Caractéristiques musculaires de truites triées sur la texture de leur chair

Among fish quality traits, flesh texture is an important sensory quality trait for consumer but also for processing plant during filleting or slicing. 35 fish upon 700 were selected as "soft" (M) or "firmed" (F) based on the mechanical resistance of the fillet using a penetrometric test with a cylinder plunger. No difference was measured between M and F fish for body weight and global or muscle adiposity. Fillet lightness was higher for F fish (p<0,05). Muscle pH, measured immediately after slaughter, was higher (p<0,001) for F fillet. Difference in fillet firmness, the selective trait at slaughter, was still significant at 48h post-mortem (pm). No difference between M and F was measured for ultimate pH (48 h pm) or white muscle fibre mean diameter. Muscle transcriptome analysis revealed, between M and F, differences in the expression of genes coding for structural components, especially for connective tissue and enzymes (metabolic and proteolytic).