Astragalus polysaccharide is the main component of Astragalus membranaceus (Fisch.) Bge. var. mongholicus (Bge.) Hsiao,which has the functions of regulating human immune function and enhancing cell metabolism.In order to investigate the optimum extracting conditions of polysaccharides from Astragalus membranaceus (Fisch.) Bge. var. mongholicus (Bge.) Hsiao,the effects of liquid-solid ratio,extraction temperature,ethanol concentration and extraction time on the yield of Astragalus membranaceus polysaccharides were investigated by single factor experiment.Box-behnken central composite design and response surface analysis were used to optimize the extraction process of astragalus mongholicus polysaccharides.The results showed that the optimal condition for polysaccharides of astragalus membranaceus mongholicus was liquid-solid ratio 11∶1 (mL∶g),extraction temperature 80 ℃,ethanol concentration 95% and extraction duration 100 min.Under such optimal conditions,the polysaccharides extraction efficiency was 3.48%,which was very close to the predicted value,indicating that the response surface analysis method was reasonable and reliable optimize.

"> Astragalus membranaceus , (Fisch.) Bge. var. , mongholicus , (Bge.) Hsiao, polysaccharides, extraction technology, response surface methodology