| 摘要: | 茯磚茶（Fuzhuan Brick Tea，FBT）在中國等地區有著悠久的歷史，並被認為是一種具有保健功能的特殊茶品，包括抗氧化、抗炎、抗肥胖、抗菌和抗腫瘤等活性。然而，其獨特的風味和多種生物活性的來源和成分仍未完全被了解，茯磚茶的主要優勢菌種為冠散囊菌 Eurotium cristatum，被認為其與茯磚茶的特色和功能密切相關。菌種能利用茶葉中的有機物質，產生多種化合物並提高其生活性，其中包括沒食子酸。沒食子酸是茶葉中的一種重要抗氧化物質，具有抗氧化和抗發炎等生物活性，對人體健康有益。儘管茯磚茶具有如此多的潛在好處，但關於發酵條件對茯磚茶品質和功能的影響的研究相對較少。因此，本研究專注於探討發酵條件對 E. cristatum 發酵茶葉的沒食子酸含量和抗氧化特性。
本研究將分為兩個部分，第一部分為分離並篩選研究所需之金花菌種，成功在茯磚茶中分離純化出 Eurotium cristatus DK，經 16S rDNA 檢測結果鑑定為 Aspergillus cristatus DUCC5705。第二部分探討各發酵條件—茶葉粉末添加量起始 pH 值、不同碳源及添加量、不同氮源以及發酵溫度，並依生產沒食子酸能力以及抗氧化活性等參數進行最適化討論。本研究成功找出最適化發酵條件—添加 4%茶葉粉末、起始 pH 值 4.0、3%乳糖、3%麥芽萃取物及發酵溫度 30℃。實驗結果顯示金花菌發酵茶的沒食酸含量可達 0.22-0.29 g/g，相當於5.5-7.25%的茶葉乾種，高於五倍子(2 - 4% 乾重) 中沒食子酸含量。綜合上述結果 Eurotium cristatus DK 與茶發酵，可展現出高沒食子酸的轉化率且具有高生物活性的茶葉發酵成品，並將研究結果應用於茶飲以及保健食品的開發。
;Fuzhuan Brick Tea (FBT), has a long history in China and other regions. It is considered a special type of tea with health-promoting functions, including antioxidant, anti-inflammatory, anti-obesity, antibacterial, and anticancer activities. However, the origins and components of its unique flavor and various biological activities are still not fully understood. The predominant microorganism in FBT is Eurotium cristatum, a fungus, which is believed to be closely associated with the characteristics and functions of FBT. This microorganism can utilize the organic compounds in tea, producing various compounds and enhancing their bioavailability, including gallic acid. Gallic acid is an important antioxidant found in tea and possesses bioactive properties such as antioxidant and anti-inflammatory effects, which are beneficial to human health. Despite the potential benefits of FBT, there have been relatively few studies on the impact of fermentation conditions on the quality and functionality of FBT. Therefore, this study focuses on the effect of fermentation conditions on the content of gallic acid and antioxidant properties of E. cristatum-fermented tea.
The study is divided into two parts. The first part is isolating and screening the required strain, and Eurotium cristatus DK was successfully isolated and purified from FBT, identified as Aspergillus cristatus DUCC5705 through 16S rDNA analysis. The second part explores various fermentation conditions — the amount of tea powder added, the initial pH value, different carbon sources and additions, different nitrogen sources, and fermentation temperature, optimizing these conditions based on the production of gallic acid and antioxidant activity. The study successfully identifies the optimal fermentation conditions, which include adding 4% tea powder, initial pH of 4.0, 3% lactose, 3% malt extract, and fermentation temperature 30°C.
Experimental results show that the content of gallic acid in the fermented tea by E. cristatus DK can reach 0.22-0.29 g/g, equivalent to 5.5-7.25% of the dry weight of tea. This is higher than the gallic acid content found in Gallanut (2-4% dry weight). In summary, the fermentation of tea with E. cristatus DK shows a high conversion rate of gallic acid and produces a tea fermentation product with high biological activity. These research findings can be applied to the development of tea beverages and health food products. |
