Studies On The Preparation, Properties And Structure Of Soluble Soybean Polysaccharide Iron Complex

Using soluble soybean polysaccharide as raw material, prepare two complexes of solublesoybean polysaccharide-iron (Ⅱ) and soluble soybean polysaccharide-iron (Ⅲ), andoptimize the preraration of soluble soybean polysaccharide iron complex with responsesurface methodology. Study the physical properties, antioxidant activity, proliferation ofbifidobacteria and structure of soluble soybean polysaccharide-iron (Ⅲ) complex. Explorethe feasibility of ion exchange column reaction of soluble soybean polysaccharide with iron.(1) In order to optimize the synthesis process of soluble soybean polysaccharide ironcomplex, on the basis of single factor, a design of response surface methodology was used toanalyze the impact of mass ratio of soluble soybean polysaccharide and catalyst sodiumcitrate, pH, reaction time and temperature on iron content, and the prediction model wasestablished.The analysis of variance revealed that, for soluble soybean polysaccharide-iron(Ⅱ) complex, the optimum conditions obtained were mass ratio of soluble soybeanpolysaccharide and catalyst sodium citrate1.89:1, pH3.89, reaction time1.56h andtemperature60.6℃. Value of iron content predicted by the model was23.08%. Measuredvalue of iron content was21.89%. For soluble soybean polysaccharide-iron (Ⅲ) complex,the optimum conditions obtained were mass ratio of soluble soybean polysaccharide andcatalyst sodium citrate1.92:1, pH8.89, reaction time1.47h and temperature69.8℃. Value ofiron content predicted by the model was31.94%. Measured value of iron content was30.56%.The synthesis processes of soluble soybean polysaccharide iron complex optimized byresponse surface methodology can be used to guide the actual production.Comparison of the coordination reaction of divalent iron and trivalent iron with solublesoybean polysaccharide showed that the reaction of trivalent iron with soluble soybeanpolysaccharide was easier, and the combination rate was higher, too.(2) Soluble soybean polysaccharide-iron (Ⅲ) complex was a stable complex whichdoesn't precipitate at pH1~14. The studies of antioxidant activity showed that its hydroxylradical-scavenging activity, nitrite scavenging activity and lipid peroxidation inhibition werebetter than soluble soybean polysaccharide. At the concentration of10mg/mL, hydroxylradical-scavenging rate, sodium nitrite scavenging rate and lipid peroxidation inhibition rateof soluble soybean polysaccharide were15.97%,53.95%and34.89%, when the same rates ofsoluble soybean polysaccharide-iron (Ⅲ) complex were29.63%,67.54%and77.89%.Studies on the proliferation activity of bifidobacteria showed that soluble soybean polysaccharide and its iron(Ⅲ) complex had a role in promoting the proliferation and activityof bifidobacteria, and the growth-promoting effects in vitro of soluble soybeanpolysaccharide-iron(Ⅲ) complex was higher than soluble soybean polysaccharide.(3) The structure of soluble soybean polysaccharide-iron (Ⅲ) complex was identifiedby UV-vis spectroscopy, circular dichroism, fourier transform infrared spectroscopy, X-raydiffraction and transmission electron microscopy. The results showed that the carboxyl ofsoluble soybean polysaccharide subsequently reacted to iron.β-FeOOH structure as ironcore, soluble soybean polysaccharide combining with the surface of iron core to obtained thecomplex.(4) The reaction of soluble soybean polysaccharide with Fe3+in ion-exchangechromatography (IEC) column was studied in this paper. UV-vis, XRD and FTIR wereadopted to analyze the mechanism of the technology and structure of the complex, and toprovide a reference for the integration of soluble soybean polysaccharide from separation tocoordination reaction.