Bitterness in Fish Protein Hydrolysatesand Methods for Removal

Egidijus DauksasRasa SlizyteTurid RustadIvar Stomz!

ABSTRACT. Enzymatic hydrolysis is a processing method for recover-ing protein from under utilized fish biomass and fish by-products. How-ever, the hydrolysis process often creates bitter taste in the product. Thebitterness restricts the practical uses of these hydrolysates. The presenceof bile in whole fish and fish viscera is shown to cause bitterness in fishprotein hydrolysates. The fat and ash content could also cause bittertaste. The content of total amino acids and hydrophobic amino acids didnot correlate with bitterness.

Three different methods were used to eliminate or reduce bitternessfrom FPHs after enzymatic hydrolysis with commercial enzymes:(I) treatment with endopeptidases (Flavourzyme@). (2) extraction withbutanol and (3) treatment with cholestyramine rcsin. Flavourzymc@ did