Development and characterization of a carvacrol nanoemulsion and evaluation of its antimicrobial activity against selected food-related pathogens

Carvacrol has been recognized as an efficient growth inhibitor of food pathogens. However, carvacrol oil is poorly water-soluble and can be oxidized, decomposed or evaporated when exposed to the air, light, or heat. To overcome these limitations, a carvacrol nanoemulsion was developed and its antimicrobial activity against food pathogens evaluated in this study. The nanoemulsion containing 3% carvacrol oil, 9% surfactants (HLB 11) and 88% water, presented good stability over a period of 90 days. In general, the carvacrol nanoemulsion (MIC: 256 mu g ml(-1) for E. coli and Salmonella spp., 128 mu g ml(-1) for Staphylococcus aureus and Pseudomonas aeruginosa) exhibited improved antimicrobial activity compared to the free oil. The carvacrol nanoemulsion additionally displayed bactericidal activity against Escherichia coli, P. aeruginosa and Salmonella spp. Therefore, the results of this study indicated that carvacrol oil nanoemulsions can potentially be incorporated into food formulations, wherein their efficacy for the prevention and control of microbial growth could be evaluated.

Automated summary

A carvacrol nanoemulsion with good stability and improved antimicrobial activity against food pathogens compared to free oil was developed in this study, indicating its potential for incorporation into food formulations for microbial growth prevention and control.