Debittering and Hydrolysis of a Tryptic Hydrolysate of β‐casein with Purified General and Proline Specific Aminopeptidases from Lactococcus lactis ssp. cremoris AM2

In this study, purified β‐casein was hydrolysed with trypsin to produce a bitter substrate. The role of 3 aminopeptidases, a general aminopeptidase lysyl‐ para ‐nitroanilide hydrolase (KpNA‐H), X‐prolyl dipeptidyl aminopeptidase (Pep X) and aminopeptidase P (Pep P) each purified from Lactococcus lactis ssp. cremoris AM2, in the hydrolysis and debittering of the tryptic hydrolysate of β‐casein, was then studied. The hydrolysates were analyzed for percentage degree of hydrolysis (DH%) and bitterness score. Results indicate that the hydrolysis and debittering potential of the general aminopeptidase (KpNA‐H) is limited in the absence of proline specific aminopeptidases. Statistically significant (p < 0.001) reductions in bitterness were obtained following incubation of the tryptic digest of β‐casein with specific combinations of the above aminopeptidases.