Physicochemical changes and bitterness of whey protein hydrolysates after transglutaminase cross-linking

Abstract Whey protein hydrolysates are widely used in hypoallergenic formulas. The extensive hydrolysis required to reduce the protein antigenic potential frequently generates bitter-tasting peptides. This study investigates the effect of transglutaminase (TG) catalyzed cross-linking on physicochemical characteristics and bitter taste of whey protein hydrolysates. The chromatographic analysis showed a slight increase in the relative concentration of peptides (p   0.05) in the intensity (6–7, on a scale up to 9) and duration (38 s) of the bitterness sensation were observed. Possibly, the presence of free glutamine and the significant amount of short peptides with no glutamine or lysine residue may have decreased the opportunities for cross-linking formation; therefore, the presence of bitter-tasting peptides was unchanged as a consequence of TG-treatment.