Study On The Eetraction And Application Of Corn Bran Dietary Fiber

In order to give full play to its functions and economic value, promote the value-addedutilization of food processing by-products, the deeped development and utilization of cornbran was studied in this paper. The extraction technology by the Ultrasonic of corn brandietary fiber(CDF), the effect of CDF on the dough rheological properties, and the applicationin the dumpling skins and steamed bread were investigated in this paper. By NuclearMagnetic Resonance(NMR) and Magnetic Resonance Imaging(MRI) to study the effect ofCDF on the existing state, the migration and distribution of the water in the skin of dumplingsand steamed bread.The content of corn bran components was: total dietary fiber content66.21%, solubledietary fiber content2.98%, protein content3.51%, starch content8.16%, fat content4.11%,moisture content7.73%, ash content1.12%.An experiment design with four factors and three levels were utilized based on the singlefactor test according to Central Composite Design using corn peel as raw materials. Responsesurface analysis(RSA) was used with total dietary fiber(TDF) as response. The resultindicated that the optimum condition were: corn peel particle size40mesh size, liquid-solidratio25mL/g, ultrasonic power90%, ultrasonic time80min, content of TDF86.84%.After being squeezed, the main nutrients of CDF changed. The content of TDF remainedroughly the same. The content of soluble dietary fiber increased and that of fat, starch andprotein obviously decreased.With the addition of corn bran dietary fiber extracted by the Ultrasonic(CDF1) andCDF1processed by extrusion (CDF2), moisture content of the flour decreased. CDF1andCDF2had some effects on properties of dough, and can improve the dough farinographcharacteristics. And the effect of CDF2improved dough farinograph characteristics wassuperior to the effect of CDF1. CDF1and CDF2had a dual role on tensile properties of dough,and the difference was obvious. The deterioration of CDF1on dough is obvious, while CDF2is not.Adding CDF1, CDF22%to8%in the dumpling skin, the water absorption wasincreased, cooking loss decreased, and the cooking quality was improved. In the range2%to8%, the textural properties of the dumpling skin were better. Adding CDF1, CDF22%to6%in the steamed bread, height to diameter ratio and hematocrit was increased, whiteness wasdecreased, the textural properties of steamed bread were better. There were different mobility of water in the dumpling skin and steamed bread. Becauseof the addition of dietary fiber in the dumpling skin and steamed bread, the free watermolecules decreased in the number, mobility weakened. when the adding amount was toomuch, the free water molecules increased in the number, mobility enhanced. With the increaseof dietary fiber amount, the MRI signal gradually strengthened in the cut layer of dumplingskin and steamed bread. The distribution of the proton was more even in the cut layer ofdumpling skin and steamed bread added with CDF2.