CONICET | Buscador de Institutos y Recursos Humanos

Tea (Camellia sinensis (L.) K., Theaceae) is cultivated in Argentina in the northeastern region (provinces of Misiones and Corrientes), between 26 ° and 28 ° south latitude, the most austral region of the world. The objective of this study was to determine the total polyphenol content and the antioxidant capacity in vitro of green and black tea samples from twelve different commercial suppliers consumed by argentinean people, in order to determine whether some brands may be more efficacious in their potential to increase endogenous antioxidant activity. Total polyphenol content was determined according to the International Standard method (ISO) 14502-1 for the determination of substances characteristic of green and black tea. The antioxidant capacity assays were determined by the inhibition of stimulated linoleic acid peroxidation (FTC) and the free radical scavenging activity (DPPH). Green tea showed higher polyphenols content than black tea. The total polyphenols concentration in green tea was found to vary from (21,02 ± 1,54) to (14,32 ± 0,45) % gallic acid equivalents (GAE) while in black tea ranged from (13,97 ± 0,97) to (8,42 ± 0,55) % (GAE), except for one black tea brand which showed the highest polyphenol content (17,62 ± 0,42) (P < 0.05). A similar profile was observed for the antioxidant capacity determined with both methods. The antioxidant activities were well-correlated with the total polyphenol content (y = 0,0896 x + 0,0032; r2 = 0,9935) for FTC and (y = 0,1118 x + 0,1676; r2 = 0,9141) for DPPH. This is the first systematic survey of teas from Argentinean markets for the quantification of tea polyphenols and antioxidant activity, and could have potential for the quality assessment of teas in this market. Acknowledgments This work was support by UBACY B 090.