Freezing of Foods: Mathematical and Experimental Aspects

Freezing is a widely used method to extend the shelf life of foods. However, the frozen products are subjected to temperature fluctuations during storage and shipping, which cause events such as ice recrystallization and moisture/mass migration that further damage food quality. This paper reviews the mechanisms of ice crystal formation, propagation, and glass transition and presents experimental results about the effect of freeze-thaw cycles on ice recrystallization. The mathematical models for prediction of freezing time and description of heat and mass transfer during the freezing process are also addressed. The crystal formation and moisture/mass mobility involve multiscale characteristics, while the traditional modeling can only describe single-scale averaged effects. Therefore, the hybrid mixture theory (HMT), which is based on multiscale balance laws and entropy inequality, is also discussed in the context of the freezing problem to predict phase change, crystal growth, and thermomechanical effects.