Theoretical models of vegetable drying by convection

Mass Transfer Mechanisms during Dehydration of Vegetable Food: Traditional and Innovative Approaches

“…The term model is difficult to precisely define. An intuitive definition may be expressed as follows: a model is a structure similar to the original (Pabis, 2007). A model is an abstract system that may be obtained also from the results of experimental process performed on the existing original.…”

“…In other word, empirical model states the existence of a new empirical regularity between independent and dependent variables but it cannot provides any scientific explanation. Instead, if the model is theoretical it may provide information on both the action of the original and its structure which promoted that action (Pabis, 2007). Theoretical model is obtained deductively from the true statements of the theory; it results logically from the theory.…”

“…In general, some theoretical models have been developed using as starting point the biological theory related to the cell membrane changes as in the case of osmotic dehydration, the volume changes during drying or on the basis of porous media approach. Pabis (2007) developed a non linear theoretical model of the kinetics of convective drying of cut vegetables that takes into account the shrinkage of vegetable tissue: 00 0 11 1 11…”

“…This model was used in different operative conditions showing a good capability to fit experimental moisture content values in the first region of drying curves (Pabis, 1999;Sojak, 1999;Pabis, 2007). Spiazzi & Mascheroni (1997) developed a model composed by a system of ordinary differential equations that take into account the main mass transfer ways in cellular tissues, product shape, size and variation during drying as well as the chemical composition of the product, of the osmotic solution and their mass ratio.…”