USE OF AN ULTRASONIC TECHNIQUE TO EVALUATE THE RHEOLOGICAL PROPERTIES OF CHEESE AND DOUGH

The utility of an ultrasonic technique to evaluate the rheological properties of viscoelastic food samples has been demonstrated. Rheology can be described by the rates of mechanical energy dissipation and storage during the wave propagation. As ultrasonic wave propagates through a material, it creates mechanical vibration of material particles. Detailed development of the experimental technique, analysis of data, and results are described and illustrated in this paper. Some key experiments were carried out using a transmission method to obtain time-domain spectra. The time-domain responses were digitized; frequency spectra were obtained by Fourier transformation. Food materials studied included cheese and dough of various moisture contents. Good qualitative agreement was found between the ultrasonic technique and traditional rheometry. Thus, there is potential of developing an on-line ultrasonic rheological sensor for non-invasive and non-destructive evaluation of foods.