Effect of puroindolines on dough rheological properties

Puroindolines proteins are related to grain hardness and affect milling yield, flour particle size, damaged starch content and water absorption. Little information is available on the role of puroindolines in dough rheology. This study aimed at investigating the rheological properties of durum wheat (T. durum, Svevo cv, S), soft-textured durum wheat (Soft Svevo, SS), soft wheat (T. aestivum, Alpowa cv, A) and hard-textured wheat (Alpowa with 5DS distal end deletion, AD). Samples were kindly provided by Dr Morris (USDA-ARS, Western Wheat Quality Lab). Gluten aggregation properties (GlutoPeak test, GPT), dough mixing properties (Farinograph test), extensibility (micro-Extensograph test), and pasting properties (Micro-Visco-Amylograph test, MVAG) were measured. GPT profiles showed AD exhibited a higher area under the curve than A (1498 vs 787 GPE) at maximum torque, indicating strong gluten. SS showed a lower area under the curve than S (969 vs 1467 GPE) at maximum torque. Differences in particle size and damaged starch (S vs SS and A vs AD) are responsible for differences in maximum torque (GPT), water absorption and dough development time. Moreover, AD showed higher stability than A (8.5 vs 2.2 min). While, dough from SS was slightly less stable than dough from S (3.3 vs 2.5 min). AD showed higher resistance to extension than A (108 vs 82 BU), while no differences in dough extensibility were measured between S and SS. MVAG profiles showed that AD had lower pasting temperature (59 vs 61 ∘C), higher peak viscosity (638 vs 566 BU), lower breakdown (303 vs 323 BU) and higher setback values (746 vs 631 BU) than A. Conversely, SS showed higher pasting temperature (60.8 vs 58.3 ∘C) and higher peak viscosity (723 vs 849 BU) than S. This study showed that puroindolines affect rheological properties and pasting properties, but the trend is different in T. aestivum and T. durum.