採收成熟度及貯藏溫度對椪柑貯藏壽命之影響

Influences of Maturity at Harvest and Storage Temperature on the Storability of 'Ponkan' Mandarin (Citrus reticulata Blanco)

本研究連續三個貯藏年期以苗栗縣公館鄉所產之椪柑分三種成熟度採收，四種不同溫度貯藏。結果發現早採的品質較差，遲採的較易腐爛及失重，而以每年11月14日至23日間採收著色率約達40%之果實最耐貯藏。椪柑貯藏在5°C之低溫達三個月時造成嚴重寒害；10°C也有時造成少數果實輕微的寒害。貯藏在20°C的高溫則果實腐爛率及失重率較高。因此，貯藏在12.5°至15°C之間壽命最長而品質劣變最慢。採收成熟度及貯藏溫度適當時椪柑有三個月的貯藏壽命。如果腐爛率可以控制，尚可貯藏到四個月，但品質會顯著降低。

Ponkan' mandarins were harvested at 3 maturity levels from Miaoli, Taiwan and stored under 4 temperatures in 3 consecutive storage seasons. The fruit harvested early had poorer quality and that harvested late had higher decay and weight loss rates compared to the fruit harvested at 'optimum' maturity, which had the best storability. The optimum maturity occurred between November 14 and 23 while the fruit had about 40% yellow coloration on the rind. Ponkan stored at 5°C for 3 months developed severe chilling injury. A small percentage of the fruit stored at 10°C for 3 or 4 months developed minor chilling injury symptoms also. The fruit stored at 20°C had higher percentages of decay and weight loss and had faster quality deterioration compared to 'optimum' storage temperature. The optimum temperature for long term storage of Ponkan was found to be 12.5- 15°C, which provided the fruit best storability. Ponkan harvested at the optimum maturity and stored at the optimum temperature has a reasonable storage life span of 3 months. If decay percentage can be kept low, the storage life might be extended to 4 months, but some sacrifice in quality should be expected.