Mathematical modeling of eggplant drying: Shrinkage effect Original Research Article

In this paper two mathematical models with shrinkage effect describing eggplant drying are developed and discussed. The models are both modified diffusion equations and take differently into account changes of eggplant slice structure during drying. In the first model a diffusion coefficient variable with the water content is considered while in the second model a fictitious convective term is introduced. The two models are both suitable to describe the analyzed drying processes. Moreover, their equivalence is analytically demonstrated. Parameters values are estimated through a nonlinear regression procedure by comparison with the drying experiments carried out at different temperatures. Information about thickness evolution, derived from the models, are found to be in agreement with experimental data.