where A0 was the absorbance of the control (without sample), A1 was the absorbance in the presence
of the sample, and A2 was the absorbance without DPPH. The EC50 valuee, defined as the amount of
antioxidant necessary to decrease the initial DPPH˙ concentration by 50%, were calculated from the
results. Measurements were calibrated to a standard curve of prepared ascorbic acid (6.25–200 g/mL)
y = 0.0074x − 0.0110, R2 = 0.9958.