Volatilomic Profiling of Early-Stage Biotransformation Enables Identification of Diagnostic Volatiles in Escherichia coli-Contaminated Chicken Meat

E. coli inoculation in food can be accompanied by a series of biochemical changes, during which both microbial activity and food matrix degradation may contribute to the formation of volatile organic compounds (VOCs). The composition and variation in these VOCs depend on the food, the contaminating microorganisms, and storage conditions. This study investigated VOC evolution in E. coli-inoculated chicken meat over 48 h using HS-GC-IMS and HS-SPME-GC-MS, detecting 57 and 50 VOCs, respectively. HS-GC-IMS showed advantages in detecting low-molecular-weight compounds. Through OPLS-DA and KEGG-based pathway analysis, several stage-associated VOCs were identified as candidate VOCs, including benzaldehyde (early stage of the 48 h incubation period), 3-methylbutanol and 3-(methylthio) propanal (middle stage of the 48 h incubation period), and 3-methyl-3-buten-1-ol, phenethyl alcohol, and methyl N-hydroxybenzenecarboximidate (late stage of the 48 h incubation period). Further analysis suggested that the formation of these VOCs may involve lipid oxidation, amino acid degradation, and microbial metabolism, providing a basis for the further validation of VOC-based approaches for monitoring changes in E. coli-inoculated poultry meat.