Effect of Heat Treatment on the Antioxidant Activity as Well as In vitro Digestion Stability of Herring (Clupea harengus) Protein Hydrolysates

The aim of this study was to determine the effect of heat treatment on the antioxidant properties of herring meat and then subjecting it to hydrolysis with Alcalase (R) and testing these activities in the obtained protein hydrolysates. Another objective was to evaluate the antihypertensive activity and free amino acid profile of herring hydrolysates and to assess the stability of antioxidant properties against simulated digestion. The best biological activities present fried herring hydrolysates - 29.19% ability radical scavenging, sterilized canned hydrolysates - 2.55 mu mol TE/mg for FRAP value, raw and boiled herring hydrolysates were characterized by 89.89% Fe 2+-chelating activity. After simulated digestion, the radical scavenging ability and the FRAP value of hydrolysates from thermally processed raw materials decreased. However, decrease in Fe2+-chelating activity after simulated digestion was only noted for hydrolysates from boiled herring. The results show that heat treatment and In Vitro digestion affect the biological activities of herring protein hydrolysates.