Numerical simulation and microtomography study for drying a deformable isodiametric-cellular food

Abstract

The aim of this work is the simulation of volumetric strain of tuberous crop during drying. We propose a poroelastic model for predicting the drying kinetics and volume loss of potato cubes during convective drying. The Biot’s theory of poroelasticity was used, which considers the Lamé parameters, Young’s modulus and Poisson’s ratio. Drying kinetics and volumetric strain were modeled and compared versus experimental data. An X-ray microtomograph coupled with image analysis was used to visualize the shape and size of the samples during drying. Drying experiments were conducted at 50, 60 and 70 °C, 20% RH, with an air velocity of 1 and 2 m/s. The drying process was interrupted several times to perform tomographic acquisitions. We found a period of ideal shrinkage, nevertheless, the volumetric strain reveals a kinetic behavior over time. The model computes the volumetric strain, which describes correctly the experimental data obtained by microtomography.

Causal factors concerning the texture of French fries manufactured at industrial scale

“…The development of a strong, elastic skin has major effects on the development of porosity during the drying of plant cellular tissue, as shown with a multiphysics model incorporating large deformation mechanics ( Jin and van der Sman, 2022 ). A similar phenomenon is also observed during the drying of seeds ( Bai et al, 2019 ), drying of maltodextrin droplets ( Siemons et al, 2020 , 2022 ), and drying of potato tissue ( Santiago et al, 2021 ). We think in French fries this mechanism leads to development of cavities rather than small pores, as shown by the appearance of blisters and cavities when a dense skin is formed ( Van Loon et al, 2007 ).…”

“…Intensities as measured with XRT scales with the moisture content, as has been shown for dried wood ( Watanabe et al, 2008 ). Hence, XRT may equally be applied to measure moisture distribution in French fries, as is also suggested by the study on vegetable tissue ( Santiago et al, 2021 ).…”