香蕉催熟之研究（三）臺蕉封外加乙烯之後熟反應與溫度及香蕉成熱度間之關係

Studies on the Ripening of Bananas III. Ripening Responses of Taiwan Bananas to Exogenous Ethylene in Relation to Temperature and Fruit Maturity

臺蕉對外加乙烯1000ppm處理24hrs之呼吸率、乙烯產生量以及後熱轉色之反應，因溫度與香蕉成熟度之不同有極大之差異。在16°C或以下溫度，只有高成熟度（約8分熱）之香蕉可被乙烯激發呼吸更年上升與自動催化乙烯大量產生以及後熟轉色；較低成熟度（約5分到7～7.5分熟）之香蕉，雖在外加乙烯處理期間亦刺激呼吸率之增加，但當乙烯移去後，呼吸率又下降而無法激發呼吸更年上升。在20°C或在25°C乙烯處理後再移至20°C，則所有香蕉均可被外加乙烯激發呼吸更年上升與自動催化乙烯大量產生及後熟轉色。提高溫度會增加香蕉對外加乙烯之敏感度，而有助於加速散發香蕉之呼吸更年上升。此外，溫度愈高，外加乙烯處理以激發香蕉呼吸更年上升所需之處理時間愈短，在27°C乙烯處理後再移至20°C後熟者，乙烯處理僅需8小時即可激發香蕉之呼吸更年上升，在20°C者需16小時，而在15°C，則乙烯處理時間雖長至43小時，亦不足以激發香蕉呼吸更年上升。就臺蕉而言，若外加乙烯刺激呼吸率之增加未超過60mg CO2/kg/hr以上時，均不足以刺激香蕉之呼吸更年上升與後熟轉色。

In response to exogenous ethylene treatment (1000 ppm for 24 hrs), the respiration rate, ethylene production and color change of Taiwan bananas varied greatly with the temperature and fruit maturity. At 16°C or below, exogenous ethylene initiated the climacteric rise and autocatalytic ethylene production of those fruits with higher maturity. For fruits with lower maturity, ethylene stimulated the respiration rate but it declined rapidly after removal of ethylene. No climacteric rise nor autocatalytic ethylene production were induced in these fruits. With ethylene treatments at 20°C, or at 25°C then transferred to 20°C, all fruits showed climacteric rise and autocatalytic ethylene production regardless of maturity. High temperature increased the sensitivity of bananas to exogenous ethylene with respect to the initiation of climacteric rise. Ethylene treatment at 27°C for 8 hours initiated the subsequent climacteric rise at 20°C. It took 16 hours ethylene treatment at 20°C to obtain the same result. At 15°C, ethylene treatment for as long as 43 hours could not induce the banana to ripen. It was found that the respiration rate must exceed 60 mg CO2/Kg/hr in order to induce the climacteric rise and ripening of Taiwan bananas.