Optimization of essential oil combinations for enhanced antibacterial properties using mixture design methodology

This study investigated the synergistic antibacterial potential of combining essential oils (EOs) from origanum, rosemary, and pepper using mixture design methodology. The EOs were extracted and analyzed by GC/MS, and their major compounds were identified as carvacrol, 1,8-cineole, and β-caryophyllene, respectively. A simplex-centroid mixture design was employed to optimize the EO combinations for enhanced antibacterial activity against pathogenic bacteria. The data were fitted to second-order polynomial equations, and the models were validated using Fisher tests and lack-of-fit assessments. High coefficients of determination (R² values near 1) indicated strong correlations between the models and experimental data. Residual analysis showed random distribution, confirming the validity of the fitted models. Desirability analysis suggested an optimal EO combination, which was experimentally validated, achieving 47.38% inhibition of <i>Listeria</i> and 50% inhibition of <i>Salmonella</i>. These findings highlight the potential of combining EOs through mathematical modeling to enhance their preservative effects. This study underscores the promise of natural EO mixtures as effective alternatives to synthetic preservatives for ensuring food safety and quality.