Mathematical methods available to optimize heat sterilization of prepackaged foods are critically reviewed. Heat transfer models, with special relevance to those considering external resistance to heat transfer, are discussed. Different optimization methods and constraints are analysed and their applicability is evaluated. Several objective functions suggested in the literature to minimize quality degradation, energy consumption or economic costs are presented along with their impact on optimum conditions. The use of variable heating medium time temperature profile in order to improve sterilization conditions, both interms of mass average and surface quality retention, is also extensively reviewed. The review suggests that sufficient experimental evidence is lacking. Most models do not provide experimental validation and it is thought that this impairs the potential applications that would arise.
- Numerical modelling