CHANGE IN AMINO ACIDS COMPOSITIONS OF BEEF WITH CONCENTRATED FATTENING OF CATTLE

Abstract

In the article the authors examine nutritive value of beef generated on concentrate fattening of beef cattle according to content of fat, protein and amino acids. Specimens for chemical analysis have been taken from the longest muscle of dorsum (Musculus longissimus dorsi). For comparative analysis three specimens have been selected: two from beef and one from porkmeat. The first sample has been prepared from beef of traditional fattening (I t.f.), the second one – from marbled beef (II c.f.) and the last one - from pork (III p.). The first and third samples have been extracted from cooled production realized in fresh form, on half carcass transection on second last rib. As for the second specimen an end product has been taken that is realized in cellophane vacuum package under the firm name «Marbled beef medallion», produced on cattle grain fattening «Black Angus» (correct name – Aberdeen-Angus breed) during 200 days. Chemical analysis has been conducted in researching centre Federal Science Centre «All-Russian Scientific-Researching and Technological Institute of Poultry Industry» under the Russian Academy of Science in 2018. Chemical and amino acid content has been examined in air-dried material of muscular tissue. The group of authors has discovered that in beef muscular tissue produced on concentrate fattening the content of protein is 20-23% less and fat is about five times more than in muscle of pork and beef generated on traditional fattening. The total content of amino acids of concentrate group was 23.4% less that in beef cattle muscle under the standard fattening and 19.6% less than in pork muscle. Deterioration of nutritive value arises due to increase of fat content and decrease of amino acids that are a part of globular and fibrillary proteins.