Rapid Authentication of Pig Leather and Synthetic AlternRapid Authentication of Pig Leather and Synthetic Alternatives using NIR Spectroscopy and Chemometrics Approachatives using NIR Spectroscopy and Chemometrics Approach

This study investigates the discrimination between pig leather and Polyurethane (PU) leather using Near-Infrared (NIR) spectroscopy combined with chemometric techniques. Genuine leather derived from pig hides presents unique biochemical signatures linked to its collagen structure. In contrast, PU leather is a synthetic polymer engineered to replicate the visual and tactile properties of natural hides. Differentiating between these two materials is particularly crucial in industrial and cultural contexts, such as halal certification, where accurate authentication is crucial. Principal Component Analysis (PCA) was first employed as an unsupervised method to explore natural clustering. The PCA score plot revealed a clear separation between pig leather and PU leather, with the first principal component (PC-1) explaining 96% of the total variance, confirming that the dominant chemical features are sufficient for preliminary discrimination. For supervised classification, Partial Least Squares Discriminant Analysis (PLS-DA) revealed clear separation in the score plot. The model was supported by robust calibration and validation statistics, with high coefficients of determination (R² > 0.99) and low Root Mean Square Error (RMSE). Overall, these findings demonstrate that portable NIR spectroscopy, coupled with chemometrics, provides a rapid, non-destructive, and reliable authentication method with significant potential for industrial quality control, fraud prevention, and regulatory compliance.