鄭宗記臺灣大學：生物產業機電工程學研究所洪悅慈Hung, Yueh-TzuYueh-TzuHung2007-11-262018-07-102007-11-262018-07-102007http://ntur.lib.ntu.edu.tw//handle/246246/52939本研究開發一套整合單寧與胺基酸含量檢測之螢光流動注射分析系統，檢測原理分別為單寧對3-aminophthalate螢光團之螢光消光特性與鄰苯二甲醛 (o-phthalaldehyde, OPA)和胺基之螢光生成反應。由於兩者均有相同之激發波長(340 nm) 和接收波長 (425 nm)，故可在同一台偵測儀器、同一套系統流路之檢測環境下依序檢測茶品中之單寧及胺基酸含量，開發一套簡便之線上茶品檢測系統。文中探討樣品注射體積、反應流路長度、OPA濃度、2-mercaptoethanol濃度及溶劑pH值等系統參數之最適化情形，並確認單寧酸溶液對OPA試劑之干擾情形與四種主要胺基酸之相對螢光發光響應。本系統對單寧酸和茶胺酸之檢量範圍分別為 50-250 μg mL-1以及0.1-1 μg mL-1，CV 值小於5 % (n = 3)，檢測速度為每小時20個樣品。本系統應用於台茶12號所製作之包種茶，探討製造過程中包括茶葉採摘條件、萎凋時間、冷泡茶方法等變因對茶湯內單寧與胺基酸含量之影響。本研究尚針對四種不同市場價格之台灣烏龍茶進行含量檢測，並與其市場價格進行初步分析探討。A fluorometric flow-injection analytical system for determining both tannin and total amino acid content is proposed. The sensing principles are based on the quenching effect of tannin on the fluorescence of 3-aminophthalate and the fluorogenic reaction of amino acids with o-phthalaldehyde (OPA), respectively. Both reactions were integrated into a fluorometric flow-injection system with the same excitation and emission wavelength (340/425 nm). A three-way valve was introduced to switch between the reagents for sequential determination of tannin and amino acids. Parameters of operation condition were optimized, and interference of tannic acid on the fluorescence intensity of OPA-amino acids reaction was investigated. The linear dynamic range for tannic acid and theanine were 50-250 μg mL-1 and 0.1-1 μg mL-1 (CV < 5%, n = 3), and the sample throughout was 20 samples h-1. Effects of plucking position of tea plants, withering time and steeping method on tannin and amino acids in consumer tea brew of Pouchong tea in Taiwan were analyzed by the proposed system. Analytical results of commercial oolong tea products in Taiwan were compared to their market prices.口試委員審定書 致謝 中文摘要 ii Abstract iii Index iv List of Figures vi List of Tables vii Chapter 1 Introductions 1 Chapter 2 Literatures Review 4 2.1 Major categories and manufacturing process of tea 4 2.2 Methods for quality evaluation of tea 6 2.3 Tannin and amino acids in tea and their roles in tea manufacture 8 2.3.1 Flavonoid components and tannin in tea 8 2.3.1.1 Flavonoid components and their roles in tea manufacture 8 2.3.1.2 Tannin and its physiological function 11 2.3.2 Theanine and amino acids in tea 13 2.3.2.1 Theanine and its role in tea physiology 13 2.3.2.2 Amino acids in tea and their roles in tea manufacture 15 2.4 Analysis of tannin and amino acids in tea 17 2.4.1 Analysis of individual components in tea 17 2.4.2 Quantitative determination of tannin in tea 19 2.4.3 Fluorometric determination of tannin in tea based on the quenching effect on 3-aminophthalate (3-APA) fluorescence 21 2.4.4 Determination of total amino acid content in tea 23 2.4.5 Fluorometric determination of total amino acid content in tea based on the fluorogenic reaction of o-phthalaldehyde (OPA) with amino acids 25 Chapter 3 Experiments 27 3.1 Chemicals 27 3.2 Preparation of buffers and reagents 27 3.3 Setup of flow-injection manifold 28 3.4 Manufactures of tea samples from fresh tea leaves 30 3.5 Preparation of tea extraction from tea leaves 30 Chapter 4 Results and Discussions 32 4.1 Typical responses and system performance of the proposed system 32 4.1.1 Calibrations of tannic acid and theanine 32 4.1.2 Cross-interference of tannic acid for OPA reagent 34 4.1.3 Relative outputs for major amino acids in tea 36 4.2 Parameters optimization of the proposed system 38 4.2.1 Effects of sample injection volume and the length of mixing coil 38 4.2.2 Effects of chemicals concentration and pH value in OPA reagent 40 4.3 Applications for green tea and partially fermented tea 42 4.3.1 Effect of plucking position on Pi-Lo-Chun green tea infusions 42 4.3.2 Effect of withering time on Pouchong tea infusions 44 4.3.3 Effect of cold-brew method on Pouchong tea infusions 46 4.3.4 Comparison of analytical results and prices of commercial oolong tea 48 Chapter 5 Conclusions and Prospects 50 References 51478758 bytesapplication/pdfen-US單寧酸發光胺澀味甘味部份發酵茶tannic acidtheanineastringencyumamiluminolpartially fermented teathesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/52939/1/ntu-96-R94631011-1.pdf