2.4. Antioxidant activity (AOX) assay
The antioxidant activity was analyzed through the method of
2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging. The
extraction method was the same as the extracts prepared for the TP
assay and the determination was carried out by the procedure of
Brand-williams et al. (1995). Results were calculated with the
formula as follows:
DPPH radical scavenging activity (%) = [(A0 A1 )/A0] 100
With A0 refers to absorbance of the control, A1 refers to absorbance
of the samples (Gorinstein et al., 2004).