Chain-Breaking Antioxidant Activity and Cyclic Voltammetry Characterization of Polyphenols in a Range of Green, Oolong, and Black Teas
- 14 August 2003
- journal article
- research article
- Published by American Chemical Society (ACS) in Journal of Agricultural and Food Chemistry
- Vol. 51 (19), 5798-5802
- https://doi.org/10.1021/jf030086q
Abstract
A series of eight green, eight oolong, and 17 black teas have been analyzed for polyphenol content by absorbance at 272 nm and cyclic voltammetry response at an inert carbon electrode, a new method developed to provide a rapid measure of easily oxidizable polyphenols in beverages. The chain-breaking antioxidant activity of the teas has also been determined during the chain oxidation of methyl linoleate in a pH 7.4 micellar solution, for which realistic kinetic parameters have been derived. While higher mean values were obtained for green teas than for oolong and black teas, the differences were not large, and the spread of values within each type was considerable. The absorbance at 272 nm correlated well with the cyclic voltammetry response only for green teas and black teas taken on their own. The cyclic voltammetry measure and the antioxidant activity correlated well only for the green teas, where the polyphenol content is dominated by epigallocatechin gallate.Keywords
This publication has 20 references indexed in Scilit:
- Characterisation of polyphenols in green, oolong, and black teas, and in coffee, using cyclic voltammetryFood Chemistry, 2003
- Total Phenol, Catechin, and Caffeine Contents of Teas Commonly Consumed in the United KingdomJournal of Agricultural and Food Chemistry, 2002
- Chain-Breaking Antioxidant Capability of Some Beverages as Determined by the Clark Electrode TechniqueJournal of Medicinal Food, 2001
- Simulated intestinal digestion of green and black teasFood Chemistry, 2001
- Analysis of caffeine and flavan-3-ol composition in the fresh leaf ofCamellia sinesis for predicting the quality of the black tea produced in Central and Southern AfricaJournal of the Science of Food and Agriculture, 2000
- The gastrointestinal tract: A major site of antioxidant action?Free Radical Research, 2000
- Antioxidant Potential of Theaflavins. A Pulse Radiolysis StudyJournal of the American Chemical Society, 1997
- An Investigation of the Antioxidant Activity of Black Tea Using Enhanced ChemiluminescenceFree Radical Research, 1997
- Tea ChemistryCritical Reviews in Plant Sciences, 1997
- The formation of an enantiomerically pure product of free radical coupling. The chemistry of diphenylcarbene in polycrystalline S-(+)-2-butanolJournal of the American Chemical Society, 1985