Application of Oregano Essential Oil Against Salmonella Enteritidis in Mayonnaise Salad

The aim of this study was applying oregano essential oil (OEO) from the Mediterranean regions, rich in Carvacrol and traces of p-Cymene and γ-Terpinene like prevention strategy against Salmonella Enteritidis (SE), controlling its multiplication in vegetable salad prepared with mayonnaise. An overnight culture at 30°C with 104CFU/mL of SE ATCC 13076 was inoculated in the salad containing mayonnaise and 0.2% (v/v) of OEO. A survival curve of SE in the salad under refrigeration (8℃) and at room temperature (30℃) after 0, 1, 2, 4, 8, 24 hours of incubation was done. A decrease in the multiplication rate of SE in the mayonnaise salad with OEO was observed. There was a reduction of > 0.5 log until 4 hours at 30℃ and until 24 hours at 8℃ in relation to the control. Our data suggest that OEO provides additional protection able to increase the safety of vegetable salad with mayonnaise contaminated with SE, but not for those subjected to temperature abuse. From Food Safety point of view this study has identified the use of OEO like natural antimicrobial able to reduce the SE growth, an enteropathogen associated with foodborne disease around the world in products derived from eggs such as mayonnaise.