TITLE:
Hydration Characteristics of Selected Varieties of Paddy Rice from Nigeria
AUTHORS:
C. Ejebe, E. M. Kwofie, M. Ngadi
KEYWORDS:
Rice Paddy, Parboiling, Hydration Rates, Saturation Time, Diffusion Coefficient, Activation Energy
JOURNAL NAME:
Advances in Chemical Engineering and Science,
Vol.9 No.1,
January
10,
2019
ABSTRACT:
In this study, water absorption characteristics of some rice
varieties (Bisalayi, FARO 61, FARO 60, FARO 52 and FARO 44) from Nigeria were studied at 30°C, 45°C, 60°C and 75°C by determining the increase in grain
weight as a function of time during soaking. Differences in moisture content
among the selected varieties of paddy during soaking were significant (P 2 of
(0.834 - 0.997).
Water absorption rate was found to increase with soaking temperature, while
water saturation time decreased with temperature. Average values of diffusion
coefficients of moisture during soaking of paddy rice at different temperatures (30°C, 45°C, 60°C and 75°C) were estimated as 6.25 × 10 -11, 6.28 × 10 -11, 7.02 × 10 -11, and 5.51 × 10 -11 and 5.52 × 10 -11 m2/s
for Bisalayi, FARO 61, FARO 60, FARO 52 and FARO 44, respectively. The activation energies of the
diffusivity through different varieties of rice grains werecalculated using Arrhenius-type equation for diffusion
dependence on temperature and were determined as 41.96, 38.69, 40.16, 34.05 and
42.12 kJ/mole for Bisalayi, FARO 61, FARO 60, FARO 52 and FARO 44 for the
respectively rice variety above.