Generalized moisture diffusivity for food drying through multiscale modeling

Abstract

Drying plant-based food materials can be time consuming and energy intensive, making optimization of its processes essential. However, current mathematical models are plagued with condition-dependent diffusivities restricting their performance in developing optimal drying strategies. Multiscale modeling is one technique which can help transition towards a more physics-based approach, improving model's predictive capabilities. This research constructs a multiscale food drying model utilizing a generalized moisture diffusivity to investigate its predictive capabilities. The study investigates two food materials (apple and potato) convective drying at two different temperatures (47 °C and 64 °C). Additionally, to be able to utilize the generalized diffusivity, cell rupturing must be considered. Therefore, a theoretical rupturing threshold was developed exploiting the equilibrium vapor pressure to recognize which transport mechanisms were occurring. The generalized diffusivity was able to distinguish between the two materials and was able to describe the experimental data accurately at both drying temperatures. The generalized property resulted in diffusivities with the range of 1.94 × 10 −10 -5.14 × 10 −10 m 2 /s. • A multiscale model with a generalized diffusivity for food drying is investigated. • Multiscale model investigates two materials drying at low and medium temperatures. • Theoretical cell rupturing threshold is developed using equilibrium vapor pressure. • Multiscale model can predict if and when cell rupturing occurs.