Effect of Amylase,Glutamine Aminotransferase and Xanthan Gum on Rheological Properties of Qat-Wheat Mixed Flour Dough

The color,texture and rheological properties of 20% oat-wheat mixed flour dough were determined and compared with pure wheat dough. Amylase,glutamine aminotransferase,amylase(1.5 U/g)and glutamine aminotransferase(1.5 U/g),two enzymes(1.5 U/g each)and xanthan gum(0.3 g/100 g)were added to improve the properties of oat-wheat mixed flour dough. As a result,glutamine aminotransferase prolonged the stable time of mixed dough to(6.95±0.07) min and increased the hardness. The combination of amylase and glutamine aminotransferase min,reduced the weakening degree of oat wheat flour and improved the gluten quality of the dough. And the ΔE value of the dough added amylase and glutamine aminotransferase was the largest,the closest to the wheat dough and the best for the improvement of the dough color. The combination of amylase and glutamine aminotransferase as well as the combination of amylase,glutamine aminotransferase and xanthan gum improved the elasticity of 20% oat wheat mixed dough,and there was no significant difference with wheat flour dough. The results showed that the elastic modulus(G'),viscous modulus(G″)and loss angle tangent value(tanδ)curves of the two schemes were the best in improving the rheological properties of 20% oat wheat mixed dough. In conclusion,the combination of amylase and glutamine aminotransferase as well as the combination of amylase,glutamine aminotransferase and xanthan gum can effectively improve the quality of 20% oat wheat mixed dough.