摘要
茶與咖啡是目前世界上最廣泛之飲料，另外咖啡葉為優良之保健素材開發來源，而且咖啡葉茶是屬低咖啡因之飲料，在臺灣咖啡葉茶並不普遍，由於特殊之青草味 (earth odor)影響其接受性，因此尚未普遍，本研究擬改良咖啡葉茶製造之技術，透過發酵技術改善降低咖啡葉茶青草味(六碳醇、醛類)含量之影響，促使咖啡葉茶之香氣以改善接受性。新鮮咖啡葉茶中methyl salicylate有 13.69%，在製造後之咖啡葉茶中反而增加到26.18%具有特殊藥草之氣味，芳樟醇氧化物含有16.35%仍然大於 2-ethyl 1-hexanol 青草味(土氣味)數量3.34%，新鮮咖啡葉中所含的醛類化合物共計有七種n-hexanal、E-2-hexenal、E,E-2,4-hexadienal、E-2-heptenal、 E,Z-2,4-heptadienal、E,E-2,4-heptadienal和E,E-2,4-nonadienal，佔有45.29%，發酵製造咖啡葉茶後醛類化合物全部轉換消失，咖啡葉茶內新生成的醛類是furfural、benzaldehyde和 5-methyl furfural等揮發性化合物醛類有9.47%，另外酮類2-octanone具有葡萄酒氣味佔3.69%，上述這些重要香氣對整體咖啡葉茶香氣有很大影響，咖啡葉茶具有藥草酒氣味、烏龍茶培火香、紅茶甜香與發酵香特殊氣味混合在一起，所以將咖啡葉茶香氣定位屬於紅茶類香氣。
並列摘要
Most commonly seen drink in the world is coffee and tea. Coffee leaf is an excellent source of health materials and low in caffeine. However, coffee leaf tea is not common probably due to its special earth odor. In this study, we proposed a modified coffee leaf tea manufacturing technology via fermentation to reduce the earth odor, six-carbon alcohols and aldehydes, in the coffee leaf tea. The methyl salicylate content in fresh coffee leaf tea was 13.69 %, but in our coffee leaf tea, it increased to 26.18 % to give an odor of special herbs. Linalool oxide level was 16.35 %, which was more than 2-ethyl 1-hexanol (3.34 %, earth odor). Fresh coffee leaves were found to have 45.29% aldehydes, which were n-hexanal, E-2-hexenal, E, E-2,4-hexadienal, E-2-heptenal, E, Z-2,4-heptadienal, E, E-2,4-heptadienal and E, E- 2,4-nonadienal. Those aldehydes disappeared after fermentation and new aldehydes generated in the coffee leaf tea were furfural, benzaldehyde, and 5-methyl furfural (9.47 %). In addition, a wine odor ketone 2-octanone was produced (3.69 %), an important aroma in coffee leaf tea. In summary, this coffee leaf tea has an herb wine odor, oolong tea roasting odor, black tea sweet odor, and special fermented aroma. Therefore, the coffee leaf tea was aroma belongs to black tea aroma.