Transglutaminase cross-linking of milk proteins and impact on yoghurt gel properties
Transglutaminase cross-linking of milk proteins and impact on yoghurt gel properties
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DOI：
10.1016/j.idairyj.2007.01.019
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发表时间：
2007-11-01
影响因子：
3.1
通讯作者：
Kulozik, Ulrich
中科院分区：
文献类型：
--
作者：
Boenisch, Martin P.;Huss, Manfred;Kulozik, Ulrich
研究了一种新的酸奶工艺，其中乳蛋白通过含有谷胱甘肽（TG + GSH）的微生物转氨酶（TG）制剂共价交联。由于未加热的牛奶通常对TG的反应性较低，因此应用TG + GSH以实现非抑制性交联，而不需要超出巴氏灭菌条件的预热处理。在TG+GSH孵育阶段之后，在发酵之前通过热处理酸奶乳使酶失活。在酸奶发酵过程中，TG + GSH对发酵时间没有负面影响，TG + GSH促进了蛋白质的交联，使蛋白质的表观粘度和聚合度都比不加GSH的TG高。此外，不同比例的酪蛋白乳清蛋白（CWP比率）被用来研究这两种蛋白质组分对共价交联酸奶凝胶结构的影响。结果表明，酸奶凝胶的交联度、表观粘度与CWP比之间存在一定的关系。在4 ℃下储存长达6周期间，对于由交联乳蛋白制备的搅拌型酸奶凝胶，流变学性质和蛋白质聚合度没有变化。(c)2007爱思唯尔有限公司保留所有权利。
A novel yoghurt process was investigated in which milk proteins were covalently cross-linked by a microbial transglutaminase (TG) preparation containing glutathione (TG + GSH). As unheated milk is normally less reactive towards TG, TG + GSH was applied to enable non-inhibited cross-linking without requiring a pre-heat treatment beyond pasteurisation conditions. After the TG+GSH incubation phase, the enzyme was inactivated by heat treatment of the yoghurt milk prior to fermentation. During yoghurt fermentation, no negative effect of TG + GSH on fermentation time was found. Protein cross-linking by TG + GSH was enhanced, resulting in higher apparent viscosity and a higher degree of protein polymerisation than that given by TG without GSH. Furthermore, different ratios of casein to whey proteins (CWP ratios) were used to investigate the effect of both protein fractions on covalently cross-linked yoghurt gel structures. The results showed a relationship between extent of cross-linking, apparent viscosity and CWP ratio of the yoghurt gels. During storage for up to 6 weeks at 4 degrees C, no changes in theological properties and degree of protein polymerisation were measurable for stirred yoghurt gels prepared from cross-linked milk proteins. (c) 2007 Elsevier Ltd. All rights reserved.