A Unified Mass Transfer Model for Cereal and Legume Hydration

Miano A.C. · Food Biophysics (2026) · DOI: 10.1007/s11483-026-10222-9

Resumen

A phenomenological Weibull reparameterization with mass-balance consistency for grain hydration kinetics is still lacking despite the coexistence of two well-known behaviors: downward concave shape (DCS) and sigmoidal patterns. This study proposes a Modified Weibull Model (MWM), derived as the analytical solution of a differential water mass balance in which the effective mass transfer coefficient follows a power-law time dependence. The model constitutes a phenomenological Weibull reparameterization with mass-balance consistency, with the novelty residing principally in its formal mass-balance derivation, which establishes the formal consistency of the Weibull-type form with a mass-balance framework and assigns phenomenologically motivated interpretations to its parameters. The model introduces a shape parameter (n) with proposed phenomenological interpretation as a seed coat mass transfer pathway index. Specifically, n < 1 describes DCS behavior with high initial permeability that decreases over time, n = 1 corresponds to pseudo-first-order kinetics, and n > 1 produces sigmoidal curves with a definable inflection time associated with maximum hydration rate. The model was evaluated against using 36 hydration datasets from five grain species, considering both cultivar variability and initial moisture content (M₀). The MWM achieved high goodness-of-fit (R² ≥ 0.9957), successfully capturing both kinetic regimes within a single framework. A key finding is the exploratory exponential decrease of n with increasing M₀ in legumes (based on six moisture levels per species), which may reflect the progressive seed coat plasticization. In contrast, corn exhibited a constant n (~ 0.54), indicating that structural morphology dominates hydration behavior. The MWM provides a unified framework for describing grain hydration kinetics, enabling systematic comparison across species, cultivars, and initial moisture contents under a common parameter set. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2026.

Instituciones: Universidad Privada del Norte