Extraction And Properties Of Brasenia Schriberi Polysaccharides

The technology for extracting polysaccharides from defreezed Brasenia schreberi was studied . Results are as follows:extracted for 3hr,the ration of material to liquid is 1:5,and solvent is 0.015mol/L NaOH,temperature is 30℃,the polysaccharides named RBPⅠ.The system HPSEC-MALLS-UV-RI was used to detect the composition of BSPⅠ.The protein in BSPⅠis not connect with the polysaccharides.Then Sevage,Trichloroaceticacid and enzymatic hydrolysis with ultrafiltration were used to remove the protein from RBPⅠ.The results showed methods of enzymatic hydrolysis are better then others,the results are 0.1% Alcalase, pH 8.5, 50℃enzymatic hydrolysis for 4hr, BSPⅡis gained. BSPⅢis the polysaccharides yield after ultrafiltration and ethanol precipitation.The removal of protein is 75.7%,the yield loss of polysaccharides was 9.7%.BSPⅢwas purified by gel PL aquagel-OH MIXED 8μm.Two fraction of polysaccharide BSPⅢ-a and BSPⅢ-b were obtained. HPSEC-MALLS-UV-RI system was used in study of the Mw and composition of BSPⅠ,BSPⅡ,BSPⅢ,BSPⅢ-a and BSPⅢ-b.The major fraction BSPⅢ-a was eluted as a single symmetrical narrow peak on HPSEC and Mw was 1.851×106.GC was used in Monosaccharide component determination of BSPⅢ,BSPⅢ-a and BSPⅢ-b.The FT-IR analysis revealed that BSPⅢ-a was a polysaccharide.Rheological and gel properties of raw polysaccharides of Brasenia schreberi (BSPⅢ) was studied.The results shows that BSPⅢwith low concentrations were pseudoplastic fluid and their flow curves had a good correlation with the power law model.The synergy of BSPⅢ,Xanthan gum and carrageenan were also studied. The mixture of BSPⅢand carrageenan was a kind of heat reversible gel,the maximum synergy was found when carrageenan/ BSPⅢwas 9:1,the gel point increased 1℃and melt point increased 14.6℃; no synergy was found between BSPⅢand Xanthan gum.The study of the interaction between BSPⅢand SPI shows that,the viscosity increased with the content of BSPⅢincreasing,the maximum gel strength was found when the content of BSPⅢwas 0.1%,the second denatured temperature disappeared when the content of BSPⅢwas higher than 0.3%.