Antioxidant activity was determined by the 2,2-diphenyl-1-picryl-hidrazil (DPPH) radical-scavenging method according to Sanchez-Moreno et al. (1999). The absorbance was measured at
517 nm, using a spectrophotometer (UV-2100). Total antioxidant activity was expressed as the percentage inhibition of the DPPH radical and was determined using the following equation