TITLE:
Hydrodynamic Modelling, Thermodynamic and Textural Variations during Common Beans Soaking
AUTHORS:
E. M. Kwofie, O. I. Mba, M. Ngadi
KEYWORDS:
Common Beans, Soaking, Thermodynamics, Kinetics, Bean Hardness
JOURNAL NAME:
Advances in Chemical Engineering and Science,
Vol.9 No.1,
January
4,
2019
ABSTRACT: Hydrodynamic characteristics and its associated thermodynamic and textural variation of three common Malawian beans varieties (Boma, Sugar and Mandondo) during
soaking were evaluated at four temperature regimes (25°C, 35°C, 45°C and 55°C). The equilibrium water uptake of 127% ± 5% was reached in 10, 6, and 4 hours respectively, for 25°C, 35°C and 45°C. Not much variation was observed between 45°C and 55°C except for sugar beans where equilibrium water uptake was reached within two hours of soaking at 55°C. Three models namely Peleg, two-parameter Mitscherlich model and viscoelastic model were used to evaluate the comparative predicting capabilities of the bean hydrodynamic characteristics. All models predicted the water absorption accurately (R2 > 0.903, RMSE activation kinetic parameters to be between 25 - 65 kJ/mol. Sugar beans were found to be the least hard. At room temperature, its hardness reduced by 58% within 2 hours of soaking. At higher temperature (55°C) hardness values were reduced to 12.5%, 11.1% and 15.0% within the first hour for Boma, Sugar and Mandondo beans, respectively.