製程與採收季節對茶葉抽出物抗氧化活性之影響

Influence of Manufacturing Processes and Harvesting Seasons on the Antioxidant Activity of Tea Extracts

黃志煜(Chih-Yu Huang) ； 吳志鴻(Jyh-Horng Wu) ； 張振生(Cheng-Sheng Chang) ； 葉永廉(Yung-Lien Yeh) ； 張上鎮(Shang-Tzen Chang)

《國立臺灣大學生物資源暨農學院實驗林研究報告》 17卷4期 (2003/12) Pp. 231-237

https://doi.org/10.6542/EFNTU.200312_17(4).0004

摘要

本研究分別針對不同製造過程茶葉及不同採收季節之精製茶進行抗氧化活性比較。茶葉抽出物係以甲醇萃取，然後續以高效能液相層析儀對各製程與各採收季節茶葉中之主成分作定量分析，了解其間的差異；至於茶葉抽出物之抗氧化能力評估則採用DPPH自由基清除試驗以及總酚類含量測定之。試驗結果顯示，不同的製造過程確實會對茶葉的抗氧化活性造成影響，其抗氧化能力依序為精製茶＞粗製茶＞新鮮茶葉，此乃因為精製茶的兒茶素含量最高，而新鮮茶葉的含量最低，由此得知加工越多的茶葉，其酚類化合物的含量會增多，且其抗氧化能力越強。至於不同採收季節精製茶之抗氧化特性，試驗結果顯示，生長氣候對茶葉中之成分具有相當的影響，其中，以冬茶的杭氧化能力最好，秋茶次之，春茶最差，此乃因為冬茶的兒茶素含量最高，而春茶的含量最低。

關鍵字

茶 ； 抗氧化 ； 兒茶素 ； DPPH自由基清除試驗 ； 總酚類含量

並列摘要

To understand the influence of manufacturing processes and harvesting seasons on antioxidant activity of tea extracts, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging effect and total phenolic contents were evaluated in this study. In addition, the catechin contents of methanolic extracts from various tea specimens, including (-)-epigallocatechin (EGC), (-)-epigallocatechin gallate (EGCG) and (-)-epicatechin gallate (ECG), were also quantified by using high performance liquid chromatography (HPLC). Results demonstrate that antioxidant activity is actually affected by manufacturing processes. The DPPH radical scavenging effect is in the order of refined tea, crude tea, and fresh leaves, since refined tea contains much more catechins than fresh leaves does. Accordingly, the more processes are involved in tea manufacturing; the tea with better antioxidant activity is produced. On the other hand, harvesting season also affects it significantly. Among the tested tea specimens, the crude extract of winter tea shows an excellent antioxidant activity. On the contrary, spring tea shows the worst as a result of the less catechin contents.

並列關鍵字

Tea ； Antioxidant ； Catechin ； DPPH radical scavenging assay ； Total phenolic contents