Collaborative Innovation Center of Provincial and Ministerial Co-construction for Seafood Deep Processing, China.
National Engineering Research Center of Seafood, China.
Food Funct. 2022 Aug 30;13(17):8930-8940. doi: 10.1039/d2fo01255c.
The development of beverages with high protein concentrations has received considerable interest. Nevertheless, the unwanted protein aggregation and gelation of proteins caused by the pasteurization process are currently posing a significant obstacle. Herein, we describe a facile but robust approach to enhance the heat stability of soy proteins (SPs) by preheating at alkaline pH values. When the modified SPs were reheated at a concentration of 2% (w/v), the anti-aggregation properties of the modified SPs were confirmed without any further increase in the size of the particles. Even at concentrations as high as 20% (w/v), the modified protein suspensions preserved their flowability when reheated, whereas the control sample had already gelled at 10% (w/v) concentration. The fluorescence and circular dichroism (CD) spectra indicated that the structures of the modified SPs unfolded and their conformational integrity was diminished after modification. These changes contributed to the reduced unfolding of soy protein and the decreased exposure of active sites during reheating, which inhibited the cross-linking between soy protein molecules during reheating. Meanwhile, the increased surface charge also inhibited the secondary aggregation behavior, improving the thermal stability of protein particles. These findings show that preheating in combination with alkaline pH can be successfully applied to improve the thermal stability of soy proteins, providing a feasible technique and essential insights into the application of soy proteins in protein-enriched liquid systems.
高浓度蛋白质饮料的开发受到了广泛关注。然而，目前巴氏杀菌过程中蛋白质的不受欢迎的聚集和凝胶化仍然是一个重大障碍。本文介绍了一种通过在碱性 pH 值下预加热来增强大豆蛋白 (SP) 热稳定性的简便但稳健的方法。当改性后的 SPs 在 2%（w/v）的浓度下再次加热时，证实了改性 SPs 的抗聚集特性，而无需进一步增加颗粒的大小。即使在高达 20%（w/v）的浓度下，改性蛋白悬浮液在再次加热时仍保持其流动性，而对照样品在 10%（w/v）浓度下已经凝胶化。荧光和圆二色性 (CD) 光谱表明，改性 SPs 的结构展开，其构象完整性在修饰后降低。这些变化导致大豆蛋白的展开减少，在再次加热过程中活性部位的暴露减少，从而抑制了再次加热过程中大豆蛋白分子之间的交联。同时，增加的表面电荷也抑制了二次聚集行为，提高了蛋白质颗粒的热稳定性。这些发现表明，预加热与碱性 pH 值相结合可以成功地应用于提高大豆蛋白的热稳定性，为富含蛋白质的液体系统中大豆蛋白的应用提供了一种可行的技术和必要的见解。
