Preparation And Purification Of Konjac Oligosaccharide And Its Double Metal Complex Modification

Konjac oligosaccharide(KOS)is an important part of functional sugar,because of its unique physical and chemical properties,the great medicinal value and health function,have huge demand in food,medicine,etc.And further on the metal complexmodification can be beneficial to the body for the safety of the metal ions,and absorption.But in view of current situation of the research and application,there are following three questions in the process of KOS' preparation,purification and modification:? in the process of preparation of konjac oligosaccharide,the degradation method of konjacglucomannan is very single,a variety of methods of combining the research is not much,it also can't effectively play to the advantages of various methods.? Purification is a key process of oligosaccharidepreparation,the simple and efficient method of separation and purification has yet to be further developed;? The current metal complexing modification research is only limited to the single metal ions complexation with oligosaccharide,the complex modification of two kinds of metal ions has not been reported.In view of the above problem,with the development of the two metal complexing modified konjac oligosaccharidepreparation for the purpose,the subject aims to put forward and to optimize the degradation,purification and modification of preparation process.The specific contents and conclusions are follows:(1)Konjac oligosaccharide's ultrasonic-enzyme preparation and process optimization.With konjac powder as substrate,using the beta mannose and ultrasonic method to degrade the konjacglucomannan,the experiment explored the initial concentration of konjac powder,amount of enzyme,solution temperature,ultrasonic power,ultrasonic time in the degradation process,five factors whether have effect for obtained rate of oligosaccharide and the decomposition rate of konjac powder,and analyze the surface morphology and material content of the konjac powder before and Konjac oligosaccharide after enzymolysis.The result showed that:the best initial concentration of konjac powder is 45 to 60 g/L,with enzyme quantity range from 0.3%to 0.4%,enzyme solution temperature range from 45 to 55?,ultrasonic power is 80-100 w,ultrasonic time is 30-40 min.The surface structure and composition of konjac powder before and konjac oligosaccharide after enzymolysis showed that:the raw konjac oligosaccharide was flat surface distribution density of holes,the C/O on the surface of oligosaccharide after enzymolysis has reduced.(2)Konjac oligosaccharide's research of membrane separation and purification.According to the requirements of the konjac oligosaccharideseparation,designing integration of UF,NF process for purification of raw konjac oligosaccharide.Experiment explores the operating pressure,cross-flow velocity,temperature,material liquid concentration on two membrane separation effect of the system,also compare to analyzing the membrane fouling problem in ultrafiltration system and the cleaning strategy.The results show that the optimized inquiry after operating parameters,respectively,operating pressure is 0.15MPa(UF),1.5 MPa(NF);cross-flow velocity is 55 cm/s;feed liquid temperature is 25?(UF,NF);material liquid concentration is 15 g/L(NF).Analysis of ultrafiltration membrane fouling and exploration of cleaning strategies showed that organic pollution is the main reason which caused the flux of membrane system declined,the best solution for cleaning is 0.1%NaClO+0.2%HCl,it can make the membrane water flux recovery rate of more than 90%.UF,NF has a good separation effect to konjac oligosaccharide,its recovery rate can reach more than 88.5%,the purity of oligosaccharide of product material liquid can reach 92.7%.(3)Preparation and structure characterization of modified konjac oligosaccharide.On the basis of preparation and purification of konjac oligosaccharide,using the Fe,Cu,Fe-Cu,respectively for metal ions complexation of modified konjac oligosaccharide.Experiment explored different preparation factors in the modification process on KOS-Cu-Fe in the influence of the rate of metal combination,using FTIR,SEM,EDX and other technology for characterization of its structure.Compared and explored the related properties of the modified konjac oligosaccharide.The result showed that:the KOS-Cu-Fe preparation of modified konjac oligosaccharide is successful,the best preparation conditions,respectively,pH 6.0,n(Cu)/n(Fe)is 3,temperature is 50?,total 12mg for the amount of metal;KOS-M characterization of structure and testing of the content prove that the success of the metal ions complexation,the surface of modified KOS-Cu-Fe and KOS-Cu show rich porous structure,the combination rate of metal closely related to C/O of KOS-M;inquiry result show that KOS-M has inhibition effect on e.coli and yeast proliferation,the inhibition order is KOS-Cu-Fe>KOS-Fe>KOS-Cu,KOS-M's adsorption performance of urea molecules were increased,the adsorption capacity order is KOS-Cu-Fe>KOS-Cu>KOS-Fe.