Effect Of Shear Processing On The Quality Of Tartary Buckwheat Dough And Bread

In order to improve the quality of buckwheat bread and improve the ductility of the dough,a shearing technique was used to treat the pre-gelatinized buckwheat dough.The tartary buckwheat wheat mixed dough is a mixture of buckwheat dough and wheat flour.The shear treatment controls three parameters,including the water content of tartary buckwheat dough,the shearing time and the shear strength of the tartary buckwheat dough.Dynamic rheological frequency scans,temperature scans,stress scans and microstructures of tartary buckwheat dough were studied;texture tests,tensile tests,and microstructures of buckwheat-wheat mixed doughs;specific volume,acidity,color,hardness,texture properties and sensory evaluation of tartary buckwheat bread were studied.The results of the study are as follows:After the shearing treatment,the G’ and G’ values of tartary buckwheat dough decreased,indicating that the dough firmness decreased;the loss factor tan σ had no significant change,the value was about 0.1,indicating that the rheological properties of the dough approached the elastic body.In the temperature scanning test,the G’ and G’ values of tartary buckwheat dough were stable in the range of 25-60°C.When the temperature exceeded 60°C,the G’and G’ values began to decrease.And when the shearing time and shear strength became higher,decreases speed of G’ and G’ values became slower.The stress scan showed that after shearing the dough was more fluid and the range of linear viscoelasticity became narrow.The unsheared tartary buckwheat dough has a weak internal binding force,and it is difficult to form a continuous dough,and show as fragments under the e-microscope.With the increase of the shearing time,the internal binding force of the dough is gradually increased,the surface of the dough becomes more continuous,and the gaps are also less.As the water content of tartary buckwheat dough increase,the surface of the dough will become discontinuous and become fine crumbs in the end.The maximum stretching distance of tartary buckwheat-wheat mixed dough is lower than wheat dough,and the addition of extruded buckwheat causes poor ductility of the mixed dough.After the 60 s shear treatment,the maximum stretching distance of the mixed dough significantly increased,and it was no significant difference with the wheat dough.The hardness of the mixed buckwheat mixed dough was significantly higher than that of the wheat dough.After the shear treatment,the hardness and cohesiveness of the mixed dough were significantly decreased,and the elasticity was improved.Pre-gelatinized tartary buckwheat bread had a significant decrease in acidity,but the acidity increased with the shear treatment.The specific volume of wheat bread is the largest.shear treatment for 60 s can significantly increase the specific volume of tartary buckwheat bread.Compared with wheat bread,the hardness of tartary buckwheat bread has a significant increase.The shear treatment can reduce the hardness and hardening rate of tartary buckwheat bread significantly.The shear treatment had no significant effect on the chroma of buckwheat bread.The untreated tartary buckwheat bread has a bitter taste and the lowest overall acceptability.After the squeezing treatment,the bitterness was significantly reduced and the overall acceptable get the highest sensory score the same as wheat bread.