Use of the Acoustic Impulse-Response Technique for the Nondestructive Assessment of Manchego Cheese Texture

Manchego cheese pieces were hit with an impact probe and the acoustic response was recorded, analyzed, and used to assess the textural characteristics of the cheese pieces. The textural parameters measured by traditional instrumental methods increased during ripening, although the pattern of the increase was different for different batches. For the 2 acoustic impact probes used in this study, a change in the frequency spectrum took place as cheese matured, increasing higher frequencies and the energy content. Multiple linear regression (MLR) and partial least square regression (PLSR), considering the acoustical variables extracted from the spectrum, allowed for a good estimation of cheese texture. The textural characteristics of the cheese surface and in particular the maximum force in compression experiments (R2 > 0.937 for MLR and R2 > 0.852 for PLSR) were accurately predicted by the acoustic method; however, the texture of the central layers of the cheese are poorly assessed (R2 < 0.720). The results obtained show the feasibility of using acoustic systems to assess Manchego cheese texture, aiding its classification.