Optimization of extraction process by response surface methodology and preliminary characterization of polysaccharides from Phellinus igniarius

Polysaccharides of Phellinus igniarius have many bioactivities. In this study, response surface methodology along with Box–Behnken design based on the single-factor experiments was firstly applied to optimize the extraction conditions by its liquid-cultured mycelia. According to analysis, extraction temperature and ratio of mycelia to water significantly affected extraction yield. The optimal conditions were extraction temperature 70 °C, extraction time 1.5 h and the ratio of mycelia to water 1:6.2. Under these conditions, the maximal yield of crude intracellular polysaccharide (IPS) from mycelia was 50.39 ± 0.41 mg/g, which was agreed with model predictions. The preliminary characterization was mainly β-galactan by gas chromatograph and infrared spectrum analysis.