Antimicrobial effect of nanoemulsions prepared using juniper essential oil in different ratios on fish spoilage and foodborne pathogenic bacteria

In this study, the antimicrobial effect of juniper essential oil at different concentrations (2%, 4%, and 6%) on foodborne pathogens and spoilage bacteria was evaluated. The bacterial species tested included Staphylococcus aureus, Salmonella Paratyphi A, Vibrio vulnificus, Photobacterium damselae, and Proteus mirabilis. In addition, GC-MS analysis of juniper essential oil was performed and a total of 30 compounds were detected as a result. According to GC-MS results, the most dominant component of juniper essential oil was α-Pinene with 90.05%. Antimicrobial activity was analyzed using the agar disk diffusion method, where inhibition zone diameters were measured, and the Minimum Inhibitory Concentration and Minimum Bactericidal Concentration values were determined. The results of the study showed that the antimicrobial activity of juniper essential oil increased significantly with increasing concentration. The Gram-positive bacterium Staphylococcus aureus was inhibited even at the lowest concentrations, with the maximum inhibition zone observed at 6 µL/mL. On the other hand, among Gram-negative bacteria, Vibrio vulnificus was determined as the most sensitive species against juniper essential oil and the highest inhibition zone diameter was 64.00±3.46. In addition, the lowest MIC-MBK (12.5-50) values were recorded in this species. Photobacterium damselae and Salmonella Paratyphi A demonstrated moderate inhibition, whereas Proteus mirabilis was determined to be the most resistant species, showing limited inhibition even at higher concentrations. In conclusion, juniper essential oil exhibits a dose-response relationship and has been shown to be a potential antimicrobial agent, particularly against foodborne pathogenic bacteria. These findings suggest that juniper essential oil can serve as a natural alternative to ensure food safety and prevent spoilage. Future studies are recommended to focus on different application methods and formulations of juniper essential oil to further explore its efficacy. Keywords: Juniper Essential Oil, Foodborne Pathogens, Fish Spoilage Bacteria, Nanoemulsion