Evaluation of the Antibacterial Effect of Polylactic Acid Films Containing Oak Ethanolic Extract and Cinnamon Essential Oil against Foodborne Pathogens

Background: Today, the prevalence of foodborne illnesses has led to the widespread use of medicinal plants. This study aims to investigate the antibacterial effect of polylactic acid (PLA) films containing oak ethanolic extracts incorporated with cinnamon essential oil against a range of foodborne pathogens. Methods: The oak extract was obtained by soaking method and the cinnamon essential oil was extracted using a Clevenger apparatus. PLA films containing 2% concentration of oak extract and cinnamon essential oil were prepared, homogenized, cast, and stored at 4°C. Subsequently, the antimicrobial efficacy of various concentrations of the extract against pathogenic bacteria was examined using the disk diffusion method. Results: The film containing 400 mg/mL of ethanolic extract along with 3% cinnamon, showed the largest non-growth zone (with a diameter of 31.5 mm against Staphylococcus aureus). Furthermore, the film with a concentration of 100 mg/mL of extract displayed the smallest non-growth zone against Salmonella typhimurium, measuring 13.54 mm in diameter. Conclusion: Based on the obtained results, the combination of oak extract and cinnamon essential oil has a strong inhibitory effect against common foodborne pathogens. Consequently, these substances may be useful for enhancing the safety and extending the shelf life of various food products.