| 摘要： 鳳梨以低溫或常溫等方式進行貯運，一般業者多以5-10℃為貯運時之貯藏溫度，僅少數業者使用12.5℃。低溫貯藏2週再經25℃櫥架4天，貯於5℃之果實內部褐化症狀皆已達5級（即褐化面積佔果心及其附近果肉面積50%），故評定為喪失櫥架壽命；而貯於12.5℃之果實，經同樣貯藏及櫥架期後，果實內部褐化程度才達1級（即褐化面積佔果心及其附近果肉面積1-2%），顯示，最適合‘台農17號’之貯運溫度為12.5℃，在此溫度下可貯藏4週再加25℃下4天櫥架仍保有商品價值。目視記錄褐化指數並綜合亮度、彩度及色相角之變化，可客觀表達較微小的顏色變化，有助於褐化情形之判讀。果實貯藏於12.5℃和25℃並移入25℃櫥架4天後，苯丙氨酸解氨酶(phenylalanine ammonia lyase；PAL)及過氧化物酶(peroxidase；POD)活性均隨貯藏時間之延長而增加，而貯於5℃之果實PAL和POD活性顯著低於貯於12.5℃之果實。多酚氧化酶(polyphenol oxidase；PPO)活性隨貯藏時間之延長而降低，但貯於12.5℃之果實顯著高於貯於5℃及25℃之果實。Although both cold and room temperatures are used for storage of pineapple fruits in industry, 5℃ is currently more common storage temperature for this commodity than 12.5℃ or 25℃. The purpose of this study is to investigate the optimum storage temperature for 'TN 17' pineapple fruit, a dominant cultivar in Taiwan. Our results showed that 'TN 17' pineapple fruits developed severe internal browning of fruit tissues (browning intensity index 5 or ＞ 50% browning tissue area) and had lost marketability after 2 weeks at 5℃ plus 4 days shelf (25℃); in contrast, the discoloration symptom of the fruits stored at 12.5℃ was less obvious (browning intensity index 1 or 1-2% browning tissue area) for the same storage period. The phenylalanine ammonia-lyase (PAL) and peroxidase (POD) activities of 'TN 17' pineapple fruits stored at 12.5℃ or 25℃ plus 4 days at 25℃ increased with storage time; but the enzyme activities of PAL and POD of the 5℃-treated fruits were significantly lower than those of fruits stored at 12.5℃. Moreover, the polyphenol oxidase (PPO) activity of 12.5℃-treated fruits was significantly higher than those of 5℃-or 12.5℃-treated samples, though the enzyme activity of all the three treatments decreased with storage time. |
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