Quinoa flour addition improves the rheological properties and resistant starch content of wheat dough: From the view of starch physicochemical properties and starch-protein interaction

Quinoa has emerged as a premier substitute for wheat, and it has been widely embraced by the food industry. The present study aims to investigate how varying levels of wheat flour substitution with quinoa flour impact dough rheology, protein network structure, starch physicochemical properties, and dough digestibility. With the increasing quinoa flour incorporation level, the protein network was gradually diluted due to the lack of glutenous protein. However, the proportions of small starch granules and long amylopectin chains increased significantly, resulting in an improved viscoelasticity of quinoa-wheat dough. Substituting wheat flour with quinoa flour effectively slowed starch digestion, increasing resistant starch content from 39.37 % to 67.08 %. This substitution promoted the formation of a more stable and well-organized structure, as evidenced by the increased starch resistance to enzymatic hydrolysis during short-range orderliness assessments. Microstructural analysis indicated that the synergy between small starch granules and the protein network enhanced starch molecular orderliness and reduced starch hydrolysis by digestive enzymes, particularly at a 25 % quinoa flour incorporation level. In conclusion, this study provides a foundation for adopting quinoa-and-wheat-based products in the food industry, paving the way for innovative applications. • Quinoa flour inclusion stabilizes the network of quinoa-wheat dough. • Quinoa flour inclusion optimizes rheological properties of quinoa-wheat dough. • Quinoa flour increases small starch granules content in quinoa-wheat dough. • Quinoa-wheat doughs had higher resistant starch content. • Quinoa flour inclusion retards starch digestibility of quinoa-wheat dough.