Ultrahigh pressure extraction of polysaccharides from Cordyceps militaris and evaluation of antioxidant activity

Four polysaccharide fractions (CMP-1, CMP-2, CMP-3 and CMP-4) were extracted from cultured Cordyceps militaris (CM) using ultrahigh pressure extraction (UHPE), and purified using ultrafiltration, DEAE-Sepharose Fast Flow and Sephadex G-100 column chromatography. The effects on yields of crude polysaccharides (CCMP) were investigated by the response surface methodology (RSM) based on Box-Behnken Design (BBD). The optimal extraction condition for UHPE was: 5.18 min, 424 MPa, and 43.5 degrees C. Under these conditions, the CCMP yield was 14.89 +/- 0.68%. The chemical characterizations of CMPs were determined by gas chromatography and high performance gel permeation chromatography (HPGPC). The antioxidant activities of CMPs were evaluated by ferric reducing antioxidant power (FRAP) and free radical scavenging assay. CMPs are composed of D-glucose, D-galactose and D-mannose, demonstrating noticeable antioxidant activities in a concentration-dependent manner. UHPE as an effective and environmental-friendly technique could be employed for extracting active ingredients from plants. (C) 2014 Elsevier B.V. All rights reserved.