Pang Xin-Hui, Yang Yang, Bian Xin, Wang Bing, Ren Li-Kun, Liu Lin-Lin, Yu De-Hui, Yang Jing, Guo Jing-Chun, Wang Lei, Zhang Xiu-Min, Yu Han-Song, Zhang Na
Key Laboratory of Food Science and Engineering of Heilongjiang Province, College of Food Engineering, Harbin University of Commerce, Songbei District, Harbin 150076, China.
Heilongjiang Academy of Sciences, Harbin 150000, China.
Foods. 2021 Jul 13;10(7):1618. doi: 10.3390/foods10071618.
In order to make HPI have a wide application prospect in the food industry, we used EGCG to modify HPI. In this study, we prepared different concentrations (1, 2, 3, 4, and 5 mM) of (-)-epigallocatechin gallate (EGCG) covalently linked to HPI and use methods such as particle size analysis, circular dichroism (CD), and three-dimensional fluorescence spectroscopy to study the changes in the structure and functional properties of HPI after being covalently combined with EGCG. The particle size data indicated that the covalent HPI-EGCG complex was larger than native HPI, and the particle size was mainly distributed at about 200 μm. CD and three-dimensional fluorescence spectroscopy analyses showed that the conformation of the protein was changed by conjugation with EGCG. The β-sheet content decreased from 82.79% to 66.67% after EGCG bound to the protein, and the hydrophobic groups inside the protein were exposed, which increased the hydrophobicity of the protein and changed its conformation. After HPI and 1 mM of EGCG were covalently bonded, the solubility and emulsifying properties of the covalent complex were improved compared with native HPI. These results indicated that HPI-EGCG conjugates can be added in some foods.
为了使高纯度大豆分离蛋白（HPI）在食品工业中具有广阔的应用前景，我们使用表没食子儿茶素没食子酸酯（EGCG）对HPI进行改性。在本研究中，我们制备了不同浓度（1、2、3、4和5 mM）的与HPI共价连接的（-）-表没食子儿茶素没食子酸酯（EGCG），并使用粒度分析、圆二色性（CD）和三维荧光光谱等方法研究HPI与EGCG共价结合后其结构和功能特性的变化。粒度数据表明，共价HPI-EGCG复合物比天然HPI大，且粒度主要分布在约200μm。CD和三维荧光光谱分析表明，与EGCG结合后蛋白质的构象发生了变化。EGCG与蛋白质结合后，β-折叠含量从82.79%降至66.67%，蛋白质内部的疏水基团暴露出来，这增加了蛋白质的疏水性并改变了其构象。HPI与1 mM的EGCG共价结合后，共价复合物的溶解性和乳化性能相比天然HPI有所提高。这些结果表明，HPI-EGCG缀合物可添加到某些食品中。
