Recombinant rice quiescin sulfhydryl oxidase (rQSOX) has the potential to improve the flour processing quality, but the mechanisms remain unclear. The effects of rQSOX on bread quality, dough rheology, and gluten structure and composition, with glucose oxidase as a positive control, were investigated. rQSOX addition could improve the dough processing quality, as proved by enhanced viscoelastic properties of dough as well as a softer crumb, higher specific volume, and lower moisture loss of bread. These beneficial effects were attributed to gluten protein polymerization and gluten network strengthening, evidenced by the improved concentration of SDS-insoluble gluten and formation of large gluten aggregates and the increased α-helix and β-turn conformation. Furthermore, decreased free sulfhydryl and increased dityrosine in gluten as well as improved H₂O₂ content in dough suggested that the rQSOX dough strengthening mechanism was mainly based on the formation of disulfide bonds and dityrosine cross-links in gluten by both thiol/disulfide direct exchange and hydrogen peroxide indirect oxidation pathways.

中文翻译：

---

重组大米 Quiescin 巯基氧化酶通过硫醇/二硫化物交换和过氧化氢氧化增强面筋结构

重组水稻槲皮素巯基氧化酶（rQSOX）具有提高面粉加工质量的潜力，但其作用机制尚不清楚。以葡萄糖氧化酶为阳性对照，研究了 rQSOX 对面包质量、面团流变学以及面筋结构和组成的影响。rQSOX的添加可以提高面团的加工质量，这可以通过增强面团的粘弹性以及更柔软的面包屑、更高的比容和更低的面包水分损失来证明。这些有益效果归因于面筋蛋白聚合和面筋网络强化，这可以通过提高 SDS 不溶性面筋的浓度和形成大面筋聚集体以及增加的 α-螺旋和 β-转角构象来证明。此外，_面团中2 O ₂含量表明rQSOX面团强化机制主要是基于通过硫醇/二硫键直接交换和过氧化氢间接氧化途径在面筋中形成二硫键和二酪氨酸交联。