The Research On The Short Milling Production Technology Of Whole Wheat Flour

The nutritional function of the Whole Wheat Flour(WWF)is gradually being recognized by consumer,however,the existence of bran and wheat germ can affect the qualities of whole wheat flour,and its products.In order to improve the edible quality of WWF,and realize the scale up development and industrialization,strong gluten,middle-strong gluten and middle gluten wheat are used as the raw materials to discuss the effects of different light de-branning degrees and particle sizes on the qualities of wheat kernel,WWF and its steamed bread respectively by direct grinding method.The parameters of the bran roller are optimized by orthogonal method.The effects of the water content on tempering,as well as adding stone mill on the qualities of WWF and its steamed bread are studied.Studies are conducted on the effect of different de-branning degrees(dry method)on the qualities of wheat kernel,WWF and its steamed bread by direct grinding method.The results show that the yield of WWF is decreased and the unit power consumption is increased.Ash content,hardness index and Thousand Kernel Weight(TKW)of the wheat kernel are decreased by 0.08% ~ 0.17%,0.89 ~ 2.42,1.25% ~ 3.79%,respectively,with increased de-branning degrees.However,the volume-test weight is increased by 9.6 g/L ~ 23.4 g/L.The ash content and damaged starch value(UCD)of the WWF are decreased by 0.06% ~ 0.14% and 0.5 ~ 2.1,respectively,The Insoluble Dietary Fiber(IDF)and Total Dietary Fiber(TDF)of the WWF are reduced by 0.16% ~ 0.49% and 0.05% ~ 0.17%,respectively.The soluble dietary fiber is raised by 0.09% ~ 0.33%.Farinograph stability time of the WWF is increased by 0.1 min ~ 0.7 min,whereas the softening degree is decreased by 4 FU ~ 18 FU.Hardness,gumminess,and chewiness are decreased by 348 g ~ 1114 g,259 ~ 549,and 73 ~ 346,respectively.The springiness and resilience are increased by 0.012 ~ 0.031 and 0.022 ~ 0.066,respectively.The total sensory score and L value of steamed bread are increased significantly,indicating that the light de-branning treatment can significantly improve the rheological properties of the WWF and the qualities of steamed bread.Researches are carried out to study the effect of different particles sizes on the qualities of WWF and its steamed bread by direct grinding method.The results show that the moisture content of the WWF is decreased by 0.07% ~ 0.26% with the decreased particles sizes,comparing with the 60 meshes particle size WWF,however,the value of the whiteness and damaged starch(UCD)are increased by 1.6 ~ 2.6 and 0.7 ~ 1.9,respectively,whereas IDF and TDF of the WWF are decreased by 0.14% ~ 0.34% and 0.06% ~ 0.18%,respectively.SDF is increased by 0.07% ~ 0.19%.Besides,with the 80 meshes particle size,the index of the peak viscosity,final viscosity and stability time of the WWF are the highest.Nevertheless,water absorption is increased by 0.3% ~ 0.9%.Specific volume and the index of elasticity of WWF steamed bread are optimal when the particle size is 80 meshes.The steamed bread made of middle-strong gluten wheat with 80 meshes particle size enjoys the highest total sensory score.The parameters of the bran roller are optimized by orthogonal method.The results show that the teeth number of 1B is 3.2 per centimeter,the rolling clearance is 0.30 mm,the teeth number of 2B is 6.3 per centimeter,the rolling clearance is 0.08 mm,the teeth number of 3B is 9.4 per centimeter,and the rolling clearance is 0.03 mm.The effect of different tempering degrees on the qualities of WWF and its steamed bread by bran recombining process are studied.The results show that the whiteness of WWF is increased by 0.4 ~ 1.0,and the falling number of three kinds of WWF are increased by 16.7 s ~ 42.5 s,17.2 s ~ 38.9 s,and 13.8 s ~ 28.9 s,respectively,and the value of damaged starch(UCD)is decreased by 0.4 ~ 1.1.The peak viscosity,bottom viscosity,final viscosity,peak time and gelatinization temperature are increased by 20 cP ~ 76 cP,18 cP ~ 48 cP,28 cP ~ 84 cP,0.02 min ~ 0.14 min,and 0.31℃ ~ 1.48℃,respectively.The water absorption of WWF is reduced by 0.7% ~ 2.8%.The development time and stability time of dough is lenghtened by 0.1 min ~ 0.4 min.The specific volume of its steamed bread is increased by 0.1 mL/g ~ 0.3 mL/g.The L value of both surface and interior are increased,and the hardness decreased by 175 g ~ 362 g.The sensory score of the specific volume,color and internal structure of steamed bread are improved.Studies are made on the effect of adding stone mill on the qualities of WWF and its steamed bread by bran recombining process.The results show that the moisture content and falling number of the WWF are decreased by 0.15% ~ 0.45%,18.2 s ~ 34.7 s,respectively.After adding the stone mill,the value of whiteness,sand content and the value of damaged starch(UCD)are increased by 0.5 ~ 0.6,0.002% ~ 0.006%,and 0.6 ~ 1.2,respectively.The peak viscosity,breakdown and setback value of WWF are decreased by 42 cP ~ 79 cP,6 cP ~ 20 cP,and 13 cP ~ 47 cP,respectively,while the water absorption is increased by 1.2% ~ 2.3%.The L value of the surface and internal are increased,the hardness is decreased by 358 g ~ 624 g.The sensory score including color,internal structure,elasticity and odor of steamed bread are increased significantly,and its flavor is stronger after adding the stone mill,among which,steamed bread made of middle-strong gluten wheat with tempering of 15% enjoys the highest total sensory score.