米糠酸败诱导的蛋白质氧化对米糠清蛋白界面性质的影响

研究米糠酸败诱导的氧化修饰对米糠清蛋白界面性质的影响。结果显示，米糠酸败会诱导米糠清蛋白发生羰基化和巯基氧化反应。米糠清蛋白的乳化性、乳化稳定性、起泡能力和起泡稳定性与其羰基含量、α-螺旋/β-折叠呈极显著（P＜0.01）负相关，与游离巯基含量、表面疏水性、Zeta电位绝对值、溶解度呈极显著（P＜0.01）正相关。结果表明，米糠氧化酸败产物诱导米糠清蛋白通过蛋白质-蛋白质相互作用（二硫键、非二硫共价键、疏水作用力等）形成可溶性和不可溶的聚集体，导致蛋白质分子柔性和表面疏水性下降，分子间静电斥力减弱，进而对米糠清蛋白的界面性质产生负面影响。

Effects of Protein Oxidation Induced by Rice Bran Rancidity on the Interfacial Properties of Rice Bran Albumin

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.