Debittering of Protein Hydrolysates Using Aeromonas caviae Aminopeptidase

The bitter-tasting peptide solutions prepared from the protease hydrolysate of milk casein and soy protein were treated with aminopeptidase produced by Aeromonas caviae T-64. The bitterness of these solutions were significantly reduced with an increase in the amount of released free amino acids. Hydrophobic amino acids having Δf values more than 1500 cal/mol, such as valine, isoleucine, leucine, tyrosine, and phenylalanine, accounted for more than 76% of the free amino acids released by the aminopeptidase. The results suggest that the enzyme hydrolyzed bitter peptides containing hydrophobic amino acids in the N-terminal region and the bitterness of the peptides were reduced by removal of these amino acids. Keywords: Debittering; protein hydrolysate; Aeromonas aminopeptidase; bitter peptide