Microscale Modelling of Flow, Heat and Mass Transport During Vacuum Cooling of Porous Foods: Effective Property Computation

Abstract

A microscale modelling framework to compute effective properties related to flow, heat and mass transfer during vacuum cooling (VC) of porous foods was developed. A heterogeneous computational domain reconstructed from steamed bread (SB) was used for modelling, while the cellular water transport in SB investigated using nuclear magnetic resonance was applied for model validation. The computed porosity (63.47 ± 1.05%), effective permeability (1.91 ± 0.39 × 10−11 m2), effective thermal conductivity, (0.33 ± 0.08 W m−1 K−1), and effective diffusivity (5.56 × ± 0.24 10−8 m2 s−1) were in the same range as those measured from the experiment/literature. Also, the analysis revealed that microstructural variability significantly affected the estimated effective properties. The microscale model yielded results similar to the lumped formulation but provided details not visible in the latter. Therefore, the developed model provides a framework for multiscale modelling, which could lead to a better understanding of the underlying moisture loss mechanisms during VC.