採收日期及貯藏溫度對桶柑品質及耐貯藏力之影響

Influences of Harvesting Date and Storage Temperature on the Quality and Storability of Tankan (Citrus tankan Hayata)

本研究連續三個貯藏年期以苗栗縣公館鄉所產之桶柑，在每年12月至翠年1月下旬之間分間隔約20日之三個日期採收，並分四至五種不同溫度貯藏。結果發現採收日期與果實在貯藏中之腐爛率或失重率關係不明顯，但晚採者糖度及糖／酸比較高而酸度較低。貯藏在0°及5°C之果實有寒害發生，而，貯藏在20°C之果實則腐爛率及失重率偏高。貯藏在10°，12.5°及15°C之果實無明顯一致之腐爛率或失重差異，但只有在15°C之果實始終未發現類似寒害引起之異味。因此，依據本研究之結果可推薦貯藏用桶柑應該在1月中、下旬採收並貯藏在15°C。實用之貯藏期限為四個月，但亦可勉強貯藏到五個月，唯品質較差。

Tankan. a hybrid of Citrus reticulata and C. sinensis, was harvested on 3 different dates at about 20day intervals from Miaoli, Taiwan in 3 consecutive harvesting seasons. The fruit was then stored under 4 to 5 temperatures for 2 to 5 months. Harvesting date had no significant effect on the percentages of decay and weight loss during storage, but the fruit harvested late had higher soluble so lids (SS), lower titratable acidity (TA), and higher SS/TA ratio. Tankan stored at 0° and 5°(had chilling injuries. The fruit stored at 10°, 12.5°, and 15°C had similar decay and water loss rates, but some fruit stored at 10° and 12.5°( developed off-flavors which seemed to be related to chilling injury. The fruit stored at 20°C had higher rates of decay and weight loss and poorer orange-color development on the rind when compared to similar fruit stored at 10°-15°C. The optimum harvesting dates of Tankan for storage seem to be mid- and late January, and the optimum storage temperature be 15°C. Under optimum conditions, Tankan can be stored for 4 months. Storage period may be extended to 5 months with some sacrifice in fruit quality.