Acoustic techniques to detect eye formation during ripening of Emmental type cheese

For eye forming cheeses such as Emmental, Gouda, Maasdam and others, ripening is the critical stage in which eyes and other sensory properties develop. For this type of cheeses, it is relevant to detect when eyes appear and when they have reached their optimum size and number. This article presents an interdisciplinary approach to detect and monitor eye formation in Emmental type cheese by using an acoustic technique. Two digital signal processing methodologies were studied: first order momentum of the spectrum and signal cross-correlation. Acoustic results were compared with two destructive standard methods (texture analysis and humidity determination) and evaluation of photographs of cheese wheels cut in half. Results show that acoustic parameters allow to detect different stages of eye formation and their results are consistent with information obtained from cheese images. Acoustic evaluation proves to be a non-destructive method to monitor eye formation in Emmental type cheese ripening.