[ 摘要 ]

原住民在傳統釀酒，係用「白麴」當菌種，製作小米酒。小米發酵過程中，發酵液中以黴菌繁殖最快，於液態發酵第5天達最高。酵母菌於液態發酵第3天即明顯地快速生長，至第7天達高峰。由其發酵液中可分離出Saccharomyces cerevisiae, Candida holmiie , Lactobacillus brevis及Pediococcus pentosaceus等四類菌株，而S. cerevisiae為用於發酵乙醇之酵母菌。小米酒釀造過程中，酒精濃度隨著發酵時間而增加，在第30天其酒精濃度約為13.5﹪，至一年酒精濃度達約14﹪，但在第30天已無法分離得到菌種。小米酒發酵初期，其總酸度逐漸增加，推測是來自於根黴、酵母菌之代謝產物，亦可能由乳酸菌所產之乳酸所影響。小米酒發酵過程中，glutamic acid為酵母菌利用氮之主要來源，且glutamic acid亦會生合成lysine, arginine及threonine。酒類熟成期為香氣形成之重要關鍵，胺基酸代謝可產生高級醇，isoleucine及leucine可經由生合成作用，而成高級醇分別為2-methyl-1 butanol及3-methyl-1 butanol。乳酸加乙醇縮合可生合成乳酸乙酯(ethyl lactate)，經由GC、GC-MS之分析，證實乳酸乙酯為小米酒中之主要香氣成分。



[ 英文摘要 ]

Millet wine produced following the aborigine procedure was found to use so-called “white-cake” as a fungus source. During the fermentation period, mold grew quickly and had a peak quantity at 5 days after inoculation. Yeast also developed quickly after 3 days’ fermentation and had a peak quantity at after 7 days’ fermentation. From millet fermentation slurry, Saccharomyces cerevisiae, Candida holmiie , Lactobacillus brevis and Pediococcus pentosacus were isolated and characterized. Saccharomyces cerevisiae is believed to produce ethanol. During the early stage of millet wine making, the total titratible acid increased with increasing the fermentation period. Ethanol concentration in the millet wine was 13.5﹪,and increased to 14.0﹪after one year’s storge. Glutamic acid was used as a major nitrogen source during fermentation, and part of them were used to synthesize lysine, arginine, and threonine. Higher alcohols, 3-methyl-1-butanol and 2-methyl-1-butanol were found to be derived from isoleucine and leucine respectively. Ethyl lactate was characterized by using GC or GC-MS. The formation of ethyl lactate was ascribed to the existence of large amount of ethanol and lactic acid in millet wine.