Kinetics of cowpea starch gelatinization based on granule swelling

Granule size measured by laser diffraction was employed to describe the gelatinization kinetics of cowpea starch. During isothermal heating of the starch suspensions over the temperature range 67-86 degrees C, the granule mean diameter increased rapidly initially and gradually leveled off to an equilibrium Value that showed both power law and exponential dependency on temperature. Gelatinization of the starch followed pseudo first-order kinetics after an initial time lag that diminished with increased heating temperature. The gelatinization rate constant increased with temperature and could be described by the Arrhenius model with an activation energy of 233.6 kJ/mole.