A predictive model for the non-thermal inactivation of Salmonella enteritidis in a food model system supplemented with a natural antimicrobial

Home-made taramasalad, a traditional Greek appetizer, was inoculated with Salmonella enteritidis supplemented with different concentrations of oregano essential oil (0.0, 0.5, 1.0, 2.0% v/w) and stored at different temperatures (5, 10, 15, 20°C). The product’s pH was adjusted from 4.3 to 5.3 with lemon juice. At each combination of the environmental factors, the bacterial counts were modelled as a function of time in order to estimate the kinetic parameters of the pathogen. For comparison, two different models were used. A reduction of Salmonella enteritidis was observed in all cases and its death rate depended on the pH, the storage temperature and the essential oil concentration. Death responses as a function of pH, storage temperature and concentration of oregano essential oil were described using a quadratic function which was then used to predict the death of Salmonella enteritidis in home-made taramasalad of different compositions.