Response surface analysis of microwave‐assisted extraction of polysaccharides from cultured Cordyceps militaris

Abstract BACKGROUND: Microwave‐assisted extraction was employed to extract polysaccharides from cultured Cordyceps militaris. The optimal conditions for polysaccharide extraction were determined by response surface methodology. Box–Behnken design was applied to evaluate the effects of three independent variables (microwave power, extraction time and ratio of solution to solid) on the polysaccharide yield of C. militaris. RESULTS: Correlation analysis of the mathematical‐regression model indicated that a quadratic polynomial model could be employed to optimize the microwave‐assisted extraction of polysaccharide. Response surface plots showed that microwave power, extraction time and ratio of solution to solid exhibited independent and interactive effects on the extraction of polysaccharide. The optimal conditions to obtain the highest polysaccharide yield of C. militaris were a microwave power of 744.8 W, an extraction time of 4.2 min and a ratio of solution to solid of 31.1 mL g−1. CONCLUSION: Under these optimal conditions, the experimental values agreed with the predicted values, using analysis of variance, indicating the goodness of fit of the model used and the success of response surface methodology for optimizing microwave‐assisted extraction of polysaccharide from C. militaris. Copyright © 2009 Society of Chemical Industry