Proteolysis of beta-casein as a marker of Grana Padano cheese ripening.
Proteolysis has a critical role in defining the typical organoleptic characteristics of Grana Padano, a well-known Italian cheese. During the ripening process, hydrolysis of beta-casein produces different fragments, the most abundant and widely studied of which are gamma-caseins, three polypeptides containing the HOOC-terminal portion of beta-casein. By sodium dodecyl sulfate-PAGE and a specific anti-beta-casein monoclonal antibody, two beta-casein-derived bands were identified in Grana Padano cheese: betaa and betab. Thanks to the identification of the amino acid sequences, it was shown that: a) betaa contains gamma1-casein [beta-casein (29-209)] and the correlated peptide [beta-casein (30-209)]; b) betab contains gamma2-casein [beta-casein (106-209)] and gamma3-casein [beta-casein (108-209)]. The production of betaa and betab by the three enzymes most involved in cheese proteolysis (pepsin, chymosin, and plasmin) was evaluated by performing in vitro digestions. A significant correlation between abundance of some polypeptides and ripening process was shown.
Gaiaschi
A
A
Inst. Pharmacological Sciences, University of Milan, Italy.
Beretta
B
B
Poiesi
C
C
Conti
A
A
Giuffrida
M G
MG
Galli
C L
CL
Restani
P
P
D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal / Q000032:analysis; D002364:Caseins / Q000032:analysis / Q000378:metabolism*; D002611:Cheese / Q000032:analysis*; D012085:Chymosin / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D005341:Fibrinolysin / Q000378:metabolism; D005511:Food Handling; D010434:Pepsin A / Q000378:metabolism; D010446:Peptide Fragments / Q000032:analysis* / Q000737:chemistry; D013997:Time Factors
D000911:Antibodies, Monoclonal; D002364:Caseins; D010446:Peptide Fragments; D005341:Fibrinolysin; D010434:Pepsin A; D012085:Chymosin