Use of NDSS to discriminate between Parmigiano Reggiano and Grana Padano PDO and their ripening times from grated cheese spectra.

This study focuses on using spectral data recorded with two different Near-Infrared (NIR) instruments (a benchtop and a portable device) to differentiate between Parmigiano Reggiano (PR) and Grana Padano (GP) Protected Designation of Origin (PDO) cheeses and their ripening times. Key findings showed that NIR spectroscopy effectively discriminated between PR and GP, with spectral range differences linked to their chemical composition, including fat, protein, and carbohydrate content. Specifically, certain wavelength ranges (1375-1400 nm, 1205-1250 nm, and 1410-1440 nm) were identified as significant in distinguishing PDO labels, highlighting the roles of fat and protein content in the cheese classification. Spectral features are also distinguished between ripening times, with specific wavelength bands tied to biochemical modifications during maturation, such as changes in moisture, protein, and fat content. In terms of instrument performance, the benchtop device achieved high accuracy in PDO classification (up to 0.97 F1 score), particularly when using a first derivative pre-treatment. The portable device performances showed higher variability but performed flawlessly for PDO classification. While both instruments effectively classified cheeses of distinct ripening ages, they were less successful at detecting samples containing mixtures of different aged cheeses. The portable instrument showed better results when combining the visible spectrum (350-950 nm) with the NIR spectrum (950-1650 nm), capturing surface color changes alongside internal structural transformations related to aging. Overall, the study validates the potential of NIR spectroscopy, especially when combined with established preprocessing techniques, as a powerful non-destructive tool to authenticate specific cheese PDO and assess ripening stages.