Inactivation Kinetics of Escherichia coli O157:H7, Salmonella enterica Serovar Typhimurium, and Listeria monocytogenes in Ready-to-Eat Sliced Ham by Near-Infrared Heating at Different Radiation Intensities

Abstract

The aim of this study was to investigate the inactivation kinetics of Salmonella enterica serovar Typhimurium, Escherichia coli O157:H7, and Listeria monocytogenes on ready-to-eat sliced ham by near-infrared (NIR) heating as a function of the processing parameter, radiation intensity. Precooked ham slices inoculated with the three pathogens were treated at different NIR intensities (ca. 100, 150, and 200 μW/cm2/nm). An increase in the applied radiation intensity resulted in a gradual increase of inactivation of all pathogens. The survival curves of the three pathogens exhibited both shoulder and tailing behavior at all light intensities. Among nonlinear models, the Weibull distribution and log-logistic model were used to describe the experimental data, and the statistical results (mean square error and R2 values) indicated the suitability of the model for prediction. The log-logistic model more accurately described survival curves of the three pathogens than did the Weibull distribution at all radiation intensities. The output of this study and the proposed kinetics model would be beneficial to the deli meat industry for selecting the optimum processing conditions of NIR heating to meet the target pathogen inactivation on ready-to-eat sliced ham.