Casein-liposome complex loading basil essential oil: Preparation, antibacterial effect, and preservative effect on braised beef

Liposomal encapsulation enhances the stability of essential oils, while simple liposomes are plagued by lack of targeting and low release rate. Herein, bacteria-secreted protease-triggered liposomes (BEO-clip) were prepared from basil essential oil-loaded liposomes (BEO-lip). The physiochemical properties, antibacterial effect and mechanism against Staphylococcus aureus of the prepared liposomes were investigated, the liposomes were also utilized for the preservation of braised beef. BEO-clip presented higher storage and thermal stabilities. In addition to a stronger bactericidal effect against S. aureus , BEO-clip exhibited a bacteria-secreted protease-dependent BEO release and sustained antibacterial effects. BEO-clip showed a more intense interaction with S. aureus , causing membrane disruption, declined membrane potential, and increased surface charge. Both BEO-lip and BEO-clip effectively inhibited the microbial growth in braised beef during storage. BEO-clip significantly restrained lipid oxidation, suppressed the increase of pH and total volatile base nitrogen, delayed the deterioration of color and texture, without comprising sensory quality.