The use of ultrasound and shear oscillatory tests to characterize the effect of mixing time on the rheological properties of dough

This work examined the effect of mixing time on three different flour dough systems: bread-flour wheat dough, all-purpose flour wheat dough, and cake flour wheat dough. Both ultrasound and conventional rheology techniques were used to examine the effect of mixing on these dough systems. Fundamental ultrasound results were obtained at 3.5 MHz; velocity and attenuation showed peak values at the optimum mixing time. Similar results were observed by using conventional rheology, which showed peaks in both storage and loss shear moduli at the optimum mixing time. Thus, there was an agreement between the results obtained by conventional rheology and ultrasound measurements, which shows the potential of ultrasound as an on-line quality control technique for dough-based products. The results of this work were explained with respect to molecular changes in the dough system as the mixing process proceeded; particular emphasis was placed on the presence of free water and bound water. (C) 2004 Elsevier Ltd. All rights reserved.