1-Methylcyclopropene Improves the Postharvest Physiological Characteristics and Fruit Quality of 'Colorpple' and 'Manhong' Apple Cultivars during Storage at Warm and Cold Temperatures

Methods by which to realize the postharvest preservation of the new apple cultivars 'Colorpple' and 'Manhong' are unknown. Hence, the objective of this study was to evaluate the effects of 1-methylcyclopropene (1 -MCP) on the postharvest physiological characteristics and storage quality of 'Colorpple' and 'Manhong' apples. Harvested apples were treated with 1 -MCP (1 mu L<middle dot>L -1 ) and stored for 40 days under warm temperature (20 +/- 1 degrees C) and for eight months under cold (0 +/- 1 degrees C) temperature conditions. Untreated fruits were used as control groups. Ethylene production and respiration rates were lower in all treated fruits stored at a warm temperature. However, 1 -MCP had minimal effects on flesh firmness, weight loss, or the soluble solid content (SSC), affecting only the titratable acidity (TA) at 40 days. Higher L * (20 and 30 days) and lower a * (30 and 40 days) values were observed only in the fruit skins of untreated 'Colorpple' apples. Additionally, skin greasiness increased in the untreated 'Colorpple' (30 and 40 days) and 'Manhong' (20 days) apples. Slight levels of fruit decay were observed in 'Colorpple' (30 days) and 'Manhong' (30 and 40 days). At a cold temperature, 1 -MCP induced lower ethylene production and respiration rates and higher flesh firmness and TA in both cultivars, while weight losses as well as skin color and SSC changes were not detected. A lower SSC/TA ratio was observed in treated fruits after 6-8 months of storage. Moderate to severe skin greasiness was observed in both untreated apple types. Overall, this study suggests that a 1 -MCP treatment improves the postharvest physiological characteristics and fruit quality of 'Colorpple' and 'Manhong' apples; 1 -MCP is more effective for long-term storage of these cultivars at cold temperatures but is less effective at ambient temperatures.