Modeling the high pressure inactivation kinetics of Listeria monocytogenes on RTE cooked meat products

High pressure (HP) inactivation curves of Listeria monocytogenes CTC1034 (ca. 107 CFU/g) on sliced RTE cooked meat products (ham and mortadella) were obtained at pressures from 300 to 800 MPa. A clear tail shape was observed at pressures above 450 MPa and the log-linear with tail primary model provided the best fit to the HP-inactivation kinetics. The relationships between the primary kinetic parameters (log kmax and log Nres) and pressure treatments were described by a polynomial secondary model. To estimate HP-inactivation of L. monocytogenes in log (N/N0) over time, a one-step global fitting procedure was applied. The secondary model was integrated into the primary model and the combined equation was fitted to the entire data-set to readjust parameter values. Validation of the developed models both under dynamic conditions and using external independent data supported their suitability for predictive purposes, e.g., to set the process criteria required to meet food safety objectives.Industrial relevanceQuantitative mathematical models for predicting inactivation of pathogens by HPP provide useful tools for a process optimization and real time control of a unit operation. The developed models can assist food industries to define the process criteria compatible with the Food Safety Objectives for Listeria monocytogenes in RTE cooked meat products.

► HP-inactivation of L. monocytogenes on RTE cooked meat products was modeled.
► Among primary models, the log-linear with tail provided the best fit.
► A linear relationship between pressure and log kmax or log Nres was observed.
► One-step global fitting provided two different equations to predict HP-inactivation.
► Validated models seem useful for food industries to define safe HP process criteria.