Effect of Exogenous Ethylene Concentration and Fruit Temperature on the Minimum Treatment Time Necessary to Induce Ripening in Banana Fruit

The minimum treatment time necessary for ethylene to induce ripening (MTT) in banana fruit was examined in relation to the concentration of applied ethylene and temperature.Little difference was observed in the magnitude and rate of the climacteric between the fruits treated with ethylene only for the MTT period and those continuously exposed to ethylene. Evolution of ethylene from fruit treated with exogenous ethylene for a period less than the MTT may return to a preclimacteric level on removal to air. Applied ethylene probably induces an increase in both ethylene forming enzyme (EFE) and 1-aminocyclopropane-1-carboxylic acid (ACC) synthase activity, with EFE activity increasing first. Although the actual MTT of fruit varied considerably in different clusters, the difference in MTT for different conditions was almost constant within one cluster. The data suggest that there may be a linear relation between the MTT of bananas and the logarithm of the applied ethylene concentration, and that the effect of treatment temperature may be expressed as a quadratic function.