Multifaceted characterization of lactoferrin and (-)-epigallocatechin-3-gallate (EGCG) interactions: development of the pickering emulsions for microencapsulated functional foods.

In this study, we explored the application of lactoferrin-(-)-epigallocatechin-3-gallate (LF-EGCG) complex with rapeseed, soybean, walnut, peanut and sesame oil for the preparation of Pickering emulsions and its spray-dried microcapsules. Spectroscopy and molecular docking revealed that LF-EGCG binds via hydrogen bonds, hydrophobic interactions, and van der Waals forces. Structural analysis demonstrated that 0.4 wt% LF-EGCG formed compact, thermally stable complexes with superior interfacial activity. The main reason was that 0.4 wt% LF-EGCG had the higher percentage of β-sheet and the lower percentage of α-helix. In addition, the Pickering emulsion based on walnut oil, stabilized with LF-EGCG, exhibited superior rheological properties, antioxidant capacity, and storage stability, while also improving bioavailability during in vitro digestion. The main reason was that walnut oil had a unique oil surface structure, which made the emulsion more resistant to environmental stresses such as mechanical forces, temperature fluctuations, and oxidative degradation. Post spray-drying, walnut oil microcapsules showed optimal rehydration properties. These research established LF-EGCG as an effective stabilizer for functional emulsion systems while providing critical processing parameters for industrial-scale production of nutraceutical-loaded Pickering emulsions microcapsules in food applications. It also provides a potential market for Pickering emulsions microcapsules in instant beverages.