Baking properties of flour and nutritional value of rye bread with brewer's spent grain

This study aimed to determine the changes in the baking value of rye flour and the content of nutrients in rye breadstuff under the influence of partial rye flour (RF) replacement with brewer's grains (BSG): barley (BBSG) and, barley with buckwheat (BBSG + B). Compared to rye flour (RF), BBSG and BBSG + B contained significantly more total protein, dietary fiber, lipids and ash, and less starch, which significantly modified contents of these ingredients in breadstuff with 10% of BSG in a mixture with RF. Under the influence of both supplements, the initial and final gelatinization temperature increased, and the measured viscosities of the gruel decreased, especially in the BBSG samples. The dough softening was reduced by replacing flour with BBSG + B, while increased by adding BBSG. The supplements increased the water absorption of the flour by 4–6%, which resulted in an increase in the bread productivity with their 10% share. The volume of breadstuff decreased significantly in the samples with 20% of BSG. In the organoleptic assessment, the breadstuffs with BBSG and BBSG + B were rated higher than the rye breadstuff. Breads containing 10% of BBSG + B or BBSG were ranked the highest.