Modelling of Hydration Characteristics of Five Varieties of Cowpea Grains

Abstract

Introduction: The hydration of grains is a process that consists of soaking them in water in order to increase their moisture content and this is a crucial step in industrialized processing and provides several beneficial effects on their physicochemical and nutritional qualities.
 Aims: This study focused on modeling of hydration characteristics of five varieties of cowpea which are: Gombe, Oloyin white, Drum, Oloyin brown and Sokoto cultivated in Nigeria.
 Methodology: The experiments were carried out using electronic water bath at five temperatures (30, 40, 50, 60, and 70°C) in three replications. The amount of water absorption by five selected varieties of cowpea grains was calculated by measuring the increase in the mass of soaked grains per time. Five standard models of water absorption were fitted to the experimental data. Coefficient of determination (R2), chi-square (x2) and root mean square error (RMSE) were used to evaluate the models.
 Results: The initial moisture content of the saturated cowpea was estimated as 13.56 ±1.15, 15.05 ±2.27, 13.30 ±0.37, 10.85 ±0.13, 12.40 ±0.13 for Gombe, Oloyin white, Drum, Oloyin brown and Sokoto varieties respectively. The water uptake of the cowpea was faster at the initial stage and gradually slow down until the equilibrium moisture content was attained for all the varieties.
 Conclusions: Weibull model was adjudged as the best fitted model for describing the water absorption property of all the varieties of the cowpea and the Activation energy of Gombe, Oloyin white, Drum, Oloyin brown and Sokoto varieties are 42.26 ± 4.65, 40.36 ±8.90, 39.47 ±8.62, 43.08 ±5.25 and 39.66 ±6.72 respectively.

Moisture diffusivity, hardness, gelatinization temperature, and thermodynamic properties of ultrasound assisted soaking process of cowpea

“…There were significant differences ( p ≤ .5) in activation energy of conventional and different amplitudes of ultrasound soaked cowpeas obtained from diffusion and texture kinetics of both above and below gelatinization temperatures. Values of this study agree well with the literature value of 3.37–43.08 kJ mol −1 for the activation energy of hydration of different cowpea varieties at different soaking temperature ranges (Isa, Oyerinde, Jimoh, & Jegede, 2019; Sobukola & Abayomi, 2011). The activation energy of pigeon pea grains observed in a temperature range of 35–75°C and 75–100°C was 21.93 kJ mol −1 and 18.49 kJ mol −1 , respectively (Kate & Giri, 2020).…”

Influence of extrusion cooking on physicochemical properties and starch digestion kinetics of Sphenostylis stenocarpa, Cajanus cajan, and Vigna subterranean grains

“…Hydration properties have been successfully used in the screening of feed materials for different botanical origin/source [45,46] and varietal [47][48][49] differences, effects of processing techniques as well as effects of extrusion variables such as processing temperature, moisture [38], and mechanical stress. Increased water absorption potential of legume induced by extrusion have been reported for common bean (Phaseolus vulgaris), pinto and navy beans and legume pasta of faba beans, lentils and black gram beans extruded at 80-180˚C [31,[50][51][52] and range PLOS ONE from 30.5-165% in these grain legumes.…”