The Production Of Inulin And Its Effection On Lactobacillus Growth

Inulin is a kind of polysaccharides. It consists of linear chains of β-2,1-linkedD-fructofuranose. The difference in molecular weight account for the distinctly differentfunctional and technological attributes. In this paper, the crude inulin extract was obtainedfrom burdock followed by ethanol fractionation. Products of relatively homogenerousdifferent molecular weight were obtained from fractionation. The effection of the addition ofinulin on lactobacillus growth also were studied. Furthermore, the method also beenestablished to detect molecular weight of inulin. This study provided theoretical basis forfurther study on the relationship between molecular weigh and functional, technologicalattributes of inulin and selective using of inulin. The main results were the following:The equation based on intrinsic viscosity and molecular weight of glucan wasestablished([η]=0.09074M0.4985, r=0.999), its application in detecting molecular weight ofinulin has been proved feasible according to HPGPC. The applied method provided sufficientsensitivity to detect molecular weight of inulin.Inulin extract was obtained from burdock followed by purification and ethanolfractionation. After acidic hydrolysis and assayed by HPLC, inulin was consisted of fructose.Purified inulin showed a single peak after HPGPC. The result showed inulin was pure and itspurity was highter.Inulins with different molecular weight were obtained from different ethanolconcentrations. Most fractions could be precipitated by50%~80%ethanol, the scale of below50%was9.6%. The production effect of inulin was detected by gel filtration chromatographyand molecular weight was measured by viscosity. The fractions were relatively homogenerous.Inulins with different molecular weight could be obtained by fractionation. The ethanolfractionation provided a quick and reliable method for producing different molecular weightof inulin.Inulin can stimulate two lactobacillus strains growth.1%inulin in MRS medium hadbetter growth-promoting function. The function of inulin-Ino topped the list, stronger than that of inulin-Ins and inulin-Inh. Two lactobacillus strains showed different growth states inMRS medium using inulin as the carbon source. Two lactobacillus strains had strongerfermentability of inulin-Ino than that of inulin-Ins and inulin-Inh. The PI values resultdemonstrated that all the three inulins had prebiotic effects, and the one with low molecularweight had better beneficial effects.