Proteomic study of proteolysis during ripening of cheese made with Cynara cardunculus L.

Abstract

The pistils of wild and cultivated cardoons are used as vegetal coagulant to produced several traditional ewe´s and goat´s cheeses, some of them benefit from protected designation of origin (PDO) status in which Cynara cardunculus flower extracts have been successfully employed and legally required. The type of coagulant agent is one of the main factors responsible for the variability in cheese characteristics, being therefore its effect on the proteolysis a subject of profound study. A precise analytical technique is essential to understand the impact of different factors on cheese proteolysis. In this study three electrophoretic techniques have been used to evaluated the cheese proteolysis namely (1) urea polyacrylamide gel electrophoresis (Urea-PAGE) and (2) sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) for the insoluble fraction of cheese and (3) twodimensional gel electrophoresis (2-DE) for the soluble fraction. Results showed that urea-PAGE was the best method for cheese insoluble fraction analysis. Both urea PAGE and 2-DE methods are complementary and proteomic tools are helpful in understanding the proteolysis of ewe’s cheese.