Alkali extraction polysaccharides from millet by orthogonal design

The alkali extraction process of polysaccharides from millet was investigated.The effects of alkali concentration,extraction temperature,liquid to solid ratio and extraction time on the extraction rate were studied with single-factor experiments.Then the optimization experiments of orthogonal design with four factors and three levels were carried out and the optimal conditions combination was obtained.The results showed that the order of factor influencing on polysaccharides yield is successively liquid to solid ratio,extraction temperature,alkali concentration and extraction time.The established optimum alkali extraction technical combination conditions are alkali concentration 0.8 mol/L,extraction temperature 80.0 ℃,liquid to solid ratio 20.0∶1 and extraction time 1.0 h.Under these conditions,the yield of polysaccharides is 47.27 mg/g.