Characterization of the chemical differences between solvent extracts from Pu-erh tea and Dian Hong black tea by CP-Py-GC/MS

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• 作者：Jia-shun Gong^a ; ^{gong199@163.com} ; Chao Tang^a ; Chun-xiu Peng^b
• 关键词：Pu-erh tea ; Black tea ; Extract ; Tea pigment ; CP&ndash ; Py&ndash ; GC/MS
• 刊名：Journal of Analytical and Applied Pyrolysis
• 出版年：2012
• 期刊代码：46_01652370
• 类别：ch
• 出版时间：May, 2012
• 卷：95
• 期：Complete
• 页码：189-197
• 文件大小：532 K

摘要

Solvent extracts from a type of Pu-erh tea and Dian Hong black tea were characterized by Curie-point pyrolysis-gas chromatography-mass spectroscopy (CP-Py-GC/MS). The ethyl-acetate extracts from both teas showed similar CP-Py-GC/MS results, with main pyrolytic products of carbon dioxide, caffeine, o-phenols, and phthalate esters. During pyrolysis, the n-butanol extract from Pu-erh tea formed carbon dioxide (38.92%of total pyrolytic products), alkaloids (49.7%), and nitrogen oxides (8.38%), as well as a small fraction of esters. The n-butanol extract from Dian Hong tea formed mainly alcohols, amines, esters, phenols, carboxylic acids, and alkaloids. The raw theabrownin extracts (ethanol precipitates) from the two teas produced substantially different CP-Py-GC/MS results. The raw theabrownin extract from Pu-erh tea formed mostly carbon dioxide during pyrolysis, whereas the counterpart extract from Dian Hong tea formed mainly carbon dioxide (48.23%) and nitrogen oxides (35.39%). The 3.5-100 kDa fractions separated from the theabrownin extracts of the two teas showed similar CP-Py-GC/MS results, whereas the fractions <3.5 kDa and >100 kDa formed substantially different pyrolytic products. These results showed that solvent extracts from Pu-erh tea and Dian Hong tea had substantially different chemical compositions and structures. The study suggested that CP-Py-GC/MS can be used to effectively identify chemical differences between tea extracts.