Melatonin prolongs the shelf life of snow peas by regulating the antioxidant system

Postharvest snow peas (Pisum sativum var. saccharatum) exhibit rapid quality deterioration characterized by chlorophyll degradation, tissue wilting, and accelerated senescence under ambient storage conditions. To address this postharvest challenge, we investigated the efficacy of melatonin immersion treatments (50, 100, and 500 μmol L⁻¹) combined with refrigerated storage at the 4 ± 0.5 °C for 42 days. Experimental protocols involved a 30 s immersion in melatonin solutions followed by air drying (25 °C, 60 min). Researches showed the reduction of the rot rate in snow peas with 100 μmol L⁻¹ melatonin treatment. Furthermore, its application effectively maintained good color and sensory quality, improved free radical scavenging power and metal reduction power, decreased reactive oxygen species levels such as H₂O₂ and O₂·^-, and promoted ascorbic acid - glutathione cycle, consequently elevating the levels of antioxidants as well as antioxidant enzymes. The results demonstrated that melatonin could be used as a fresh-keeping technology to improve the value and prolong the storage time of snow peas.