Comparing the hydrolysis degree of industrialization byproducts of Withemouth croaker (Micropogonias furnieri) using microbial enzymes

Enzymatic modification of proteins is being increasingly studied, with the aim of adding commercial and nutritional values to byproducts. Thus this work aims to study the hydrolysis degree obtained by different enzymes and compare among different Withemouth croaker (Micropogonias furnieri) byproducts: mechanically separated meat, protein isolate and bones. To obtain the peptides, an enzymatic hydrolysis was performed, the reaction occurred in a thermostated bath using three separate enzymes under optimal conditions of each: Alcalase (pH 8.0, 50°C), Flavourzyme (pH 7.0, 50°C) and Protamex (pH 7.0, 40°C), the concentration of enzyme and protein substrate was 1:10 (U/g) according to the specific activity of each enzyme and when the hydrolysis process became constant the reaction was stopped by inactivating the enzyme at 85°C/10 min. The different enzymes tested showed the ability to hydrolyze proteins from both protein isolate and the demineralized croaker bones (DCB), with the DCB showing a higher hydrolysis degree, using the enzyme Protamex, and showing higher affinity for this enzyme by the substrate. It was also noted that the degree of hydrolysis is not correlated with the percentage of free tyrosine.