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頁籤選單縮合
題名 | 包種茶中無機成分之含量與其浸出率之研究 |
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作 者 | 張鳳屏; 楊光盛; | 書刊名 | 臺灣茶業研究彙報 |
卷期 | 13 1994.01[民83.01] |
頁次 | 頁121-138 |
分類號 | 473.4 |
關鍵詞 | 包種茶; 無機元素; 浸出率; 品質管制; 品評; Paochung tea; Inorganic element; Extracted percentage; Quality control Sensory evaluation; |
語文 | 中文(Chinese) |
中文摘要 | 為明瞭包種茶無機元素含量與標準泡茶法所沖泡出的茶湯無機元素浸出量之關 係,選取包種茶樣20點,經分析結果,茶葉磷、鉀、鈣、銓、鐵、錳、硼、鍶、鉬、鎳、鋁、 鋇及矽含量與其第一泡茶湯諸元素浸出量皆呈極顯著正相關,而鋅、銅與鈉等元素二者間則 無明顯相關。以標準泡茶所沖泡之第一泡茶湯無機元素平均浸出率,磷為18.5%,鉀為54.3%, 鈣為1.4%,鍶為19.9%,鐵為1.2%,錳為13.2%,鉰為7.0%,鋅為33.9%,硼為17.5%,鍶 為6.8%,鈉為27.5%,鉬為7.0%,鎳為26.5%,鋁為5.2%,鋇為1.0%及矽為7.3%,鎘與鉛 則濃度極低無法偵測出。無機元素浸出量第一泡茶湯明顯高於第二泡茶湯。 選擇包種茶比賽茶樣90點,以官能評審方式分成四個品級,再分析茶葉無機元素含量, 結果中上品級以上的茶樣,磷含量在0.30%以上;品質較差的茶樣,磷含量較低。鈣、錳、 鋁、鍶、鋇與矽含量高之茶葉品質較差。 以包種茶標準泡茶法,探討不同浸泡時間,茶葉用量及水質對茶湯無機元素浸出濃度、可溶 分濃度、電導度值與pH值之影響。在茶葉用量同為3克下,浸泡時間從4分鐘到7分鐘,茶 湯可溶分濃度與電導度值隨之增高,pH值則稍為降低,磷、鉀、鋅、硼、鉬及鎳浸出量亦隨 之增加,鎂、鐵、錳、銅、鈉與鋁浸出量則以浸泡6分鐘較7分鐘稍高,鈣、鍶與鋇浸出量 以5分鐘最多,6與7分鐘則降低,可能與茶葉內多之酚類或各種有機酸再吸附或複合及沈 澱有關。在浸泡時間同為6分鐘,用水量均為140毫升,不同茶葉用量下,茶湯可溶分濃度 與電導度值隨茶葉用量增加而升高,pH值隨茶葉用量增加而降低。1克茶葉用量,茶湯各種 無機元素浸出率較高,但茶湯滋味淡薄;3克到6克茶葉用量,茶湯無機元素浸出率除鈉外, 大部分皆維持在一定範圍內。包種茶標準泡茶法下,茶湯電導度值在0.50∼1.00d S/m,可 溶分濃度在2.5∼5.5mg/ml範圍,低於此範圍則滋味平淡;高於此範圍則滋味濃烈且苦澀味 加重。自來水中鉀、鈣、鎂、鍶、鋇與鈉等元素含量高,經沖泡出茶湯所含該項元素濃度亦 高,茶湯水色較深暗,滋味較無新鮮感。蒸餾水因所含無機元素濃度甚低,所沖泡出茶湯中 無機元素較易溶出,茶湯水色較明亮,滋味也較鮮醇。 |
英文摘要 | Twenty samples of Paochung tea were selected to clarify the relationships between the contents and extraction rates of inorganic elements. The results showed that the contents of P、K、Ca、Mg、Fe、Mn、B、Sr、Mo、Ni、Al、Ba and Si in the tea samples were significantly correlated with the extraction rates of first-made tea soup in positive relations, while Zn, Cu and Na were not. The average extraction rates of inorganic elements in first-made tea soup were : P 18.5%, K 54.3%, Ca 1.4%, Mg 19.9%, Fe 1.2%, Mn 13.2%, Cu 7.0%, Zn 33.9%, B 17.5%, Sr 6.8%, Na 27.5%, Mo 7.0%, Ni 26.5%, Al 5.2%, Ba 1.0% and Si 7.3%, respectively. The concentration of Cr, Cd and Pb were too low to be detected by Inductively Coupled Argon Plasma Spectrophotometer (ICP). The results also showed that the above inorganic elements were extracted much more in the first-made tea soup than in the consecutive soup. Ninety tea samples of TTES No.13, produced at Mingchien, Nantow Hsien for tea competition in spring of 1992, were collected and classified to four ranks by well experienced tea tasters, then the inorganic elements of these samples were analyzed by ICP. The data showed that the tea samples ranked above fair quality were with P concentration higher than 0.3%. The P concentrations were lower for the poor quality tea samples. If the contents of Ca, Mn, Al, Sr, Ba and Si were higher, the quality of the tea would be worse. The standard tea-making method of Paochung tea was used to study the effects of tea-making time, quantity of tea samples and water quality on the concentration of the extracted inorganic elements and soluble solids, Electrical Conductivity (E.C.) and pH values of tea soup. When the sample weight was set to 3.0g, and the tea-making time ranged from 4 to 7 minutes, the concentration of the soluble solids and the E.C. values of tea soup increased as the time increased. The extraction rates of Mg, Fe, Mn, Cu, Na and Al also increased as the time range from 4 to 6 minutes. For Ca, Sr, and Ba, the concentration. were the highest at tea-making time set to 5 min., and when the time increased, the extraction rates decreased. It is possibly related to the result of complexation or precipitation of the poly phenols or organic acids contained in tea. When the tea-making time was set to 6 min, and the volume of water set to 140ml, the soluble solids and Electrical Conductivity value of tea soup increased as sample weight increased, on the contrary, pH value decreased. When the weight of tea sample was 1.0 g, the extr-action rates of various inorganic elements of tea soup were much higher, while the taste was lighter. When sample weight increased from 3 to 6g, the extraction rates of the inorganic elements would keep at a constant level with the exception of Na. Using the standard tea-making method of Paochung tea, the E.C. values of the tea soup ranged from 0.50 to 1.00 dS/m, and the concentration of soluble solids ranged from 2.5 to 5.5 mg/ml. When the index values were lower than these ranges, the taste of the tea soup will be fairly light; otherwise, the taste would be strong and bitter. The color and taste of the tea soup made from tap water would be strong and bitter. The color and taste of the tea soup made from tap water would be darker and stale because of the contents of K, Ca, Mg, Sr, Ba and Na were high in tap water. On the other hand, the concentration of inorganic elements of dist-illed water were relatively low, so the inorganic elements of the tea sample tend to be dissolved more easily. The color of the tea soup made from distilled water would be more bright and the taste would be fresh and fragrant. |
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