Comparison of overall water uptake by corn kernel with and without dissolved calcium hydroxide at room temperature

In the present work we investigated the kinetics of the overall water uptake by three corn varieties (Cacahuazintle corn, Yellow Dent corn and Chalco corn) soaked in water and in alkaline solution with two different concentrations of Ca(OH)₂. The behavior of the difference of moisture gain as a function of soaking time at room temperature suggest that the water uptake in alkaline solution is a kinetic process governed by physical changes in corn components, which depend on the Ca(OH)₂ concentration and the endosperm type of the corn kernel. Our results show that the uptake of water takes place in different kinetic stages of reaction and diffusion process. Each stage was correlated with a specific structural change that occurs in the pericarp, in the aleurone layer and in the outermost structure of the endosperm. The endosperm type and pericarp thickness were found to extend the reaction and diffusion process, the harder the endosperm and thicker the pericarp of the corn kernel the slower the kinetic process.