Duan Jia Wen, Wang Xin Yu, Zhang Shi Lin, Ding Yan, Zhu Xue Qin, Zhang Tie Hua, Dong Zhou Yong
College of Food Science and Engineering, Jilin University, Jilin, Changchun 130062, China.
College of Food Science and Engineering, Jilin University, Jilin, Changchun 130062, China.
Int J Biol Macromol. 2025 Jul;318(Pt 1):144854. doi: 10.1016/j.ijbiomac.2025.144854. Epub 2025 May 31.
In this study, atmospheric pressure cold plasma (ACP) technology was used to assist in the construction of whey protein isolate-epigallocatechin gallate non-covalent complexes (WPI-EGCG). The mechanism by which ACP treatment influences the conformational relationship of the complexes was systematically analyzed. The EGCG binding ratio, free amino and sulfhydryl content, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) changes confirmed that the ACP treatment was able to significantly enhance the non-covalent interactions between WPI-EGCG through the oxidative modification and molecular cross-linking induced by the activated particles. The EGCG grafting rate was increased by 22.28 % compared to the un-ACP-treated samples. Secondary structural changes in whey protein isolate (WPI) were induced by atmospheric pressure cold plasma (ACP), as revealed by Fourier transform infrared spectroscopy (FTIR) and fluorescence spectroscopy analyses. The microenvironment of the tryptophan residue became increasingly polar due to tertiary structure unfolding. Scanning electron microscopy (SEM) further revealed a transition of the complexes from dense lamellae to porous network structures. The complexes' surface hydrophobicity, solubility, emulsification activity, foaming stability, and antioxidant qualities were notably improved due to the structural modifications induced by ACP. This study provides a theoretical basis for plasma technology to modulate protein-polyphenol structural and functional properties, and broadens the application path of ACP in food macromolecule modification.
在本研究中，采用大气压冷等离子体（ACP）技术辅助构建乳清蛋白分离物-表没食子儿茶素没食子酸酯非共价复合物（WPI-EGCG）。系统分析了ACP处理影响复合物构象关系的机制。EGCG结合率、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（SDS-PAGE）变化证实，ACP处理能够通过活化粒子诱导的氧化修饰和分子交联显著增强WPI-EGCG之间的非共价相互作用。与未进行ACP处理的样品相比，EGCG接枝率提高了22.28%。傅里叶变换红外光谱（FTIR）和荧光光谱分析表明，大气压冷等离子体（ACP）诱导了乳清蛋白分离物（WPI）的二级结构变化。由于三级结构展开，色氨酸残基的微环境变得越来越极性。扫描电子显微镜（SEM）进一步揭示了复合物从致密薄片向多孔网络结构的转变。由于ACP诱导的结构修饰，复合物的表面疏水性、溶解性、乳化活性、泡沫稳定性和抗氧化性能显著提高。本研究为等离子体技术调控蛋白质-多酚结构和功能特性提供了理论依据，拓宽了ACP在食品大分子修饰中的应用途径。
