Isolation And Purification Of Water-Soluble Polysaccharides From Actinidia Chinensis Fruit

Processes for the isolation and separation of water-soluble polysaccharides from Chnensis Actinidia fruit were studied. Methods for the polysaccharides extraction, proteins removing, concentrating and precipitating were investigated. Ion Exchange Chromatography and Size Exclusion Chromatography were used in the further separation and purification for the raw polysaccharides, the primary properties of separated polysaccharides were characterized.The efficiency of classic and ultrasound-assisted extraction of polysaccharides with hot water from Chinensis Actinidia pulp were studied. The results showed that comparing with classic hot water extraction, ultrasound-assisted extraction would improve the extracting efficiency by 13%. Trichloraceticacid (TCA) and cuprum sulphate (CuSO4) were suit for the proteins removing, 3%(V/V) TCA solution (2mol/L) or 4% (V/V) CuSO4 solution(2mol/L) could remove the proteins in juice fare well while the loss of polysaccharides were quite little. Ultrafiltration could be used for the concentrating of polysaccharides and improve the content of polysaccharides about 10 times. 55%(V/V) Ethanol could precipitated the polysaccharides in juice completely.Further separation for raw polysaccharides was carried out by using Ion Exchange Chromatography in packed DEAE Sepharose Fast Flow column and Size Exclusion Chromatography in packed Sephadex column. The results of IEC show pHS.O was fit for the adsoption of polysaccharides. The borate buffer system was chosen for the adsoption (condition: pHS.O, O.lOmol/L buffer, flowrate 1.25ml/min) and elution (condition: pHS.O, 0.2mol/L&0.3mol/L consequence, flow rate 0.4ml/min) of polysaccharides by which the raw polysaccharides could be separated into two components. Sephadex G150 was chosen as a gel in SEC for the separation of polysaccharides (condition: column volume 20ml, sample volume 0.4ml, eluting rate 0.3ml/min), the raw polysaccharides could be separated into three components.The molecular weight (MW) of three separated polysaccharides were measured by means of High Performance Liquid Chromatography and the results showed their molecule weight was approximate 10K.D. These three polysaccharides contains -OH group and a-D-glucide were detected by Infrared spectrum. The completely hydrolysates of polysaccharides component 1 contained D-glucose, D-mannose and L-Rhamnose by paper Chromatography, thin layer Chromatography and gas Chromatography.