古樹普洱茶的功能成分與感官品評之研究

Abstract

本研究以百福藏倉所提供之三款不同樹齡古樹普洱茶樣品為對象，探討不同茶樹樹齡在功能性化學成分與感官品質表現之差異性。研究方法結合高效液相層析（HPLC）分析與結構化感官品評，針對表沒食子兒茶酚沒食子酸、表沒食子兒茶酚、表兒茶酚沒食子酸、表兒茶酚、沒食子兒茶素沒食子酸酯與咖啡因等六項功能性指標成分進行定量分析，並從香氣、口味與口感三大構面進行感官評估，進一步建構內含成分與感官品評之對應關係。研究結果顯示，茶樹樹齡與茶葉內含物組成存在明確結構差異。低樹齡樣本中酯型兒茶素（如EGCG、ECG）與咖啡因濃度相對較高，表現出較強的苦澀感與湯體厚重特徵；而高樹齡樣本則轉向以非酯型兒茶素（如EGC、EC）為主，對應明顯提升的滑順度、濃稠度與細緻度，呈現出層次更為平衡且協調的風味特徵，相較之下，香氣與口味構面未呈現穩定對應關係。此外，三款古樹普洱樣本之EGCG與咖啡因濃度普遍高於文獻所報導之多數市售普洱與綠茶樣品，反映古茶樹長期次生代謝所形成之功能性成分累積潛力。雖於高濃度沖泡條件下（如實驗萃取與感官品評應用）可能接近歐盟食品安全局所建議之每日攝取上限，惟日常飲用情境中所採用之沖泡比例與飲用頻率遠低於實驗條件，實際攝取量難以構成超標風險。本研究證實茶樹樹齡確實影響普洱茶之成分結構與感官表現，並指出非酯型兒茶素為口感品質提升之關鍵成分。建議未來產品開發可結合標準化沖泡建議與科學溝通策略，以強化其功能性價值定位，並確保使用安全性。此發現有助於釐清古樹茶品質形成機制，並可作為未來品質評估、產品開發與消費教育之科學基礎。

This study investigated the differences in functional chemical composition and sensory performance of Pu-erh tea derived from ancient tea trees of varying ages, using three representative samples provided by Baifu Cangcang. Six key bioactive compounds, namely EGCG, EGC, ECG, EC, GCG, and caffeine, were quantified through high-performance liquid chromatography (HPLC). In addition, a structured sensory evaluation was conducted encompassing three sensory dimensions: aroma, taste, and mouthfeel. The primary objective was to explore the influence of tree age on tea quality by examining the correlations between chemical composition and sensory attributes. The results revealed a distinct structural differentiation in chemical composition associated with tree age. Samples collected from younger trees, approximately 300 years old, exhibited higher concentrations of ester-type catechins such as EGCG and ECG, along with caffeine. These chemical profiles corresponded to more pronounced bitterness and a heavier, more astringent mouthfeel. Conversely, samples from older trees, aged over 1,000 years, showed a compositional shift toward non-ester-type catechins, such as EGC and EC. These compounds were positively associated with greater smoothness, viscosity, and delicacy, resulting in a more balanced and harmonious flavor profile. Among the three evaluated sensory dimensions, only mouthfeel demonstrated a stable and consistent correlation with the chemical composition. In contrast, aroma and taste appeared to be influenced by volatile compounds or processing factors, lacking systematic associations with the quantified components. Moreover, the concentrations of EGCG and caffeine in all three ancient tea samples were generally higher than the values reported in the literature for most commercial Pu-erh and green tea products. This observation suggests a potential accumulation advantage of bioactive compounds resulting from prolonged secondary metabolism in ancient tea trees. Although the high-concentration testing conditions may approach the daily intake limits established by the European Food Safety Authority (EFSA), typical drinking scenarios involving lower infusion ratios and consumption frequency are unlikely to pose excessive intake risks. This study affirms that the age of tea trees significantly influences both the chemical composition and the sensory expression of Pu-erh tea. In particular, non-ester-type catechins were identified as major contributors to improved mouthfeel quality. These findings provide a scientific basis for future quality assessment, standardization of sensory indicators, and the development of evidence-based brewing recommendations. Furthermore, the integration of compound profiling with consumer-facing communication strategies may help enhance the perceived value, safety, and acceptance of ancient tree Pu-erh tea in contemporary markets.