Thyme Essential Oil: Inhibition of Foodborne Bacteria and Effects on Microbial and Physicochemical Properties of Refrigerated Pork

Background: Overuse of antibiotics and chemical preservatives accelerates the emergence of drug-resistant bacteria and threatens food safety. Thyme essential oil (TEO) is a promising natural alternative; however, the application of TEO in food systems and the antibacterial mechanism underlying its effects require further elucidation. Objective: Thus, this study aimed to investigate the antibacterial activity and mode of action of TEO against foodborne bacteria and to evaluate its preservative effects on refrigerated pork. Methods: Minimum inhibitory concentrations (MICs) were determined. Membrane integrity was assessed by Propidium iodide (PI) staining under fluorescence microscopy, and DNA binding was analyzed by gel retardation assay. Pork samples were treated with TEO and stored at 4 °C. Microbial growth, bacterial community diversity and structure, pH, drip loss, total volatile basic nitrogen (TVB-N), thiobarbituric acid reactive substances (TBARS), tissue morphology, and sensory quality were monitored during storage. Results: TEO exhibited MICs of 0.5–2.5 mg/mL, disrupted bacterial membranes, and showed potential interaction with DNA. TEO also demonstrated clear antioxidant capacity. In refrigerated pork, TEO moderately inhibited microbial growth, enriched bacterial community diversity, influenced microbial structure, maintained lower pH and drip loss, reduced TVB-N and TBARS values, preserved tissue integrity, and improved sensory scores throughout storage. Conclusions: TEO exerts antibacterial effects and effectively preserves pork quality by modulating the microbial ecosystem and retarding oxidative spoilage. These findings support its application as a natural and effective food preservative.