荔枝採收成熟度之研究

A Study on the Picking Maturity of Lychee (Litchi chinensis Sonn.)

荔枝在常溫下不耐貯藏，在樹上成熟期間果實仍會繼續增加。在不同成熟階段荔枝果內各成分變化最明顯著為有機酸之含量。果實愈趨成熟含酸量愈低；而還元糖與蔗糖之含量在荔枝近熟與完熟期間則不大變化。荔枝最好之品質應於果皮著紅色達50-75%時採收，因此時果肉含有0.2~0.3%之有機酸量，果皮易剝開，果肉風味佳適合於製罐冷藏及冷凍。較青之荔枝因味酸香致品質遜，反之，過熟之荔枝因太甜，酸不足及組織含纖維較多亦影響其品質。

Lychee, one of the non-climacteric fruits, can not be stored at room temperature. The size and weight of the fruit can gradually increase on the tree when it becomes mature. The significant variation of fruit components at different maturity of at different coloration of the lychee fruit is acid content; the riper the lychee, the less the acid content. However, there is a little change in its invert sugar and sucrose content from near ripe to full ripe. Lychee fruit having the best quality should be harvested when its pericarp turns red at about 50-75%, or when its acid content decreases to be 0.2-0.3%, and it is more suitable for cold storage, canning, or frozen-pack. The under-ripe fruit has always poor quality with more sour taste, less flavor; Contrarily, the over-ripe fruit with more fibrous texture and too sweet taste has not so good quality either.