Debittering and hydrolysis of a tryptic hydrolysate of beta-casein with purified general and proline specific aminopeptidases from Lactococcus lactisssp cremoris AM2

In this study, purified P-casein was hydrolysed with trypsin to produce a b itter substrate. The role of 3 aminopeptidases, a general aminopeptidase ly syl-para-nitroanilide hydrolase (KpNA-H), X-prolyl dipeptidyl aminopeptidas e (Pep X) and aminopeptidase P (Pep P) each purified from Lactococcus lacti s ssp. cremoris AM2, in the hydrolysis and debittering of the tryptic hydro lysate of beta -casein, was then studied. The hydrolysates were analyzed fo r percentage degree of hydrolysis (DH%) and bitterness score. Results indic ate that the hydrolysis and debittering potential of the general aminopepti dase (KpNA-H) is limited in the absence of proline specific aminopeptidases . Statistically significant (p<0.001) reductions in bitterness were obtaine d following incubation of the tryptic digest of <beta>-casein with specific combinations of the above aminopeptidases.