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

Coalho cheese of Ceara 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 beta-casein, 4 from beta A2-casein, 4 from beta A3-casein, 25 from alpha S1-casein, 5 from alpha S2-casein, and 4 from x-casein. Phosphorylated peptides were identified, one from alpha S1-casein and 17 from beta-casein. Other reports on the bioactivity of casein-derived peptides have shown that the beta-casein peptide (193-209) exhibits immunomodulatory, antimicrobial and antihypertensive activity. The peptides beta-casein (58-72), beta-casein (193-202), alpha s1-casein (85-91), alpha s1-casein (1-9), as well as alpha s2-casein (189-197) have antihypertensive activity. The fragment alpha S1-casein (1-23) is an immunomodulatory and antimicrobial peptide. These results can be a marker to determine the authenticity of this Brazilian cheese. (C) 2016 Elsevier Ltd. All rights reserved.