Prior roasting of wheat impacts on the functionality of flour prepared from it: Part 2. Wheat protein functionality

Background and ObjectivesIn the accompanying paper (Part 1), it was reported that forced convection roasting of wheat before milling can be directed to tailor the viscosifying properties of flour. The objective of the present work was to examine the effect of prior wheat roasting on flour proteins.FindingsEffective control of wheat roasting conditions proved to be essential to avoid the irreversible loss of flour functionality as deduced from the flour ethanol and lactic acid solvent retention capacity and mixography data. Response surface models predicted roasting at 108 degrees C and 80 Hz (135 s) to maintain protein integrity. The microstructure of flour and isolated starch as well as X-ray diffraction patterns revealed starch to be relatively unaffected by this heat treatment.ConclusionsFlour produced from roasted wheat can still be used for products that require the formation of a gluten network.Significance and NoveltyProtein is more sensitive to roasting conditions than starch.