Water uptake kinetics in soaking of grass pea

Abstract

Grass pea (Lathyrus sativus) is a pulse of great importance for food and feed due its high resistance to poor environmental conditions. However, it contains anti-nutritional factors and a neurotoxin, which is partially lost during soaking. A first approach to mass transfer during the soaking of grass pea was carried out by modeling the water uptake during soaking time using empirical mathematical models. The water uptake behavior was successfully described by the Peleg and the Exponential models, with these models showing several advantages when compared to the Mitscherlich and Page models. Both models estimated an increase of the equilibrium moisture content at temperatures between 50 °C and 100 °C, and detected an increasing effect of the area per volume ratio of the seed on the water uptake rate, but only at 75 °C and 100 °C. Additionally, grass pea presented a high true porosity, 13.651%, showing that it contains a large empty volume into which water can enter by capillary flow. Solids loss was observed to be high, varying from 18% at 25 °C to 44% at 100 °C for long soaking times, confirming that its effect in soaking cannot be neglected.

Use of empirical and diffusion models in the description of the process of water absorption by rice

“…It is interesting to mention the higher amount of information that can be provided by a diffusion model in different physical situations involving heat and/or mass transfer (Da Silva et al , 2010, 2013a, b, 2014a, b), when compared to empirical models (Quicazán et al , 2012; Oliveira et al , 2013; Marques et al , 2016; Shafaei et al , 2016; Li et al , 2020; Costa et al , 2021); or works that simply present experimental data (Cruz et al , 2011) describing the same physical situation. Diffusion models provide not only the kinetics of the studied phenomenon, but also allow predicting the distribution of the variable of interest in the domain, at any time, enabling studies that depend on the gradient of this variable of interest.…”

Utilização de extratos vegetais e emulsificantes para obtenção de um colorante natural em pó através da técnica de secagem em camada de espuma

“…Para descrever a secagem de um produto agrícola ao longo do tempo, vários modelos matemáticos são usados. Dentre esses, podem ser citados os modelos difusivos (Silva et al, 2008;Silva et al, 2014a) e também os modelos empíricos (Silva et al, 2012;Costa et al, 2022). Dos métodos de secagem existentes, o processo de secagem por camada de espuma que é considerado uma técnica simples que pode ser aplicada em alimentos sensíveis ao calor, pegajosos e com alto teor de açúcar, como polpas de frutas e sucos.…”

Proposition of empirical equations to describe the kinetics of water absorption by film-coated maize seeds during germination

“…In general, various types of mathematical models are used to describe the migration of water in a porous medium over time, including diffusion models (distributed mass transfer analysis) (Silva et al, 2008;Da Silva et al, 2014;Silva et al, 2014) and empirical models (lumped models) (Silva et al, 2012;Costa et al, 2022). In the use of diffusion models, moisture contents must be given on a dry basis and, in this case, the parameters of interest for describing the kinetics are the convective mass transfer coefficient and the effective mass diffusivity.…”