Effect of 1-methylcyclopropene on kiwifruit softening

Premature softening induced by ethylene is a serious commercial problem limiting the storage life of kiwifruit. The objective of this study was to evaluate the effectiveness of 1-MCP in extending storage and shelf life and preventing postharvest softening of kiwifruit. Exposure to 100 nl l-1 1-MCP at room temperature for 12 h or at low temperature ( 5°C) for 24 h was applied with a single or double treatment before or/and after storage. The fruit were also treated with a single application at 250 nl l-1 1-MCP. Following storage at 0°C, the fruit were kept at 20°C. The results show that exposure to 100 and 250 nl l-1 1-MCP delayed softening in kiwifruit after shelf life. An application before storage was more effective than treatment after storage. Double treatment was slightly more effective compared to a single application. Furthermore, a single application of 1-MCP at room and low temperature was equally effective in delaying the loss of firmness. In a separate experiment, kiwifruit were treated three days after harvest, after curing, with 100 nl l-1 1-MCP at room temperature for 12 h and stored in air at 0°C with or without ethylene absorber. Following storage, the fruit were kept at 20°C. 1-MCP treated fruit were significantly firmer than untreated fruit after storage and shelf life. Kiwifruit treated and stored without ethylene absorber had comparable or superior values of firmness to untreated fruit stored with ethylene absorption. In both trials, 1-MCP had no effects on soluble solids content and acidity. No significant differences were observed in fruit rot, caused by Botrytis cinerea.