%0 Journal Article
%T Diffusion models for the description of seedless grape drying using analytical and numerical solutions
%A Wilton Pereira da Silva
%A Cleide Maria Diniz Pereira da Silva e Silva
%A J¨¹rgen Wolfgang Precker
%A Josivanda Palmeira Gomes
%A Pedro Luiz Nascimento
%A Laerson Duarte da Silva
%J Agricultural Sciences
%P 545-556
%@ 2156-8561
%D 2012
%I Scientific Research Publishing
%R 10.4236/as.2012.34065
%X This article compares diffusion models used to describe seedless grape drying at low temperature. The models were analyzed, assuming the following characteristics of the drying process: boundary conditions of the first and the third kind; constant and variable volume, V; constant and variable effective mass diffusivity, D; constant convective mass transfer coefficient, h. Solutions of the diffusion equation (analytical and numerical) were used to determine D and h for experimental data of seedless grape drying. Comparison of simulations of drying kinetics indicates that the best model should consider: 1) shrinkage; 2) convective boundary condition; 3) variable effective mass diffusivity. For the analyzed experimental dataset, the best function to represent the effective mass diffusivity is a hyperbolic cosine. In this case, the statistical indicators of the simulation can be considered excellent (the determination coefficient is R<sup>2</sup> = 0.9999 and the chi-square is ¦Ö<sup>2</sup> = 3.241 ¡Á 10<sup>¨C4</sup>).
%K Optimization
%K Convective Boundary Condition
%K Diffusion Model
%K Finite Volume Method
%U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=20096