Prolong the postharvest shelf life of spinach through the antioxidative ability of melatonin

•Melatonin treatment delayed senescence and maintained quality of spinach;•Melatonin treatment maintains the color of spinach and chlorophyll content in spinach leaves.•Melatonin treatment increases antioxidant enzyme activity;•Melatonin treatment can scavenge reactive oxygen species (ROS). Spinach is also known as Persian cuisine, it is rich in nutrients such as protein, vitamin C and minerals, and has high nutritional value. In this study, Spinach was treated with melatonin in order to prolong its shelf life. Melatonin has strong antioxidant effects as an endogenous free radical scavenger. The spinach was sprayed with 0.10, 0.20 and 0.30 mg/mL melatonin solution after harvesting, and distilled water was used as control for low temperature storage at 4 °C. The results showed that melatonin spraying Spinach delayed the degradation of chlorophyll, especially the treatment of 0.20 mg/mL melatonin was the most effective. The content of soluble sugar and soluble protein in spinach tissue was kept high, the accumulation of malondialdehyde (MDA) was reduced, and the activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) were increased. These findings suggested that melatonin treatment may be a useful technique to prolong the postharvest life of spinach and improve its quality.