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題 名 | 包種茶貯藏期間成茶揮發性成分之變化=Changes in Volatile Components of Pouchung Teas during Storage |
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作 者 | 陳玉舜; 區少梅; | 書刊名 | 中國農業化學會誌 |
卷 期 | 36:6 1998.12[民87.12] |
頁 次 | 頁630-639 |
分類號 | 473.4 |
關鍵詞 | 包種茶; 貯藏試驗; 揮發性成分; 官能品評; Pouchung teas; Storage test; Volatile components; Sensory evaluation; |
語 文 | 中文(Chinese) |
中文摘要 | 本研究之目的以青心烏龍與臺茶十二號製成之包種茶分別於-20℃, 25℃及45℃ 下貯藏六個月的成茶樣品為材料,鑑定其揮發性成分及探討貯藏期間此等揮發性成分之變化 。每三個月以上部空隙╱氣相層析儀╱氣相層析質譜儀鑑定與分析其揮發性成分,以及利用 六位受訓練的品評員及30位消費者型品評員分別進行成茶香氣之感官品評與茶湯之整體消費 者喜好性。兩種包種茶樣品之成茶揮發性成分經氣相層析質譜儀鑑定,共計40 種,其中以 dimethyl sulfide 含量最高,其於青心烏龍與臺茶十二號分別為7.42與5.78ppm。貯 藏期間貯藏於-20℃之茶樣揮發性成分含量上均無變化,而其他兩種溫度下貯藏者,青心烏 龍與臺茶十二號分別有6及4種成分如dimethyl sulfide, ethyl acetate, 2-hexanone 及 trans-2-hexenal 等之含量隨貯藏時間之增長而下降,而有5及6種和propionaldehyde, n- capronaldehyde 及 acetic acid之含量增加。而pentanal 與2,4-heptadinal在青心烏龍以 及2,5-hexanedione與4-methyl-2-pentylamine在臺茶十二號茶則出現於貯藏一個月後,然 後漸增。在貯藏期間揮發性成分之總量變化與兩種包種茶成香氣品評分數及整體喜好性之間 的相關係數均在0.08左右,而青心烏龍及臺茶十二號之整體喜好性與成香氣品評分數之相關 係數則分別為0.83及0.87 |
英文摘要 | Pouchung teas made of Chin-shin Oolong and Taiwan Tea-12 (TTES-12) stored at - 20,25 and 45℃ for 6 months were used as experimental materials. The purposes of this study were to identify their volatile components and to investigate their changes during storage. Their volatile components were identified using a Headspace Sampler/Gas Chromatograph/Mass Spectrometer. The changes in volatile components were examined every 3 months. At the same time, the aroma intensities and overall preference of these Pouchung teas were also evaluated by 6 well-trained and 30 consumer-type panelists, respectively. Totally, 40 volatile components in these two Pouchung teas were identified. Among them, dimethyl sulfide was found to be the most abundant one with amounts of 7.42 and 5.78 ppm in the Chin-shin Oolong and TTES-12 teas, respectively. During storage, components in tea stored at -20℃ did not change significantly. For those samples stored chromatogrphy. The N-terminal amino acid sequence of the CGTase expressed from B. subtilis was found to be consistent with that of the B. macerans CGTase. The B. subtilis CGTase also has enzyme activities similar to those of the B. macerans CGTase. The results revealed that B. subtilis harboring pHG produces the authentic CGTase of B. macerans. Two point- mutated cgt genes, E344D and E344Y, were also introduced onto this vector system. E344D and E344Y CGTase produced from transformated B. subtilis showed reduced starch digestion and coupling activities compared to the wild type enzyme. The relative enzymatic activity of E344D CGTase decreased in both acidic and alkaline pH ranges. These mutated enzymes also showed different affinity for starch molecules as revealed by electrophoresis. |
本系統中英文摘要資訊取自各篇刊載內容。