Effects of different dietary polyphenols on conformational changes and functional properties of protein-polyphenol covalent complexes
Effects of different dietary polyphenols on conformational changes and functional properties of protein-polyphenol covalent complexes
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DOI：
10.1016/j.foodchem.2021.130071
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发表时间：
2021-06-04
期刊：
影响因子：
8.8
通讯作者：
Huang, Jinbao
中科院分区：
文献类型：
--
作者：
Liu, Xiangju;Song, Qibin;Huang, Jinbao
在本研究中，通过自由基接枝制备了乳清分离蛋白 (WPI) 和四种多酚（表没食子儿茶素没食子酸酯 [EGCG]、槲皮素 [QC]、芹菜素 [AG] 和柚皮素 [NG]）的缀合物。多酚结合当量、游离氨基和巯基含量以及十二烷基硫酸钠-聚丙烯酰胺凝胶电泳的结果证实了WPI与多酚之间的共价相互作用。傅里叶变换红外光谱和荧光光谱分析确定了复合物的潜在结合位点并确定了蛋白质结构的变化。粒度分布和扫描电子显微镜数据证明了复合物中缀合物粒度和表面变化的增加。缀合过程显着提高了多酚的抗氧化性能和热稳定性，而表面疏水性则大大降低。 WPI-EGCG 具有最好的功能特性，其次是 WPI-QC、WPI-AG 和 WPI-NG。
In this study, conjugates of whey protein isolate (WPI) and four polyphenols (epigallocatechin gallate [EGCG], quercetin [QC], apigenin [AG], and naringenin [NG]) were prepared through free-radical grafting. The results for polyphenol binding equivalents and content of free amino and sulfhydryl groups as well as those from sodium dodecyl sulfate-polyacrylamide gel electrophoresis confirmed the covalent interaction between WPI and the polyphenols. Fourier transform infrared spectroscopy and fluorescence spectrum analysis identified the potential binding sites of the complexes and determined changes in the protein structure. The particle size distribution and scanning electron microscopy data demonstrated increases in conjugate particle sizes and surface changes in the complexes. The conjugation process significantly increased the polyphenols' antioxidant properties and thermal stabilities, whereas surface hydrophobicity was substantially reduced. WPI-EGCG had the best functional properties, followed by WPI-QC, WPI-AG, and WPI-NG.