Acoustic sensor fusion approach for rapid measurement of modulus and hardness of Cheddar cheese

This article describes the acoustic sensor fusion approach for measurement of the Young's modulus and hardness of Cheddar cheese. A new piezoelectric sensor system was developed to investigate the characteristics of the resonance frequency change of a PZT (lead zirconate titanate) probe with the mechanical properties of Cheddar cheese. In addition to the piezoelectric sensor measurement, ultrasound velocity and spectrum analysis were performed using the pulse-echo and through-transmission technique to evaluate the ultrasound propagation velocity through the sample and the corresponding spectrum. The squared correlation (R²) values for the prediction of Young's modulus and hardness were 0.834 and 0.506 using the piezoelectric sensor and 0.827 and 0.850 using the ultrasound velocity. Fusion of the measurements from piezoelectric and ultrasound sensor into a multi-layer neural network model resulted in improved predictions for Young's modulus and hardness of Cheddar cheese with an accuracy of 97.5 and 98.4%, respectively. Results demonstrated that acoustic sensor fusion approach has a potential for rapid determination of Young s modulus and hardness of Cheddar cheese.