Effects of 1-methylcyclopropene on oxidative damage, phospholipases and chilling injury in loquat fruit

BACKGROUND: Low-temperature storage is commonly used for loquat (Eriobotrya japonica Lindl.) fruit to inhibit decay and extend postharvest life, but it also increases the severity of chilling injury (CI) in red-fleshed fruit. 1-Methylcyclopropene (1-MCP) has been used to reduce the development of Cl in cold-stored loquat. However, the effects of 1-MCP on changes in antioxidant system and phospholipase activity and their relation to Cl have not been investigated. The objective of this study was to determine whether the 1-MCP-induced modification in antioxidant system and phospholipase activity is linked to the reduced Cl in cold-stored loquat fruit. RESULTS: 1-MCP treatment significantly alleviated Cl in 'Fuyang' loquat fruit. The treatment markedly inhibited the accumulation of malondialdehyde, superoxide radicals and hydrogen peroxide and the increase in electrolyte leakage. In addition, 1-MCP-treated fruit exhibited significantly higher catalase activity and lower lipoxygenase (LOX) and phospholipase C (PLC) activities than control fruit during storage. CONCLUSION: These results suggest that LOX and PLC are associated with the induction of Cl in loquat fruit. 1-MCP might reduce Cl by inhibiting LOX and PLC activities and alleviating oxidative damage. (C) 2009 Society of Chemical Industry