Spettroscopia nel vicino infrarosso e metodi di dterminazione analitici innovativi per la valorizzazione delle produzioni casearie del Ragusano DOP

Near Infrared Spectroscopy and innovative analytical methods for the valorization of Ragusano DOP cheese - The aim of this study was to apply and evaluate different innovative techniques for chemical composition and sensorial profile evaluation of PDO Ragusano cheese, at different stages of ripening. Approximately, 250 cheese samples were analyzed using Foss XDS Rapid ContenetTM spectrophotometer 400-2500 nm in spectral range, in the reflectance mode. In detail, Soxhlet e Dumas methods, in alternative to Van Gulik and Kjeldahl traditional methods, were evaluated to calibrate fat and protein parameters. Besides chemical analyses, sensory profiles were determined as a further characterization of this PDO cheese. The results from sensory analyses have allowed to quantify, one by one and increasingly with perception, each sensory parameter, and finally to classify cheeses as A class (rank netween 91 and 100) and B class (rank between 80 and 90). The results of NIRS prediction showed the RSQc values close to unit for both fat (0.93) and protein (0.95). SEC and 1-VR values were good for protein and fat, and prediction in cross validation errors (SECV) were 0.51 and 0.89 for protein and fat, respectively. The ratio performance deviation between DS and SECV resulted higher for protein (4) than for fat (2.8). This ratio is considered a robust indicator if its value is more than 2, so it is valuable for accurate quantitative determinations. The spectral information to distinguish the sensory classes A and B was similar, so it was enable to classify this information. This experimental work showed that these innovative methods might be used to check quality of the product, allowing to increase the number of determinations and to reduce the analyses costs. Keywords: Ragusano DOP cheese, NIRS