All data were expressed as means ± standard errors of
triplicate measurements and analysed by SPSS for Windows
(ver. 10.1). One-way analysis of variance (ANOVA)
and Duncans multiple range test were carried out to test
any significant differences between solvents used. Statistical
comparisons between variables (e.g., polyphenol with
method # 1–polyphenol with method # 2, antioxidant
activity of black tea–antioxidant activity of mate tea and
polyphenol of black tea–polyphenol of mate tea) were performed
with Students t-test. Differences were considered
significant at p < 0.05. Correlations between variables were
established by regression analysis