Optimization of extraction technology of polysaccharide from foxtail millet using response surface methodology

Abstract

The experiment of extraction of polysaccharide from foxtail millet was investigated. Response Surface Methodology (RSM),based on a threelevel, three variablesBox-Behnken design (BBD), was employed to obtain the best possible combination of liquid-solid ratio(X1: 15.0-25.0 mL?g-1),extraction time (X2: 1.5-2.5h), and extraction temperature (X3: 65.0-75.0?C)for maximum polysaccharide yields. The experimental data obtained were fitted to a second-order polynomial equation using multiple regression analysis and also analyzed by appropriate statistical methods (ANOVA). The optimum extraction conditions were as follows: liquid-solid ratio 20.7mL?g-1, extraction time 2.0h, extraction temperature 72.3?C. Under these conditions, the experimental yield was 8.08mg?g-1, which is well in close agreement with8.02mg?g-1predicted value by the model.