Enzymatic Hydrolysis of Small Yellow Croaker Scraps for Preparing Flavor Precursors

Small yellow croaker scraps were enzymatically hydrolyzed to obtain flavor precursors. The simultaneous use of alcalase and flavourzyme was found to be the best choice for the production of flavor precursors with higher degree of hydrolysis (DH),and the hydrolysis conditions including material/liquid ratio,hydrolysis duration,enzyme dosage,initial pH and hydrolysis temperature were optimized by single factor method and response surface methodology based on Box-Benhnken experimental design. The optimized values of the four hydrolysis conditions were determined as follows:material/liquid ratio,1:7; hydrolysis temperature,55 ℃; initial pH,8.0; alcalase dosage,2.5%; and ourzyme dosage,3.0%. Under these conditions,the DH was 40.11%,and the contents of total amino acids,essential amino acids and four delicious amino acids in the obtained hydrolysate were 86.383,32.785 g/100 g and 38.384 g/100 g,increasing by 67.56 %,82.02 % and 79.52% in comparison with those of the start material,respectively. Moreover,the obtained hydrolysate had a strong flavor of small yellow croaker.