Thermal characterization of rice starches - American Chemical Society

Thermal Characterization of Rice Starches: A Polymeric Approach to. Phase Transitions of Granular Starch. Costas G. Biliaderis,* Cheryl M. Page, Terry...
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J. Agric. Food Chem. 1986, 3 4 , 6-14

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Thermal Characterization of Rice Starches: A Polymeric Approach to Phase Transitions of Granular Starch Costas G. Biliaderis,* Cheryl M. Page, Terry J. Maurice, and Bienvenido 0. Juliano

The thermal properties of eight purified rice starches varying in physicochemical characteristics were investigated by differential scanning calorimetry (DSC) and thermomechanical analysis (TMA). There were significant correlations between DSC transition temperatures and gelatinization temperatures obtained by photometry, transition enthalpies and gelatinization temperatures, and volume expansion at 90 or 95 OC and amylose content. Although the Flory-Huggins theory for polymer melting fits the experimental data, it is not applicable to starch/water systems because of their irreversible (nonequilibrium) melting behavior. Water acts as a plasticizer (at