Multi-scale interactions in whey protein-dual polyphenol complexes: Structure characterization, interfacial behavior,
Yunping Yao1, Bing Wang1, Zehui Zhang1
1State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Food Quality and Health of Tianjin, College of Food Science and Engineering, Tianjin University of Science & Technology, Tianjin, 300457, China.
Abstract:
While individual polyphenol-whey protein isolate (WPI) interactions are partially understood, how dual-polyphenols regulate WPI colloidal properties remains unclear. This study elucidated the combined interaction of resveratrol (RES) and epigallocatechin-3-gallate (EGCG) with WPI. RES-EGCG bind to WPI via hydrogen bonding and van der Waals forces. Multi-spectroscopy showed that EGCG in the dual-polyphenol complex reduced α-helix and increased β-sheet. The ternary complex, prepared at an initial RES:EGCG molar ratio of 1:1, showed optimal interfacial and antioxidant performance. Lipid hydroperoxide (ROOH) formation and decomposition kinetics in emulsions showed that RES-EGCG jointly controlled lipid oxidation: suppressing ROOH formation and minimizing its decomposition. Quantum chemical calculations indicated that the ternary complex exhibited a smaller HOMO-LUMO gap, suggesting enhanced electron-transfer tendency. Correlation analysis linked α-helix to interfacial activity (r = 0.74-0.93) and β-sheet to antioxidant activity (r = 0.71-0.90). This work clarifies the combined interaction and provides a strategy for designing complex WPI-based colloidal ingredients.
