Four new methods of debittering protein hydrolysates and a fraction of hydrolysates with high content of essential amino acids.

Extraction of enzymatic protein hydrolysates with azeotropic secondary butyl alcohol (SBA) or aqueous ethanol (AE) or aqueous isopropranol (AI), seems to be an efficient and generally applicable method for removal of bitter compounds. The bitter peptides are concentrated in the alcohol-phase which has an extremely bitter taste. It has a concentration of 40-70 p. 100 essential amino-acids. In the alcohol-phase leucine, isoleucine, phenylalamine and tryptophan were particularly increased. Experiments showed that the bitterness of the alcohol-soluble fraction could be reduced by applying the plastein reaction. A reduction in bitterness of protein hydrolysates could also be achieved by applying hydrophobic interaction chromatography. Of tested gels, hexyl-sepharose was found to be the most effective for debittering of protein hydrolysates.