Research on melatonin in fruits and vegetables and the mechanism of exogenous melatonin on postharvest preservation

Melatonin, a natural compound, was first found in animals. It is a hormone secreted by the pineal gland and plays a role in regulating circadian rhythm. In recent years, many studies have shown that melatonin plays a significant role in delaying the senescence of postharvest fruits and vegetables (F&V), maintaining the postharvest quality of F&V, and prolonging the shelf life of postharvest F&V. This paper reviews recent research progress in melatonin and expounds on the content of melatonin in F&V and the effect of exogenous melatonin on F&V. The mechanism of melatonin on maintaining the postharvest quality of F&V and prolonging their shelf life is discussed. The positive effects of exogenous melatonin on the postharvest preservation of F&V are summarized, mainly including increasing endogenous melatonin content, improving quality indicators, enhancing antioxidant capacity, alleviating chilling injury, and inhibiting bacterial growth. We conclude by discussing the applicability and potential of melatonin while highlighting future perspectives in this research field.