Peptide profile of Coalho cheese: A contribution for Protected Designation of Origin (PDO).

Coalho cheese of Ceará and the Jaguaribe region of Brazil has been studied to determine its peptide profile. Peptides generated by the action of peptidases upon cheese proteins were separated by reverse-phase HPLC to give 28 fractions. Peptide sequencing after MS/MS fragmentation enabled the identification of 116 different peptides; 74 of them originated from β-casein, 4 from βA2-casein, 4 from βA3-casein, 25 from αS1-casein, 5 from αS2-casein, and 4 from κ-casein. Phosphorylated peptides were identified, one from αS1-casein and 17 from β-casein. Other reports on the bioactivity of casein-derived peptides have shown that the β-casein peptide (193-209) exhibits immunomodulatory, antimicrobial and antihypertensive activity. The peptides β-casein (58-72), β-casein (193-202), αs1-casein (85-91), αs1-casein (1-9), as well as αs2-casein (189-197) have antihypertensive activity. The fragment αS1-casein (1-23) is an immunomodulatory and antimicrobial peptide. These results can be a marker to determine the authenticity of this Brazilian cheese.