Extraction and preliminary purification process for polysaccharides from solid rice culture medium of Cordyceps militaris

The extraction and preliminary purification of polysaccharides from solid rice culture medium of Cordyceps militaris were studied, and the optimal condition for starch removal by Ca(NO3)2was determined. Orthogonal test was used to study the optimum polysaccharides extraction condition and Sevag method was used for deproteinization, providing reference for the extraction and purification of polysaccharide. The optimal condition for starch removal was 80% Ca(NO3)2, solid to liquid ratio 1/20(g∶ml), extraction 3 times at 100 ℃, and the removal rate was 42.57%. The optimum condition for extracting polysaccharides was solid liquid ratio 1/30(g∶ml), extraction 3 h at 100 ℃, extraction for 2 times, and the extraction ratio was3.31%. The solution was extracted for one time with the polysaccharides solution and Sevag ratio 1:3, the effect was good with the deproteinization rate of 94.2% and the polysaccharide loss was only 20.95%.