Choix et validation d’un modèle de comportement pour le séchage convectif de la datte Deglet-Nour

Abstract

Drying being a physically complex phenomenon, the biological diversity of the foodstuffs and their natural heterogeneity make that the recourse for modeling means becomes of a major technico-economic interest. The currently available literature shows an abundance of work treating the modeling of food drying, but few authors were interested in knowledge or behavior models related to date fruits. The main objective of this work is to exploit some experimental results of Deglet-Nour date drying carried out on a pilot drier with perpendicular convective drying. Date samples were harvested from Oued-Righ area in the south-east of Algeria. To this end four model equations were retained, on the basis of former work available in literature, namely, (a) Page equation (b) Logarithmic Model (c) Model of Midilli (d) Two terms exponential Model. The experimental drying curves were fitted by a non-linear regression analysis using the CurveExpert software. Obtained results classified the two exponential terms as the best model which was, then, generalized on a range of drying temperatures between 35C and 70C.The parameters of the generalized model equation were smoothly correlated with the drying air temperature. In addition, the adopted range of validity was checked by the bibliographical data as being the interval of heat treatment ensuring the good quality of the final product.