Resveratrol-mediated protein conformational changes to enhance the emulsifying properties of ovalbumin-based...

Compared with natural proteins, protein microgels better enhance the performance and stability of high internal phase Pickering emulsions (HIPPEs), with promising food industry applications. In this study, ovalbumin-resveratrol (OVA-RES) composite microgel particles were synthesized via a top-down approach to fabricate HIPPEs, which showed significant improvements in viscoelasticity, storage, centrifugal, and thermal stability. To clarify the stabilization mechanism, the morphology, structure, and physicochemical properties of composite microgels under different RES concentrations were characterized. The results revealed that the optimal performance was attained at a RES concentration of 0.12 mM: at this concentration, RES induced a conformational transition of OVA primarily through hydrophobic interactions. Specifically, the α-helix content decreased from 23.65 % to 12.60 %, the β-sheet content increased from 36.55 % to 49.20 %, and the free sulfhydryl group content rose from 19.12 μmol/g to 21.57 μmol/g. Furthermore, the surface activity of the composite microgels was significantly enhanced, as evidenced by increased hydrophobicity, reduced surface tension, and an elevation in contact angle from 53.6° to 72.85°. In the present study, the emulsifying properties of OVA microgel particles were successfully enhanced through the incorporation of RES, providing new insights into natural protein-polyphenol composite microgels as efficient emulsifiers. Meanwhile, this work develops a feasible food-grade emulsion stabilization and delivery platform for the incorporation of RES into emulsion-based food systems. Future research will further focus on the bioactive functions of OVA-RES composite microgels in food systems, as well as their specific applications and industrialization potential in the food sector.