- 期刊
野生普洱古樹茶富含具抑制流感病毒功效的多酚化合物－木麻黃素
Tea from Wild Pu'er Tree is Rich in Strictnin, A Phenolic Compound Possessing Inhibitory Potency on Influenza Virus
摘要
普洱茶依栽培方式的不同分為灌木型台地茶及喬木型古樹茶。為了因應市場量產的需求，台地茶採集約栽培，植株矮化且易於採收；而古樹茶多為五米以上的喬木，目前分人為管理的馴化型及野生型兩種，皆須以人工攀爬採摘。一般而言野生型古樹茶葉片較厚實硬挺，產量較為稀少，其成茶被視為是普洱茶中的珍貴茶品。根據本實驗室分析不同栽培型式的普洱茶之茶湯成份結果，顯示所有普洱茶均有水溶性鞣花單寧－木麻黃素（strictinin），其中以野生普洱茶的含量特別高；然而，此多酚化合物於台灣烏龍茶中幾乎偵測不到。木麻黃素具熱不穩定的特性，加熱後裂解成沒食子酸（gallic acid）與鞣花酸（ellagicaicd）。透過抑制流感病毒之實驗，觀察到木麻黃素與其熱裂解產物皆具有抗流感的能力，且以鞣花酸的抑制效果最佳。近年來雲南茶廠所發展的渥堆發酵（經微生物的作用）可將生普洱茶快速轉化成熟普洱茶，經由分析各種不同的熟普洱後，發現兒茶素、木麻黃素等多酚物質的含量都有下降的趨勢，部分茶樣的多酚物質全數消耗殆盡。從實驗結果得知，這些茶多酚是對人體有助益的活性物質，因此轉化熟普洱茶時若能保留這些茶多酚活性物質，特別是保留由木麻黃素轉化累積的鞣花酸，應有助於提升熟普洱茶的保健及抑制流感病毒的功效。
並列摘要
Pu'er tea plants are mainly cultivated as shrubs or trees for the production of ＂Tai-di tea＂ and ＂Gu-shu tea＂, respectively. For commercial mass-production of Tai-di tea, tea plants are domestically cultivated in a highly compacted manner. In contrast, Gu-shu tea is produced from large tea trees that may grow tall domestically or naturally in the wild forests. Pu'er tea product from wild trees is generally considered better. According to our study, the strictinin, almost undetectable in Taiwan oolong tea, is the major phenolic compound in Pu'er teas, particularly those produced from wild trees. Due to its thermal instability, strictinin could be completely decomposed to gallic acid and ellagic acid during the heating process. The plaque reduction assay demonstrates that strictinin, as well as its thermal degraded products possess inhibitory potency on influenza virus, with ellagic acid having relatively higher inhibition activity. Recent advances in post-fermentation process has allowed expedited conversion of raw Pu'er teas to ripened ones, however, the current study examining various ripened Pu'er teas has found that phenolic compounds are at least partially or completely degraded in their infusions. Therefore, it is suggested that to maintain the antiviral activity, post-fermentation processes should be monitored to sustain sufficient quantities of phenolic compounds, particularly ellagic acid converted from strictinin in the final products of ripened Pu'er teas.