On the capacity of a crust–core model to describe potato deep-fat frying

A relatively simple crust–core model for heat and mass transfer during potato frying in a domestic fryer is developed. The model combines features of previous existing core–crust models with the scope to reduce the number of external parameters, to reduce the computational effort and to restrict the output variables to those experimentally measured, without sacrificing their ability to describe the process. The dynamics of the oil bath temperature is explicitly modeled. Comparisons show a fair agreement between theoretical and experimental oil and potato temperatures evolution in all the examined cases. However, the degree of agreement regarding vapor fluxes depends on frying conditions indicating thus the limited capacity of crust–core models to describe potato deep fat frying. The deviation between the theoretical and experimental data suggests the way of improvement towards a model that should include the effect of surface water evaporation and of a water diffusion zone with finite thickness that separates potato core and crust.

► Model estimates the temperature evolution inside the fryer, potato, and vapor flux. ► Model results compare favorably with experimental temperatures in the potato and oil. ► Success in describing vapour flux is restricted to higher oil temperatures. ► A simple analytical model for evaluation of convective heat transfer coefficients. ► The surface water evaporation should be considered in future modeling efforts.