Effects of 1-MCP and Pre-harvest Fruit Bagging Treatments on Cold Storability of the Red-fleshed Apple 'Kurenainoyume'

The evaluation of storability for the type 2 red-fleshed apple 'Kurenainoyume' is essential to expand its consumption for table and processing use, as the cultivation area of this cultivar has extended year by year. There is also little available information whether cold storage affects the skin and flesh coloration of 'Kurenainoyume' (type 2 apples). In the present study, we evaluated the effect of 1-methylcyclopropene (1-MCP) treatment on the storability of bagged and non-bagged fruit for respective table and processing use over 3 years. Furthermore, we determined the maximum storage duration of both bagged and non-bagged fruit with 1-MCP. No change was observed in the soluble solid content during cold storage regardless of 1-MCP and bagging treatments. The malic acid content, flesh firmness, and skin and flesh coloration decreased with longer storage duration, but the decrease in these parameters was alleviated by 1-MCP treatment. Without 1-MCP, the storage duration of both bagged and non-bagged fruit to maintain flesh firmness and coloration at acceptable levels was about 90 days after harvest (DAH). With 1-MCP, bagged fruit for table use could be stored for about 180-210 DAH with no severe decrease in flesh firmness. Non-bagged fruit for processing use could also be stored for the same duration as bagged fruit, but the flesh firmness severely deteriorated. Although cooling treatment during the fruit growing stage improved flesh coloration, we found that cold storage did not promote this factor.