Introduction. This work is aimed at studying of baking properties and amino acid composition of bioactivated disintegrated amaranth grain as an ingredient for wheat and spelt bread making. Materials and methods. Amaranth grain of Kharkivskyi-1 variety, soaked at the hydro module of 1:1 for 12-48 hours, was used to obtain bioactivated disintegrated amaranth grain. Consumer, sensory, physicochemical characteristics of wheat and spelt bread, and its protein biological value were analyzed at 15-25% of the semi-finished product substitution of wheat or spelt flour. Amino acid composition was determined by the ion exchange liquid chromatography. Results and discussion. Incorporation of the bioactivated disintegrated amaranth grain (BDAG) into wheat and spelt bread formulations at 15-20% of the flour substitution led to increase in the specific volume of the loaves by 7-21% due to increased enzymatic activity and improved bioavailability of essential minerals during dough fermentation. The amaranth grain soaking should be 36 hours to achieve the improved sensory properties of the product. The complex quality of the wheat and spelt bread significantly depended on the flour substitution by the BDAG (56%, p= 0.007) and duration of the amaranth grain soaking (62%, p=0.038), respectively. The duration of the amaranth grain soaking had the dominant effect on the quality of the wheat bread and spelt bread with BDAG. Owing to biochemical processes, bioactivated disintegrated amaranth grain showed the improved amino acid score by 1.5-2.7 times for all essential amino acids, and 1.8-2.1 times increased content of essential and nonessential amino acids. Incorporation of 20% of the BDAG into the wheat bread formulation led to 2.4-fold increase of lysine content in the products, and the scores of essential amino acids reached up 133-213%. Bread with added BDAG contains 1.6-1.7 times more essential and nonessential amino acids. Utility of the protein followed the ascending order: wheat flour -> amaranth grain -> wheat bread -> bioactivated disintegrated amaranth grain -> wheat bread with bioactivated disintegrated amaranth grain. Protein biological value of the bread with BDAG increased up to 76%. Conclusions. The duration of the amaranth grain soaking was the dominant factor influencing the bread quality, and providing a significant improvement in the protein biological value.
