Potential role of exogenous melatonin involved in postharvest quality maintenance of Vitis labrusca × vinifera ‘Kyoho’

Abstract BACKGROUND Melatonin is an endogenous free radical scavenger with antioxidant activity that preserves the commercial value of postharvest fruits and delays fruit senescence. To explore the effect of exogenous melatonin on antioxidants and aroma volatile compounds of grapes ( Vitis labrusca × vinifera ‘Kyoho’), the grapes were treated with distilled water (control), 50 μmol L −1 of melatonin (M50), and 100 μmol L −1 of melatonin (M100) for 30 min and were then stored at 4 °C for 25 days. RESULTS Exogenous melatonin decreased the rachis browning index, the decay development, the weight loss rate, the berry abscission rate, and the respiration rate, promoted the accumulation of total phenolics and total flavonoids, and delayed the reduction of anthocyanins and total soluble solids. In volatile compounds, the accumulation of esters, aldehydes, and alcohols in grapes was promoted, and the terpenes content was reduced by exogenous melatonin. CONCLUSION Exogenous melatonin had potentially positive effects on the postharvest life and quality maintenance of grapes. These findings provide theoretical support for the application of melatonin in grape storage and preservation. © 2023 Society of Chemical Industry.