Optimization of nitrogen recovery in the enzymatic hydrolysis of dogfish (Squalus acanthias) protein. Composition of the hydrolysates.

The recovery of nitrogen in the enzymatic hydrolysis of dogfish shark muscle was optimized by the use of response surface methodology. The optimum values for enzyme/substrate ratio, temperature and pH were found to be 3.7% (w/w), 55.3 degrees C, and 8.3, respectively. The dogfish protein hydrolysate produced under these conditions contained a high crude protein concentration (> 85%), and its high nutritional value was indicated by the presence of all essential amino acids, and by high PER values. These results indicate the potential for dogfish protein hydrolysate to be used in lieu of vegetable proteins as a protein supplement in foods.