Collagen content and properties of skeletal muscle were studied among selected (FP) and unselected
(WP) Atlantic salmon lines that were reared together to avoid any environmental effects. The FP group
had significantly higher body weight at harvesting, softer texture and lower connective tissue yield compared
with the WP group. The relative collagen fractions (acid, pepsin, insoluble) were similar, but the FP
group had a greater abundance of amino acids involved in collagen triple helix conformation and stabilisation
(Gly, Pro, Hyp and Hyl), whilst the Lys content was greater for the WP group, indicating a more
aggregated collagen. The connective tissue denaturation temperature was lower for the FP group, coinciding
with a lower degree of collagen self-assembly and intermolecular-crosslinks. It is concluded that
selective breeding has resulted in lower connective tissue stability of Atlantic salmon fillets.