Sericultural & Agri-Food Research Institute Guangdong Academy of Agricultural Sciences/Key Laboratory of Functional Foods, Ministry of Agriculture and Rural Affairs/Guangdong Key Laboratory of Agricultural Products Processing, Guangzhou 510610, China; College of Life Science, Yangtze University, Jingzhou, Hubei 434020, China.
Sericultural & Agri-Food Research Institute Guangdong Academy of Agricultural Sciences/Key Laboratory of Functional Foods, Ministry of Agriculture and Rural Affairs/Guangdong Key Laboratory of Agricultural Products Processing, Guangzhou 510610, China.
Food Chem. 2020 Dec 15;333:127492. doi: 10.1016/j.foodchem.2020.127492. Epub 2020 Jul 7.
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 HO. 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，表达并鉴定了重组水稻谷胱甘肽巯基氧化酶（rQSOX），并进一步评估了其对面粉加工品质的性能。纯化的 rQSOX 以二硫苏糖醇为底物时表现出最高的巯基氧化活性（1.96 IU/mg），同时产生 HO。rQSOX 催化二硫苏糖醇氧化的最适温度和 pH 值分别为 60°C 和 pH 8.0。并且 rQSOX 在 80°C 孵育 1 小时后仍保留其最大活性的 50%。此外，rQSOX 的添加改善了面团的粉质特性，表现为面团稳定时间的增加和软化程度的降低，以及面团的黏弹性增强。添加 rQSOX（10 IU/g 面粉）对面团的比容（37%）和弹性（17%）有显著的提高，并使馒头的硬度显著降低一半，这归因于面筋网络的增强。研究结果为 rQSOX 在面粉加工业中的应用提供了一定的理论依据。
