In this study, recombinant rice quiescin sulfhydryl oxidase (rQSOX) was expressed and characterized, and its performance in flour-processing quality was further evaluated. The purified rQSOX exhibited the highest sulfhydryl oxidation activity (1.96 IU/mg) using dithiothreitol as a substrate, accompanying the production of H₂O₂. The optimal temperature and pH were 60 °C and pH 8.0 for rQSOX catalyzing oxidation of dithiothreitol. And rQSOX retained 50% of its maximum activity after incubation at 80 °C for 1 h. Moreover, rQSOX supplementation improved the farinograph properties of dough, indicated by the increased dough stability time and decreased degree of softening, and enhanced viscoelastic properties of the dough. Addition of rQSOX (10 IU/g flour) provided remarkable improvement in specific volume (37%) and springiness (17%) of the steamed bread, and significantly reduced the hardness by half, which was attributed to the strengthened gluten network. The results provide an understanding for rQSOX using in flour-processing industry.

在这项研究中，表达和表征了重组水稻槲皮素巯基氧化酶（rQSOX），并进一步评估了其在面粉加工品质中的性能。以二硫苏糖醇为底物，伴随着H ₂ O ₂的产生，纯化的rQSOX表现出最高的巯基氧化活性（1.96 IU / mg）。。rQSOX催化二硫苏糖醇氧化的最佳温度和pH分别为60°C和pH 8.0。在80°C孵育1小时后，rQSOX保留了其最大活性的50％。此外，rQSOX补充剂改善了面团的粉质仪性能，这是由于增加了面团的稳定时间并降低了软化程度，并增强了面团的粘弹性。加入rQSOX（10 IU / g面粉）可使bread头的比容（37％）和弹性（17％）显着提高，并且硬度显着降低一半，这归因于面筋网络的增强。结果为在面粉加工行业中使用rQSOX提供了理解。