A one-dimensional unsteady state mathematical model with variable physical property parameters is developed to simulate the freezing
time of individual food in freezing process. The phase-change problem in the freezing process is solved with apparent heat capacity
approach, and the physical property change is described with a quadratic curve. The model’s numerical algorithm is finite-difference
method with Crank–Nicolson scheme, which is programmed with Visual Basic 6.0. The predicted temperature history of cucumber slice
in freezing process is validated with a set of actual experimental data. The predicted freezing times of spherical, cylindrical and tabulate
foodstuffs are also validated with several sets of experimental data, and the accuracies of freezing times predicted by the model are all
better than that of several other models in the literatures based on the same experimental data. In all the cases, the linear regression
correlation coefficients (R2) between predicted and experimental values are over 0.989, which means that the model could be used to
predict the freezing time and the temperature history of spherical, cylindrical and tabulate food with various physical properties at
different cooling medium temperatures. So it could be used to give a guideline for freezing experiments, freezing equipment design
and frozen-food production.