FRUIT WEIGHT LOSS AND PERICARP WATER LOSS OF HARVESTED LONGAN FRUIT IN RELATION TO PERICARP BROWNING

Longan (Dimocarpus longan Lour.) fruit is highly susceptible to water loss and pericarp browning in storage. Postharvest pericarp browning of the fruit greatly affects its shelf-life. ‘Fuyan’ longans showed 5.84, 10.37 and 23.98% of total fruit weight losses, and 13.59, 26.40 and 42.78% of pericarp water losses, when stored at 10°C and 50% RH for 1, 2 and 6 days, respectively. However, minimal weight loss in aril and seed was observed. And, the selective dehydration of pericarp tissues occurred while little movement of water between the aril and the pericarp was found. The weight loss of the fruits and water loss in pericarp tissues significantly correlated to the pericarp browning at the 1% level. On the other hand, fruits stored in plastic bags under low temperatures reduced the moisture losses and pericarp browning. ‘Fuyan’ fruits packed in bags made of 0.015 mm polyethylene film and held for 15 days at 20°C lost 2.87% on a fresh weight basis, while they lost 2.01% at 4°C for 30 days. At the same time, storage at low temperature also retarded pericarp browning and extended the longan’s shelf-life.