Hydration kinetics of cereal and pulses: New data and hypothesis evaluation

Abstract

This work described the hydration kinetics of several grains from the legumes and cereal families, which many of them were studied for the first time. In addition, some comparisons among the different hydration kinetics were performed to corroborate some hypothesis about this process. By comparing the hydration kinetics of the studied grains and fitting their data to suitable equations, the idea that this process is very complex was reinforced. It is difficult to say how intrinsic properties of the grains (color, size, specie, family, structure or composition) affect the hydration process. Some reported hypothesis about the hydration process were argued. For instance, it was demonstrated that some hypotheses about the grains hydration are not completely true: the grains with darker color seed coat do not always hydrate slower than the lighter color ones; the grains with sigmoidal behavior can hydrate faster than the grains with downward concave shape behavior; the bigger size grains sometimes hydrate slower than the smaller ones. It was concluded that the hydration process behavior and velocity are affected by many intrinsic properties of the grains (composition and structure, in a complex interaction) acting together to give the representative hydration kinetics behavior of each curve. Practical applications From the academic point of view, the results of this work will help to avoid misunderstandings during the study of the grains hydration process, as many hypotheses were reanalyzed and argued. Furthermore, it provides new data, in special for sigmoidal behavior grains, which is very scarce in the literature. From the industrial point of view, this work provides data about the hydration kinetics of several grains, which is very useful for the process design.

Using ultrasound for improving hydration and debittering of Andean lupin grains

“…In the case of Andean lupin, the value of this parameter was 0.013 ± 0.001 min −1 , similar to many legume grain as dark red kidney beans, fava beans, and white kidney beans (Miano, Sabadoti, Pereira, & Augusto, 2017). The parameter τ is related to the necessary time to change the permeability of the seed coat (Figure 1b), when it become completely permeable to water due to the change on its components from the glassy to the rubbery state .…”

“…It should be mentioned that this result depends on the applied volumetric power of ultrasound, since as the power is increased; the hydration is accelerated (Yildirim et al, ). In addition, the grain structure‐composition is responsible for the hydration kinetics characteristics (velocity and maximum absorbed water) (Miano, Sabadoti, et al, ), which can affect how ultrasound enhances the process.…”

Oat hydration kinetics at different temperatures: Evaluation, model, and validation

“…The obtained hydration kinetics data of the grain was first fitted to Peleg's model (Equation (1)); the model is an empirical model widely used to describe the hydration kinetics data of grains with downward concave shape behavior (Miano, Sabadoti, et al, ). where M t is the moisture content of the grain (% db) at each time, t (min); k 1 and k 2 are the water absorption rate parameter (min . % db −1 ) and equilibrium moisture content rate parameter (% db −1 ); M o is the initial moisture content of the grain (% db).…”

“…The obtained hydration kinetics data of the grain was first fitted to Peleg's model (Equation (1)); the model is an empirical model widely used to describe the hydration kinetics data of grains with downward concave shape behavior (Miano, Sabadoti, et al, 2017).…”

“…The hydration behavior of grains have been studied and their kinetics mathematically described in several studies to predict the moisture uptake of different grains at different temperatures, such as rice (Balbinoti, Jorge, & Jorge, 2018); sorghum (Kashiri, Daraei Garmakhany, & Dehghani, 2012); wheat (Kashaninejad, Dehghani, & Kashiri, 2009); adzuki beans (Oliveira et al, 2013), among others (Miano, Sabadoti, Pereira, & Augusto, 2017). The hydration studies, however, were mostly conducted at isothermal conditions.…”