Concerning any structure–activity relationships, the o-dihydroxy groups in the B-ring and the hydroxyl group in the C-ring are associated with the antioxidant properties of the flavonoids ( Faria et al., 2005). When comparing the antioxidant activity of the commercial standard samples (control and biotransformed) with those of the samples of green tea and yerba mate, the antioxidant activity of the standards was observed to be much higher. This was expected because the green tea and yerba mate samples are more diluted than the commercial standard samples, largely due to the extraction process used. The commercial standard samples showed a high degree of purity,

which raised the antioxidant power of these samples (Table 1 and Table 2). Few studies have investigated the use of enzymes in extracts of teas. Interestingly, the data from this study reveal important Ceritinib information about the increase in antioxidant capacity of these drinks after treatment with tannase. This result was confirmed by analysis of ORAC and DPPH. This study demonstrated that tea treated with tannase exhibits greatly increased antioxidant capacity in vitro.

The tannase may be able to hydrolyse find protocol the substrates contained in these teas, and the products of hydrolysis may significantly increase the antioxidant capacity of these drinks. This study yielded the identification of an important polyphenol in each tea extract (chlorogenic acid from yerba mate and epigallocatechin gallate for green tea) and the finding that treatment of the extracts with tannase increased their antioxidant power. These results demonstrate the ability of tannase to catalyse hydrolysis on several different substrates from the tea extracts tested and confirm that the reaction results in higher antioxidant capacities for those polyphenols. The increase in antioxidant capacity of tea extracts and commercial standards following tannase treatment was ascertained using the

ORAC and DPPH assays, which, in both analyses, confirmed the result of increased antioxidant capacity of all biotransformed samples. The ORAC assay provides a novel and efficacious method for evaluating the potential antioxidant Selleckchem Paclitaxel activities of various compounds and biological samples. Further studies are needed to determine the mechanism and potential applications of tannase in order to increase the antioxidant capacity of green tea and yerba mate. The authors acknowledge the financial support of FAPESP and are grateful to the São Francisco University. “
“In recent years, several studies employing the biopolymer chitosan have been developed in the areas of science and technology. This polysaccharide is obtained from renewable resources and currently chitosan is intensively studied due to its application in the pharmaceutical, cosmetics, biomedical, biotechnological, agricultural, and food industries (Mourya & Inamdar, 2008).