RESUMEN
Exogenous melatonin application at 0, 1, 10, 100, and 1000 µM retarded cap browning of button mushrooms (Agaricus bisporus) by 78.35, 31.40, 30.91, 27.17, and 32.50 %, respectively.Mushrooms treated with 100 µM melatonin also had lower weight loss and higher firmness. During the first 5 days of storage at 4 °C, higher H2O2 accumulation may serve as a signal for promoting endogenous melatonin accumulation by triggering the expression of TDC, T5H, SNAT, and ASMT genes, beneficial for preserving membrane integrity. Besides, the higher accumulation of phenols in mushrooms treated with 100 µM melatonin may be ascribed to higher PAL and lower PPO gene expression and enzyme activity. Moreover, higher DPPH scavenging capacity in mushrooms treated with 100 µM melatonin may be ascribed to the higher accumulation of phenols and ascorbic acid.