VARIATION IN TEXTURE OF FARMED ATLANTIC SALMON (SALMO SALAR L). RELEVANCE OF MUSCLE FIBER CROSS-SECTIONAL AREA

Sammendrag

Mechanical properties were studied between and within fillets of 80 conventionally farmed Atlantic salmon (3.5 kg) using a Warner-Bratzler blade (WB) and a 12.5-mm flat-ended cylinder. The relationship between the muscle fiber cross-sectional area versus mechanical response variables was examined. The average muscle fiber area differed significantly between salmon of similar size. Mechanical properties also varied substantially among individuals and between locations within fillets, showing firmer texture in the posterior fillet part on average. Shear force (WB) was 2-2.4 times higher with a wider range for analyses performed perpendicular than parallel to the muscle fibers. Raw fillets with low fiber cross-sectional area (< 12.500 mu m(2) on average) had significantly firmer texture compared with fillets with larger fibers. However, correlation analyses of individual data showed relatively low overall influence of muscle fiber size on the texture properties (r <= 0.35). Thus, the texture of salmon fillets is clearly multifactorial where muscle fiber size is not a major determinant.