Proteomic and peptidomic profiling of Brazilian artisanal 'Coalho' cheese.

Background: Artisanal 'Coalho' cheese is a product typically popular in the Brazilian north-eastern region. Production of this cheese represents about 9.2% of the internal crude product of Pernambuco State. Several peptides are generated from hydrolysis of αS1 -, αS2 -, β-, and κ-caseins during manufacture of this cheese. The commercial importance of Brazilian artisanal 'Coalho' cheese justifies the examination of both the protein and peptide profiles of cheeses from six cities of the semi-arid region of Pernambuco State, Brazil.

Results: SDS-PAGE of the aqueous extracts of 'Coalho' cheeses (WSP) showed bands of lactoferrin, β-lactoglobulin, β-lactoglobulin (dimer), α-lactoalbumin, bovine serum albumin, α-casein, β-casein, κ-casein and para-κ-casein. A total of 57 to 72 peptides were confirmed by mass spectra in the different samples of 'Coalho' cheese which 32 known peptides (11 from αS1 -casein, three from αS2 -casein, 15 from β-casein and three from κ-casein), comprising seven caseinphosphopeptides. Among the unidentified peptides, three showed high intensity peaks in all 'Coalho' cheeses studied (with molecular weights of 1597, 1725/1726, 2778/2779 Da).

Conclusion: The proteomic studies revealed peptides that may represent molecular markers or fingerprints for investigating the quality control and regional characterisation of these 'Coalho' cheeses. © 2016 Society of Chemical Industry.