QUALITY OF FISH-PROTEIN HYDROLYSATES FROM HERRING (CLUPEA-HARENGUS)

Fish protein hydrolysates were prepared, using minced fillets and Alca lase and papain, from raw herring and from herring defatted by ethanol extraction, cooking and pressing. Physicochemical, sensory and storag e properties as well as the molecular weight sizes in spray-dried hydr olysates were evaluated. Fat extraction before;hydrolysis reduced degr ee of hydrolysis. Alcalase hydrolyzed samples to a higher degree than papain. Ethanol extraction reduced fishy odor to barely detectable lev els. Papain hydrolysates were more bitter than those made with Alcalas e. Color and nonenzymic browning measurements indicated darkening duri ng 3 mo storage at room temperature (approximate to 20 degrees C).