Interactions between Myofibrillar Proteins and Quercetin: Underlying Mechanisms and Effects on Interfacial Film Formation and Emulsion Stability.

Mechanisms underlying myofibrillar protein (MP)-quercetin interactions and the effects of these interactions on interfacial film formation and MP emulsification properties were investigated. These interactions represent an enthalpy-driven, spontaneous, and exothermic process predominantly driven by hydrogen bonds, van der Waals forces, hydrophobic interactions, and disulfide bonds. Myosin showed multiple binding sites for quercetin. Partial unfolding of MPs was observed at low quercetin concentrations (10 and 50 μmol/g), accelerating the rates of interfacial diffusion, penetration, and rearrangement of MPs. This improved interfacial film elasticity and mechanical strength, increasing interfacial protein content, reducing MP emulsion particle size, and enhancing emulsion stability. However, MP aggregation and MP-quercetin complex formation were observed at high quercetin concentrations (100 and 200 μmol/g), which impaired the interfacial adsorption and emulsifying performance of MPs. These findings were validated by analyzing MP emulsion microstructures. These results offer a theoretical basis for polyphenol application in emulsified meat products.