Caractéristiques de la chair de la truite arc en ciel : 1- composition chimique et cellularité du muscle et des tissus adipeux

Chemical composition and size of libre and adipose cells in the flesh of rainbow trout were studied. The flesh of fish includes a superficial red muscle which is composed of small fibres (beta red type) and a deep while muscle which is the main tissue and is composed essentially of a mosaic of small and large fibres (alpha white type). The mean size of muscle fibres increased with trout body weight. The amount of collagen in the flesh was low (below 1% of fresh muscle weight) and thermosoluble collagen seemed to be more variable than acidosoluble collagen. Thus, the quality of the flesh would depend on the characteristics of muscle tissues. Lipid content in the flesh of trout of market size reared in fresh water was low (below 10% of fresh weight) and it was located in abdominal and dorsal subcutaneous adipose tissues. Adipose tissues were generally composed of two populations of adipose cells, the small adipose cells (20/30 microns) beeing present in developing adipose tissue and large adipocytes whose size increased with the lipid content of the flesh

Caractéristiques de la chair de la truite arc en ciel : 2- composantes physiques et sensorielles

Some results on physical and sensory characteristics of the flesh of rainbow trout are reported. When fish was fed a diet not supplemented with carotenoid pigments, the color of the flesh was pale. The texture of the flesh of the trout assessed by physical and sensory tests was not tough and slightly elastic. The other parameters : smell, flavor or fat taste were low. Thus the flesh of rainbow trout is a rather neutral product. Texture of flesh assessed by instrumental methods and sensory evaluation was modified significantly by environnemental factors (temperature, water flow rate). Analysis of relationships between chemical composition and texture showed that lipid content affected texture of raw product but not that of cooked product

Control of skeletal muscle fibres and adipose cells size in the flesh of rainbow trout

International audienc

Caractéristiques de la chair de la truite arc en ciel : 1- composition chimique et cellularité du muscle et des tissus adipeux

National audienceChemical composition and size of libre and adipose cells in the flesh of rainbow trout were studied. The flesh of fish includes a superficial red muscle which is composed of small fibres (beta red type) and a deep while muscle which is the main tissue and is composed essentially of a mosaic of small and large fibres (alpha white type). The mean size of muscle fibres increased with trout body weight. The amount of collagen in the flesh was low (below 1% of fresh muscle weight) and thermosoluble collagen seemed to be more variable than acidosoluble collagen. Thus, the quality of the flesh would depend on the characteristics of muscle tissues. Lipid content in the flesh of trout of market size reared in fresh water was low (below 10% of fresh weight) and it was located in abdominal and dorsal subcutaneous adipose tissues. Adipose tissues were generally composed of two populations of adipose cells, the small adipose cells (20/30 microns) beeing present in developing adipose tissue and large adipocytes whose size increased with the lipid content of the flesh