Multiscale modeling for food drying: A homogenized diffusion approach

Abstract

Fruits and vegetables have a heterogeneous microstructure which dynamically changes during drying. Currently, food drying models approximate the material's structure through utilizing a representative elementary volume which adopts a larger scale of description and considers the fluid phases as fictitious continuums. This assumption limits the ability of the models to capture the heterogeneity of food material. The multiscale modeling is considered to have the ability to overcome this limitation and advance the understanding of the micro level transport processes. This research aims to develop a multiscale homogenization model for food drying. The homogenization was performed on the cellular structure of apple tissue considering intracellular (bound) water and free water separately to calculate the effective diffusivity for convective drying. The simulation was performed at three different drying temperatures (45 °C, 60 °C and 70 °C), and the results were validated using experimental data. The homogenized diffusivity approach described the experimental data well and provides new insight into how to consider the heterogeneous structure of food material utilizing knowledge of the microstructural evolution. • A multiscale model was developed to consider the heterogeneously distributed water. • Microscale domains were created using knowledge of the microstructural evolution. • The model was able to describe convective drying at low/medium temperatures. • The results were validated and compared with two existing diffusivity methods.