Optimization of enzymatic hydrolysis of Alaska pollock frame for preparing protein hydrolysates with low-bitterness

To obtain hydrolysates with high nitrogen recovery (NR) and low-bitterness Alaska pollock frame (APF) was treated by high-pressure cooking at 120 degrees C for 30 min and hydrolyzed with ten different commercial proteases MEAP (Mixed enzymes for animal proteolysis) hydrolysates exhibited the best characteristics (high NR and low bitter taste) which had high content of oligopeptides with molecular mass lower than 1355 Da The optimum hydrolysis conditions using MEAP were determined as follows temperature 45 degrees C hydrolysis time 300 min enzyme to substrate ratio (E/S) of 1 2 g/100 g liquid-solid ratio 6 1 and initial pH 8 0 The NR and DH (degree of hydrolysis) of the hydrolysates were 76 89% and 18 09% whereas the bitterness value was lower than that of 01 g/L tea alkaloid The essential amino acid chemical scores (CS) were greater than 08 (0 8-1 4) in pollock frame hydrolysates (PFH) which exhibited high nutritional value It showed that APF and PFH as high-quality protein source may have a wide application (C) 2010 Elsevier Ltd All rights reserved