Search

This work presents a new ultrasonic system with a transmission mode in the 100-200 kHz frequency range. The system, composed of ultrasonic point sources, is used to monitor the mechanical properties of cheese during the early phases of production. First, our specialized sensor system is presented, and then the results obtained with the system model are compared to the results of actual experiments using the system to monitor the evolution of the medium during draining. The results of a rheological compliance test and shock pulse ultrasonic amplitude measurements agree and correspond quite accurately to the mechanical properties of the evolving physical state of the medium. This method could be used in the future to study the effect on the final cheese quality of the process parameters that interfere with cheese grain consolidation during the draining process.

Abstract: In this paper, a low frequency, dry contact, ultrasonic technique devoted to the study and characterization of cheeses at the beginning and the end of ripening period is investigated. For compact or weakly opened matrix found in the early step of cheese making, ultrasonic velocity is indicated to represent the viscoelastic properties of the matrix. But, limitations occur in the use of ultrasound especially for mature cheeses which present very high degrees of opening. As ultrasound becomes no longer usable, a tap-test acoustic technique has been developed and employed for cheese classification. A good correlation between ultrasonic data and tap-test data is shown. [Copyright &y& Elsevier]