Starch other than gluten may make a dominant contribution to wheat dough mixing properties: A case study on two near-isogenic lines

Abstract Protein and starch are the two most abundant components in wheat flour that co-influence dough processing quality. Studies have demonstrated that protein content and composition play a decisive role in wheat dough development. Additionally, starch has a significant effect on dough behaviour. The physicochemical and mixing properties of two wheat near-isogenic lines (NILs; NILZX1 and NILZX2) with different high-molecular-weight glutenin subunits (HMW-GS) were analyzed to shed light on the role of starch and protein in the dough mixing process. The NILZX1 dough with superior HMW-GS combination had higher protein content than NILZX2 dough. Whereas NILZX1 had a lower storage modulus and shorter dough stability time than NILZX2. During the mixing process, the torque of NILZX1 dough was lower than that of NILZX2; the microstructure of NILZX1 dough was greatly destroyed in the starch-dominant phase, leading to inferior dough quality. NILZX2 with higher B-type starch content, relative crystallinity, and viscosity showed greater dough quality. Taken together, physicochemically, starch had a more substantial effect on the dough mixing properties than protein in the two NILs. The findings provide a foundation for exploring the contribution of starch to dough properties.