The properties of wheat flour dough during manufacturing of baked products were studied using a combination of rheological and microstractural techniques. Interactions between the dough and processing equipment are dependent on the rheological properties of the dough. When wheat flour dough is manufactured into various products, the dough is subjected to large deformations in operations such as mixing, moulding, sheeting or proving. Since dough is visco-elastic, not only the magnitude of the deformation, but also the deformation rate is important in these interactions. Experiments with dough sheeted between two rollers were carried out to determine the interactions between dough relaxation, equipment settings and final product quality. Complex interrelationships, that affected the results of bread making and pastry sheeting processes, were observed. These inter-relationships involve factors such as relaxation time, dough density, and roller speed and diameter, and influence the way product qualityis optimized in an automated production setting. Dough rheological properties are determined by dough components with length scales ranging from the nano scale of chemical constituents through to the micro-structure of separate dough phases or structures. During mixing and sheeting, microstructural components, such as the protein network and gas bubbles, undergo significant changes that have a large impact on dough rheological properties. We used visualization experiments to reveal the mechanisms by which the dough protein network develops during high speed mixing and dough sheeting processes.
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