Hydration Kinetics of Red Kidney Beans (Phaseolus vulgaris L.)
Document Type Article
Journal of Food Science
Abstract
Soaking of dry red kidney beans was studied at 20, 30 40 and 60°C by the method of weight gain until equilibrium conditions were attained. Water absorbed during soaking was a function of both soaking time and temperature. Soaking at high temperatures increased the hydration rate constant and decreased soaking time to achieve equilibrium. Compared to unblanched beans, the application of a pre-blanching step considerably reduced hydration times of blanched beans. Due to the plasticity effect acquired upon blanching, blanched beans showed a significantly high hydration rate constant and exhibited a more constant equilibrium moisture content regardless of soaking temperature. Activation energy values (Ea) of the hydration process were 6.48 Kcal/mole for blanched and 14.25 for unblanched beans.