Retaining the 'essence'of essential oil: Nanoemulsions of citral and carvone reduced oil loss and enhanced antibacterial efficacy via bacterial membrane perturbation.

Essential oils (EO), which can be extracted from different edible, therapeutic and herbal plants, have been well known as natural antimicrobial additives. However, it is usually hard to attain high antimicrobial efficacy of these EOs, when these are used in different combinations for the control of foodborne microbes, because of their low solubility in water and interactive binding. Here, we report an optimized oil-in-water (o/w)nanoemulsification process for citral and carvone which generated mean droplet size of 11-19 nm. It was found that nature of surfactant viz., Brij-58 vs leaf extract of Lantana camara (LC)plays crucial role in determining the overall stability and size of the droplets. The screened nanoemulsions (NEs), when stored for long duration, showed minimal decrease in oil content with retention of antioxidant activity. The prepared NEs documented enhanced antibacterial activity compared to pure oils whereas higher degree of killing was observed towards Pseudomonas aeruginosa. The NEs also showed killing of both the bacteria on wound dressing cotton gauze bandages (GB). The outcome of the present study may be used for the development of safe and biocompatible antibacterial agents.