The rheology and structure of wheat gluten proteins

The unique viscous and elastic properties of wheat gluten are largely respo nsible for the end properties of wheat flours. These properties are determi ned by the structures of the proteins and their interactions with each othe r and other dough components. At present, we still have little understandin g of factors that influence elastic and viscous behaviour at the molecular level. With this work, we aim to understand the molecular basis of the biop hysical and functional properties of wheat gluten using a combination of rh eological and spectroscopic methods on characterised protein fractions from gluten and those derived from protein engineering. Protein fractions from wheat and homologous proteins from barley and rye ha ve been tested using dilute solution viscometry, and dynamic oscillatory te sting on the Rheometrics Fluids Spectrometer (RFSII, Rheometric Scientific Inc., USA). Protein samples at a number of different moisture contents were tested at 25 degrees C and the effect of strain and frequency of these pro teins were determined. The increased understanding of gluten protein and homologous barley protein functionality should facilitate the more efficient use of wheat gluten pro teins in traditional end uses and identify new areas in which they could be utilised.