Valorization of common bean protein extraction residues: production and characterization of polysaccharide-rich ingredients for food applications

Insoluble residue from common bean protein extraction was used to obtain three polysaccharide-rich ingredients: bean starch, fiber-rich flour, and carbohydrate-rich flour. The residue was fractionated by water suspension and centrifugation. Bean starch had high purity (90.71%) with minimal ash and fiber contamination. Its granules were oval to semi-elliptical, with slight surface porosities and some adhered protein bodies, showing a typical legume "C" crystallinity pattern, and gelatinization temperature of 74.65 °C. Viscosity curves were similar to those of bean starch in its native state. Fiber-rich flour had particles 5.6 times larger than carbohydrate-rich flour, due to higher fibrous content. It also showed higher water (5.09 g/g) and oil (1.52 g/g) holding capacities than carbohydrate-rich flour (3.16 g/g and 0.96 g/g, respectively). Phytate levels in both ingredients were below 0.7%, and no tannins were detected. This study demonstrates that the protein extraction process preserved flour macromolecules, reinforcing the potential of these byproducts in food applications.