柠檬酸钠辅助谷氨酰胺转移酶对牦牛乳凝胶特性的研究  

Study on Properties of Yak Milk Gel with Sodium Citrate Assisted Transglutaminase

作　　者：李赵敏 杨林 张辉 辜雪冬 祝亚辉 LI Zhaomin;YANG Lin;ZHANG Hui;GU Xuedong;ZHU Yahui(College of Food Science,Key Autonomous Region Laboratory of Food Science and Engineering,Xizang Agriculture and Animal Husbandry College,Nyingchi 860000,China)

机构地区：[1]西藏农牧学院食品科学学院食品科学与工程重点自治区实验室,西藏林芝860000

出　　处：《中国乳品工业》2020年第6期18-21,35,共5页China Dairy Industry

基　　金：2018年农畜加工关键技术研发(藏财教指2018-54号)(503118004);食品科学与工程重点学科建设(503118009);班戈畜牲(50020602)。

摘　　要：为了解决牦牛酸奶在贮藏和运输过程中易出现凝胶破碎和乳清析出等质构缺陷。本实验主要研究了柠檬酸三钠(TSC)对经谷氨酰胺转移酶(MTGase)处理的脱脂牦牛乳形成凝胶的持水力、硬度和流变特性的影响。将不同浓度的柠檬酸三钠(0、10、30和50mmol/L)加入到牦牛乳中,分散均匀后重新调整pH至6.55~6.65,然后加入MTGase以促进牦牛乳酪蛋白的共价交联反应。将上述分散体系用1.4%(w/v)D-葡萄糖酸-δ-内酯(GDL)于42℃下酸化4~5 h。结果表明,当TSC的浓度分别为0、10、30和50 mmol/L时,牦牛乳酪蛋白胶束形成的颗粒直径分别为300、110、70、30 nm。在0~30 mmol/L范围内,随着TSC浓度的增加,经过MTGase处理后的牦牛乳形成的酸凝胶的硬度、持水力和屈服应力呈显著的增加趋势,超过30 mmol/L,凝胶的硬度、持水力和屈服应力逐渐降低。总体而言,TSC能够将牦牛乳酪蛋白胶束分解成较小的颗粒,在MTGsae存在的条件,能显著改善牦牛乳酸凝胶的质构缺陷。in order to solve the texture defects of yak yogurt during storage and transportation,such as gel breakage and whey precipitation,etc.The effects of TSC on hydrostatic properties,hardness and rheological properties of defatted yak milk treated with MTGase were studied.Different concentrations of trisodium citrate(0,10,30,and 50 mmol/L)were added to the yak milk,and the pH was adjusted to 6.55~6.65 after uniform dispersion.Then MTGase was added to promote the covalent crosslinking reaction of yak cheese protein.The above dispersion system was acidified by 1.4%(w/v)d-gluconate delta lactone(GDL)at 42℃for 4~5 h.The results showed that when the TSC concentrations were 0,10,30 and 50 mmol/L,the particle diameters of yak cheese protein micelles were 300,110,70 and 30 nm,respectively.In the range of 0 to 30 mmol/L,with the increase of TSC concentration,the hardness,hydraulic holding and yield stress of the acid gel formed by the yak milk treated with MTGase showed a significant increase trend,and the hardness,hydraulic holding and yield stress of the gel gradually decreased after the treatment of 30 mmol/L.In general,TSC can decompose the yak cheese micelle into smaller particles,which can significantly improve the texture defects of yak lactic acid gel under the conditions of MTGsae.

关 键 词：柠檬酸三钠 D-葡萄糖酸-δ-内酯 凝胶 共价键 

分 类 号：TS252.1[轻工技术与工程—农产品加工及贮藏工程]