Ultrasonic-assisted extraction of polysaccharides from Hohenbuehelia serotina by response surface methodology.

An ultrasonic-assisted procedure for the extraction of polysaccharides from the fruiting body of Hohenbuehelia serotina was investigated using response surface methodology. The effects of four factors on the yield of polysaccharides were studied. The optimized conditions were extraction temperature 94 °C, extraction time 3.0 h, ratio of water to raw material 110:1 and ultrasonic power 480 W. Under these conditions, the experimental yield of polysaccharides was 17.45±0.18%, which was well matched with the predictive yield of 17.54%. The molecular weight of polysaccharide was ranged from 1.19 × 10³ to 1.55 × 10⁴ Da. The polysaccharides were composed of ribose, arabinose, mannose, glucose and galactose in a ratio of 0.65:0.69:9.35:14.24:5.47. Then, the structural features of untreated materials, hot water extraction residue and ultrasonic-assisted extraction residue were compared by SEM. Results indicated that ultrasonic-assisted extraction technology could be an effective and advisable technique.