A simple and accurate method for lamb traceability based on gas chromatography-ion mobility spectrometry

For economic gain, lower-grade mutton is sometimes mislabeled and sold as premium lamb. To ensure authenticity, this study employed gas chromatography-ion mobility spectrometry (GC-IMS) combined with chemometrics to trace lamb samples from four regions. While incubation at 60 °C released more volatile organic compounds (VOCs) than at 40 °C (185 vs. 81), the heat-induced compounds masked origin-specific signatures, establishing 40 °C as the optimal temperature for reliable traceability. An OPLS-DA model identified 15 key VOCs with a variable influence on projection (VIP) >1, such as pentanal (D), acetoin (D), and hexanal. Integrated metabolomics revealed that lamb VOCs are co-regulated by branched-chain amino acid (BCAA) degradation, lipid oxidation, and energy metabolism, with BCAA degradation particularly prominent in samples from Ningxia, Gansu, and New Zealand, serving as a key discriminant. Linear discriminant analysis (LDA) achieved 100 % initial classification and 97.4 % cross-validation accuracy, demonstrating a robust method for lamb origin traceability.