Studies On Enzymatic Regulatory Mechanism Of Quality From Whole-wheat Dough

The quality of wheat products is closely related to dough characteristics.Whole wheat flour contains all the nutrients in wheat grains such as dietary fiber,long-term intake can improve human health level.Dietary fiber and other components can dilute the wheat endosperm gluten concentration,leading to the deterioration of dough quality.Dough quality deterioration mechanism and the research for improvement can provide help for the nutritional flavor of flour products.In this study,whole wheat flour was prepared by bran-grinding.Farinograph,Extensograph,SEM,FTIR and NMR were used for evaluating the effect of wheat bran particle size,glutamine transferase and glucose oxidase on the quality of whole-wheat dough,and the effects of the main components of wheat bran on the enzymatic regulation of whole wheat dough were studied.The objective was to investigate the Interference mechanism of main components of wheat bran on the enzymatic regulation of whole wheat dough,and laid the theoretical basis for further quality improvement of whole-wheat products.The main research contents and results are as follows:1?Effects of wheat bran grain size on the rheological properties of wheat dough and the structure of gluten protein.The formation of the gluten network structure in the WWD was based on the solvation of gluten and water,the combination of glutenin and gliadin formed a three-dimensional gluten network with certain elasticity and extensibility,thus supported the dough skeleton structure,while starch and wheat bran played a role in filling the network structure.The presence of wheat bran in whole wheat flour diluted the gluten concentration,reduced the stability and extensibility of the dough,made a shearing effect on the gluten protein,inhibited the water absorption of gluten and reduced the stability of secondary structure of the protein and protein aggregation in WWD,resulting in gluten protein network structure of the discontinuity.With the decrease of the grain size of wheat bran,the water absorption,viscosity and recovery of the whole wheat dough gradually increased,and the stability time,elasticity,extensibility and weakening degree of the dough showed increased first and then decreased.Excessive bran particle size of whole-wheat dough(327?m)group had the shear damage to the dough,resulting in gluten protein discontinuity.The too small bran particle size(<144?m)group increased the space barrier of dough formation,interfered the intermolecular crosslinking of proteins and the binding of gluten to starch granules.The suitable bran particle size of whole-wheat dough(209?m)had a higher stability time and a more stable protein secondary structure.The starch and wheat bran were evenly filled in the gluten protein network,which was beneficial to gluten protein absorption,the gluten had a good characteristics.2?Effects of GOX and TG on the regulation of the quality of whole wheat dough.The addition of GOX and TG to whole wheat flour promoted the formation of gluten network structure,enhanced the elasticity and stability of the whole wheat dough,but reduced the extensibility of the gluten protein network.With the increase of GOX and TG addition,the peak area of T₂₂ increased,the peak area of T₂₁ decreased,and some of the bound water became weakly bound water,which promoted the hydration of gluten protein to form gluten network structure.GOX and TG promoted the cross-linking between small molecules of glutenin and lysine,making low molecular weight protein fragments polymerized into high molecular weight protein polymer,and increased the polymer molecular weight and gluten degree of protein cross-linking,thus making gluten protein skeleton gradually thickening,starch and wheat bran filled in the network skeleton,forming a more continuous uniform network structure.3?Effects of wheat bran composition on the characteristics of whole wheat dough and enzyme regulation mechanism.Cellulose has little effect on dough stability time,but the arabinoxylans shortened the dough stability time,FA through the promotion of AX gel formation made water absorption capacity of AX further strengthened,the gluten formation process was blocked and the dough stability time was reduced.AX and FA had coordination effec when they added to dough at the same time,the stability time was further shortened.GOX and TG reduced the content of SH,which could promote the weakening of water bound in the dough,so that part of the water state changed from the deep bound state into weakly bound water,dough stability time extended.TG had a greater effect on albumin and globulin than GOX.