Effects of the ethylene-action inhibitor 1-methylcyclopropene on postharvest quality of non-climacteric fruit crops

1-Methylcyclopropene (1-MCP) (SmartFresh™) is an ethylene antagonist widely used to retain quality and prolong the postharvest storage period of various climacteric fruits in which ethylene plays a critical role in regulation of the ripening process. Nonetheless, it has been found that exposure to 1-MCP may affect certain ripening-related processes also in non-climacteric fruits. In this review, we summarize the current knowledge regarding the effects of 1-MCP on quality and postharvest storage performances of various non-climacteric fruit crops, including grape, cherry, pomegranate, citrus, strawberry, pitaya, prickly pear, lychee, loquat, and olive. Overall, the main observed effects of 1-MCP on postharvest storage performance of non-climacteric fruits were: (1) inhibition of senescence processes, such as rachis browning in grapes, scale senescence in pitaya, and leaf senescence of ‘Shatangju’ mandarins marketed with attached leaves; (2) inhibition of development of physiological disorders such as scald development in pomegranate, pericarp browning in litchi, and internal browning in loquat; and (3) inhibition of degreening and color change, as observed in various citrus fruits, strawberry, pitaya, prickly pear and olive. Beside these major effects, exposure to 1-MCP had divergent effects on fruit respiration and ethylene production rates, and on decay development, with differing and sometimes contradictory effects observed in different crops and tissues. Finally, exposure to 1-MCP had just minor effects on internal fruit-quality parameters, including nutritional quality and flavor. In the future, it may be worth considering the commercial application of 1-MCP as a means of retaining the green color, reducing physiological disorders, and retarding senescence processes in certain non-climacteric fruits.