Ultrasonic-assisted extraction and antioxidant activity of polysaccharides recovered from white button mushroom (Agaricus bisporus)

Ultrasonic-assisted extraction (UAE) of polysaccharides from white button mushroom (Agaricus bisporus) was studied. The four parameters, ultrasonic power, extraction temperature, extraction time, and the ratio of water volume to raw material weight (W/M ratio), were optimized using the central composite design (CCD) with a quadratic regression model built by using response surface methodology (RSM). The optimal extraction conditions found were: ultrasonic power 230 W, extraction temperature 70 °C, extraction time 62 min, and W/M ratio 30 ml/g, where the highest A. bisporus polysaccharides (ABPS) yield of 6.02% was achieved. From HPGPC analysis, the molecular weight of ABPS was 158 kDa. Chemical and spectroscopic studies illustrated ABPS was only composed of Glc with β-type glycosidic bond. In addition, the antioxidative activity of ABPS was investigated by measuring its scavenging ability on DPPH and hydroxyl in vitro. The results indicated that ABPS has good antioxidant activity.