Modeling cross-contamination during poultry processing: Dynamics in the chiller tank

•Mathematical model for cross-contamination dynamics of poultry during chilling process.•Express contamination and cross-contamination in terms of model parameters.•Non-pathogenic Escherichia coli micro data used to fit model parameters.•Quantified rules of thumb for cross-contamination risk and chlorine control.

Understanding mechanisms of cross-contamination during poultry processing is vital for effective pathogen control. As an initial step toward this goal, we develop a mathematical model of the chilling process in a typical high speed Canadian processing plant. An important attribute of our model is that it provides quantifiable links between processing control parameters and microbial levels, simplifying the complexity of these relationships for implementation into risk assessment models. We apply our model to generic, non-pathogenic Escherichia coli contamination on broiler carcasses, connecting microbial control with chlorine sanitization, organic load in the water, and pre-chiller E. coli levels on broiler carcasses. In particular, our results suggest that while chlorine control is important for reducing E. coli levels during chilling, it plays a less significant role in the management of cross-contamination issues.