Heat treatments can prolong the shelf-life of some fruits and sometimes provide effective alternatives to chemical insecticides. However, effects of sufficient hot air treatment to kill insects (50 degrees C for 10 min) on cell wall-degrading enzyme activities in banana and associated processes, which could potentially be either positive or negative, have not been previously described. Thus, this study addressed these effects by examining selected enzyme activities, pulp softening and phenomena associated with ripening (changes in peel color, weight, firmness, respiration rates and ethylene production) in hot air-treated and control bananas. The results show that ethylene production, respiration rates, color changes of peel and pulp softening in bananas were all inhibited by hot air treatment. It also inhibited the increases in pectin methyl esterase, polygalacturonase and pectate lyase activities that typically occur in the pulp during ripening. Of these three enzymes, polygalacturonase was found to be most strongly correlated with pulp softening. The results suggest that hot air treatment retards ripening processes in bananas including changes in color and pulp softening by inhibiting respiration and ethylene production. (C) All Rights Reserved