Nanoemulsion containing Lippia origanoides essential oil: characterization, chemical composition, antibacterial activities

Essential oils are vital for controlling microbial growth due to their antimicrobial properties, which disrupt bacterial cell membranes and inhibit metabolic processes, thereby preventing biofilm formation. This study assessed the antimicrobial efficacy of Lippia origanoides essential oil and its chemical composition in the development of a nanoemulsion. The essential oil predominantly comprises carvacrol (41.56%), thymol (12.56%), and p-cymene (12.49%), yielding a total of 2.13%. The nanoemulsion was characterized by a droplet size of 30.00 ± 1.70 nm, a polydispersity index of 0.25 ± 0.03%, Zeta potential -23,96 ± 3,61 mV, Whiteness index 27,93 ± 1,17, Refractive index 1,34 ± 0,00. The minimum inhibitory concentration (MIC) for the unencapsulated essential oil (OELO) ranged from 1,360 µg/mL to 5,460 µg/mL, while the nanoemulsion (NE-OELO) demonstrated significantly lower MIC values, ranging from 156 µg/mL to 1,250 µg/mL. These findings indicate that NE-OELO is more effective than OELO, emphasizing the benefits of nanoemulsions in enhancing the antimicrobial activity of essential oils. This research could pave the way for innovative products that improve food safety by effectively targeting harmful microorganisms.