The invention discloses a preparation method of banana
polysaccharide, and the preparation method comprises the following processes in sequence: the banana is washed to be clean,
cut to pieces and soaked and processed with acid solution, and then blanched with hot water for a few minutes, cooled, and beaten for stand-by, and then water is added to be extracted. The
hydrolysis is performed with double
enzyme, and then the
enzyme inactivation is performed; the liquid is filtered, and the
clear liquid is alcoholized and settled statically over night. The liquid is centrifuged and filtered, the deposit is taken and then washed for two times respectively with 95 percent of ethyl
alcohol and
acetone, and then dried with vacuum, and the banana
polysaccharide crude product is obtained. The banana
polysaccharide crude product is taken to be dissolved, centrifuged and filtered with water, and then adsorbed, separated and purified through a DEAE
chromatography column on the filtrate, the object is collected and then ultrafilted with ultra
filtration membrane, and trapped fluid is collected, alcoholized and settled statically over night. The fluid is centrifuged and filtered, the deposit is washed for two times respectively with 95 percent of ethyl
alcohol and
acetone, and then dried with vacuum, and the high-purity banana polysaccharide is obtained. The extraction method is simple and safe, no
pollution is produced, the yield is high, the production cost is low, the purity of the obtained banana polysaccharide is high, and the preparation method is suitable for the large-scale industrialization production.