|Watkins, C. - CORNELL UNIVERSITY|
Submitted to: Postharvest Biology and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 23, 1999
Publication Date: N/A
Interpretive Summary: A recently developed gaseous compound referred to as 1-MCP shows a great deal of promise for maintaining quality and extending the storage life of horticultural commodities, including fruits, vegetables and flowers. The beneficial effects of 1-MCP stem from its ability to block the action of the gaseous plant hormone ethylene, which generally hastens the rate of deterioration of plant tissues after harvest or any kind of stress. Ethylene is particularly important in stored apples, as it accelerates ripening, softening and loss of tartness. In this study, the benefits of prestorage treatment with 1-MCP were examined for fruit of four apple cultivars that differ in their rates of ripening and ethylene production. It was found that whereas 1-MCP treatment generally delayed or prevented ripening and helped maintain quality in fruit of all four cultivars, the dose required for optimal effects varied. Also, in 'Law Rome' apples, 1-MCP Pgreatly reduced the incidence and severity of the costly storage disorder superficial scald, possibly by preventing ethylene-induced synthesis of a compound that has been linked with scald development. This kind of information will be vital for the apple industry to practically apply the benefits of 1-MCP treatment on a commercial scale with different varieties of apple fruit.
Technical Abstract: The potential for commercial application of 1-methylcyclopropene (1-MCP) to maintain quality of 'McIntosh', 'Empire', 'Delicious' and 'Law Rome' apples under air and controlled atmosphere (CA) storage conditions was investigated. These cultivars represent early, mid and late season apples with ripening rates ranging from fast to slow. 1-MCP gas concentrations used were 0.5, 1 and 2 ul 1-1, generated from measured amounts of Ethylblo (TM) powder. Fruit of each cultivar were removed from storage at six week intervals during 30 weeks in air, or at eight week intervals during 32 weeks in CA, and evaluated after one and seven d at 20 degrees C. Effects of 1-MCP were greater in CA than air storage. A dose response of internal ethylene concentrations and flesh firmness to 1-MCP was found in 'McIntosh' and 'Law Rome', but 'Delicious' and 'Empire' ripening was generally prevented by all 1-MCP concentrations. 1-MCP reduced superficial scald incidence, and accumulations of a-farnesene and conjugated trienols during air storage. The results indicate that the efficacy of 1-MCP is affected by cultivar and storage conditions, and that successful commercial utilization of the chemical will require understanding of these relationships.