Exogenous melatonin alleviates browning of fresh-cut sweetpotato by enhancing anti-oxidative process

• Melatonin treatment delayed the browning of postharvest fresh-cut sweetpotato. • Melatonin can enhance the anti-oxidative process of sweetpotato. • Melatonin has great potential to inhibit the browning in fresh-cut produce. Sweetpotato is an important and nutritionally rich crop. Melatonin (MT) possesses great potential for promoting the postharvest preservation of vegetables and fruit. However, the function of MT in postharvest sweetpotato is rarely characterized. Here, the functional mechanism of exogenous MT was evaluated in fresh-cut tuberous root of sweetpotato. Experimental results revealed that MT treatment strongly delayed the browning of postharvest fresh-cut sweetpotato. During the storage of the fresh-cut tuberous root of sweetpotato, exogenous MT reduced the activities of enzymes related to browning, and decreased the contents of reactive oxygen species (ROS) and the degree of membrane lipid peroxidation. Meanwhile, MT treatment maintained higher antioxidants levels, thus effectively inhibited browning and prolonged shelf life of fresh-cut sweetpotapo. In addition, exogenous MT induced the expression of genes related to the antioxidant pathway in sweetpotato. In conclusion, this study demonstrated that exogenous MT alleviates fresh-cut sweetpotato browning by enhancing anti-oxidative process, thereby laying a theoretical foundation and providing a scientific basis for delaying the browning in sweetpotato by MT treatment in the future.