Comparative Study between Conventional and Microwave-assisted Pasteurization of Packaged Milk by Finite Element Modeling

Abstract

In this study a comprehensive computer simulation model was developed to evaluate and compare temperature distribution, flow pattern, slowest heating zone (SHZ) location and processing time in pre-packaged milk duringmicrowave-assisted pasteurization (MWP) and conventional pasteurization (CNP). Temperatures predicted by simulations were successfully validated against experimental data. C-value, color and thiamine kinetics coupled totemperatures predicted by simulation model were used to assess the impact of the process on product quality. Considering an equivalent microbial safety between both processes, MWP achieves a more uniform heating and,consequently, reductions of 28.6% in processing time and 14.8% in overall quality losses. Color changes were 35.5 and 37.0% for MWP and CNP, respectively; while thiamine losses were lower than 1% in both cases.Additionally, container orientation was evaluated for MWP, showing that horizontal orientation provided better temperature distribution and reduced quality losses.