Optimizing Salmonella Enteritidis inactivation in Salmon (Salmo salar) by the combined treatment of UV-LED and of Origanum vulgare essential oil nanoemulsion.

The combination of oregano essential oil (OVEO) and its nanoemulsion (nOVEO) with UVC-LED treatment was optimized for maximum S. Enteritidis inactivation while mitigating lipid oxidation and color changes using a response surface methodology. Individually nOVEO was two-fold more efficient in S. Enteritidis inactivation than OVEO. The combination of UVC-LED with nOVEO led to higher pathogen inactivation and lower oxidation compared to OVEO, which seemed to have a saturation point. The optimum levels of each combined treatment (UVC-LED + OVEO = 4,974 mJ/cm2 + 12.25 mg/mL and UVC-LED + nOVEO = 1,752 mJ/cm2 + 8.50 mg/mL) inactivate more than 1 log CFU with low oxidation (0.11 mg malondialdehyde/kg). However, only the use of nOVEO resulted in low color changes (ΔE = 3.6), besides required milder conditions. Therefore, the combination of nOVEO with UVC-LED proved to be a feasible non-thermal hurdle approach to control S. Enteritidis in salmon while retaining its quality. [Display omitted] • Oregano essential oil (OVEO), its nanoemulsion (nOVEO), and UVC-LED improve salmon safety. • The S. enteretidis inactivation Kinect of all individual treatments were studied. • The combination of OVEO + UVC-LED and nOVEO + UVC-LED was studied and optimized. • Combination between either OVEO or nOVEO with UVC-LED increased pathogen reduction without antagonism. • Optimized nOVEO and UVC-LED reached pathogen inactivation with low oxidation and color changes. [ABSTRACT FROM AUTHOR]