Studies on Effects of Microbial Transglutaminase on Gluten Proteins of Wheat. II. Rheological Properties.

The effects of microbial transglutaminase (TG) on the dough properties and the baking performance of wheat flour with strong gluten and high baking quality were studied by farinograph measurements, creep-recovery tests with dough, extension tests with gluten, and baking tests. A very low concentration of TG caused a significant decrease in the maximum strain of the dough. This decrease was closely related to the TG concentration. Extension tests with gluten showed that increasing concentrations of TG led to a drastic decrease of the extensibility and an increase of the resistance to extension. When concentrations of TG were too high, a complete loss of dough and gluten structure was obtained. On the other hand, with low concentrations of TG, no difference could be detected between the control bread and the bread containing TG in the baking test. With higher concentrations of TG, dough handling became extremely difficult, and the loaf volume decreased substantially due to a loss of structure in the dough. Therefore, the use of TG to improve the dough properties and the baking performance is recommended for flours with weak gluten and poor baking performance.