Total Phenol, Catechin, and Caffeine Contents of Teas Commonly Consumed in the United Kingdom

Levels of total phenol, catechins, and caffeine in teas commonly consumed in the United Kingdom have been determined using reversed phase high-performance liquid chromatography. Tea bags or tea leaves were purchased from local supermarkets and extracted in boiling water for 5 min. The resulting data...

Full description

Saved in:
Bibliographic Details
Published in:Journal of agricultural and food chemistry 2002-01, Vol.50 (3), p.565-570
Main Authors: Khokhar, S, Magnusdottir, S. G. M
Format: Article
Language:English
Subjects:
Air. Soil. Water. Waste. Feeding
Biological and medical sciences
Caffeine - analysis
Catechin - analysis
Chromatography, High Pressure Liquid
Environment. Living conditions
Fermentation
Food Handling
Medical sciences
Phenol - analysis
Public health. Hygiene
Public health. Hygiene-occupational medicine
Tea - chemistry
United Kingdom
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Levels of total phenol, catechins, and caffeine in teas commonly consumed in the United Kingdom have been determined using reversed phase high-performance liquid chromatography. Tea bags or tea leaves were purchased from local supermarkets and extracted in boiling water for 5 min. The resulting data showed considerable variability in both total phenols [80.5−134.9 mg/g of dry matter (DM) in black teas and 87−106.2 mg/g of DM in green teas] and catechins (5.6−47.5, 51.5−84.3, and 8.5−13.9 mg/g of DM in black, green, and fruit teas, respectively); this was most probably a result of differing agronomic conditions, leaf age, and storage during and after transport, as well as the degree of fermentation. Caffeine contents of black teas (22−28 mg/g of DM) were significantly higher than in less fermented green teas (11−20 mg/g of DM). The relative concentration of the five major tea catechins ranked EGCG > ECG > EC > EGC > C. The estimated U.K. dietary intakes of total tea catechins, calculated on the basis of an average tea consumption of three cups of tea (200 mL cup, 1% tea leaves w/v), were 61.5, 92.7, and 405.5 mg/day from fruit teas, black teas, and green teas, respectively. The coefficients of variation were 19.4, 88.6, and 17.3%, respectively, indicating the wide variation in these intakes. The calculated caffeine intake ranged between 92 and 146 mg/day. In addition, many individuals will consume much larger quantities of tea, of various strengths (as determined by the brewing conditions employed). This broad spread of U.K. daily intakes further emphasizes the need for additional research to relate intake and effect in various population groups. Keywords: Tea; Camellia sinensis; phenol; catechins; caffeine; dietary intake
ISSN:0021-8561
1520-5118
DOI:10.1021/jf010153l