In-Line Dynamic Acoustic Behavior of a Viscoelastic Complex Media: Dough Application

The main objective of this study was to understand the physical law characterizing dough during kneading. Throughout the process, dough is subjected to extensional deformation resulting from the mechanical component and the development of holes in the matrix. For that, we developed a very low frequency acoustic device (< 100 Hz) to follow the mechanical evolution of the dough through an in-line acoustic sensor with part of the mixer playing the role of an acoustic receiver (ear-phone), which exploits the background noise of the process. Depending on the physical state of the product, acoustic amplitude of sound was chosen to represent the evolution of the matter. Via a signal processing modulus this sensor shows the mechanical progress of the dough by means of a curve with critical points. The results show that the acoustic component is able to follow the evolution of the physical properties of the matter in situ. The results using various technological parameters indicate that a high degree of sensitivity can be reached with non-destructive acoustic techniques in highly absorbing media.