Fig. 2. Determination of antioxidant activity of vitamin C, resveratrol, β-piceid and α-piceid isomers by (A) DPPH, (B) FRAP, and (C) hydroxyl radical scavenging method.

Each compound was used at concentration ranges between 0 to 2 mM. Values are expressed as mean ± SD from triplicates. A: DPPH radical scavenging activity at 30 min and 5 h, B: FRAP radical scavenging activity at 30 min, 8 h, and 24 h, C: hydroxyl radical scavenging activity at 30 min and 5 h.