Fat contained in the salmon skins is valuable natural fish oil. It is rich in n-3 polyunsaturated fatty acids and the protein substances contained therein consist mainly of collagenous protein. Therefore, the salmon skins are a good source for producing fish oil and for manufacturing collagen and gelatine. A condition for using salmon skins in order to manufacture collagen or gelatine is to remove its fat causing thermal or chemical denaturation of collagenous proteins. This is possible provided physical methods are used. It was found that the simplest and most effective method of releasing oil from salmon skins is pressing. It was shown that the application of ca. 3 MPa pressure makes it possible to release up to 90% of the fish oil contained in salmon skins. The content of residual fat in salmon press cake is still around 10%. If the press cake is intended for use as a raw material for producing fish collagen or gelatine, then, the fat therein should be removed using other methods.
salmon skins, fish oil, pressing method