| Summary: | 碩士 === 高苑科技大學 === 化工與生化工程研究所 === 100 === It is new emerging style for tea drink preparation by applying food microbiological fermentation differed in traditional tea manufacture. In previous study, we have successfully produced the low- or high-ethanol ethanol drink by yeast, Saccharomyces cerevisias Meyen ex Haxen , fermenting green tea liquid which were composed of 25 g green tea, 750 mL RO water, and various amount of sucrose. In order to expand its production capacity in this study, the fermentation were performed at room temperature by mixing 300 g green tea with 2%, 8% or 16% sucrose and yeast in 3000 mL RO water. The fermented green tea liquids were sampled to analyze the yeast growth and the change of tea contents during the fermented period. The yeasts are the major dominant species in 2%、8% and 16% green-tea fermented liquid solutions. As a whole, the yeast growth has demonstrated to be an increasing growth tendency which first repetitively increased and then decreased, and trended again, etc. All the fermented green tea liquids contained obvious amount of total polyphenolics that is between 0.055 and 0.115 mg gallic acid equivalents/ml. All the fermented green tea liquids contained potent antioxidant activity. The DPPH radical scavenging activity is between 0.055 and 0.095 mg Trolox equivalents/ml. Although there were sucrose-added difference at the beginning fermentation stage, the difference of total sugar amount among all tested groups became less obvious after later stage’s fermentation.。By GC analysis, more ethanol production occurred at higher sucrose-added groups. The 16% green-tea fermented liquid has the highest ethanol production. All 2%, 8% and 16% green-tea fermented liquid can not be detected the existence of methanol, but little acetic acid. By HPLC analysis, all fermented green tea liquids have demonstrated obvious tea polyphenols amount and distribution. Therefore, all sucrose-added groups can produce safe tea drink. Based on aforementioned information, the fermented green tea liquid has potentially become an excellent health-protection drink.
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