Proteolysis during the ripening of goats' milk cheese made with plant coagulant or calf rennet

Powdered plant coagulant (PPC) obtained from the cardoon (Cynara cardunculus) was compared with calf rennet (CR) for the manufacture of goats' milk cheese, by determining difference in the proteolysis throughout ripening. There were no substantial differences between the compositions of cheeses made using the two types of coagulants. However, cheeses manufactured with PPC exhibited higher levels of pH 4.6-SN than cheese made using CR. The extent of breakdown of α_s-casein, as measured by urea-PAGE, was greater in cheese made using PPC than cheese made using CR. The formation of hydrophobic peptides and the ratio of hydrophobic/hydrophilic peptides throughout the ripening were higher in cheeses made with PPC than in cheeses made with CR. Principal component analysis (PCA) of peak heights of RP-HPLC peptide profiles of the ethanol-soluble and ethanol-insoluble fractions distributed the samples according to the coagulant used in their manufacture. Quantitative differences in several peptides were evident between the two types of cheese.