concentration was 500 nL L−1. Fans were used to maintain air cir-culation. Another batch of fruit (controls) in a 71 L sealed chamberwas not treated with 1-MCP. All fruit in the 1-MCP treatment weretreated together, and so were all fruit in the control treatment.After 1-MCP treatment, fruit were stored on pallets at 15◦C and85–90% RH. Every 3 days, 18–24 random fruit were taken from thepallets in the 15◦C room, and were divided into two equal groups.The first group (9–12 fruit) was used to determine quality param-eters (color, firmness, total soluble solids, smell, eating quality)immediately after removal from the 15◦C room.When durian fruit become ripe, both pulp and husk (peel) losewater and shrink. As the pulp shrinks more, this results in a spacebetween pulp and husk. The onset of the presence of this spaceis well correlated with the onset of good eating quality. When thefruit surface is knocked with an object such as a knife, the grower orother specialist will be able to tell by the acoustic response if thereis a cavity, thus if the fruit is ripe. In the present tests, the initialparameter for ripeness was the acoustic response. This response,if indicating that a cavity was present, was subsequently tested bythe quality panel.The second group of 9–12 fruit taken out of 15◦C storage wasplaced at 25◦C and 80–90% RH for ripening. To induce ripening,ethephon at 4800 L L−1was applied by brush at the cut surface ofthe cut stalk. Fruit held at 25◦C were subjected to acoustics mea-surements and subsequent tests for good eating quality (overallacceptability). Fruit was considered ripe when the acoustic mea-surement indicated a cavity, which was confirmed by an eatingquality that was higher than 3 on the scale used. In ripe fruit, color,firmness, total soluble solids, and smell were determined. Shelf lifeat 25◦C was defined as being the same as the time to ripeness.