咖啡再製酒於熟成期間品質之變化

Quality Changes of Coffee Liqueur Made of Different Rice Wines as Base during Aging

楊曉涵(Siao-Han Yang) ； 石正中(Jeng-Jung Shyr)

《臺灣園藝》 62卷1期 (2016/03) Pp. 65-76

摘要

本研究中以‘台中秈糯1號、‘台中秈糯2號’、‘台中秈10號’、‘台中糯70號’、‘高雄145號’、‘台農71號’、‘桃園3號’、‘台梗9號’、’台梗16號’、與‘欽雄早秈糯’等十品種稻米所釀製之蒸餾酒作為浸泡基酒之原料，將No.16標準篩過篩的中度烘焙咖啡粉，經五週時間浸泡處理後，於20℃下熟成，於第0,30,60,90,120,150及180天取樣分析色澤、透射比、酒精度、咖啡因及揮發性物質之變化，以瞭解不同米種米酒於熟成期間對咖啡再製酒品質之影響。咖啡再製酒之色澤隨著熟成的時間增加，L值降低，而a、b值上升，顯示熟成會使咖啡再製酒色澤加深。隨著熟成時間增加，咖啡再製酒的透射比逐漸下降，以‘台中秈糯2號’之透射比較高。酒精度隨著熟成時間的增加而減少，以‘欽雄早秈糯’酒精度下降最為明顯，於180天後酒精度減少0.93％。隨著熟成時間的增加，10種米酒所製備之咖啡再製酒咖啡因含量皆增加，而以‘台中秈10號’之咖啡因含量顯著較其他9種米酒低，熟成第180天含量為251.0 mg．L^(-1)。咖啡再製酒主要揮發性物質(乳酸乙酯、己酸乙酯、異戊醇、正丁醇、呋喃甲醇)之含量會隨著熟成時間而增加，而苯乙醇會隨著成時間增加而減少，正丙醇含量隨著熟成時間增加先增加後減少。

關鍵字

熟成 ； 咖啡再製酒 ； 揮發性成分 ； 色澤 ； 咖啡因

並列摘要

This study used distilled rice wine from japonica rice (‘KS-145’, ‘TN-71’ , ‘TY-3’, ‘TG-9’, ‘TG-16’), indica rice (‘TC-10’), glutinous rice (‘TC-70’) and indica glutinous rice (‘TC-1’ , ‘TC-2’, ‘CH’) as alcoholic base for making coffee liqueur. After being immersed in distilled rice wine for 5 weeks, the medium-roasted coffee powder was allowed to mature at 25℃for 180 days and was taken for analyses at each 0, 30, 60, 90, 120, 150, and 180 day. The color of the coffee liqueur, which was made of rice wine as base, darkened according to the length of aging process, with the decrease in Hunter L value and increase in a and b values. However, the transmittance of coffee liqueur made of different rice wines as base decreased with the increase of aging time, with ‘TC-2’ having the highest transmittance. The alcohol content of coffee liqueur made of ‘CH’ rice wine as base decreased in accordance with the increase of aging time, with 0.93% less in alcohol content after 180 days. Following the increase of aging time, the caffeine content of coffee liqueur also increased, with ＂TC-10’ showing the lowest caffeine content, 251.07mg．L^(-1) at 180 days. Butyl alcohol, isoamyl alcohol, ethyl hexanoate, ethyl lactate and furfuryl alcohol content in the coffee liqueur increased with the growth of aging time, but 2-phenylethanol content decreased with the reduction of aging time. As for n-Propylalcohol content, it increased at the beginning of aging and afterward decreased.

並列關鍵字

aging ； coffee liqueur ； volatile ； color ； caffeine