title: Study of catechin and xanthine tea profiles as geographical tracers.
abstract: The contents of gallic acid, epigallocatechin gallate, epigallocatechin, epicatechin, epicatechin gallate, catechin, caffeine, theophylline, and theobromine were determined in a set of 45 tea samples, including fermented (black and red) and nonfermented (green) teas of different geographical origins (i.e., China, Japan, Kenya, Sri Lanka, and India). A reversed-phase high performance liquid chromatographic method with gradient elution and photometric detection at 275 nm was used to carry out the analysis. Before the HPLC determination, an extraction step was developed using a mixture of acetonitrile and water (60:40, v/v). Pattern recognition techniques involving principal component analysis (PCA) and linear discriminant analysis (LDA) were applied to differentiate the tea samples according to their geographical origins. Catechins, gallic acid, and tea alkaloids are adequate chemical descriptors to distinguish between fermented and nonfermented tea samples cultivated in different geographical areas.
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, University of Seville, 41012 Seville, Spain.
authors.forename: Pedro L
authors.initials: PL
authors.lastname: Fernández
authors.forename: Fernando
authors.initials: F
authors.lastname: Pablos
authors.forename: María J
authors.initials: MJ
authors.lastname: Martín
authors.forename: A Gustavo
authors.initials: AG
authors.lastname: González
mesh_terms: D002110:Caffeine / Q000032:analysis; D002392:Catechin / Q000032:analysis*; D002681:China; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005707:Gallic Acid / Q000032:analysis; D007194:India; D007564:Japan; D007630:Kenya; D013188:Sri Lanka; D013662:Tea / Q000737:chemistry* / Q000145:classification; D013805:Theobromine / Q000032:analysis; D013806:Theophylline / Q000032:analysis; D014970:Xanthines / Q000032:analysis*
chemical_list: D013662:Tea; D014970:Xanthines; D002110:Caffeine; D005707:Gallic Acid; D002392:Catechin; D013806:Theophylline; D013805:Theobromine