Lipozyme RM IM在人乳替代脂合成中的循环利用及结构变化  

Recycling and Structural Analysis of Lipozyme RM IM in the Synthesis of Human Milk Fat Substitutes

作　　者：刘小如[1,2,3] 颜佳 谭登峰 邓泽元 李静[1,2,4] LIU Xiaoru;YAN Jia;TAN Dengfeng;DENG Zeyuan;LI Jing(State Key Laboratory of Food Science and Resources,Nanchang University,Nanchang 330047,China;College of Food&Technology,Nanchang University,Nanchang 330047,China;International Institute of Food Innovation,Nanchang University,Nanchang 330031,China;National Dairy Technology Innovation Center,Hohhot 010110,China)

机构地区：[1]南昌大学食品科学与资源挖掘全国重点实验室,江西南昌330047 [2]南昌大学食品学院,江西南昌330047 [3]南昌大学国际食品创新研究院,江西南昌330031 [4]国家乳业技术创新中心,内蒙古呼和浩特010110

出　　处：《食品科学》2024年第14期60-66,共7页Food Science

基　　金：国家乳业技术创新中心开放性课题(2022-开放性课题-4);江西省科技厅重点研发项目(20212BBF63033);赣鄱俊才支持计划项目(20232BCJ22046);江西省重点研发计划项目(20233BBF6004);国家自然科学基金地区科学基金项目(32260565)。

摘　　要：目的:研究Lipozyme RM IM在人乳替代脂合成中的应用及其在循环利用中结构的变化。方法:以sn-2高棕榈酸甘油三酯和游离脂肪酸为底物,在Lipozyme RM IM催化下同步合成主要成分为1,3-二油酸-2-棕榈酸甘油三酯(1,3-dioleoyl-2-palmitoylglycerol,OPO)和1-油酸-2-棕榈酸-3-亚油酸甘油三酯(1-dioleoyl-2-palmitoyl-3-linoleoylglycerol,OPL)的人乳替代脂,考察合成过程中OPO与OPL含量、油酸与亚油酸含量、总棕榈酸含量、sn-2棕榈酸含量、酶活力、脂肪酶二级结构信息和内源荧光强度等指标,研究LipozymeRMIM在合成人乳替代脂中的应用及其循环利用特性。结果:以中国母乳脂质数据库为依据评判所合成人乳替代脂指标,Lipozyme RM IM循环使用第1次时,人乳替代脂中OPO相对含量为19.41%,OPL相对含量为17.04%,总脂肪酸中油酸相对含量为35.63%,亚油酸相对含量为22.30%,总棕榈酸相对含量为28.80%,sn-2棕榈酸相对含量为52.40%;当Lipozyme RM IM循环使用至第17次时,母乳结构脂中OPO相对含量为8.50%,OPL相对含量为7.62%,总脂肪酸中油酸相对含量为28.62%,亚油酸相对含量为13.38%,总棕榈酸相对含量为38.26%,sn-2棕榈酸相对含量为58.40%,均与中国母乳脂质范围一致。但Lipozyme RM IM循环使用超过17次后,酶法合成产物脂质组成与中国母乳脂质范围相差甚远。结论:Lipozyme RM IM作为一种酯交换能力优异的脂肪酶,在合成人乳替代脂的过程中可以累计使用17次,证明了固定化脂肪酶在合成人乳替代脂中有较好的循环使用特性。该研究为脂肪酶在人乳替代脂合成中的广泛应用提供了参考依据,同时也为连续性反应器合成人乳替代脂过程中脂肪酶的循环利用提供了参考。Objective:To study the application of Lipozyme RM IM in the synthesis of human milk fat substitutes and its structural changes during recycling.Methods:Using sn-2 high palmitate triglyceride and free fatty acid as the substrates,human milk fat substitutes mainly consisting of 1,3-dioleoyl-2-palmitoylglycerol(OPO) and 1-dioleoyl-2-palmitoyl-3-linoleoylglycerol(OPL) were synthesized synchronously under the catalysis of Lipozyme RM IM.The amounts of OPO and OPL,oleic acid,linoleic acid,total palmitic acid and sn-2 palmitic acid as evaluated against the Chinese breast milk lipid database,and the activity,secondary structure and endogenous fluorescence intensity of the lipase were investigated as a function of the number of cycles of enzyme recycling.Results:At the first cycle of recycling,the relative contents of OPO and OPL in human milk fat substitutes were 19.41% and 17.04%,respectively.The relative contents of oleic and linoleic acid in the total fatty acids were 35.63% and 22.30%,respectively.The relative contents of total palmitic acid and sn-2 palmitic acid were 28.80% and 52.40%,respectively.When Lipozyme RM IM was recycled for the 17th time,the relative contents of OPO and OPL in human milk fat substitutes were 8.50% and 7.62%,respectively.The relative contents of oleic and linoleic acid in the total fatty acids were 28.62% and 13.38%,respectively.The relative contents of total palmitic acid and sn-2 palmitic acid were 38.26% and 58.40%,respectively.All of them fell within the range of breast milk lipids in China.However,the lipid composition of the enzymatically synthesized product was far from the range.Conclusion:Lipozyme RM IM,with excellent transesterification ability,could be repeatedly used up to 17 times in the synthesis of human milk fat substitutes in this study,proving good recycling properties.This study provides a reference for the extensive application of lipase in synthesis of human milk fat substitutes and the recycling of lipase in the synthesis of human milk fat substitutes in a continuous

关 键 词：Lipozyme RM IM 人乳替代脂 酶的循环利用 酶的稳定性 

分 类 号：TS252.4[轻工技术与工程—农产品加工及贮藏工程]