Abstract

Unsteady fluid mechanics and convective heat transfer in the sterilization of canned tuna chunks immersed in a non-Newtonian fluid by a Darcy-Brinkmann-Forchheimer porous model has been studied numerically by a conjugate mathematical model. The coupled equations were solved by the Finite Volume method with the SIMPLE algorithm. The model developed related the sterilization time and temperature distribution with the kinetics of C. botulinum inactivation and the degradation of two relevant vitamins in canned tuna, riboflavin, and thiamin. Additionally, the effect of the covering liquid in the sterilization process and nutrients loss from canned tuna was investigated. The results showed that the sterilization time decreases in fluids with low viscosity, as water and brine, compared to CMC. The cases investigated had a different response to achieve complete sterility, considering the preservation of nutrients. Obtaining a balance between operating time and energy cost allows improving the process to make it more efficient. Industrial relevance: Modeling of bacteria inactivation and vitamin degradation in liquid-solid food mixtures is of great interest because the extended number of relevant food processes involve heat transfer in these matrices, where is mandatory an accurate estimation of time and conditions essential for a complete sterilization process.