在本研究中以屏東香蕉研究所栽種之有機北蕉( Pei-Chiao )為原料，於溫度2 0 °C 、濕度9 0% RH 恆溫恆濃機中催熟20天，根據顏色將香蕉熟成度分為7級，級數愈高代表熟成度愈高，並分析香蕉 在不同熟成度時之堅實度、總可溶性固形物、多酌氧化酵素(polyphenol oxidase) 活性、過氧化酵 素( peroxidase ) 活性、總酌類化合物與DPPH 自由基清除效果變化。研究結果顯示， 香蕉熟成過程 中，堅實度下降而總可溶性固形物增加， 多酌氧化酵素活性由第l級之0 . 04 U/g.如增加至第7 級之 2.31 U/g.fw ; 過氧化酵素活性由第l 級之0 . 04 U/g . fw增加至第7級之1. 9 0 U/g .fw ' 此酵素活性之增 加，說明了成熟香蕉更易發生酵素性褐變作用。在抗氧化能力方面， DP PH自由基清除能力之1 Cso 值由第l 級1 1 6 . 9 7 mg/mL 下降到第6 級的51 .46 mg/mL '此時具最佳抗氧化效果。

In this study, Pei-Chiao were ripened at 20 °C, 90% RH for 20 days to evaluate the effects of ripen ing on firmness , total soluble solid contents, polyphenol oxidase activity, peroxidase activity, total phenolic contents and DPPH free radical scavenging ability. Data showed that the hardness decreased and total soluble sol id contents increased during increasing ripening periods. Polyphenol oxidase activity increased from 1st stage of 0.04 U/g.fw to 7th stage of 2.31 U/g.fw， and peroxidase activity increased from Ist stage of 0.04 U/g.fW to 7th stage of 1.90 U/g .fW. The increasing of these enzymes illustrated that bananas caused enzymatic Maillard reaction easier during ripening. With respect to antioxi dative activity, the ICso value of DPPH free radical scavenging ability decreased from 1st stage of 116.97 mg/mL to 6th stage of 51.46 mg/mL , and this stage with best antioxidative activity.