Microwave Sterilization: Interlinking Numerical Modelling, Food Packaging, and Engineering Solutions

Microwave sterilization has seen many innovative solutions to solve its primary problem of non-uniform heating. Since its initial studies in the late 1940s, there were solutions that were put forward to address, such as using mechanical holders to contain the inner pressure of the package with food materials, use of fluids instead of mechanical holders, use of strong containers or polymeric packages, and use of monolayer and multilayer packaging. But even all these solutions could not entirely solve the problem of non-uniform heating. After the 2000s, the rise in numerous numerical simulations and modelling software, opened the doors to further explore this field of research with more details and to numerically model the multi-physics phenomenon. However, studies have still not been sufficient to commercially deploy microwave sterilization systems to their full potential. Challenges such as temperature measurement, pressure measurement and control, usage of the right packaging material, and homogeneous heat distribution are still to be addressed, all while developing an energy-efficient process using numerical modelling and simulation tools. Hence, this review aims to study the microwave sterilization systems since the early days of research and the packaging aspect during the microwave sterilization process. The review also explores the potential held by the numerical simulation and modelling tools in this field of microwave sterilization.