Cereal Chem 67:286-291   |  VIEW ARTICLE

Interactions of Starch and Sugar Water Measured by Electron Spin Resonance and Differential Scanning Calorimetry.

J. M. Johnson, E. A. Davis, and J. Gordon. Copyright 1990 by the American Association of Cereal Chemists, Inc. 

Electron spin resonance (ESR) was used to evaluate the mobility of water in starch-water mixtures (12-50% H2O); ESR and differential scanning calorimetry (DSC) were used to study the effect of different sugars on starch-water interactions. TEMPO, a non-hydrogen-bonding hydrophilic probe, was used as the ESR reporter molecule for solution mobility. DSC was used to determine differences in onset temperatures for the starch thermal transitions. Both sugar type and concentration influenced the temperature range over which the events of starch transformations occurred. An increase in ESR correlation time for TEMPO, indicating less mobility in the aqueous phase, generally occurred when the amount of water was reduced or after heat treatment of starch-sugar-water mixtures. The sugars progressively raised the temperature of starch gelatinization measured by DSC with increasing concentration ESR results showed differences between the effect of different sugars in the heat treatment temperatures required to increase correlation time. These differences corresponded to differences noted for onset temperature of starch transitions as seen by DSC when different sugars at equal concentration were evaluated. The order of effectiveness of sugars in increasing DSC onset temperatures, as well as increasing ESR correlation time, was fructose, glucose, maltose, and then sucrose.