State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, People's Republic of China.
State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, People's Republic of China; College of Food Science and Technology, Henan University of Technology, 100 Lianhua Street, Hi-tech Development Zone, Zhengzhou, Henan 450001, People's Republic of China.
Food Chem. 2020 Nov 1;329:126800. doi: 10.1016/j.foodchem.2020.126800. Epub 2020 Apr 18.
The role of polyphenol oxidase (PPO) in the browning of fresh wet noodle sheets (FWNS) was discussed. To release the chemical formation mechanism of the dark spots formed on FWNS, the reconstituted FWNS and PPO-catechol reaction systems were prepared. Different from the overall color change of FWNS, almost all the melanins in dark spots were indirect products of PPO catalysis. The PPO catalytic dehydrogenation was an essential step for the formation of dark spots, but once the phenol dehydrogenation products were formed, the dark spots could still form through a further polymerization process, even though the PPO was completely deactivated. The optimum pH for the phenolic dehydrogenation in FWNS was about 7, and the alkaline condition was advantageous to the progress of the polymerization. Comprehensively, the maximum amount of dark spots was formed at about pH 9.
探讨了多酚氧化酶（PPO）在鲜湿面条（FWNS）褐变中的作用。为了揭示 FWNS 表面黑斑形成的化学形成机制，制备了再水合 FWNS 和 PPO-儿茶酚反应体系。与 FWNS 的整体颜色变化不同，黑斑中的几乎所有黑色素都是 PPO 催化的间接产物。PPO 催化脱氢是形成黑斑的必要步骤，但一旦形成了苯酚脱氢产物，即使 PPO 完全失活，黑斑仍可通过进一步的聚合过程形成。FWNS 中酚类脱氢的最适 pH 值约为 7，碱性条件有利于聚合反应的进行。综合考虑，在 pH 值约为 9 时形成了最多的黑斑。
