Cellulase-assisted extraction and antioxidant activity of polysaccharides from Rhizoma imperata

•The extraction conditions were 69.48 min, 45.36 °C, pH 4.58, cellulase 1200 U/g.•The RPs yield reached up to 0.67% (w/w).•The RPs show high antioxidant ability.

In this study, the cellulase-assisted extraction and antioxidant activity of the polysaccharides from Rhizoma imperata were investigated. To improve the yield of R. Imperata polysaccharides (RPs), the extraction conditions were optimized as follows: time, 69.48 min; temperature, 45.36 °C; pH, 4.58; cellulase amount, 1200 U/g. Under these optimum conditions, the yield of RPs reached 0.67% (w/w), and was higher than that of the traditionally aqueous extraction method. The sugar content in the RPs product reached up to 93.25% (w/w). The RPs product has high antioxidant activity including hydroxyl radical scavenging activity and 2,2-diphenyl-β-picrylhydrazyl radical scavenging activity at the concentration of 100 mg/mL.