Evaluation of dough conditioners and bran refinement on functional properties of intermediate wheatgrass (Thinopyrum intermedium)

Cultivating perennial crops such as intermediate wheatgrass, (IWG) (Thinopyrum intermedium), benefits the environment, e.g. by reducing nitrogen run-off compared to cultivation of annual crops like wheat. However, IWG's ability to form a gluten-network is low, and processing modifications may be needed to improve it. Our objective was to study the effect of bran reduction and addition of dough conditioners (wheat protein isolate, vital wheat gluten, ascorbic acid, xylanase, transglutaminase) on extensibility, resistance to extension and protein secondary structures of IWG dough. Grain kernels were analyzed for dimensions and chemical composition. IWG from two locations was used, hard red wheat served as reference. IWG kernels were thinner, lighter, and of lower bulk density than wheat; flour contained more insoluble dietary fiber, protein and ash; and dough was less extensible. Growing location affected fiber and protein content, and was associated with structural and rheological differences. Bran addition increased β-sheets and resistance to extension, but decreased β-turns and extensibility. Transglutaminase increased resistance to extension and affected protein conformation, especially α-helices. Wheat proteins addition had similar, but less pronounced effects. Future studies to evaluate different levels and combinations of dough conditioners, and their effects on bread characteristics, are needed.