Influenza del sistema di sacrificazione su trote iridee di allevamento. I - Considerazioni biochimiche

A total of 223 rainbow trout (Salmo gairdneri) bred in captivity were used to evaluate the effects on muscle tissue quality and on various biochemical and physical characteristics, of four different methods of slaughter : percussive stunning (PS), asphyxiation (AS), carbon dioxide narcotization (CN) and electrocution (EL). In order to evalutate the degree of ante mortem stress suffered by the fish, samples were taken at slaughter to determine the following biochemical parameters : glycogen, glucose, glucose-6-phosphate (G-6-P), lactic acid and glycolytic potential (G.P). The fish were then preserved whole in crushed ice at a temperature of 2 + 3°C for 6 days, during which time the rigor mortis and pH were evaluated daily. On the basis of the data obtained from this study, carbon dioxide narcotization (CN), because of its simple application and the guarantees it offers of better preservability of frozen fresh fish, could be used on a wider scale in industry.