Heat and mass transfer model for pork carcass precooling: Comprehensive evaluation and optimization

In this study, we construct a three-dimensional heat- and mass-transfer model to determine the moisture loss and spatio-temporal distribution of pork carcass temperature during precooling. We consider how convection, evaporation, and radiation affect the heat- and mass-transfer process and compare and analyze how precooling conditions affect the precooling rate, uniformity, and moisture loss of pork carcasses. The results reveal nonuniform precooling between different parts of single carcasses, mainly because of the nonuniform heat transfer on the pork carcass surface. However, for the overall precooling space, no significant difference appears in the rate of temperature decrease between individual carcasses. In addition, the ambient humidity most strongly affects carcass moisture loss, and the precooling temperature most strongly affects temperature uniformity and precooling rate. Finally, by comprehensively evaluating the effects of different precooling conditions on carcass precooling performance, the optimal precooling conditions are determined, namely, the air velocity, precooling temperature, ambient humidity, and initial carcass temperature of 10 m/s, 0 °C, 95 %, and 37 °C, respectively. This study thus provides an important theoretical basis and a useful reference for the determination of optimal precooling conditions and the comprehensive evaluation and optimization of pork carcass precooling.