Response Surface Analysis for the Optimization of Extraction Process for Polysaccharides from Tricholoma matsutake and Antioxidant Activity of the Extracted Polysaccharides

Objective: To develop an optimized enzymatic method for extracting polysaccharides from Tricholoma matsutake with a combination of cellulase, pectinase and neutral protease and to evaluate the antioxidant activity in vitro of the extracted polysaccharides. Methods: On the basis of single-factor experiments, a four-factor, three-level Box-Behnken design was utilized for the mathematical modeling of polysaccharide yield as a function of material/water ratio, medium pH and hydrolysis time and temperature. This was followed by response surface analysis of the developed mathematical model. The antioxidant activity of Tricholoma matsutake polysaccharides was determined by pyrogallol autoxidation and free radical-scavenging assay. Results: The optimum condition for the extraction of Tricholoma matsutake polysaccharides were found to be hydrolysis at 35 ℃ for 71 min with a material/solvent ratio of 1:40(g/mL) at pH 5. Under these conditions, the model-predicted and experimentally measured values of polysaccharide yield were 7.06% and 6.95%, respectively, revealing a relative error of only 1.56% between them. The Tricholoma matsutake polysaccharides had a strong capacity to scavenge superoxide anion(IC50 = 0.565 mg/mL) and DPPH free radical(IC50 = 0.454 mg/mL). Conclusion: The proposed extraction method is efficient, simple and applicable for the extraction of polysaccharides form Tricholoma matsutakes and the extracted polysaccharides have significant antioxidant capacity in vitro.