Portable Near-Infrared Spectroscopy for Non-Destructive Traceability of Storage Temperature in Vacuum- Packed Chorizo Paio dry-cured sausages

Near-infrared spectroscopy (NIRS) represents a promising non-destructive analytical technique for quality control and traceability in meat products. In this study, the feasibility of portable NIRS technology was evaluated to discriminate the storage temperature of sliced and vacuum-packed Chorizo Paio dry-cured sausages stored under conventional refrigeration (4 ± 2°C) or room temperature (20 ± 2°C) for different storage periods (2, 4, and 6 months), without opening the package. Spectral data were acquired directly through the packaging using a MicroNIR™ 1700 portable spectrometer and processed using Partial Least Squares–Discriminant Analysis (PLS-DA). Qualitative classification models were developed for each storage time to identify samples according to storage temperature. The models showed strong discriminative performance regardless of storage duration, with coefficients of determination in cross-validation higher than 0.90. Validation using an independent data set confirmed the robustness and reliability of the models, yielding classification accuracy values above 95% and Matthews correlation coefficients ranging from 0.87 to 1.00. Relevant spectral regions associated with lipid and moisture-related absorptions were identified as key contributors to discrimination. These findings demonstrate the potential of portable NIRS as an effective, rapid, and non-invasive tool for monitoring and tracing storage conditions in dry-cured sausages, supporting its application for on-line quality assurance and authenticity control in the meat processing and distribution sectors.