Whey Protein Microcapsules Coated With Anionic Polysaccharides Enhance EGCG Bio‐Accessibility Through Protein–Ligand Interactions

Epigallocatechin‐3‐gallate (EGCG) suffers from poor stability and limited bioavailability, severely restricting its therapeutic potential in functional foods. This study developed whey protein‐pectin‐coated solid/oil/water bilayer emulsions to microencapsulate EGCG and enhance its delivery efficiency. Whey protein‐pectin microcapsules achieved exceptional encapsulation efficiency (82.50%) and bio‐accessibility (66.65%), dramatically outperforming other polysaccharide combinations. The encapsulated EGCG demonstrated significantly superior antioxidant activity compared to free EGCG during gastrointestinal digestion, with 2,2‐diphenyl‐1‐picrylhydrazyl and 2,2‐azino‐bis‐(3‐ethylbenzothiazoline‐6‐sulfonic) acid assays confirming enhanced radical scavenging capacity. Scanning electron microscopy analysis revealed uniform, thermally stable microcapsules with optimal structural integrity. Molecular docking and dynamic simulations elucidated that multiple EGCG‐pectin ligands form robust noncovalent interactions with whey proteins through hydrogen bonding and van der Waals forces, creating stable emulsion networks confirmed by Fourier‐transform infrared spectroscopy and secondary structure analysis. This breakthrough demonstrates that WPI‐pectin microencapsulation represents a transformative strategy for stabilizing bioactive compounds, offering unprecedented opportunities for developing next‐generation functional food delivery systems with enhanced therapeutic efficacy.