Physicochemical characterization, rheological properties, and antimicrobial activity of sodium alginate-pink pepper essential oil nanoemulsions
Pink pepper essential oil, Nanoemulsion, Microfluidization, Antimicrobial activity, Sodium alginate
Essential oils (EO) have antimicrobial properties, but they have low water solubility. Nanoemulsions improve dispersion, protect EOs, improve antimicrobial efficacy offering a solution for food applications. This study assessed the physicochemical, rheological, and antimicrobial properties of sodium alginate-pink pepper essential oil (PPEO) nanoemulsions, produced by microfluidization. Nanoemulsions exhibited droplets sizes < 450 nm with multimodal size distributions. Polydispersity index (PdI) ranged from 0.273 to 0.638 and zeta (ζ) potential from -45.2 mV to -63.3 mV. Encapsulation efficiency (EE) varied between 68.21% to 82.16%. Newtonian behavior was observed for nanoemulsions and non-Newtonian pseudoplastic behavior for coarse emulsion. Antimicrobial testing revealed efficacy against Staphylococcus aureus and Listeria monocytogenes, with minimum inhibitory concentrations (MIC) of 200 µg/mL for both and minimum bactericidal concentration (MBC) of 800 µg/mL and 400 µg/mL, respectively. Therefore, this study highlights the promising benefits of employing nanoemulsions as delivery systems for flavoring and preservative agents in the food industry.