Study On Arabinoxylan Characteristics In Different Varieties Of Wheat

In this experiment six varieties of high-quality wheat, medium gluten in HenanProvince，was used as whearaw materials, and they are grinded into flour and wheat bran withBrabender mill. Water-soluble arabinoxylan (WEAX) and water insoluble arabinoxylan(WUAX) was obtained from bran and flour respectively, and their physical and chemicalproperties were further studied. Then the extracted arabinoxylan (AX) was added to flour,exploring the influence on farinograph properties and Chinese steamed bread quality. And themain contents and conclusions are as follows:Firstly, six batches of samples were gotted from wheat grain with white processingmachine, and then AX content, ash content and whiteness of these samples were determined.It was proofed that in wheat grain AX content decreased from the outside to the inside.Furthermore, the AX content and ash content was a significant linear positive correlation, andAX content and whiteness was a significant linear negative correlation.Secondly, because of large particle size of wheat bran, the prior processing for bran wasnecessary. In order to get more arabinoxylan，three pretreatment methods were used,including grinding, super micro grinding and fermenting. The results showed that the WEAXyield among control samples, grinding samples, super micro grinding samples andfermentation samples was significant different, but the WUAX yield between grindingsamples and fermentation samples was not significant different. In the experiment, WEAXwere extracted with water, and WUAX in wheat bran was obtainded with alkaline solution,however, in the flour, WUAX was gotted by centrifugation method.Thirdly, the experiment approved that, AX also had very good foam stability capacity,particularly alkali-soluble AX, which was excellent at1.2%(w/v) concentration. Morever AXhad a strong capacity of water absorption, tested by farinograph, wheat bran WEAX couldabsorb6.1times its own weight of water, whereas wheat bran WUAX8.3times, flourWUAX9.7times, flour WEAX7.7times. AX also had a high viscosity, measured by theviscometer, the result showed that wheat flour WEAX was2.57dl/g, wheat bran WEAX3.79dl/g, wheat bran WUAX6.18dl/g. Dissolving in the solution of ammonium persulfate,AX appeared oxidative cross-linking, the viscosity increased significantly.Finally, AX which had been extracted from bran and wheat flour, was added to flourwith the proportion of0.25%,0.50%,0.75%,1.00%, and the properties of wheat flour and Chinense steamed bread quality was studied. The result showed that flour water absorption,dough development times, stability times had been significantly impacted. Besides, WEAXcould improvet Chinese steamed bread quality, and0.50%was the best, while the WUAXmade Chinese steamed bread quality deteriorate.