Multicomponent Diffusion during Osmotic Dehydration Process in Melon Pieces: Influence of Film Coefficient

Abstract

The water loss and sugar gain modeling during the dehydration process is useful as a technique for predicting the operating conditions and the process time. The transfer of sucrose and fructooligosaccharides (FOSs) to melon and water to solution was modeled based on generalized form of Fick's second law for simultaneous diffusion and resolved by the finite element method using the software package COMSOL Multiphysics 3.2. The diffusion coefficients, the mass transfer coefficient and the Biot number were determined using the simplex optimization method by minimizing the percentage errors. The optimized main diffusion coefficients were 21.07 × 10 −11 m 2 /s for sucrose, 15.60 × 10 −11 m 2 /s for water and 8.96 × 10 −11 m 2 /s for FOS. The simulation results exhibited good fits to the experimental values, which validates the model predictive ability. The developed system for diffusion simulating water and solutes will enable control and modulation of the sucrose and FOS content in melon pieces. PRACTICAL APPLICATIONSThe use of functional sugars in fruits generates a new range of food taking into account the growing consumer market of these products. The study of processes involved in osmotic dehydration, as well as mass transfer simulation and modeling, is a useful predictive tool for the food industry, for assisting in the process time optimization among other variables involved.

Osmotic Dehydration of Yacon Using Glycerol and Sorbitol as Solutes: Water Effective Diffusivity Evaluation

“…The rate of diffusion of water from any material tissues depends upon factors such as temperature and concentration of the osmotic solution, the size and geometry of the material, the solution to material mass ratio, and the level of agitation of the solution. A number of publications have described the influence of these variables on mass transfer rates during osmotic dehydration (Angilelli et al 2014;Silva et al 2014b;Mercali et al 2011;Dionello et al 2007; Rastogi and Raghavarao 2004;Shi and Le Maguer 2002). Silva et al (2014b) also stated that the characteristics of the osmotic agent used, such as its molecular weight and ionic behavior, strongly affect dehydration, both water loss and solute gain.…”

Influence of film coefficient during multicomponent diffusion – KCl/NaCl in biosolid for static and agitated system using 3D computational simulation

“…The mathematical model used was based on a generalization of Fick's 2 nd law and on Dnsager equation (1945). The finite element formulation considering the simultaneous three-dimensional mass transfer of two solutes is described by Borsato et al (2012) and Angilelli et al (2015). Some simplifying assumptions were made according to Angilelli et al (2015).…”

“…The finite element formulation considering the simultaneous three-dimensional mass transfer of two solutes is described by Borsato et al (2012) and Angilelli et al (2015). Some simplifying assumptions were made according to Angilelli et al (2015). The solute diffusion occurred in a three-dimensional volume Ω⊂R 3 associated with a set of coordinates X, Y, Z, the hypothesis that the diffusion coefficient or diffusivity is constant over the concentration regardless of the position and the immersion time of the solid is accepted, the diffusion of the solvent, the solute was considered as the predominant process in the mobility and the process takes place under substantially isothermal conditions and the contraction of the sample during the procedure was negligible.…”

“…Currently there are mathematical models seeking to model diffusion processes and other phenomena. A method that is commonly used is the Finite Element Method (FEM), which is basically the domain discretization in several elements (Hao et al, 2016;Angilelli et al, 2015). The FEM is used as a tool in several areas of engineering, chemistry and physics.…”

“…Of there is a mass transfer between the fluid and the surface, the current must go through the stationary layer, which acts as a resistive barrier. Angilelli et al (2015) evaluated the influence of the film coefficient in multicomponent diffusion during the dehydration of melon using a fructo-oligosaccharide (FDS) and sucrose solution, concluding that the presence of the film formed on the solution/solution solid interface influences the diffusion process.…”