Biological Systems Engineering, Department of


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Published in Transactions of the ASABE Vol. 49(5): 1437−1446. Copyright 2006 American Society of Agricultural and Biological Engineers. Used by permission.


An integrated mathematical model of heat transfer and temperature-dependent bacterial growth was developed to validate the safety of cooked hams during air-blast chilling. Heat transfer through a cooked ham was mathematically modeled and analyzed with a finite element method. Response of bacteria to temperatures was quantitatively described using predictive microbiology. The cumulative effect of temperature history on the bacterial growth was taken into account in the model. For chilling cooked hams from 71°C to 10°C, the maximum error between the predicted and experimental core temperature was within 2.2°C, and the deviation between the predicted and measured total weight losses was 1.1%. The bacterial growth kinetics was validated using the data from the literature. The integrated model of heat transfer and bacterial growth provided valuable insights into air-blast chilling of cooked meats for risk assessment of the final products.