Effect of solution plasma process with hydrogen peroxide on the degradation and antioxidant activity of polysaccharide from Auricularia auricula.

Solution plasma process (SPP) in combination with hydrogen peroxide (H2O2) were adopted to the degradation of Auricularia auricula polysaccharide (AAP). The results showed that SPP irradiation with H2O2 was effective for the AAP degradation. The intrinsic viscosity ([η]) of AAP solution decreased exponentially with increase in irradiation time. The degradation reaction closely fitted to the first order kinetics. The degradation rate constant after SPP irradiation with H2O2 was approximately 4.2 times that with SPP irradiation alone. GPC analysis showed that the molecular weight distribution of AAP was narrowed during degradation. FTIR and 13C NMR analysis revealed that primary structure of APP was not changed by the combination method. In vitro antioxidant activity of the polysaccharides was evaluated by determining their reducing power and radical (ABTS radical and superoxide radical) scavenging abilities. It was found that the degraded AAP possessed the higher antioxidant activity. The results suggested that SPP with H2O2 was an effective means for AAP degradation.