收穫季節、採摘部位及加工方式對於桑葉茶GABA含量之影響

Effect of harvesting seasons, picking sites and processing methods on changes of GABA content in mulberry leaf tea

廖久薰(Liao, Chiu-Hsun) ； 郭芷君(Chih-Chun Kuo) ； 邱喬嵩(Chiao-Sung Chiou) ； 吳姿嫺(Tzu-Hsien Wu) ； 楊美珠(Meei-Ju Yang) ； 施佳宏(Chia-Hung Shih)

《苗栗區農業改良場研究彙報》 9期 (2020/06) Pp. 1-14

摘要

本研究探討不同的收穫季節、採摘部位及加工方式對於桑葉茶機能性成分γ-胺基丁酸（γ-aminobutyric acid, GABA）含量變化之影響。採摘不同季節203品系以一心二葉或三至五葉桑葉為試驗材料，並以不發酵、部分發酵及完全發酵等三種加工製程製作三種桑葉茶，之後檢測桑葉茶茶湯GABA含量。不發酵處理桑葉茶以夏、秋兩季GABA含量高於春季採收，且以一心二葉製成桑葉茶之GABA含量高於三至五葉桑葉茶。部分發酵處理桑葉茶以夏季及秋季的茶樣，不論一心二葉或三至五葉皆具高量的GABA，平均超過431.1 mg / 100 g，其中以三至五葉的秋桑茶表現最好，GABA含量高達610.2 mg / 100 g。完全發酵處理桑葉茶的GABA含量會隨著收穫季節及採摘部位而影響，以一心二葉秋桑茶GABA含量達466.0 mg / 100 g為最高。總體而言，桑葉茶之GABA含量均會受發酵程度、收穫季節及採摘部位影響，本試驗結果可作為未來桑葉茶產品生產商品化之參考依據。

關鍵字

桑葉茶 ； γ-胺基丁酸 ； 季節 ； 採摘部位 ； 加工

並列摘要

This study explored the effects of different harvesting seasons, picking sites and processing methods, on the content of γ-aminobutyric acid (GABA) in mulberry leaf tea. The 203 strain of ＂two leaves and a bud＂or＂third-to-fifth leaf＂of mulberry leaves were used as test materials in different seasons. Three types of mulberry tea were prepared by different processes including non-fermentation, partial fermentation and complete fermentation, and then the GABA content of the mulberry tea were analyzed. In non-fermented mulberry leaf tea, had higher GABA content were higher in summer and autumn than in spring harvest, and GABA content of mulberry leaf tea made with ＂two leaves and a bud＂ was higher than ＂third-to-fifth leaf＂ mulberry leaf tea. Regardless the picking sites is ＂two leaves and a bud＂ or ＂third-to-fifth leaf＂ in partial fermentation treatment harvested in summer and autumn, the content of GABA was higher than 431.1 mg / 100 g dry weight on average. The highest GABA content harvested in autumn was 610.2 mg / 100 g. The GABA content of the mulberry leaf tea with complete fermentation treatment would be affected by the harvesting seasons and the picking sites, and the GABA content of the ＂two leaves and a bud＂ in autumn mulberry tea was 466.0 mg / 100 g as the highest. In general, the GABA content of mulberry leaf tea were affected by fermentation levels, harvesting seasons and the picking sites. The results of this test can be referred for the commercialization of mulberry leaf tea production in the future.

並列關鍵字

mulberry tea ； GABA contents ； seasons ； picking sites ； processes