THE STUDY OF THE GLASS-TRANSITION OF GLUTENIN USING SMALL AMPLITUDE OSCILLATORY RHEOLOGICAL MEASUREMENTS AND DIFFERENTIAL SCANNING CALORIMETRY

Hydrated glutenin was studied using mechanical spectrometry and differential scanning calorimetry (DSC). Small amplitude oscillatory measurements showed, as a function of temperature, that hydrated glutenin between 4% and 14% moisture content showed glass transition temperatures between 132 and 22-degrees-C. Over the same moisture range, glutenin samples had glass transitions temperatures between 110 and 21-degrees-C as measured by DSC. Both techniques showed that the glass transition temperature of glutenin shifted to lower temperatures with increasing moisture content. Linear approximations of the glass transition temperatures obtained by DSC vs moisture content showed a depression of about 9-degrees-C/wt. %. Both methods showed that glutenin was very sensitive to the plasticizing effect of water in the moisture range studied and appears to be an amorphous, water plasticizable polymer.