Shelf-Life of Papaya (Carica papaya L.) as Influenced by Fruit Maturity, Holding Time in Ambient and 1-Methylcyclopropene Treatment

Experiments were done to determine the postharvest responses of two fruit maturity stages (mature green, 5-15% yellow, Y) of newly harvested Carica papaya 'Kapoho' to various holding times (0, 1, 2 days) in ambient prior to treatment with 1-methylcyclopropene (1-MCP) in an air-tight chamber. Total soluble solid (TSS) at the end of shelf life was higher in 5-15Y fruit treated with 100 nl L-1 1-MCP. In the 5-15Y lot, peel yellowing was lower in fruit held for 2 days suggesting slower peel color change at 6 days after treatment (DAT) but not at 9 DAT. Visual quality was better in mature green fruit. In the 5-15Y lot, treated fruit were firmer; disease less severe; weight loss lower; and there was a 59% improvement in shelf life, 73% delay in days to edible ripe stage (DERS), 51% delay in days to disease occurrence (DDO) in fruit held 2 days relative to the control. DDO was also delayed in mature green fruit held for 1 or 2 days prior to treatment. Fruit (5-15Y) held for a day prior to treatment with various 1-MCP concentrations (0, 50, 100, 150 nl L-1) showed that 1-MCP at 100 nl L-1 resulted in a longer shelf life of 14.3 days or 30% improvement, less yellow but firmer fruit at 9 DAT as well as DERS and DDO at 23 and 25%, respectively. Respiration rate in treated 5-15Y was lower regardless of holding time. All treated fruit reached edible ripe stage. Thus, holding fruit for a day or two in ambient conditions prior to treatment with 100 nl L-1 1-MCP is effective in prolonging shelf life of 'Kapoho' papaya.