Extraction and in vitro antioxidant activity of exopolysaccharide by Pholiota adiposa SX-01

Abstract

The extraction parameters for Pholiota adiposa SX-01 exopolysaccharide (EPS) produced during submerged culture were optimized using response surface methodology. The optimum conditions for EPS extraction were predicted to be, concentration at 87.36°C, precipitation for 35.18 h at pH 8.81, and EPS production was estimated to be 8.45 g/L. The actual yield of EPS under these conditions was 8.39 g/L. The in vitro antioxidant activities of the EPS were investigated and results showed that the inhibition effects of EPS at a dosage of 250 mg/L on superoxide anion radical, hydroxyl radical and reducing power were 70.63 ± 5.26, 58.22 ± 5.41 and 0.37 ± 0.02% (absorbance at 700 nm), respectively. The results provide a reference for large-scale extraction of EPS by P. adiopsa SX-01 in industrial fermentation. Key words: Pholiota adiposa SX-01, exopolysaccharide, response surface methodology, antioxidant activity, in vitro