Study On Isolated And Purification Of Inulin And Its Antioxidant Effect

Inulin was by D-fructose in beta (2→1) glycosidic bond connecting a glucose residues formed at the end of the polysaccharide, one kind can not be intestinal digestion of carbohydrates, promoting the growth of intestinal bacteria, reducing blood sugar levels, promoting mineral absorption and other functions.In recent years, the research of inulin had quite broad. Jerusalem artichoke tuber was puachased in Fenyang city of Shanxi Province as raw material in this paper, researched inulin of Jerusalem artichoke extraction, purification, separation system of the research on the methods and process conditions, and the different degree of polymerization of inulin antioxidant activity research. Getting the following conclusion:1. Jerusalem artichoke tubers was uesd as raw material to extract inulin by ultrasonic-enzyme synergistic method.First through the single factor experiment and Plackett-Burman screening test to determine inulin extraction process significantly affect three factors-temperature,time and enzyme amount,reuse Box-Behnken central composite experiment and response surface analysis method optimized for best extraction process conditions.The results showed that material-to-liquid ratio 1:20,temperature 51.0℃,m (cellulase):m (pectinase)=1:4,ultrasonic treatment time 25min were the optimum conditions. Under these optimum conditionsthe inulin yield was 72.2%.2. The inulin crude extracted by resin decolorizing and deprotein,The screening tested by static adsorption and dynamic adsorption screening test for seven different resin, the best purification process for m (D280):m (D151)=2:1, pH 6.5, the flow rate of 3.19 mL/min, collected the liquid volume of 28.3mL/(g)resin, the crude extract of decolorization rate was 90.1%, the deprotein rate of 88.9%, inulin retention rate of 96.8%.3. To separation of inulin, used ultrafiltration method in 10KDa,5KDa, 4KDa, 1KDa ultrafiltration membrane under the best operating pressure 0.1MPa, 0.14MPa,0.16MPa,0.16MPa, and the molecular weight in 4KDa-5KDa range of inulin had higher clearance to the DPPH free radicals and OH free radicals, and the highest antioxidant activity value (AOV), reducing power was strongest.