Effects of sourdough and dietary fibers on the nutritional quality of breads produced by bake-off technology

The aim was to evaluate the effect of sourdough and dietary fiber addition, as well as partially baked frozen (PBF) technology, on biological value of proteins, lipid profile, and some minerals content in selected tissues of rats.In all breads, the limited amino acid was lysine. Proteins of PBF conventional and PBF breads with an addition of dietary fiber (PBF DF breads) had significantly higher Chemical score and Essential amino acid index in comparison to proteins of Direct bread (P < 0.05). Protein digestibility corrected amino acids score was significantly lower in Direct DF and PBF improved breads (P < 0.05).Addition of fiber to Direct and PBF bread decreased significantly total digestibility of protein compared to all groups (P < 0.05).Concentration of calcium was significantly lower in liver of rats fed with Direct sourdough and PBF improved breads in comparison to rodents fed with Direct bread. The concentration of iron was significantly higher in liver of animals fed with Direct bread. The highest level of calcium in femoral bones of rats was shown in groups fed with PBF conventional bread. The lowest level of iron was measured in femoral bone of rats fed with PBF sourdough bread in comparison to the rest of the experimental groups.

► The effect of sourdough and dietary fiber on nutritional quality of partially baked frozen (PBF) breads was studied.
► In all breads the limited amino acid was lysine.
► Proteins of PBF conventional and PBF breads with added dietary fiber had better chemical indices in comparison to proteins of Direct bread.
► Addition of fiber to Direct and PBF breads decreased significantly total digestibility of proteins.