Ultrasound-assisted extraction and comparison of extraction methods based on antioxidant activities of polysaccharides from Flammulina velutipes

This study was performed to optimize ultrasound-assisted extraction (UAE) of polysaccharides from Flammulina velutipes using response surface methodology (RSM). The optimum extraction conditions producing a maximum F. velutipes polysaccharide (FVP) yield of 20.52% were as follows: material granularity ( X 1 ), 400-mesh; ultrasonic power ( X 2 ), 380 W; and extraction time ( X 3 ), 25 min. The in vitro antioxidant activity of FVP prepared using UAE (FVP-UE) under optimum conditions and hot water extraction (FVP-HE) were compared using three free radical (hydroxyl radical, superoxide anion radical and 2,2-di[4-tert-octylphenyl]-1-picrylhydrazyl [DPPH]) scavenging activity and the ferric-reducing antioxidant power (FRAP) assays. The results showed that FVP S exhibited weaker ( p