2.3. Spectrophotometric assays
The radical scavenger capacities of the samples
were determined by using a 340 ATC ELISA
Plate Reader to measure the disappearance ofDPPH at 515 nm. We expressed the radical scavenger activity in terms of the amount of antioxidants necessary to decrease the initial DPPH
absorbance by 50% (EC50). The EC50 value for
each sample was determined graphically by plotting the percentage disappearance of DPPH as a
function of the sample concentration.