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 degrees 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. (C) 1999 Elsevier Science B.V. All rights reserved.