Polyphenol oxidase inhibition by Saccharomyces cerevisiae extracts: A promising approach to prevent enzymatic browning
Zebo Liu, Hui Ding, Maria Martuscelli, Saria Sajid, Haifeng Hang, Ali Mohsin, Xiao‐Feng Zhu, Huijie Sun, Jianye Xia, Zhongping Yin, Yingping Zhuang, Meijin Guo, Zejian Wang
Abstract
Polyphenol oxidase (PPO)-mediated browning can have adverse effects on foods' quality during processing. Therefore, it's important to find natural and efficient PPO-inhibitors. This study investigated the effect and mechanism of yeast (Saccharomyces cerevisiae) extract in preventing PPO-mediated browning. Firstly, 0.5 g·L−1 S. cerevisiae extracts [calculated based on reduced glutathione (GSH) concentration] significantly reduced the browning of fresh-cut vegetable and fresh juice. The browning degree decreased by the maximum of 51.92% and 102.20%, respectively. Standard validation suggested that GSH in S. cerevisiae extracts contributed significantly to the anti-browning effect. Secondly, S. cerevisiae extracts showed an IC50 of 0.077 g·L−1 against potato-derived PPO using pyrogallol as the optimal substrate. Additionally, GSH displayed non-competitive inhibitory and static quenching effect on PPO. Finally, molecular docking and dynamics simulation demonstrated that GSH in S. cerevisiae extracts could interact with non-active sites of PPO with a binding free energy of −28.53 ± 6.29 kcal/mol. The binding process was mainly driven by electrostatic interactions and Van der Waals forces. These interactions could lead to the generation of stable GSH-PPO-substrate complexes and affect PPO's activity. Therefore, this study revealed new application prospects and laid a theoretical foundation for S. cerevisiae extracts as a PPO inhibitor in the food industry.