Quantitative comparison of the eye formation in cheese using radiography and computed tomography data

Eye formation is an important quality parameter in the dairy industry for (semi-)hard cheeses in Switzerland. To monitor the formation of eyes in cheese, radiography and, more recently, computed tomography (CT) technology, are employed. In the present study, two quality indicators (eye number and total eye volume) are calculated from radiographs by two recent procedures and compared with the results from CT data. The radiograph analysis procedures underestimate both quantifiers systematically and the deviation increases with the number of eyes. In contrast to radiographic data, the distribution of the eye volumes and positions as well as their geometric shape can be calculated from the CT data. These data allowed the observation that the eyes in the considered cheeses accumulate in the centre of the cheese, are predominately of spherical shape and non-spherical eyes can be extracted by a simple geometrical criterion. These findings illustrate the advantages of the CT technology.