Effects of harvesting date on quality and storability of longan fruit

Longan fruit (Dimocarpus longan Lour.) cv. Youtanben, the major cultivar in Fujian Province of China, was used. Effects of harvesting date (harvesting at 4-day intervals from August 19 to September 12) on quality and storability of longan fruit were analyzed. The results were as follows: as fruit harvesting date delayed and maturity increased (i.e. from August 19 to September 8), pericarp color of longan fruit gradually turned from green-brown to yellow-brown, fruit shape turned from approximately long-spherical to oblate-spherical, fruit weight and size gradually increased, pericarp thickness decreased but pulp thickness increased, pulp edibility, nutritional quality and eating quality increased. Whereas pericarp color turned dark-brown, fruit quality decreased when fruit harvested over-mature (i.e. harvesting at September 12). Pericarp color, fruit weight and size, pericarp and pulp thickness, pulp edibility, contents of total soluble solids (TSS), total sugars and vitamin C, ratio of TSS to titratable acidity (TA) or total sugars to TA, and eating quality of pulp were recommended as maturity indices for longan fruit. It was suggested that longan fruit for long-term storage or long-distance transport should be harvested from August 31 to September 4, and the fruit stored at (30±2)℃ for 8 days with 84.2%～85.07% healthy rate and 3.05%～3.20% mass loss, stored at (3±1)℃ for 40 days with 98%～100% healthy rate and 0.24%～0.26% mass loss.