Antimicrobial activities of emulsion-based edible solutions incorporating lemon essential oil and sodium caseinate against some food-borne bacteria

The antimicrobial properties of two different emulsion formulations contained lemon essential oil (coarse emulsion; CE and nanoemulsion; NE) and emulsions based edible solutions incorporated with lemon essential oil and sodium caseinate (coarse emulsion based solution; CESC and nanoemulsion based solution; NESC) on food-related microorganisms (Photobacterium damselae, Pseudomonas luteola, Salmonella Paratyphi A NCTC13, and Listeria monocytogenes ATCC19112) were investigated. The chemical compositions of lemon essential oils were identified by GC–MS. Physical parameter of different formulations was also analyzed at different time intervals. The antimicrobial properties of solutions were determined by using well diffusion, minimum inhibitory concentration (MIC) and minimum bactericidal concentration, and time-kill assay. The major identified component in lemon essential oil was D limonene (38.38%). NE showed a stronger antimicrobial effect against S. Paratyphi A and L. monocytogenes with 36.50 and 38.75 mm diameter zone compared to all other formulations. Listeria monocytogenes had the highest sensitivity towards NE and NESC formulations with 3.12 mg/ml MIC values in comparison to other two formulations. The nanoemulsion and nanoemulsion based coating solution were more effective than other formulations in killing bacterial cell within a short period time.