Casein phosphopeptides (CPP) which develop in Grana Padano cheese at different ages were isolated by precipitation with Ba2+ and analysed by HPLC. Profiles were complex throughout the period between 4 and 38 months. CPP in a cheese sample 14 months old were identified by a combination of fast atom bombardment-mass spectrometry and Edman degradation. They were found to consist of a mixture of components derived from three parent peptides, β-CNf(7-28)4P, α(s1)-CNf(61-79)4P and α(s2)-CNf(7-21)4P. In total, 45 phosphopeptides were identified: 24 from α-CN, 16 from α(s1)-CN and 5 from α(s2)-CN. The presence of aminopeptidase activity during cheese ripening was deduced from the presence of a number of CPP of different lengths with the loss of one or more residues from the N-terminus. The longest had C-terminal lysine and seemed to be progressively hydrolysed by carboxypeptidases A and B to shorter peptides. CPP in cheese appeared to be shortened plasmin-mediated products. Moreover, those most resistant to further hydrolysis contained at least three closely located phosphoserine residues. The anticariogenic activity of CPP is also discussed.
|Titolo:||Phosphopeptides from Grana Padano cheese: nature, origin and changes during ripening|
PELLEGRINO, LUISA MARIA (Penultimo)
RESMINI, PIERPAOLO (Ultimo)
|Settore Scientifico Disciplinare:||Settore AGR/15 - Scienze e Tecnologie Alimentari|
|Data di pubblicazione:||1997|
|Digital Object Identifier (DOI):||10.1017/S0022029997002392|
|Appare nelle tipologie:||01 - Articolo su periodico|