Abstract: The effects of oxidative modification induced by rice bran rancidity on the interfacial properties of rice bran albumin were investigated. The results showed that carbonylation and sulfhydryl oxidation of rice bran albumin could be induced by rice bran rancidity. The emulsifying activity, emulsion stability, foaming capacity and foam stability of rice bran albumin were significantly (P < 0.01) negatively correlated with carbonyl content and α-helix/β-sheet proportions, while they were significantly (P < 0.01) positively correlated with free sulfhydryl content, surface hydrophobicity, and zeta potential. The oxidative rancidity products of rice bran induced rice bran albumin to form soluble and insoluble aggregates through protein-protein interactions via disulfide bond, non-disulfide covalent bond, and hydrophobic force, which led to a decrease in flexibility, surface hydrophobicity of protein molecule and electrostatic repulsion between molecules and consequently a negative impact on the interfacial properties of rice bran albumin.

Key words: rice bran albumin; rice bran rancidity; oxidative modification; structure; interfacial properties