Heat and mass transfer models for predicting freezing processes - a review

A study of the literature published in recent years on freezing time prediction methods, with focus on simultaneous heat and mass transfer modelling is presented. Although models published vary from analytical simple equations to numerical methods, the most fruitful work is in finding simple equations for foods with regular shapes. It is difficult to develop more precise prediction methods for one-dimensional shapes as accurate experimental data are not easy to obtain. Heat transfer coefficients are hard to estimate with typical uncertainties of +/-10-20% quoted and data on mass transfer coefficients are scarce. Research on the influence of thermal properties on the accuracy of models is useful. There are many models published for coupled heat and mass transfer for cooling, but very few models are available for freezing. Furthermore weight loss is an important factor for economic and quality reasons, therefore models should be developed in order to predict the weight loss during cooling and freezing. (C) 2000 Elsevier Science Ltd. All rights reserved.