From Fig. 2 it is apparent that contrary to ABTS and FRAP assays DPPH assay analysed lesser response and sensitiveness, even if the results measured with the individual assays showed the same trend in the whole data set. Congruency of the obtained results determined by the individual methods was tested by linear regression, and correlation of measured values between ABTS and FRAP assay was R2 ¼ 0.937 (Fig. 3), whereas between DPPH assay and ABTS assay and DPPH assay and FRAP assay it was significantly less (R2 ¼ 0.865 and R2 ¼ 0.821, respectively). These results show the congruency of the ABTS assay and FRAP assay and conversely to their incompatibility to DPPH assay. Correlation between TP and FRAP assay was at the level R2 ¼ 0.852 (Fig. 4).