Storage stability and antibacterial activity of eugenol nanoliposomes prepared by an ethanol injection-dynamic...

Eugenol is a major phenolic component with diverse biological activities. However, it is difficult to formulate into an aqueous solution due to poor water solubility, and this limits its application. In the present study, eugenol nanoliposomes (EN) were prepared by combining the ethanol injection method with the dynamic high-pressure microfluidization method. Good physicochemical characterizations of EN were obtained. The successful encapsulation of eugenol in nanoliposomes was confirmed by Fourier transform infrared spectroscopy. A good storage stability of EN was confirmed by its low variation of average particle diameter and encapsulation efficiency after 8 weeks of storage. No oil drops were found in EN after 8 weeks of storage at 4°C and at room temperature, which suggested that the poor water solubility of eugenol was overcome by nanoliposome encapsulation. Compared with that of eugenol solution, a relatively good sustained release property was observed in EN. The antibacterial activity of EN against four common foodborne pathogenic bacteria (Staphylococcus aureus, Escherichia coli, Salmonella enterica serovar Typhimurium, and Listeria monocytogenes) was evaluated in both Luria broth and milk medium.