Effects Of Water-unsoluble Arabinoxylans From Wheat Bran On Quality Of Chinese Mantou

Wheat bran usually refers to the exodermis and the aleurone layer of the kernel. Inconsideration of the process condition, we always call the residues after milling asbran, which account for about22%-25%of the wheat grain. The major componentsof the bran are arabinoxylans which can be divided into water soluble arabinoxylansand water unsoluble arebinoxylans according to the solubility. Water unsolublearebinoxylans is the major part of arabinoxylans which can improve immunity,prevent cancer and tumors, purge and reduce cardiovascular disease risk.First, we study the extraction method of arabinoxylans from wheat bran. Fivedifferent extractions were investigated in attempts to study their effects on the yieldof Water-unextractable arabinoxylans from wheat bran(B-WUAX) and the productcompositions. Using saturated barium hydroxide as the extraction we got the highestyield and purity of B-WUAX. Saturated barium hydroxide is more suitable for theextraction to study B-WUAX in laboratory.Second, an extraction method was investigated in attempts to obtain a highextraction yield of B-WUAX using saturated barium hydroxide. The ration of theweight of wheat bran to the volume of solvent, the alkaline extraction time and theextraction temperature were studied in detail. We got the center as follow: the rationof the weight of wheat bran to the volume of solvent was200:1, the alkalineextraction time was16h and the extraction temperature was70℃.Response surfacemethodology was applied to predict optimum alkaline conditions which were asfollow: The ration of the weight of wheat bran to the volume of solvent was209.69:1,the alkaline extraction time was14.32h and the extraction temperature was73.35℃.Under the optimum alkaline conditions the yield of water-unextractabkearabinoxylan reaches15.02%.Third, using ethanol to precipitate B-WUAX and dividing them into seven groups.We added them to flour respectively and researched their effect on the rheologicalcharacteristics of wheat flour dough. We found that all of them can increase pastestrength and flexibility and improve flour quality. The B-WUAX.30group has thebest effect and the B-WUAX.10, B-WUAX.20, B-WUAX.80have the worst effect.Fourth, we extracted B-WUAX from three different wheat varieties and added themto the wheat flour respectively. We use the texture analyzer and sensory evaluation to study their effect on the Chinese Mantou qualities and staling. We found thatB-WUAX can increase the volume and the sensory score of Chinese Mantou andmake them more elastic. While B-WUAX leads to gas cell perforation and decreasecrumb homogeneity.