Enzymatic hydrolysis of protein of rainbow trout viscera (Oncorhynchus mykiss). Effect of type of enzyme, temperature, pH and stirring speed

Abstract

The degree of hydrolysis (DH) of rainbow trout viscera (Oncorhynchus mykiss) using Alcalase 2.4L, Flavourzyme and Neutrase. Alcalase 2.4L presented higher DH compared with Flavourzyme and Neutrase. Therefore, the process using Alcalasa 2.4L was optimized according to temperature and pH, finding a maximum DH of 24% at pH 8.5 and 45°C in a 500 mL reactor. The process was scaled to a reactor of 7.5 L, in which the effects of the the stirring speed (75-200 RPM) and the presence of deflectors were evaluated. The results indicate that the model satisfactorily fits the DH values in the levels analyzed (R2 = 0.96). The DH depends on pH, temperature, type of enzyme, speed of agitation, work scale and presence of baffles in the reactor. This information is of importance for designing the enzymatic hydrolysis processes of an specific substrate.