Study On Extraction, Refining And Oxidationresistant Effects Of Inulin From Jerusalem Artichoke

Inulin is a linear polymer of D-fructose joined byβ(1→2)linkages and terminated with a D-glucose molecule linked to fructose by anβ(1→2) bond.It is a non-digestible carbohydrate. It preferentially stimulates the growth and activity of one or a limited number of desired bacteria in the colon thus improves host health. Furthermore, Inulin effects on blood glucose attenuation, lipid homeostasis, mineral bioavailability and immuno modulation. Along with the ability to add texture and consequently improve meological caracteristics and nutritional properties of food allows inulin to be termed a functional food.In this thesis, systematic study and optimization of process conditions of inulinase production about its key processes– extraction, decoloration, deprotein were finished. We analyzed chemical and physical properties and composition of Inulin polysaccharide, its antioxidation. The major results were shown as follows:(1) The single factor experimental results indicated that the optimal extracting conditions were as follows: temperature was 68℃, time was 70 minutes, pH 7 and ratio of liquid to material was 1:21, extraction times was 2. The extraction rate of inulin was 16.04%.(2) To romove protein in the inulin solution were studied, including the ways of sevage, borontrifluorid eaceticacid complex and slack lime. Comparing all these ways, the best was slack lime. There results suggested that the extractive juice was precipitated at pH 12 using lime. After centirfugation, the supenratant was acidified with phosphoric acid at pH 7,temperature was 80℃, time was 40 minutes. Finally the loss rate of Inulin was 20.06% and the degree of deprotein was 87.09%.(3)Depending on single factor experiment. The second regression orthogonal experimental results infered the optima1 discoloring conditions: temperature was 58℃, time was 62 minutes,activated carbon concentration was 1%. The loss rate of Inulin was 17.78% and the degree of discoloration was 68.88%.(4) The physical and chemical properties of Polysaccharide Inulin was white powder,dissolving in water, no dissolvent in some organic solvents such as ethanol, aether and acetone, containing no proteins,containing Starch, reducing sugar, and nucleic acid. By HPLC measure to test inulin and the inulin hydrolisis solution, inulin is composed of D- fructose and glucose. It includes 5 kind of inulin polysaccharide ingredient. Its average structure is 3 D- fructose unifing a glucose member.(5) Adding different concentrations of inulin for antioxidant testing, results showed that inulin has a good anti-oxidation. Its anti-oxidative effect increased with amount. Synergy test implied that inulin play a synergic role with VC and citric acid for oxidation resistance.