Mathematical model for describing corn grain dehydration kinetics after a nixtamalization process

In this research, the mathematical model associated with the hydrothermal dehydration process of Nixtamalized Corn Grains (NCG) with different Steeping Time (ST) values, allows the fitting of experimental data with initial moisture M₀ and the equilibrium moisture M_E as a function of Isothermal Dehydration Time (IDT). The moisture percentage for any time t and dehydration rate (isolines M(t) and isolines v_I respectively) of the NCG is shown by means of matrix graphics as a simultaneous function of IDT and ST. The relationship between initial dehydration rate v₀ and initial moisture M₀ establishes as a function of ST. Also, the mathematical model associated with the solution of the second Fick’s law allows calculating the diffusivity rate v_k (H₂O molecules out of NCG) and verify that the rate of change in moisture and the dynamical proportionality constant k has a non-linear dependence on the IDT and that k is directly proportional to D_{e f f} . The k values strongly relate to ST and the calcium ions percentage into NCG according to solubility lime values into cooking water (or nejayote) as a function of decreasing temperature when ST increases.