Optimization of ultrasonic-assisted extraction of water-soluble polysaccharides from Boletus edulis mycelia using response surface methodology.

Abstract

An ultrasound-assisted procedure for the extraction of water-soluble polysaccharides from the submerged-cultured mycelia of Boletus edulis was investigated using response surface methodology (RSM). Three independent variables were ratio of dried mycelia to water (X1: 1:40-1:60), extraction time (X2: 6-10min), and ultrasonic temperature (X3: 50-70°C). The statistical analysis indicated the independent variables (X2, X3), the quadratic terms (X22 and X32) and the interaction between X3 and X1 had significant effects on the yield of polysaccharides (p<.05). The optimized conditions were 56°C, 1:55 of ratio of dried mycelia to water, and a time of contact of 8.4min. Under these conditions, the experimental yield of polysaccharides was 15.48%, which was well matched with the predictive yield of 15.53%.