Non-uniformity of lethality in retort processes based on heat distribution and heat penetration data

Abstract

Heat penetration trials were conducted on different solid/liquid mixtures to determine the variability in heating parameters. Also, temperature distribution tests were performed to identify the non-uniformity in retort temperature throughout two different industrial-scale retort systems. Next, non-uniformity in the product (heat penetration data) and non-uniformity in the retort (heat distribution data) were combined through simulations to evaluate non-uniformity of microbial lethality in batch overpressure retort processing. Random heating parameters were generated by a Monte Carlo simulation and a semi-empirical approach, the apparent position numerical solution (APNS) model, was applied to simulate product time–temperature profiles. The developed approach seemed to be a useful and valuable tool to get a better insight into non-uniformity of process lethality during in-pack thermal processing of foods.