关键词: 安化黑茶, 水溶性成分, 指纹图谱, 高效液相色谱, 化学模式识别

Abstract: Objective: To fingerprint dark tea from Anhua, Hunan using high performance liquid chromatography (HPLC) and to quantitatively determine its major water-soluble constituents for the purpose of providing theoretical evidence for the identification of Anhua black tea. Methods: A total of 22 dark tea samples from Anhua, Hunan and 4 dark tea samples from other provinces (Liupu tea from Guangxi, Tusi tea from Sichuan, brick tea from Hubei and Pu’er tea from Yunnan) were fingerprinted by HPLC. The chromatographic conditions were as follows: gradient elution using 0.17% acetic acid aqueous solution as mobile phase A and acetonitrile as mobile phase B; column temperature, 30 ℃; flow rate, 1.0 mL/min; and detection wavelength, 280 nm. Similarity evaluation and principal component analysis were performed to ascertain the peaks common to these tea samples. Results: A total of 19 peaks were common to all Anhua dark tea samples with similarities ranging from 0.783 to 0.958 while the similarities between Anhua dark tea and other dark tea samples were quite low (lower than 0.3). Furthermore, the contents of gallic acid and epigallocatechin gallate in Anhua dark tea were remarkably higher than in any other dark tea, but caffeine in Liupu tea and gallocatechin in Pu’er Tea were significantly more abundant in Anhua dark tea. In addition, fuzhuanin A could be detected only in Anhua dark tea and hence regarded as an effective indicator for the identification of Anhua dark tea. Conclusion: The established HPLC fingerprinting method can be used to identify and evaluate Anhua dark tea based on fuzhuanin A content.

Key words: Anhua dark tea, water-soluble components, fingerprint, high performance liquid chromatography (HPLC), chemical pattern recognition