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Theabrownins in dark tea form complexes with tea polysaccharide conjugates.

Authors :
Chen, Xiaoqiang
Wang, Mengdie
Wang, Zhiyuan
Liu, Xiuling
Cao, Wendan
Zhang, Na
Qi, Yonggang
Cheng, Shuiyuang
Huang, Wei
Liu, Zhong
Source :
Journal of the Science of Food & Agriculture; Aug2024, Vol. 104 Issue 10, p5799-5806, 8p
Publication Year :
2024

Abstract

BACKGROUND: Theabrownins (TBs) are one of most important quality components in dark tea, but have not been produced industrially. In this study, the aqueous extract was obtained from Pu‐erh ripe tea, one kind of dark tea. Caffeine, theaflavin, catechin and saponin were removed by trichloromethane, ethyl acetate and n‐butanol in turn to obtain a TB isolate. The TB isolate was subjected to column chromatography using a macroporous resin HPD‐750 and eluted with a gradient of 0–700 g kg−1 ethanol aqueous solution. Four fractions were obtained, and named as TBs‐FC1, TBs‐FC2, TBs‐FC3 and TBs‐FC4. RESULTS: These four fractions contained polysaccharides and no small molecules such as catechins, caffeine and theaflavins as well as average molecular weights of 123.000 kDa, 23.380 kDa, 89.870 kDa and 106.600 kDa. It was revealed that they were complexes of TBs and tea polysaccharide conjugates (TPCs). Ultraviolet‐visible (UV‐visible) and infrared (IR) spectra showed the properties of TBs and TPCs. Their zeta potentials ranged from −13.40 mV to −38.80 mV in aqueous solutions at pH 3.0–9.0. CONCLUSION: This study reveals that TBs do not exist in free state but in combined state in dark tea, which provide the theoretical basis for the industrialization of TBs. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00225142
Volume :
104
Issue :
10
Database :
Complementary Index
Journal :
Journal of the Science of Food & Agriculture
Publication Type :
Academic Journal
Accession number :
177946101
Full Text :
https://doi.org/10.1002/jsfa.13431