大豆分离蛋白和蛋清复合凝胶特性的研究.docVIP

  大豆分离蛋白和蛋清复合凝胶特性的研究# 董昳廷，苏宇杰，杨严俊** （江南大学食品科学与工程国家重点实验室，江南大学食品学院，江苏无锡 214122） 5 10 15 20 25 30 35 40 摘要：大豆分离蛋白和蛋清因其良好的凝胶性能在肉制品以及豆腐等凝胶制品中广泛应用。 研究二者的复合凝胶特性可以为其复合体系在这些产品中的应用提供重要的理论基础。本文 以大豆分离蛋白和蛋清为研究对象，探讨两种蛋白质的性质对其复合凝胶性能的影响，并通 过红外对复合凝胶二级结构的分析，深入研究了凝胶的质构，保水性变化与二级结构之间的 关系。实验结果表明，随着蛋清比例的增大，蛋白复合凝胶的硬度逐渐增大，说明蛋清赋予 凝胶较强的硬度；复合凝胶的弹性先增大后减小，当蛋清与大豆分离蛋白比例为 1:1 时，复 合凝胶弹性达最大值，为 0.979；复合凝胶的保水性变化趋势与弹性一致，最高为 0.951。 蛋白复合凝胶的红外二级结构分析表明，复合凝胶的弹性和保水性与 -螺旋的含量呈正比 关系，硬度大小则与β -折叠含量呈正比。 关键词：复合凝胶；大豆分离蛋白；蛋清；凝胶特性；二级结构 中图分类号：TS253.1 The co-gelation of soybean protein isolate and egg white DONG Yiting, SU Yujie, YANG Yanjun (The State Key labtory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, JiangSu WuXi 214122) Abstract: Soybean protein isolate and egg white have been widely used in many food such as meat products and tofu because of their excellent gel properties. This paper investigated the gel properties of soybean protein isolate/egg white composite gels, using different blend ratios (0:1-1:0). Results showed that the soybean protein isolate/egg white proteins blended at the ratio of 1:1 produced gels with synergistic enhancement of springiness and water holding capacity. The springiness and water holding capacity at 1:1 were 0.979 and 0.951, respectively. Besides, the results of secondary structure of composite gels showed that the water holding capacity and springiness of composite gels increased at first and then decreased with the addition of egg white which corresponded to the level of ɑ -helix. The hardness of composite gels increased as the result of the increase in the level of β-Sheet structure when the content of egg white increased. Key words: Composite gels; soybean protein isolate; egg white; gel properties; secondary structure. 0 引言 大豆蛋白和蛋清是两种重要的食品加工原料，二者均具有多种功能特性，其中凝胶性和 持水性被广泛应用于肉制品、鱼糜制品、面制品以及凝胶制品等食品加工中。 目前，对于大豆蛋白，蛋清各自凝胶特性的研究已比较成熟[1-4]。大豆蛋白凝胶性应用 广泛，其直接应用产品—豆腐受到消费者的青睐。但是由于 7S 和 11S 蛋白的变性温度分别 为 75℃和 91[5]，大豆蛋白需在较高温度及较高蛋白浓度下才能形成较好的凝胶且当加