Characterization of wheat-flour-water doughs: a new method using ultrasound

In this paper, an original method of evaluating the physical properties of wheat-flour-water systems using high-frequency low-power ultrasound is pres ented. Most of the experiments were performed with a reflectance technique measuring the acoustic impedance of doughs. The velocity of propagation, at tenuation and viscoelastic moduli have been evaluated for both compressiona l and shear ultrasonic waves in the interval 2-10 MHz for doughs of differe nt hydrations. The 53% water content was found to be critical with respect to the presence of free water. The influence of the mixing and rest times o n the longitudinal ultrasonic parameters is also studied. (C) 2001 Elsevier Science B.V. All rights reserved.