Proteolytic Activity in Muscle from Atlantic Salmon (Salmo salar)

The maximum proteolytic activity appeared in the neutral to slightly alkaline pH range. Heat-stable alkaline proteases were detected. Optimal activity was found at pH 8 and 65°C. The activity dropped off markedly below 60°C and above 70°C. Preincubation of the muscle-extract for about 10 min at 65°C stimulated the activity. Salmon muscle was especially susceptible to proteolytic degradation at elevated temperatures. No notable differences were detected in proteolytic activities of Atlantic salmon in the feeding stage (superior quality) and in the sexually mature stage.