Factors affecting quality ofLansium domesticumto be exported from Thailand to China

Abstract

Longkong (Lansium domesticum) is a tropical fruit tree distributed throughout South East Asia. The fruit is sweet with a slightly sour taste. At maturity the peel turns yellow and the pulp becomes translucent. At present, the fruit is only exported to neighboring countries. The main problems include peel browning, fruit rot and fruit drop. Our studies revealed that water loss and exposure to ethylene are the two main factors causing peel browning. The fruit is of climacteric type, producing only a limited amount of ethylene. However, at the immature stage, the fruit had a higher rate of ethylene production, resulting in more fruit drop, than the fully colored fruit. Fruit stored below 18°C produce more ethylene than at a higher temperature, resulting in fruit drop and peel browning. A trial shipment of ten days to Shenzhen was successfully conducted with less than 5% fruit drop and fruit rot upon arrival, and less than 20% after transfer to holding temperature for 4 d. It is recommended to harvest the fruit at 13 weeks after full bloom, handle the fruit gently, remove pests hiding in the bunch with an air jet, and dip it in cold fungicide including NAA to minimize fruit rot and fruit drop. During transport the temperature should be set at 18°C. KMnO4 was found to be ineffective in removing ethylene in the container. Hence, a ventilation rate of at least two container volumes h-1 was recommended.