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.301Adeyemi, I.A., Dry-milling of sorghum for ogi manufacture (1983) Journal of Cereal Science, 1 (3), pp. 221-227Ahromrit, A., Ledward, D.A., Niranjan, K., High pressure induced water uptake characteristics of Thai glutinous rice (2006) Journal of Food Engineering, 72 (3), pp. 225-233Barrozo, M.A.S., Calado, V.M.A., Calçada, L.A., Secagem de soja em leito deslizante e recirculação pneumática: Influência da umidificação artificial (1991) ENCONTRO SOBRE ESCOAMENTO EM MEIOS POROSOS, 1, pp. 327-337. , Campinas. Anais... São Paulo: UNICAMP, 1991Beckert, O.P., Miguel, M.H., Marcos Filho, J., Absorção de água e potencial fisiológico em sementes de soja de diferentes tamanhos (2000) Scientia Agrícola, 57 (4), pp. 671-675Calado, V.M.A., (1993) Modelagem E Simulação De Secadores Em Leitos Fixo E Deslizante, , Tese (Doutorado em Engenharia Química) - Universidade Federal doRio de Janeiro - UFRJ, Rio de JaneiroChopra, R., Prasad, D.N., Standardization of soaking conditions for soybean seeds/cotyledons for improved quality of soymilk (1994) Indian Journal of Animal Sciences, 64 (4), pp. 405-410Ciabotti, S., Características sensoriais e físicas de extratos e tofus de soja comum processada termicamente e livre de lipoxigenase (2007) Ciência E Tecnologia De Alimentos, 27 (3), pp. 643-648Coutinho, M.R., Modelagem e validação da hidratação de grãos de soja (2005) Ciência E Tecnologia De Alimentos, 25 (3), pp. 603-610Coutinho, M.R., Novo modelo de parâmetros concentrados aplicado à hidratação de grãos (2007) Ciência E Tecnologia De Alimentos, 27 (3), pp. 451-455Crank, J., (1975) The Mathematics of Diffusion, , 2 ed. London: Oxford University PressEngels, C., Modelling water diffusion during long-grain rice soaking (1986) Journal of Food Engineering, 5 (1), pp. 55-73Hsu, K.H., A diffusion model with a concentration-dependent diffusion coefficient for describing water movement in legumes during soaking (1983) Journal of Food Science, 48 (2), pp. 618-622+645Hsu, K.H., Effect of temperature on water diffusion in soybean (1983) Journal of Food Science, 48 (4), pp. 1364-1365INSTITUTO ADOLFO LUTZ - IAL. Normas analíticas do Instituto Adolfo Lutz. 3 ed. São Paulo, 1985. (v. 1)Klamczynska, B., Czuchajowska, Z., Baik, B., Composition, soaking, cooking properties and thermal characteristics of starch of chickpeas, wrinkled peas and smooth peas (2001) International Journal of Food Science and Technology, 36 (5), pp. 563-572Lo, W.Y.L., Soaking soybeans before extraction as it affects chemical composition and yield of soymilk (1968) Food Technology, 22 (9), pp. 1188-1190Long, F.A., Richman, D., Concentration gradients for diffusion of vapor in glassy polymers and their relation to time dependent diffusion phenomena (1960) Journal of The American Chemical Society, 82 (3), pp. 513-519Nelson, A.I., Steinberg, M.P., Wei, L.S., Illinois process for preparation of soymilk (1976) Journal of Food Science, 41 (1), pp. 57-61Pan, Z., Tangratanavalee, W., Characteristics of soybeans as affected by soaking conditions (2003) Lebensmittel-Wissenschaft Und-Technologie, 36 (1), pp. 143-151Peleg, M., An empirical model for the description of moisture sorption curves (1988) Journal of Food Science, 53 (4), pp. 1216-1219Singh, B.P.N., Kulshrestha, S.P., Kinetics of water sorption by soybean and pigeonpea grains (1987) Journal of Food Science, 52 (6), pp. 1538-1544Sopade, P.A., Obekpa, J.A., Modelling water absorption in soybean, cowpea and peanuts at three temperatures using Peleg's equation (1990) Journal of Food Science, 55 (4), pp. 1084-1087Wang, H.L., Hydration of whole soybeans affects solids losses and cooking quality (1979) Journal of Food Science, 44 (5), pp. 1510-151
