Application of the Hsu model to soybean grain hydration

Abstract

A comparative analysis of the theoretical-experimental study, developed by Hsu on the hydration of Amsoy 71 soybean grain, was performed through several soaking experiments using CD 202 soybean at 10, 20, 30, 40, and 50 °C, measuring moisture content over time. The results showed that CD 202 soybean equilibrium moisture content, Xeq, does not depend on temperature and is 21% higher than that found by Hsu, suggesting that soybean cultivar exerts great influence on Xeq. The Hsu model was numerically solved and its parameters were adjusted by the least squares method, with maximum deviations of +/- 10% relative to the experimental values. The limiting step in the mass transfer process during hydration corresponds to water diffusion inside the grain, leading to radial moisture gradients that decrease over time and with an increase in temperature. Regardless of the soybean cultivar, diffusivity increases as temperature or moisture content increases. However, the values of this transport property for Amsoy 71 were superior to those of CD 202, very close at the beginning of hydration at 20 °C and almost three times higher at the end of hydration at 50 °C.

Analytical solution and experimental validation of a model for hydration of soybeans with variable mass transfer coefficient

“…In terms of processing soybeans to produce food, hydration is an important part of the protein extraction process as a pretreatment for the grains to have their texture characteristics altered to facilitate protein extraction (Ciabotti et al, 2009;Coutinho et al, 2010;Nicolin, 2012;Nicolin et al, 2013;Pan and Tangratanavalee, 2003). Therefore, to understand hydration kinetics it is crucial to establish an exact relationship between moisture and hydration time for the grains.…”

Soybean drying as a moving boundary problem: Shrinkage and moisture kinetics prediction

“…This matches the reality of the hydration process, given that the grains, in this process, remain submerged in water throughout the entire diffusion. The condition represented by Equation (4) was used in several works involving the mathematical modeling of diffusion in grains (Coutinho et al, 2010; Hsu, 1983; Nicolin, Coutinho, Andrade, & Jorge, 2013; Nicolin, Coutinho, Andrade, & Jorge, 2012). Equation (5) represents the speed with which the radii of the grains move throughout the drying.…”

Solução Analítica E Validação Experimental De Um Modelo Para Hidratação De Soja Com Coeficiente De Transferência De Massa Variável

“…Em termos de processamento de soja com o objetivo de produzir alimentos, a hidratação constitui uma parte importante do processo de extração de proteínas sendo um pré-tratamento dos grãos que tem como objetivo alterar as características texturais dos grãos e facilitar a extração das proteínas (CIABOTTI et al, 2009;COUTINHO et al, 2010;NICOLIN, 2012;NICOLIN et al, 2013;PAN e TANGRATANAVALEE, 2003). Portanto, a compreensão da cinética de hidratação é um fator muito importante para estabelecer uma relação precisa entre a umidade que os grãos absorvem e o tempo de hidratação.…”