Bread is often fortified with dietary fiber of various origins to meet “good” and “excellent” source-of-fiber claims. But while incorporating soluble fiber at the elevated levels needed to fulfill such claims, the high water-binding capacity characteristic of fiber can cause undesirable rheological changes to dough, namely stickiness and poor machinability, which can result in bread with low loaf volume and a coarse, crumbly texture. This occurs because the additional fiber dilutes the protein content, which stresses the gluten network and reduces gas retention.
Reinforcing the gluten network by adding vital wheat gluten or using a high-protein spring wheat flour are possible approaches to improving the volume and texture of high-fiber breads.