The tannase was probably able to hydrolyse the NVP-BEZ235 cell line substrates contained in these teas, and the products of hydrolysis apparently contributed to the increase in the teas’ antioxidant capacity. The antioxidant capacity of green tea increased by 55% after enzymatic treatment. Tannase also exhibited high activity on epigallocatechin gallate, the commercial standard substrate from the green tea, increasing its antioxidant activity by 46%. These results indicate that the tannase from P. variotii was able to hydrolyse

the ester bonds from natural substrates. Epigallocatechin and gallic acid can be formed by the degalloylation of the gallate (epigallocatechin gallate) present in the tea extract ( Fig. 1). According to Battestin et al. (2008), tannase

can completely hydrolyse the epigallocatechin INCB024360 concentration gallate in green tea to epigallocatechin and gallic acid by increasing the antioxidant activity of tea. For yerba tea, the increase of the antioxidant activity after enzymatic hydrolysis was 43%, which was a significant result. According to Miranda et al. (2008), the yerba mate is rich in several bioactive compounds that can act as free-radical scavengers. The activity of the tannase in increasing the antioxidant power of chlorogenic acid by 58% (Table 1), suggests that the enzyme was able to act on the chlorogenic acid by yerba mate extract, and that the products of this reaction contributed to the increase of the antioxidant power of this beverage. These data are consistent with the results presented in Fig. 3, in which the chlorogenic acid was found in large quantities in the yerba mate else extract. Similar results have been demonstrated by Roy et al. (2010). The antioxidant activity of green tea and yerba mate infusions has long been attributed to the polyphenolic content of green tea and yerba mate. Table 2 describes the antioxidant capacity of the various samples (chlorogenic acid, yerba mate extract, EGCG and green tea extract), before (as control) and after tannase treatment, as determined by the DPPH method.

In the DPPH method, the substances tested were reacted with the DPPH, which is a stable free radical, where a decrease in the absorbance measured at 515 nm was induced, suggesting the scavenging potential of the extracts. The results in Table 2 indicate that there is a trend for increasing radical-scavenging capacity after enzymatic hydrolysis. This trend was similar to the one observed in the ORAC results, which supports the results obtained by enzymatic treatment of the extracts. Catechins (including epicatechins) with three hydroxyl groups in the B ring are known as the gallocatechins, whereas those esterified to gallic acid at the 3-OH group in the C ring are known as the catechin gallates.