Application of response surface methodology for optimization of polysaccharides production parameters from the roots of Codonopsis pilosula by a central composite design

Response surface methodology (RSM) was used to optimize the extraction conditions of polysaccharides from the roots of Codonopsis pilosula. A central composite design (CCD) was used for experimental design and analysis of the results to obtain the optimal processing parameters. Four independent variables such as extraction temperature (degrees C), ratio of water to raw material, extraction time (h), and number of extraction (n) were investigated. The experimental data obtained were fitted to a second-order polynomial equation using multiple regression analysis and also analyzed by appropriate statistical methods. The 3-D response surface and the contour plots derived from the mathematical models were applied to determine the optimal conditions. The optimum extraction conditions were as follows: extraction temperature 94 degrees C, ratio of water to raw material 9, extraction time 2.5 h, and number of extraction 5. Under these conditions, the experimental percentage value was 15.2 +/- 0.28, which is well in close agreement with value predicted by the model. (C) 2010 Elsevier Ltd. All rights reserved.