OPTIMIZATION OF EXTRACTION TECHNOLOGY OF POLYSACCHARIDE FROM FOXTAIL MILLET USING RESPONSE SURFACE METHODOLOGY

The experiment of extraction of polysaccharide from foxtail millet was investigated. Response surface methodology (RSM), based on a three-level, three-variable Box-Behnken design (BBD), was employed to obtain the best possible combination of liquid-solid ratio (X-1: 15.0-25.0 mL.g(-1)), extraction time (X-2: 1.5-2.5 h), and extraction temperature (X-3: 65.0-75.0 degrees C) for maximum polysa-ccharide 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 20.7 mL.g(-1), extraction time 2.0 h and extraction temperature 72.3 degrees C. Under these conditions, the experimental yield was 8.08 mg.g(-1), which is well in close agreement with the 8.02 mg.g(-1) predicted value by the model.