilized GOD was improved over that of the free enzyme，resulting in a temperature range for activity of 35-45。C and a retention of 56％of its optimal a