2.3. Scavenging effect on 2,2-diphenyl-1-picryl hydrazyl radical (DPPH)
The radical scavenging ability was determined as described by Mensor et al. (2001). Briefly, one ml from 0.3 mM alcohol solution of DPPH was added to 2.5 ml from the samples with different concentrations of ginger extract. The samples were kept at room temperature in the dark and after 30 min the optic density was measured at 518 nm. The antiradical activity (AA) was determined by the following formula: