Overseas Expertise Introduction Center for Discipline Innovation of Food Nutrition and Human Health (111 Center), School of Food Science and Engineering , South China University of Technology , Guangzhou , Guangdong 510640 , China.
Graduate School of Life Science , Hokkaido University , Sapporo 060-0810 , Japan.
J Agric Food Chem. 2019 Mar 6;67(9):2660-2669. doi: 10.1021/acs.jafc.8b06646. Epub 2019 Feb 20.
The wheat catalase gene ( wcat1) was cloned and overexpressed in Pichia pastoris. The purified wCat1 exhibits its highest activity at pH 7.5 and 35 °C with K and V of 22.95 mM and 0.24 μmol/min, respectively. wCat1 could markedly improve the farinographic properties of dough, with the stability time increasing and degree of softening decreasing, and enhance the rheological properties of dough. wCat1 could also elevate bread-making quality, with increased specific volume of the bread and decreased hardness, gumminess, and chewiness, which are attributable to increased amounts of SDS-insoluble protein in dough, resulting in extended glutenin networks and thus larger pores in the fermented dough and bread crumb. The decrease of hydrogen peroxide and increase of free thiol groups in wCat1-treated dough suggest that the decomposition of hydrogen peroxide by wCat1 likely promotes disulfide-bond formation and thus the cross-linking of dough proteins.
小麦过氧化氢酶基因（wcat1）在毕赤酵母中被克隆并过表达。纯化的 wCat1 在 pH7.5 和 35°C 下表现出最高的活性，K 和 V 分别为 22.95mM 和 0.24μmol/min。wCat1 可以显著改善面团的粉质特性，使稳定时间延长，弱化度降低，并增强面团的流变学特性。wCat1 还可以提高面包的制作质量，增加面包的比容，降低硬度、胶粘性和咀嚼性，这归因于面团中 SDS 不溶性蛋白的增加，从而使发酵面团和面包屑中的谷蛋白网络扩展，形成更大的孔隙。wCat1 处理的面团中过氧化氢的减少和游离巯基的增加表明，wCat1 对过氧化氢的分解可能促进了二硫键的形成，从而交联了面团蛋白。
