Background. High nutritional value of residual oat flour, which is a by-product in the production ß-D-glucan concentration BETAVEN, was the reason to make a trial to apply it in the production of wheat and wheat-rye bread. The aim of the study was to establish
a formulation for wheat and wheat-rye bread, in which part of wheat flour would be replaced by residual oat flour (at the level 20% of wheat flour), and to check the influence of this additive on sensory and nutritional properties of the products, with special consideration to content and biological value of the proteins.
Material and methods. The material consisted of wheat flour, rye flour and residual oat flour, as well as loaves, baked with these flours. The quality of the obtained loaves was analysed taking into account: organoleptic assessment, loaf mass and volume, moisture content crumb and texture profile of the crumb. In the studied raw materials and bread, the following components were determined according to AOAC methods: protein content, fat, fiber and ash. In addition, composition of amino acids was assessed. Basing on the amino acid composition, Chemical Score (CS) and Exogenic Amino Acid Index (EAAI) were calculated, applying WHO/FAO protein standard (1991).
Results. Bread with the share of residual oats flour received high consumer acceptance (37 points), comparable to control bread (38 points) despite of lower volume. The applied amounts of oats flour did not influence moisture content and texture profile during storage. Wheat and wheat-rye loaves with the share of residual oats flour were characterised by a significantly higher level of dietary fiber, fat and protein, in comparison to control bread. It was found that biological activity of protein in wheat-rye bread was significantly higher (CS = 53.5, EAAI = 91.5) in comparison to wheat bread (CS = 47.9, EAAI = 89.9). The share of oats flour caused an increase in biological value of all bread types – wheat-oats (CS = 52.7, EAAI = 91.2), wheat-rye-oats (CS = 56.4, EAAI = 91.9).
Conclusions. The results indicate that residual oat flour is a good source of proteins with a high biological value. Beneficial amino acid composition, and high contents of dietary fiber and fat make the flour an interesting additive for the production of white bread, both wheat and wheat-rye, which could be used in the amounts up to 20% of wheat flour mass.