大葉種茶樹不同品種、採摘時期及葉位對茶多元酚含量之影響

Influences of Different Varieties, Plucking Crops and Leaf Positions on the Polyphenolic Content of Large-Leaf-Type Tea

林宜昕(Yi-Hsin Lin) ； 古國隆(Kuo-Lung Ku) ； 邱垂豐(Chwei-Feng Chiou) ； 劉景平(Ching-Ping Liu)

《嘉大農林學報》 5卷1期 (2008/02) Pp. 15-31

摘要

本研究針對大葉種茶樹探討不同品種、採摘時期及葉位對茶多元酚含量之影響，評估是否可在採摘完茶菁後，將剪枝後之老葉進一步萃取兒茶素，做為食品中之天然抗氧化物，因而增加農民之收益。試驗材料為適製紅茶的大葉種茶樹台茶8號與台茶18號，於2006年分別採摘第一次夏茶、第二次夏茶及冬茶。試驗結果顯示，在採摘季節方面，兒茶素含量都以第一次夏茶為最高，5種主要兒茶素〔(-)-EGC、(+)-C、(-)-EGCG、(-)-EC及(-)-ECG〕含量分別為4.04 mg/g、2.19 mg/g、71.82 mg/g、6.78 mg/g及14.50 mg/g，其次為第二次夏茶，而以冬茶含量最低；GA含量以第二次夏茶(1.39 mg/g)顯著高於冬茶(1.16 mg/g)；咖啡因含量則以第二次夏茶含量最高(31.28 mg/g)＞第一次夏茶(28.05 mg/g)＞冬茶(22.72 mg/g)。此外，台茶18號在5種兒茶素含量都顯著高於台茶8號，其含量分別為4.41 mg/g、2.28 mg/g、50.41 mg/g、6.39 mg/g及10.64 mg/g；但咖啡因含量則呈相反狀態，台茶8號顯著高於台茶18號。在不同採摘葉位方面，兒茶素(-)-EGCG含量隨著茶葉葉位增加而有下降之趨勢，以芽部位含量為最高(85.48 mg/g)，次高為第一葉(76.28 mg/g)、其次為第二葉含有55.58 mg/g，較少為第三葉、第四葉及第五葉，含量分別為34.96 mg/g、31.50 mg/g及33.88 mg/g，含量最少者為莖部(13.32 mg/g)。總兒茶素含量亦同於(-)-EGCG之趨勢，台茶8號以芽及第一葉含量最高，分別為96.88 mg/g及96.61 mg/g；台茶18號含量最高者為芽(131.05 mg/g)，顯著高於其他葉位。

關鍵字

大葉種 ； 多元酚 ； 兒茶素 ； 採摘時期 ； 葉位

並列摘要

This experiment used large-leaf-type tea to investigate the influences of different varieties, plucking crops and leaf positions on the polyphenolic content of tea to evaluate whether after fresh leaves were plucked, catechin could be further extracted out of the old leaves from those pruning to serve as natural antioxidants in food and thus bring fortunes for the farmers. Large-leaf-type tea, TTES No. 8 and TTES No. 18 which were suitable for black teas, were plucked in the timing of 1(superscript st) summer, 2(superscript nd) summer and winter. Experiment results were summarized as follows: When the plucking crops were taken into consideration, the 1(superscript st) summer tea was found to have the highest contents of catechins. It contained five major catechin, (-)-EGC, (+)-C, (-)-EGCG, (-)-EC and (-)-ECG, which were 4.04 mg/g, 2.19 mg/g, 71.82 mg/g, 6.78 mg/g and 14.50 mg/g, respectively. The 2(superscript nd) summer tea was next and the winter tea had the least contents of catechins. The GA content in the 2(superscript nd) summer tea was 1.39 mg/g which was significantly higher than 1.16 mg/g of winter tea. The 2(superscript nd) summer tea was found to have the highest content of caffeine, 31.28 mg/g. The 1(superscript st) summer tea was next, 28.05 mg/g, and the winter had the least, 22.72 mg/g. Those five catechins in TTES No.18 were significantly higher than those of TTES No.8 which were 4.41 mg/g, 2.28 mg/g, 50.41 mg/g, 6.39 mg/g and 10.64 mg/g, respectively. However, the caffeine content of TTES No. 18 was significantly lower than that of TTES No. 8. When the plucking positions were taken into consideration, the content of catechin (-)-EGCG decreased from top to bottom: the content of bud was the highest, 85.48 mg/g. Next was the 1(superscript st) leaf, 76.28 mg/g; then was the 2(superscript nd) leaf, 55.58 mg/g. Then were the 3(superscript rd), 4(superscript th), and 5(superscript th) leaf, which contained 34.96 mg/g, 31.50 mg/g and 33.80 mg/g, respectively. The stem contained the least content of catechin (-)-EGCG, which was 13.32 mg/g. The results of total catechins were consistent with the results of (-)-EGCG. The bud and the 1(superscript st) leaf of TTES No. 8 had the highest content of total catechins, which were 96.88 mg/g and 96.61 mg/g, respectively. The bud of TTES No. 18 had the highest total catechins content which was 131.05 mg/g and was significantly higher than those of the other leaf positions.

並列關鍵字

Large-leaf type ； Polyphenol ； Catechin ； Plucking crop ； Leaf position