Abstract:The purpose of this study was to investigate the anti-browning mechanism of L-cysteine （L-cys）on fresh-cut potatoes.The fresh-cut potatoes were treated by vacuum impregnation assisted with 0.7 g/L L-cys solution.The effect of L-cys treatment on browning index （BI），the activities of polyphenol oxidase（PPO），peroxidase（POD）and phenylalanineammonialyase（PAL），the polyphenol contents and antioxidant capacities of fresh-cut potatoes was evaluated.The results showed that the BI value，PPO activity，POD activity and PAL of fresh-cut potatoes in the experimental group were significantly lower than those of control group （p<0.05）.The polyphenol content of the experimental group was significantly lower than those of the control group（p<0.05）during 0-6 days of storage，but significantly increased in the later period of storage （p<0.05）.In addition，the antioxidant activity of fresh-cut potatoes in both groups increased first and then decreased during storage.Therefore，these results indicated that L-cys treatment could inhibit the enzymes activity in fresh-cut potatoes，thus delaying the browning of fresh-cut potatoes during storage.