Non-covalent interaction of rice protein and polyphenols: The effects on their emulsions

In this study, we investigated the non-covalent interaction mechanism between rice protein (RP) and three polyphenols with different concentrations (ferulic acid FA, gallic acid GA, and tannic acid TA) and their effects on the structure and emulsion stability of the proteins. Hydrophobic forces dominated the binding of RP to the polyphenols, and the reaction was heat-absorbing. The three polyphenols are bound to RP in the form of static quenching to form a non-covalent complex, and during the binding process, the RP provides one binding site. RP-polyphenol complexes, particularly RP-GA, enhanced ABTS scavenging and FRAP reduction. Polyphenols improved RP emulsion oxidative stability, inhibiting lipid oxidation and enhancing emulsion rheology and interfacial structure. RP-GA was most effective, maintaining low POV. These findings support the potential applications of RP-polyphenol noncovalent complexes in food processing. • Interaction with polyphenols improves rice protein (RP) antioxidant properties. • Interactions between RP and polyphenols and performance in emulsions are studied. • Hydrophobic forces and heat-absorbing dominated the binding of RP to polyphenols. • RP-polyphenol non-covalent complexes improve the oxidative stability of emulsions.