Study On The Extraction And Modification Of Corn Bran Dietary Fiber

The chemical composition of corn bran were determined in this paper,soluble dietary fiber of corn bran and insoluble dietary fiber of corn bran were extracted by the Ultrasonic. Insoluble dietary fiber was treated with chemical treatment and enzyme treatment. The soluble dietary fiber was extracted by the Ultrasonic with water as solvent, and separated and purificated by using DEAE Sepharose Cl-6B ion-exchange column and Sepharose Cl-6B gel column respectively. The raw materials and soluble dietary fiber were prepared for infrared spectrum analysis, scanning electron microscopy analysis, X-diffraction analysis, DSC analysis. The results were as follows:The content of corn bran components was: moisture content 6.87%, starch content 12.50%, protein content 8.65%, fat content 0.43%, insoluble dietary fiber content 32%, soluble dietary fiber content 12%.The best extraction conditions for insoluble dietary fiber and soluble dietary fiber were investigated by orthogonal test as follows: the particle size 20 mesh, time 60min, the ultrasonic power 60% and the ratio of material to liquid 1:15; the particle size 60 mesh, time 30min , the ultrasonic power 70% and the ratio of material to liquid 1:35.The best conditions for chemical treatment and enzyme treatment of insoluble dietary fiber were determinated by orthogonal test as follows: the optimum parameters for Alkaline treatment were pH 10, temperature 90℃, time 2.5h, and the ratio of material to liquid 1:50; The optimum parameters for acid treatment were pH 5, temperature is 100℃, time 1.5h, and the ratio of material to liquid 1:50;the optimum parameters for ZSL-B Cellulase enzyme treatment were pH 3.0, temperature 50℃, the ratio of material to liquid 1:40 and enzyme concentration 2.0mL/g; the optimum parameters for ZSL Cellulase enzyme treatment were pH 4.0, enzyme concentration 1.0mL/g,time of 150min and the ratio of material to liquid 1:40;the optimum parameters for ZSL-1300 Cellulase enzyme treatment were pH 3.0 , enzyme concentration1.0mL/g, time of 120min and the ratio of material to liquid 1:20.The results of the physicochemical properties and the Oxidation Resistance of soluble dietary fiber made from different methods were as follows: the expansion ratio of soluble dietary fiber made from four methods was the same; soluble dietary fiber made from alcohol extract drying showed the highest water holding capacity; soluble dietary fiber made from ZSL Cellulase enzyme treatment showed the highest oil-holding capacity;soluble dietary fiber by using DEAE Sepharose Cl-6B ion-exchange column had the best scavenging effect for DPPH·free radical; soluble dietary fiber made from ZSL Cellulase enzyme treatment had the best Scavenging of·OH and reducing power.SDF made by ultrasonic extraction with water as solvent and freeze-dried was purified by using DEAE Sepharose Cl-6B ion-exchange column and detected a peak at the 495nm which fraction was re-purified by Sepharose Cl-6B and detected three peaks at 495nm.The Analyses of the raw materials and soluble dietary fiber made form different methods showed: the sample made from DEAE Sepharose Cl-6B ion-exchange column particles was more uniform, and the state of the accumulation was better; the sample made from DEAE Sepharose Cl-6B ion-exchange column had good crystallinity, while the raw materials was relatively weaker; the sample made from DEAE Sepharose Cl-6B ion-exchange column had more sensitive thermal characteristics.