Postharvest Fruit Weight Loss, Pericarp WaterLoss and their Relation to Pericarp Browning ofLongan

摘要

Longan (Dimocarpus longan Lour.) fruit are very susceptible to water loss, andpostharvest pericarp browning is the most important factors affecting storage life and qualityof longan fruit. Fruit weight loss, pericarp water loss and their relation to pericarp browning oflongan （Dimocarpus longan Lour. Cv. Fuyan） under the storage conditions with (10±1)°Cand 50% relative humidity, and effects of polyethylene (PE) film bag (0.015mm thick) sealedpackaging and storage temperatures ( 4°C or 20°C.) on moisture loss and pericarp browningof longan fruit were investigated in this experiment. The results indicated that longan fruitstored for 1, 2, or 6 days at 10°C and 50% RH lost 5.84%, 10.37% and 23.98% fresh weight,respectively, and water loss from the pericarp was 13.59%, 26.40% and 42.78 %, respectively,but there was minimal weight loss of the aril and seed part. Hence, selective dehydration ofthe pericarp occurred with little movement of water between the aril and the pericarp, andwater loss of fruit was mainly from the pericarp rather than the aril. Both weight loss from fruitand water loss from pericarp were positively correlated with pericarp browning indexsignificantly (P<0.01). Storage in plastic films bags and low temperatures is effective inreducing moisture loss and desiccation-induced browning. ‘Fuyan’ fruit packed in PE filmbags and held at 20°C lost 2.87% of their weight after 15 days, while fruit held at 4°Conly lost2.01% after 30 days. Storage at 4°C also retarded pericarp browning and extended storagelife of fruit.