A tailorable interfacial dual‐binding strategy using rosmarinic acid for the oxidative stabilization of rice bran oil bodies

BACKGROUND: Rice bran oil bodies (RBOBs), as natural lipid-storage organelles, show much potential as plant-based resources but suffer from inherent oxidative instability, which restricts their industrial application. This study modified the RBOB interface using rosmarinic acid (RA) with non-covalent and covalent binding. The binding characteristics, physicochemical properties, physical stability, and oxidation resistance of the modified RBOBs were systematically evaluated, supported by correlation analysis and molecular docking. RESULTS: Non-covalent binding showed higher RA loading and efficiency, driven by reversible hydrophobic interactions and hydrogen bonding, whereas covalent binding enhanced zeta potential and reduced droplet sizes. Both methods improved physical stability, with confocal laser scanning microscopy confirming enhanced droplet dispersion in optimized non-covalent systems and a denser, coalescence-inhibiting interface in covalent systems. For oxidative stability, non-covalent binding provided superior short-term protection, significantly delaying the formation of hydroperoxides and reducing carbonyl content by 3.71%. Covalent binding offered sustained long-term inhibition, maintaining hydroperoxides at a significantly lower level and stabilizing the rate of carbonyl increase at 57.30%. Correlation analysis indicated a strong negative relationship between RA binding amount and oxidation markers in non-covalent systems, whereas covalent binding efficiency correlated positively with zeta potential reduction and negatively with oxidation. Molecular docking revealed that RA preferentially binds to the C-termini of 16/18 kDa oleosins with hydrogen bonds and hydrophobic interactions. CONCLUSION: These findings support the tailored design of RBOB-based emulsions for food applications, with non-covalently modified RBOBs being more suitable for fresh or short-shelf-life systems and covalently modified RBOBs for systems requiring prolonged oxidative stability. © 2026 Society of Chemical Industry.