The antioxidant activity of the RE was performed based on the reduction of the free radical DPPH by antioxidants present in the plant extract. This results in a decrease of a DPPH radical absorbance at 515 nm. Fig. 3 shows the scavenging activity variation provided by RE at different concentrations (0.02%, 0.05%, and 0.08%) comparatively to a synthetic antioxidant (BHT).