Application of Powder X-Ray Diffraction (p-XRD) and Chemometrics for the Classification of Cheese Varieties.

This study explores the application of powder X-ray diffraction (p-XRD) combined with chemometric analysis as an innovative approach for the quality assessment and classification of cheese varieties. A total of 64 cheese samples, including Cheddar, Kefalotyri, and Halloumi, were analyzed to investigate differences in their crystalline structures. p-XRD, a non-destructive analytical technique traditionally used in material science, was employed to obtain detailed information on the texture, composition, and internal structure of the samples. Chemometric modeling was then applied to the spectral data to classify the cheeses according to type, highlighting distinct patterns in their crystalline fingerprints. The crystalline fingerprint of each cheese type was investigated, revealing that Cheddar exhibited a low degree of crystallinity, Kefalotyri a medium level, and Halloumi a high degree of crystallinity. These differences were associated with variations in casein structure, calcium salt content, residual lactose, and other inorganic salts present in the cheeses.

The study is particularly novel in its focus on Halloumi, a traditional Cypriot cheese with Protected Designation of Origin (PDO) status. The use of p-XRD in dairy research is limited, and its application to Halloumi is unexplored. The results demonstrate that this technique, when combined with multivariate data analysis, can effectively differentiate cheese types based on subtle structural variations, thereby offering potential for quality control, authenticity verification, and process optimization.

This research paves the way for future studies into the structural characterization of dairy products, especially those produced with emerging ingredients such as milk powder. Although cheese ripening (aging) was not studied in the present work, future research may explore how maturation affects crystalline patterns, further expanding the application of this technique. The methodology developed could serve as foundation for the design of new analytical workflows in food science, and contribute to innovation in the dairy industry through enhanced quality assurance and product traceability.