百香果採收成熟度之研究（三）對果汁色澤及香氣之影響

Studies on the Picking Maturity of Passion Fruit III. Effect on Color and Flavor of Fruit Juice

雜交種百香果汁的色澤深淺與所含的類胡蘿蔔素高低成正比，不同採收成熟度的果汁在波長425nm下所測得的類胡蘿蔔素的吸光值隨成熟度之增加而增加，其吸光值與色差計測之'a'值成高度的相關（r=0.79）。應用TenaxGC吸著法單離及GC-MS純化及鑑定出百香果汁在成熟期間所存在的揮發性成分計30種，已檢定出醇類3種、萜類（terpene）3種、酯類17種及p-cymene 1種，真正表現百香果香氣的成分與總含量無關，但愈近成熟的果汁所含有的香氣成分種類愈多，揮發性香氣如歸類後依其含量高低觀察，除了酯類佔絕對高的百分率（95%）外，表現百香果芳香的醇類亦為不可缺少的成分。

A good correlation between the color intensity and the carotenoid content in hybrid passion fruit juice was obtained. The more mature fruit, the higher carotenoid content present in the juice after measuring its absorbance at 425nm. A good correlation between the carotenoid content and the 'a' value from the readings of color and color difference meter was also found in this experiment. Its r=0.79 was calculated by the regression analysis. Analyses of juice flavor volatiles using a Tenax GC with adsorption collection and desorption apparatus had identified 3 alcohols, 3 terpenes, 17 esters and 1 p-cymene in total 30 kinds of volatile components. The aroma expressed in passion fruit juice is not accordant to the total volatile component content. The results indicate the heavy aroma was found in the more mature passion fruits which contained esters as high as 95% to the total volatiles, and it was found that alcohols seem to be the important component in aroma expression.