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 S almonella enteritidis supplemented with different concentrations of oregano essential oil (0.0, 0.5, 1.0, 2.0% v/w) and stored at different temperatur es (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 ba cterial counts were modelled as a function of time in order to estimate the kinetic parameters of the pathogen. For comparison, two different models w ere used. A reduction of Salmonella enteritidis was observed in all cases a nd its death rate depended on the pH, the storage temperature and the essen tial oil concentration. Death responses as a function of pH, storage temper ature and concentration of oregano essential oil were described using a qua dratic function which was then used to predict the death of Salmonella ente ritidis in home-made taramasalad of different compositions. (C) 1999 Elsevi er Science B.V. All rights reserved.