Purpose: Develop an accurate heat and mass transfer model for predicting carcass temperature during air cooling of poultry carcasses.
Methods: The coupled heat and mass transfer model considered heat conduction, convection, radiation, and moisture evaporation. Three-dimensional geometries of poultry carcasses were generated from computer tomography images obtained from multiple carcasses. The effect of non-uniform carcass composition and non-uniform thermal properties corresponding to the meat and bone sections of the carcasses was considered. The model was developed using a combination of computer aided engineering software (e.g., COMSOL Multiphysics® and Materialise Mimics) and custom-made computer algorithms. Model validation was conducted under laboratory and industrial settings, following normal processing conditions.
Results: The developed model was in agreement with experimental data. Comparisons between the predicted and observed temperatures resulted in an RMSE of 2.3±1.5 °C, and a 0.08±0.05 log CFU/g deviation in the predicted net growth of Salmonella spp. The model was successfully adapted to provide accurate predictions using input parameters such as air relative humidity, air velocity, cooler set-point temperature, and carcass weight.
Significance: The developed model can be easily accessed and integrated with predictive microbial models through the food safety website: numodels4safety.unl.edu. It can be used to support hazard analysis, development of critical limits, estimation of potential impact of cooling deviations, and simulation of multiple processing scenarios for quantitative microbial risk assessment.