Submitted to: Society Of Experimental Biological Medicine Proceedings
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/15/1999
Publication Date: N/A
Interpretive Summary: Tea is a very highly consumed beverage throughout the world. However unlike water, the most highly consumed beverage, tea contains several classes of organic compounds which are solubilized from the tea leaf material during the brewing process. One class of these compounds is the polyphenols which have unique biological activities and may be responsible for the purported health benefits of tea. Assessment of the relationship between tea polyphenols and disease risk requires data on polyphenol content. This paper is a review of the state of methodology relative to the analysis of the various polyphenols in tea. In general, high-performance liquid chromatography (HPLC) has been developed for the analysis of the prominent polyphenols in tea and in biological samples. However for most of the polyphenol condensation products of tea, such as thearubigens, definitive methods have not been developed. These products are usually measured by colorimetric procedures which rely on total reducing activity and therefore lack accuracy and precision. In addition, only one citation was identified which measured the metabolic products of minor tea flavonoids in human studies. This review highlights the strengths and weaknesses of analytical systems for the measurement of tea polyphenols and their metabolic products. Considerable analytical research is required before appropriate tools are available for the accurate analysis of all of the polyphenol components of black tea and their metabolites in biological systems.