Volatile compounds for discrimination between beef, pork, and their admixture using SPME-GC-MS and chemometrics analysis

27 This study addresses the prevalent issue of meat species authentication and adulteration 28 through a chemometrics-based approach, crucial for upholding public health and ensuring a 29 fair marketplace. Volatile compounds were extracted and analyzed using headspace-solid-30 phase-microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). 31 Adulterated meat samples were effectively identified through principal component analysis 32 (PCA) and partial least square-discriminant analysis (PLS-DA). Through variable importance 33 in projection (VIP) scores and a Random Forest test, 11 key compounds, including nonanal, 34 octanal, hexadecanal, benzaldehyde, 1-octanol, hexanoic acid, heptanoic acid, octanoic acid, 35 and 2-acetylpyrrole for beef, and hexanal and 1-octen-3-ol for pork, were robustly identified 36 as biomarkers. These compounds exhibited a discernible trend in adulterated samples based on 37 adulteration ratios, evident in a heatmap. Notably, lipid degradation compounds strongly 38 influenced meat discrimination. PCA and PLS-DA yielded significant sample separation, with 39 the first two components capturing 80% and 72.1% of total variance, respectively. This 40 technique could be a reliable method for detecting meat adulteration in cooked meat. 41