PACKAGING TO REDUCE WATER-LOSS CAN DELAY RIPENING OF MANGO (MANGIFERA-INDICA L CV KENSINGTON-PRIDE) FRUIT

Water loss and premature ripening during postharvest handling reduce t he market quality of mango fruit. Towards investigating the use of moi sture barrier liners for mango fruit trays, relationships between in-p ackage relative humidity and weight loss and ripening of 'Kensington P ride' fruit were studied. Individual fruit were held at 20 degrees C i n sealed plastic containers (small 1.2 L buckets). The lid of each con tainer had a single circular hole. Holes were of various sizes, rangin g from 5 to 135 mm diameter. Ripening mature green fruit held at the l owest relative humidity of 57% (135 mm diameter hole) lost weight at a significantly (P less than or equal to 0.05) greater rate (10 mg/g in itial FW.day) than fruit at higher relative humidities of 59 (open air ), 60 (95 mm diameter hole), 61 (55 mm diameter hole), 71 (35 mm diame ter hole), 74 (25 mm diameter hole) and 83% (25 mm diameter hole plus free water). These fruit at higher relative humidities lost weight at rates ranging between 9 and 4 mg/g initial FW.day. Fruit softening and skin colouring rates were similar across all relative humidities. In a second experiment, mango fruit were allowed to ripen in containers w ith smaller holes, ranging from 5 to 95 mm diameter, in their lids. Fr uit at the lowest relative humidity (60%, 95 mm diameter hole) lost we ight at a significantly (P less than or equal to 0.05) greater rate (9 mg/g initial FW.day) than fruit from other treatments. Furthermore, t hese fruit ripened about 2 days sooner than fruit at higher relative h umidities: 85 (25 mm diameter hole), 88 (15 mm diameter hole), 91 (10 mm diameter hole) and 93% (5 mm diameter hole). Fruit at the higher re lative humidities lost weight at rates between 6 and 2 mg/g initial FW .day, and ripened in 6 to 12 days. Thus, hole size can be varied in or der to control in-package relative humidity and regulate mango fruit w eight loss and ripening.