Collagen content in farmed Atlantic salmon (Salmo salar L.)

To clarify fish flesh quality problems and softening of fish muscle tissue during chilled storage, the collagen content, types I and V, and its changes in solubility during storage on ice in muscle of farmed Atlantic salmon (Salmo salar L.) were analyzed. The contents of acid-soluble, pepsin-soluble, and insoluble collagen in white muscle were determined in fresh fish muscle and after 3 days of storage in ice. The total collagen content was 2.9 g kg(-1) fresh weight. During storage on ice, a progressive change in solubility of muscle collagen was found. For acid- and pepsin-soluble collagen fractions, significantly higher and lower values, respectively, were detected. The presence and quantification of types I and V collagen in the different collagen fractions was determined also, but no significant difference in solubility during storage was found. The result suggested that collagen fibers of Atlantic salmon have a high solubility in acid solutions and contain few cross-links.