Estimation of HRW wheat heat damage by DSC, capillary zone electrophoresis, photoacoustic spectroscopy and rheometry

The effect of wheat heat damage was estimated using hard red winter (HRW) wheat varieties grown in Oklahoma, and analyses were performed on wheat kernels, flour, and isolated starch. Wheat kernels were analyzed by photoacoustic spectroscopy (PAS), flour was analyzed by DSC, capillary zone electrophoresis (CZE) and rheometry, while starch was analyzed by DSC. DSC data showed little difference in the temperatures of starch gelatinization. The ΔH values increased at 50 °C storage temperature. PAS data revealed differences in sensitivities to heat between the three cultivars. The pericap of cultivar Jagger was about five times more heat resistant than the pericarp of the other two cultivars. CZE maps showed that gluten proteins from cultivar 2137 was more affected by the 60 days and 50 °C treatment than the other two cultivars. Non-linear steady shearing showed that all heat-treated flours had lower viscosity, which suggests a deleterious effect on the potential performance of yeasted baked products. Viscoelastic properties of the Jagger untreated suspension sample showed strong gluten. The linear and non-linear viscoelastic behaviours of Jagger cultivar were less altered by heat treatment than were the other cultivars.