| 摘要： ‘帝王’番石榴葉片礦物元素之分析，季節性變化顯示，除了鐵在9月後急速上升，其餘微量元素季節性變化不大，而大量元素濃度在夏季7-9月維持平穩，至冬季1-3月維持平穩變化，鈣則在4-8月急速下降，因此由整體之變化趨勢‘帝王’番石榴葉片採樣期可分為夏季7-9月，其葉片N：1.86-2.11%；P：0.14-0.16%；K：1.18-1.31%；Ca：1.05-1.78%；Mg：0.33-0.34%；Fe：74-106ppm；Mn：63-69ppm；Zn：18-24ppm；Cu：15-29pp。而冬季1-3月葉片N：1.23-1.60%；P：0.17-0.28%；K：1.23-1.60%；Ca：1.25-1.71%；Mg：0.16-0.22%；Fe：139-302ppm；Mn：86-104ppm；Zn：23-33ppm；Cu：18-48ppm，可提供葉片分析及營養診斷之參考。 ‘帝王’番石榴在不同發育階段採收後，果實之呼吸率及乙烯釋放率之變化，以直徑2cm的果實，採收當日呼吸率較高，而後逐漸下降，第4日後開始上升，但此時果實顯現褐化現象，而中果5cm、7cm的果實其呼吸率較低，而‘帝王’番石榴乙烯釋放率亦維持在很低且平穩的狀態，隨發育階段增加，乙烯釋放率愈少，幾乎無法測得。 以丙烯處理‘帝王’番石榴果實，結果顯示並無乙烯自動催化乙烯合成的之能力，此為典型非更年型果實之表現；再由其採收硬度、糖度及顏色之變化測定，‘帝王’番石榴屬於非更年型果實。 調查低溫貯藏對冬果及夏果品質之影響，將果實貯藏於1、5、10℃恆溫箱中，每週取樣調查。硬度隨著貯藏時間增加有下降的趨勢，又以貯藏於5℃為最低。可溶性固形物以冬果較高，夏果維他命C貯藏在在1℃及5℃有逐漸上升之趨勢，可滴定酸無明顯之變化；番石榴從低溫取出後外觀均無明顯的變化，但回溫25℃三天之後，均有表皮褐化的情形發生，以貯藏四週10℃最為嚴重，第五週取出回溫三天後已開始腐爛，且有菌絲的產生。結果顯示， 1℃為適合之貯藏溫度，貯藏壽命為四週。 蒸熱檢疫處理果心溫度達46.5℃維持15分鐘或35分鐘，可有效殺死東方果實蠅，但超過40分鐘則有熱傷害產生，再經1℃貯運7天可維持果實品質，可做為外銷檢疫處理及貯運流程之參考。Leaf analysis was used to determine the seasonal changes of mineral elements of‘King’guava. Results showed that the microelement changed very little except for iron, which increased rapidly after September. The macronutrient concentrations remained rather stable during the period of July to September. Likewise the trend was the same for the months of January to March. By contrast, the calcium concentration dropped rapidly from April to August. It is concluded that July to September are the proper time to collect samples for leaf analysis according to the stable condition of the elements in the leaves. The range of variation of mineral elements of‘King’guava in summer and winter are as follows, and can be used as a guide for the diagnosis of mineral disorders in guava: N：1.86-2.11%；P：0.14-0.16%；K：1.18-1.31%；Ca：1.05-1.78%；Mg：0.33-0.34%；Fe：74-106ppm；Mn：63-69ppm；Zn：18-24ppm；Cu：15-29pp for the summer crop. Leaf mineral elements in winter crop (January to March)：N：1.23-1.60%；P：0.17-0.28%；K：1.23-1.60%；Ca：1.25-1.71%；Mg：0.16-0.22%；Fe：139-302ppm；Mn：86-104ppm；Zn：23-33ppm；Cu：18-48ppm. Change in the respiration rate and ethylene production of‘King’guava at different developmental stages was also investigated. The‘King’guava fruit with a 2cm diameter was found to have a relatively high respiration rate on the day of sampling, which dropped gradually, rose again after day 4, and at the same time the fruit showed sign of browning. The respiration rate of middle-sized fruit with a diameter of 5cm to 7cm was relatively low, and the ethylene production rate from‘King’guava was also maintained at very low and steady states. No ethylene production was detected as the developmental stage advanced still further. The‘King’guava with propylene treatment was found to have no capacity of autocatalytic ethylene synthesis. It is likely to be non-climacteric as evidenced by the fruit firmness, total soluble solids and change of peel color of the guava. Effects of low temperature storage on the fruit quality of summer and winter crops stored at 1、5、10℃ were investigated. Samples were taken every week. The fruit firmness decreased with increased time of storing, and was found to be less firm at 5℃. The total soluble solids were higher in the winter fruit than those of the summer fruit. The ascorbic acid was found increased in summer crop while fruits were stored at 1℃ and 5℃. Soluble titratable acidity had no obvious change. No significant change was observed in appearance after the low temperature storage of guava, but browning symptom was found after it was returned to 25℃ for 3 days, especially those stored at 10℃ for 4 weeks. Fruit decay and hypha growth on the skin appeared to be apparent after being stored for 5 week and then returned to room temperature for 3 days. Our results showed that 1℃ seems to be the most suitable temperature for guava storage. The vapor heat treatment was an effective means of controlling the oriental fruit fly in guava fruits. The treatment temperature was 46.5℃ for 15 or 35 minutes but over 40 minutes caused heat injury. Transportation at 1℃ for 7 days could keep the fruit quality. This finding may serve as a reference for transport and quarantine when exporting guava fruits. |
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