In this study, response surface methodology was employed to optimize the extraction of polysaccharides from Phellinus nigricans mycelia. A central composite design was adopted to determine optimum parameters (extraction time, extraction temperature, extraction frequency, and ratio of water to raw material) that could yield a maximum polysaccharide. Results revealed the following optimum extraction conditions: extraction time, 2.8h; ratio of water to raw material, 28; extraction frequency, 5; and extraction temperature, 95 °C. Under optimized conditions, the experimental yield of P. nigricans mycelia polysaccharides was 15.33 ± 0.21%, which is consistent with the predicted yield. The antioxidant activity assay in vitro showed that the polysaccharides exhibited a high scavenging activity against superoxide anion, hydroxyl, and 1,1-diphenyl-2-picrylhydrazyl radicals. These polysaccharides also exhibited a strong reducing power. Thus, these polysaccharides can be used as natural antioxidants in functional foods or medicine.
Keywords: Antioxidant; Mycelia; Phellinus nigricans; Polysaccharides; Response surface methodology.
Copyright © 2013 Elsevier Ltd. All rights reserved.