Effect of cold storage and 1-methylcyclopropene treatment on fruit storage potential of ‘Summer Prince’ and ‘Summer King’ apples

The purpose of this study was to investigate the effects of cold storage and 1-methylcyclopropene (1-MCP) treatment on fruit quality and storage potential of 'Summer Prince' and 'Summer King' apples. The fruits were treated with 1-MCP at a concentration of 1 μL/L for 18 h immediately after harvest, and stored for up to 6 months under cold storage (0°C). The fruit quality during cold storage showed that the loss of flesh firmness of untreated fruits was remained at 70 N for 'Summer Prince' apple up to 4 months and 60 N for 'Summer King' apple up to 2 months, and reduced down than those results after that. In 1-MCP treatment, both cultivars maintained flesh firmness over 70N even after 6 months of storage. Titratable acidity of untreated fruits decreased to 0.32% (‘Summer Prince’) and 0.31% (‘Summer King’) for up to 3 months, but 1-MCP-treated fruits still remained at 0.33% and 0.30% for up to 4 months of storage. Internal ethylene concentration (IEC) of untreated fruits was increased after one month in both cultivars, but IEC of 1-MCP-treated fruits was significantly lower than that of untreated fruits. Skin greasiness did not occur at all. Fruit weight loss and peel color variables (L*, a*, b*) tended to a little increase during cold storage. In case of 'Summer Prince' apples, 1-MCP-treated fruits exhibited a reduced weight loss and delayed change in redness (a*). Therefore, this study suggested that the storage potential of ‘Summer Prince’ and ‘Summer King’ apples at cold storage was estimated at 3 and 2 months, respectively, but this potential would increase for up to 4 months with 1-MCP treatment in both cultivars.