in the water extract of RB fermented with M. purpureus. The TPC value in the methanol extract of non-fermented RB was in accordance with the result from other studies that showed TPC between 2.5 and 3.6 mg GAE/g sample in their non-fermented rice bran sample (Iqbal et al., 2005, Butsat and Siriamornpun, 2010 and Arab et al., 2011). The antioxidant potential of all fermented samples, assayed using the FRAP method, was significantly increased (po0.05) compared to the non-fermented samples (Table 2). The water extracts of most of the fermented samples showed higher antioxidant activity than the methanol extracts, with the highest activity observed in RB fermented with the mixed cultured of R. oligosporus and M. purpureus. It is shown in Table 2 that the increase in antioxidant activity for the water extract was almost 5-fold, with a 3-fold increase for the methanol extract, compared to non-fermented RB. However, non-fermented RB showed comparable antioxidant activity in the water and methanol extracts, while the methanol extracts of M. purpureus-fermented RB exhibited higher antioxidant activity than the water extracts. Meanwhile, the lowest antioxidant activity among the fermented samples was exhibited by the methanol extract of RB fermented with R. oligosporus and the water extract of RB fermented with M. purpureus. Nevertheless, the antioxidant potential of these two extracts was almost 2-fold higher than the nonfermented counterparts. As shown in Fig. 1(a) and (b), the TPC and antioxidant activity of fermented RB were highly correlated for both the water (R2¼0.935) and methanol extracts (R2¼0.893). Another antioxidant screening method, which determines the proton radical-scavenging action of antioxidant compounds, the DPPH radical-scavenging assay, showed contradictory results compared to those obtained in the FRAP assay (Table 2). The radical-scavenging activity of fermented RB extracts was variable, in which the methanol extracts of RB fermented with M. purpureus