Application of Predictive Models To Estimate Listeria monocytogenes Growth on Frankfurters Treated with Organic Acid Salts

Organic acid salts including sodium lactate, sodium diacetate, potassium benzoate, potassium sorbate, and their combinations were assessed as potential inhibitors of Listeria monocytogenes growth on frankfurters. Predictive models for L. monocytogenes growth on frankfurters treated with these salts were compared to select a proper L. monocytogenes growth curve model under these conditions. Sigmoidal equations, including logistic and Gompertz equations, are widely used to describe bacterial growth. In this study, the reparameterized Gompertz model provided a better fit to the L. monocytogenes growth data compared with the other models that were included in this study. Rather than a fixed value for the maximum number of organisms, the reparameterized Gompertz model allows this quantity to be estimated from the data to determine the effect, if any, of the treatments on maximum population density. This information is expected to improve practical methodology for hazard characterization of microbial pathogens on ready-to-eat meat products.