Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2014 Sep;22(3):303-309.
doi: 10.1016/j.jfda.2013.12.001. Epub 2014 Feb 28.

Catechin content and the degree of its galloylation in oolong tea are inversely correlated with cultivation altitude

Guan-Heng Chen  1 , Chin-Ying Yang  2 , Sin-Jie Lee  1 , Chia-Chang Wu  3 , Jason T C Tzen  4
Affiliations

Catechin content and the degree of its galloylation in oolong tea are inversely correlated with cultivation altitude

Guan-Heng Chen et al. J Food Drug Anal. 2014 Sep.

Abstract

The taste quality of oolong tea generated from leaves of Camellia sinensis L. cultivated in the same mountain area is positively correlated to the cultivation altitude, partly due to the inverse correlation with the astringency of the tea infusion. The astringency of oolong tea mostly results from the presence of polyphenolic compounds, mainly catechins and their derivatives. Four catechins, (-)-epicatechin (EC) and (-)-epigallocatechin (EGC) together with their gallate derivatives (with relatively high astringency), (-)-EC gallate (ECG) and (-)-EGC gallate (EGCG), were detected as major compounds in oolong tea. The degrees of catechin galloylation, designated as ECG/(EC + ECG) and EGCG/(EGC + EGCG), in both oolong tea infusions and their fresh tea leaves, were found to be inversely correlated to the cultivation altitude at 200 m, 800 m, and 1300 m. A similar inverse correlation was observed when seven more oolong tea infusions and seven more fresh leaves harvested at altitude ranging from 170 m to 1600 m were recruited for the analyses. Moreover, catechin contents in oolong tea infusions were also found to be inversely correlated to the cultivation altitude. It is proposed that catechin content and the degree of its galloylation account for, at least partly, the inverse correlation between the astringency of oolong tea and the cultivation altitude.

Keywords: Astringency; Catechin; Cultivation altitude; Galloylation; Oolong tea.

PubMed Disclaimer

Conflict of interest statement

Conflicts of interest

All authors declare no conflicts of interest.

Figures

Fig. 1
Fig. 1
Liquid chromatography profiles (0–65 minutes) of oolong tea infusions and fresh tea leaves cultivated at altitudes of 200 m, 800 m, and 1300 m at 280 nm. Caffeine and the four major catechins, (−)-epicatechin (EC), (−)-epigallocatechin (EGC), (−)-EC gallate (ECG), and (−)-EGC gallate (EGCG) are indicated.
Fig. 2
Fig. 2
Degree of catechin galloylation in oolong tea infusions and their corresponding fresh tea leaves cultivated at altitudes of 200 m, 800 m, and 1300 m. Degree of catechin galloylation was calculated as (−)-epicatechin gallate (ECG)/(EC + ECG) and (−)-epigallocatechin gallate (EGCG)/(EGC + EGCG). Data are presented as mean ± standard error of the mean of three replicates. *p < 0.05, **p < 0.01 versus altitude of 200 m.
Fig. 3
Fig. 3
Degree of catechin galloylation in 10 oolong tea infusions and 10 fresh tea leaves cultivated at altitudes ranging from 170 m to 1600 m. Degree of catechin galloylation was calculated as (−)-epicatechin gallate (ECG)/(EC + ECG) and (−)-epigallocatechin gallate (EGCG)/(EGC + EGCG). Data are presented as mean ± standard error of three replicates.
Fig. 4
Fig. 4
Chemical structures of (−)-epicatechin (EC), (−)-EC gallate (ECG), (−)-epigallocatechin (EGC), and (−)-EGC gallate (EGCG) and the putative galloylation catalyzed by the specialized enzyme, epicatechin:1-O-galloyl-β-D-glucose O-galloyltransferase. Gallate-type catechins (ECG and EGCG) are derived from nongallate-type catechins (EC and EGC) via esterification with gallic acid (indicated by broken circles in the structures of ECG and EGCG).
See this image and copyright information in PMC

References

    1. Yukihiko H. Elucidation of physiological functions of tea catechins and their practical applications. J Food Drug Anal. 2012;20:296–300.
    1. Chung SY, Huanyu J, Fei G, et al. Cancer preventive activities of tea polyphenols. J Food Drug Anal. 2012;20:318–22.
    1. Tsutomu N, Takeshi I, Yoshinori U, et al. Interaction of tea catechins with phospholipids – roles in their tastes and biological activities. J Food Drug Anal. 2012;20:305–8.
    1. Higdon JV, Frei B. Tea catechins and polyphenols: health effects, metabolism, and antioxidant functions. Crit Rev Food Sci Nutr. 2003;43:89–143. - PubMed
    1. Lee VSY, Dou J, Chen RJY, et al. Massive accumulation of gallic acid and unique occurrence of myricetin, quercetin and kaempferol in preparing old oolong tea. J Agric Food Chem. 2008;56:7950–6. - PubMed

LinkOut - more resources