Optimization of polysaccharides extraction from Tetrastigma hemsleyanum Diels et Gilg using response surface methodology.

A 15-run Box-Behnken design (BBD) was used to optimize the extraction conditions of polysaccharides from Tetrastigma hemsleyanum Diels et Gilg. Three factors such as extraction temperature (°C), extraction time (h), and ratio of water to raw material were investigated. The experimental data were fitted to a second-order polynomial equation using multiple regression analysis and also examined using the appropriate statistical methods. The adjusted coefficient of determination (R(Adj)(2)) for the model was 0.9754, and the probability value (P=0.001) demonstrated a high significance for the regression model. The optimum extraction conditions were found to be: optimized extraction temperature 83.3°C, extraction time 1.55 h and ratio of water to raw material 29.48. Under these conditions, the mean extraction yield of polysaccharides was 5.182 ± 0.093 %, which was in good agreement with the predicted model value.