Response surface methodology for optimization of the ultrasonic extraction of polysaccharides from Codonopsis pilosula Nannf.var.modesta L.T.Shen

The best ultrasonic extractions of polysaccharides with water from Codonopsis pilosula were investigated based on a Box–Behnken design. Three independent and main variables, including extraction time (min), ratio of water to raw material and ultrasonic power (W), which were of significance for the yields of polysaccharides were studied and the Box–Behnken design was based on the results of a single-factors test. The experimental data were fitted to a second-order polynomial equation using multiple regression analysis and also examined using the appropriate statistical methods. The best extraction conditions are as follows: extraction time 44 min, ratio of water to raw material 56 and ultrasonic power 320 W. Under the optimization conditions, the experimental yield was 36.264%, which was well matched with the predictive yield.