The antioxidant activity of EPS was measured by hydroxyl,superoxide, DPPH radical scavenging activity. The percentage
of hydroxyl radical scavenging ability was calculated as 1 − [(As)/(Ab)] × 100. Where, As is the absorbance of sample, and Ab is the absorbance of blank. The percentage of superoxide radical scavenging ability was calculated as 1 − [(Ao)/A] × 100. Ao and A indicate the rate of pyrogallol auto oxidation before and after addition of sample. The percentage of DPPH scavenging ability was calculated as 1 − [(As)/(Ab)] × 100.