Publication no. C-2000-0210-05R |  VIEW ARTICLE

NOTE: Modeling Starch Gelatinization Kinetics of Milled Rice Flour.

Carlos A. Ojeda (1), Marcela P. Tolaba (1), and Constantino Suárez (1). (1) Departamento de Industrias, Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria,(1428) Buenos Aires, Argentina. Cereal Chem. 77(2):145-147. Accepted November 29, 1999. Copyright 2000 American Association of Cereal Chemists, Inc.

Milled long-grain rice samples were evaluated by differential scanning calorimetry (DSC) to determine the kinetics of starch gelatinization. The experiments were conducted with milled rice flour with a 10.6% degree of milling. DSC thermograms were obtained from 35 to 110°C using heating rates between 1°C/min and 15°C/min. The rate constants were evaluated, and two activation energies were found for different temperature ranges. At <70.1°C gelatinization was not completed. It was assumed that at <70.1°C gelatinization would only affect the amorphous regions. During the subsequent phase the crystalline regions destabilized by the amorphous component begin to gelatinize. For moisture content of 70%, wet basis, and a heating rate of 12°C/min, the enthalpy of gelatinization reaches a constant value of 7.3 J/g.