The Preparation And Physiochemical Characters Of Inulin From Arctium Lappa.L

In this paper, preparation and physiochemical of inulin and its hydrolysate for production ofhigh fructose syrup were investigated.Arctium Lappa .L is a kind of yearly or biyearly vegetable with food or medicine properties.The fresh root of Arctium lappa L. is rich in inulin with the content of 10% over. First, thepreparation conditions were optimized with orthogonal experiment. The optimal choditions wereas follows: temperature 80℃, time 45 min, the ratio of material to water 1:15, times of continualextraction 2. Under these conditions ,the yield of inulin with purity of 96.75% is 12.98g/100gArctium lappa L.(wet basis). Secondly, the physiochemical properties of inulin were studied. Theanalysis of monosaccharide constitution demonstrated that inulin was mainly consisted offructose and little amount of glucose. The analytical result with HPGFC showed that themolecule weight of inulin is 3165 Da with polymerization degree of 18. Inulin is partly solublein the cool water, and the solubility increased with the increase of temperature. It is also thermolstable and hardly decomposed at 100℃ even for 8 hours. Inulin has optical activity with theoptical rotation of minus 27.30o(in the water). The viscosity of inulin solution is weak, there isalmost no change in the viscosity with the changing of shear-rate. We came to the conclusion thatinulin consists of fructose and little amount of glucose through the analysis of its constitution.Finally, preparation of high fructose syrup from inulin with the treatment of inulinase wasstudied. The main factors were obtained through investigations of their effects of reaction time,temperature, pH, inulinase and substrate concentrations on high fructose syrup. The obtainedfactors were performed with orthogonal experiment. The optimal conditions were asfollows:temperature 50℃, pH 4.5, the amount of enzyme 3mL(the total volume of the system is50mL), the concentration of substrate 15%, reaction time 4 hours. Under these conditions, highfructose syrup contains 76.78% fructose.