Quality Analysis And Application Of Germinated Wheat Flour Classified By Air Classification

After wheat germination,the part of wheat internal quality deteriorated,and the edible value decreased which could not used normally.This paper aimed on quality analysis and application of germinated wheat flour(GWF)classified by air classification,the changes of starch,protein,dough properties and flour products of flour(F1 > 45 ?m,F2,20-45 ?m,F3 < 20 ?m)after air classification were investigated.The differences in quality of GWF after air classification were systematically analyzed.The results were as follows:Through the analysis of starch properties of GWF after air classification,it could be concluded that compared with GWF,the activity of ?-amylase of F1 and F2 decreased,while F3 increased.The falling number decreased significantly with the decrease of particle size.The content of damaged starch and reducing sugar in F1 decreased,while F2 and F3 increased.The content of A,B starch and the ratio of amylose/ amylopec of F1 were similar to GWF,the content of A starch and amylopectin of F2 were the most,the content of B starch of F3 were the most.From the gelatinization properties analysed of starch,the viscosity and recovery value of F1 starch were significantly higher than those of germinated flour starch,while F3 decreased significantly.According to the analyses gelatinization temperature and DSC characteristics of starch,the gelatinization temperature was F3 > F2 > F1 > GWF > normal wheat flour(NWF).Through the analysis of protein properties of GWF after air classification,it could be concluded that compared with GWF,the activity of protease of F1 and F2 decreased,while F3 increased.Total protein content of F1 and F3 increased,but F2 decreased.Albumin and globulin content of F1 and F2 decreased,F3 increased,and gliadin content of F1 increased,but F2 and F3 had no significant difference.For disulfide bond content,F1 and F2 increased,F3 decreased.For sedimentation value and gluten quality,F1 was medium gluten flour,F2 was low gluten flour,and F3 had high protein content,but poor gluten quality.For GMP particle size and viscoelasticity,with the decrease of particle size,the overall particle size of GMP and viscoelasticity decreased.For flour SDS-PAGE electrophoresis,with the decrease of particle size,some subunit bands became lighter,and no new bands were produced.For the functional properties of gluten protein,the water holding capacity,oil holding capacity and foaming capacity of F1 and F2 were lower than those of germinated flour,while F3 was the opposite.the emulsifying capacity of F1 was higher than that of germinated flour,and F2 and F3 were lower than that of germinated flour.Through the analysis of dough properties of GWF after air classification,the results of confocal laser microscopy showed that the structure of the dough network of F1 was better than that of the GWF,F2 had the largest of holes,and F3 had the most number of holes,but the structure of the dough network was fine.According to the flour farinogram,compared with the developing time,stability time and farinogram index of GWF,F1 increased,F2 and F3 decreased.According to the tensile properties,the tensile area,resistance and ratio of F1 and F2 were higher than those of GWF,but F3 was opposite,except for elongation.According to the fermentation characteristics,the maximum height,final height and total gas production of dough decreased with the decrease of particle size,and the time of pore formation delayed.According to water distribution,after classification,with the decrease of flour size,the bound water content of dough decreased and the semi-bound water content increased.Through the analysis of product properties of GWF after air classification,the results revealed that although the color of F1 steamed bread was darker,there is no significant difference in internal quality between F1 and NWF steamed bread that was,F1 can be used as steamed bread flour.The sensory evaluation and texture evaluation of sale cake flour and F2 cake embryo,as well as sale oiled bar flour and F3 oiled barshowed that F2 and F3 was no significant difference in appearance and internal quality withat least one of sale flour,therefore,F2 and F3 could be used as cake flour and oiled bar flour respectively.In conclusion,airflow classification was an effective physical measure to improve the utilization rate of GWF,which could provide technical support for the application of ger minated wheat flour.