The hydrolytic efficiency of an extract of serine proteases from cultured Atlantic salmon (Salmo salar) pyloric caeca and four commercially available alkaline proteases (Alcalase 2.4L, Flavourzyme 1000L, Corolase PN-L and 7089) on salmon muscle mince were compared (pH 7.5, T=40°C) at the same activity level based upon Azocoll results. Alcalase 2.4L had the highest activity per g on the Azocoll substrate compared with the other enzymes. When the enzymes were added to the salmon muscle system at the same Azocoll activity level Corolase 7089 hydrolyzed the salmon muscle protein most efficiently reaching 14.4% degree of hydrolysis (%DH) within 180 min. The pyloric caeca extract (PCE) was also highly efficient (14.1%DH), followed by Flavourzyme 1000L (7.5%DH), Corolase PN-L (6.7%DH) and Alcalase 2.4L (5.6%DH) under the same reaction conditions. The reaction kinetics for each enzyme preparation was determined at different Azocoll activity units to evaluate cost effectiveness of using each enzyme in a commercial process. Alcalase 2.4L was the most cost-efficient.