Bio-based nanoemulsion formulation, characterization and antibacterial activity against food-borne pathogens

Abstract

The current study deals with the formulation and characterization of bio-based oil in water nanoemulsion and its potential antibacterial activity. A typical v/v% of eucalyptus oil (16.66%), Tween 80 (16.66%), and water (68.68%) was prepared by ultrasonication method. The mean droplet size was 17.1 nm as confirmed by dynamic light scattering. Different concentrations of the formulation ranging from undiluted to 10-, 100-, and 1000-fold dilutions were used to check the antibacterial activity in three different microorganisms, namely, Bacillus cereus, Staphylococcus aureus (Gram-positive), and Escherichia coli (Gram-negative). All three species showed a 100% bactericidal at the 10-fold dilution of the nanoemulsion formulation in the following order: B. cereus at 0th min, S. aureus at 15 min and E. coli at 1 h, respectively. A 10-fold dilution of the nanoemulsion showed that, the cytoplasmic content leakage from the bacterial species was high for S. aureus when compared to B. cereus and E. coli as determined by UV-Vis spectroscopic method. Fluorescence microscopic technique further confirmed this study.

Nanoemulsion formation and characterization by spontaneous emulsification: Investigation of its antibacterial effects on Listeria monocytogenes

“…[12][13][14] There is a growing interest in food and beverage industries for the utilization of nanoemulsion as a colloidal system for delivery of bioactive components such as antimicrobials, colors, flavours, micronutrients and nutraceuticals. [15][16][17][18][19] The applications of nanoemulsions as attractive systems has gained interest nowadays due to their unique properties such as extremely small droplet diameter in the range of 20-200 nm, [20] high physical stability, high bioavailability and optical transparency compared with other conventional emulsions. [21] Previous studies showed encapsulation of essential oils into emulsion due to the hydrophobic nature of oil this leads to higher solubility and dispersibility in aqueous media and also to reduce organoleptic properties in the food system.…”

Eucalyptus oil nanoemulsion-impregnated chitosan film: antibacterial effects against a clinical pathogen, Staphylococcus aureus, in vitro

“…[8][9][10] The antimicrobial oil-in-water nanoemulsion was shown to possess a broad spectrum of activity against bacterial pathogens due to the reduced droplet diameter. 11,12 Recently, by our group, the ultrasonic emulsification of eucalyptus oil nanoemulsion was studied, and size reduction was achieved with the aid of ultrasonication time. Also, the stabilized emulsion system was studied for topical application against S. aureus by in vitro and was shown to be nonirritant, and high wound healing activity was observed in Wistar rats in an in vivo experiment.…”

Effects of nanostructured essential oils against subterranean termites (Coptotermes gestroi)

“…PDI value provides information about the distribution of particle size, being the indicated value <0.3, as in the present study. The zeta potential, which reflects the surface charge of a nanostructure, had negative results in all nanostructures used in the tests, which was expected, as it was used a negatively charged surfactant (Sugumar et al., ; Sun et al., ). The pH of both nanoemulsions and solid lipid nanoparticles presented results between 4.0 and 5.9.…”