Amino acid composition of the longest back muscle (m. longissimus dorsi) young animals of specialised beef breeds

The relevance of the study consisted in the investigation of the qualitative characteristics of beef as a source of complete protein and the content of essential amino acids that determine its biological and nutritional value. The purpose of the study was to determine the content of non-essential and essential amino acids and conduct a comparative analysis of the amino acid composition of the longest back muscle (m. longissimus dorsi) in young animals of specialised beef breeds. The studies were conducted on Aberdeen-Angus, Volyn Beef, and Charolais bulls grown using meat cattle breeding technology in the Polissia zone of Ukraine. Control slaughter of experimental animals was performed at the age of 18 months. 3 animal units were selected from each breed, from which samples of the longest back muscle (m. longissimus dorsi) at the level of 9th-11th ribs were taken for research. The amino acid content was determined on an analyser by liquid ion exchange chromatography. Inter-breed differences in the quantitative content of non-essential and non-essential amino acids were found. In particular, the meat of Aberdeen-Angus bulls was characterised by the highest content of essential amino acids, among which methionine (6.84-16.5%), lysine (6.6-10.37%) and leucine (7.9-8.6%) dominated. For Charolais beef, elevated levels of lysine and valine were determined, while animals of the Volyn Beef breed had an advantage in leucine content. Among non-essential amino acids, glutamic acid (12.7-13.3%) and aspartic acid (8.9-10.09%) accounted for the largest share. The results obtained show that the quality of beef largely depends on breed characteristics, which determines its nutritional value, biological usefulness, and organoleptic properties. The higher content of methionine and histidine in Aberdeen-Angus meat indicates more intensive processes of intramuscular fat development, which provides better marbling and energy value of young meat of this breed. The results of the study can be used in practice for the selection and breeding of meat cattle with an optimal amino acid composition of meat to increase its nutritional and biological value