[Fractional and amino acid composition of krill proteins and the potential for obtaining protein preparations]. / Fraktsionnyi i aminokislotnyi sostav belkov krilia i vozmozhnost' polucheniia iz nego belkovykh preparatov.

Studies of the fractional composition of krill proteins demonstrated that the content of protein fractions changes depending on the time of krill catch. The highest amount of water-soluble proteins is contained by krill caught in December (64%), of salt-soluble by krill caught in June (12%), base-soluble by krill caught in May, September and February (34%). Krill protein contains from 50 to 60% of water- and salt-soluble fractions. Analysis of the amino acid composition of krill proteins showed that it does not differ essentially from that of adequate food proteins.

[Amino acid composition of protein products from fish of low market value]. / Aminokislotnyi sostav belkovykh produktov iz ryb ponizhennoi tovarnoi tsennosti.

The amino acids composition of proteins from the whole fry fish, proteinic mass and the fish protein concentrate was investigated by using ion-exchange chromatography with an automatic analyzer (AAA-881, ChSSR). A balance of amino acids recorded during preparation of the protein mass obtained in fish with inferior market value (fry herring and sand fish) is cited. It was found that the protein mass of fry contains 2.3 and that of sand-fish, 1.3 as much of the amino acids as does the whole fish. It is methionine that has been ascertained to be a limiting amino acid for fry and the products of its processing. In the protein of this fish essential amino acids comprise 43.5% of the sum-total of all the amino acids, the corresponding percentages in the protein mass and the fish protein concentrate being 42.1 and 41.7, respectively. A comparison of the amino acids composition of the study proteins as against the amino acid scale of the ideal FAO protein shows that the protein mass and the fish protein concentrate represent products of high biological value.