酸和热处理对膜分离牦牛乳酪蛋白功能特性的影响  

Effects of Acid and Heat Treatments on Functional Properties of Yak Milk Caseins Separated by Microfiltration

作　　者：王国骄[1] 杭锋[1] 洪青[1] 

机构地区：[1]光明乳业股份有限公司乳业研究院上海乳业生物工程技术研究中心乳业生物技术国家重点实验室,上海200436

出　　处：《乳业科学与技术》2016年第3期4-8,共5页JOURNAL OF DAIRY SCIENCE AND TECHNOLOGY

基　　金：上海市经委引进技术吸收与创新计划项目(14XI-1-15);上海市科学技术委员会工程中心能力提升项目(16DZ2280600)

摘　　要：选择甘肃天祝牧区的鲜牦牛乳为研究对象,采用微滤的分离方法获得牦牛乳酪蛋白,研究了在pH 6.4、6.6、6.8、7.0及80、100、120、140℃处理后牦牛乳酪蛋白的热稳定性、疏水性、粒径大小和分子质量的变化。结果表明:在pH 6.8时,不同温度处理后各个功能性质均为最差,而在远离变性温度(140℃)的条件下,酪蛋白具有良好的功能特性。在酸诱导和热处理后,蛋白质分子发生了极化,维持空间结构的疏水作用力遭到破坏,引起蛋白分子的解离或聚集,导致蛋白分子自身结构发生改变,从而影响其性质的优劣。Caseins were separated from the fresh milk of grazing yak cows in Tianzhu county, Gansu province by microfiltration to investigate changes in their heat stability, hydrophobicity, particle sizes and molecular weights after different pH treatments （pH 6.4, 6.6, 6.8 and 7.0） and heat treatments （80, 100, 120 and 140 ~C）. The results showed that functional properties of yak milk caseins at pH 6.8 revealed the most significant deterioration after each heat treatment. At a temperature far below the denaturing temperature the caseins exhibited good retention of functional properties. Both acid and heat treatments caused molecular polarization of the caseins, destroyed the hydrophobic force, which contributes to maintaining the spatial structure of the protein molecules, and accordingly induced their dissociation or aggregation, causing changes in their molecular structure and in turn affecting their functional properties.

关 键 词：牦牛乳 酪蛋白 酸和热处理 功能特性 

分 类 号：TS252.1[轻工技术与工程—农产品加工及贮藏工程]