Mathematical modeling to study influence of porosity on apple and potato during dehydration

Abstract

Several structural and physical changes in foodstuffs are the consequence of water removal during the drying process. Porosity (volume fraction of pores) is one of the key parameter that affects the quality and other properties of foods (such as apple and potato). To understand the effect of dehydration in apple and potato, in the present study an arbitrary small cubic volume element is considered which contains pores (intracellular spaces) distributed in it. Further, it is assumed that each pore in the cubic volume element is spherical. A mathematical relation is developed between porosity (volume fraction of pores) and pressure generated (due to contraction of cells during water removal) in outward direction on the surface of spherical elements containing pore. The developed relation is satisfactory in respect of experimental observations given in the literature. For the given pressure range, acquired porosity range is 0.1 to 0.92 for apple and 0.03 to 0.89 for potato which is matched with the existing experimental values. The results showed that the porosity is increasing with the increasing values of pressure, as expected, during moisture removal. Further, it is observed that the current porosity is depended on the initial porosity for both apple and potato.

Use of ultrasound for dehydration of mangoes (Mangifera indica L.): kinetic modeling of ultrasound-assisted osmotic dehydration and convective air-drying

“…Modeling the osmotic process for mangoes is more complicated due to its tissue structure. Mangoes are dense and much less porous (porosity = 0.04 to 0.05) than most fruits (pineapple porosity = 0.16 to 0.25; apple porosity = 0.18 to 0.22; strawberry porosity = 0.47) (Ozcan and Haciseferogullan 2007;Yan et al 2008;Singh et al 2015). This tissue structure imposes a higher resistance to mass transfer.…”

Impact of drying methods on the changes of fruit microstructure unveiled by X-ray micro-computed tomography

“…Previous studies on dried apple and potato also showed that forced convective drying resulted in products with a higher (Eulerian) porosity. [59][60][61] Using a Lagrangian approach, we nd that the pore volume stays almost constant for our forced convective condition. This is due to a small degree of bulk shrinkage while cells shrink during drying.…”

Eating Habits and Sustainable Food Production in the Development of Innovative “Healthy” Snacks

“…The high porosity of freeze-dried food is created as an effect of the absence of capillary forces during sublimation of the frozen water [92]. A similar value was obtained for freeze-dried gels with a combination of xanthan gum and locust bean gum [84,85], freeze-dried apple and potato [93]. In the case of freeze-dried strawberry gels, the porosity was in the range of ~88-91% [94].…”