Study On The Extraction Process And Application Of Different Wheat Dietary Fiber

The issue was derived from the subitem of the major projects in Hubei Province—Key Technical Study of Using Wheat Bran to Product Functional Foods Efficiently.In this article,the optimal parameters of extracting wheat dietary fiber from decorticated wheat bran and high-quality wheat bran flake were mainly studied.And the effects on the doughy rheological properties and the quality of steamed bread of the wheat dietary fiber extracted from the high-quality wheat bran flake were emphaticly studied.In addition,the extrusion modification of the wheat bran was preliminarily studied in this article.The results were as below:The decorticated wheat bran between 40 mesh and 100 mesh was handled byα-amylase and neutral protease. The optimal conditions were:α-amylase dosage 25U/g,temperature 60℃,time 45min; neutral protease concentration 1200U/g, temperature 50℃,time 45min.Under these conditions,the content of the insoluble dietary fiber was 80.28%.The content of the insoluble dietary fiber in the high-quality wheat bran flake was as much as 40.3%.And the starch adhering to the wheat bran flake could be effectively removed by washing.The phytic acid in the wheat bran flake was degradated by phytase,and the optimal conditions were:phytase dosage 10U/g,pH 4,temperature 60℃,time 75min.The wheat bran flake hydrolyzed by phytase was handled by cellulase.When the cellulase dosage was 800U/g and the time was 0.5h,the network structure of the dietary fiber was relaxed to some extent,but not damaged.And the mouthfeel of the dietary fiber was improved.The wheat dietary fiber flour was extruded by twin-screw extruder.And the optimal proposal was: water content of the material 20%,extrusion temperature 140℃,screw rotation speed 100r/min.Under these conditions,the water holding capacity of the wheat diatery fiber flour was 4.18g/g,the swelling capacity was 3.45mL/g,compare to the wheat diatery fiber before extrusion, 0.7g/g and 1.25mL/g increased separately. The wheat bran flake hydrolyzed by phytase(WDF₂) and the wheat bran handled by cellulase(WDF3)were added to wheat dough prorata.The floured properties were improved by the two diatery fiber.But the improved effect of WDF3 to fioured properties was better than that of WDF₂. The tensile properties were worsened by the the two diatery fiber.The deteriorative effect of WDF₂ to tensile properties was obvious,and the addition of WDF₂ in the wheat dough was not more than 5% appropriately. The deteriorative effect of WDF3 to tensile properties was not obvious,and the addition of WDF3 in the wheat dough was as much as 7% .When the addition of WDF₂ was 1%,and the addition of WDF3 was 3%,the organoleptic evaluation of the steamed bread and the texture of the steamed bread were were the best.when the addition of WDF₂ was more than 3%,and the addition of WDF3 was more than 5%,the steamed bread couldn't be accepted.In summary, the addition of WDF₂ was1%～3%,and the addition of WDF₂ was3%～5% .