Effects of 1-methylcyclopropene on ripening of greenhouse tomatoes at three storage temperatures

Tomatoes (Lycopersicon esculentum Mill., cv. Rapsodie) were harvested at the mature green stage and treated with 250 nl l(-1) 1-methylcyclopropene (1-MCP) for 24 h at 20 degreesC. The fruit were then stored for 24 days at 15, 20 or 25 degreesC at 90-95% relative humidity. Sampling was carried out at 0, 6, 12, 18 and 24 days after treatment. Treatment with 1-MCP delayed ripening as measured by changes in lycopene, chlorophyll, hue angle, polygalacturonase (PG) activity and tissue firmness. Ripening was delayed by 6 days at 25 degreesC, by 12 days at 20 degreesC, and by 18 days at 15 degreesC in 1-MCP-treated fruit. In general, 1-MCP only delayed the onset of ripening-related changes and did not significantly alter final values for measures of firmness, color (hue angle), PG activity, and lycopene and chlorophyll contents at a particular storage temperature. The results suggest that 1-MCP is most effective at delaying ripening of mature-green tomatoes when they are stored near the currently recommended temperature range of 12.5-15 degreesC. Crown Copyright (C) 2002 Published by Elsevier Science B.V. All rights reserved.