COMPARATIVE BIOCHEMICAL EVOLUTION DURING RIPENING OF BOVINE, OVINE AND CAPRINE CHEESES MANUFACTURED WITH EXTRACTS OF FLOWERS OF CYNARA-CARDUNCULUS

Changes in the main physicochemical and biochemical characteristics of bovine, ovine and caprine milk cheeses manufactured with. aqueous ext racts of flowers of Cynara cardunculus were studied throughout ripenin g (0-68 days). At the end of ripening the pH in the centre was (mean /- ISD) 5.05 +/- 0.07, 5.15 +/- 0.21 and 4.91 +/- 0.07 for bovine, ovi ne and caprine milk cheeses, respectively; whereas the pH at the top o f the cheese was 5.21 +/- 0.09, 5.44 +/- 0.12 and 5.12 +/- 0.07, respe ctively; the moisture content values of bovine, ovine and caprine milk cheeses were 37.68 +/- 2.32, 40.23 +/- 4.34 and 45.73 +/- 1.44%, resp ectively; the NaCl content values were 4.00 +/- 0.43, 4.00 +/- 0.56 an d 4.08 +/- 0.58 (%TS); the fat content values were 41.01 +/- 5.32, 63. 60 +/- 7.80 and 45.14 +/- 9.14 (%TS); the protein content values were 28.96 +/- 1.84, 22.89 +/- 2.37 and 30.02 +/- 1.22 (%TS); the water-sol uble nitrogen values were 32.91 +/- 1.76, 46.44 +/- 1.86 and 48.72 +/- 1.08 (%TN); the values of nitrogen soluble in trichloroacetic acid we re 10.25 +/- 1.93, 10.41 +/- 2.91 and 7.25 +/- 0.84 (%TN); the values of nitrogen soluble in phosphotungstic acid were 1.50 +/- 0.18, 1.87 /- 0.65 and 1.38 +/- 0.32 (%TN); finally, the free amino acid content values were 21.33 +/- 5.34, 17.51 +/- 5.08 and 23.93 +/- 4.80 mu M equ ivalents of leucine. Urea-polyacrylamide gel electrophoresis of water- insoluble fractions from cheeses indicated high degrees of proteolysis of alpha(s1)-casein in bovine cheeses and more extensive proteolysis of the alpha(s)-casein region in caprine than in ovine cheeses, but a moderate degree of proteolysis of beta-casein in all types of cheese; electrophoregrams of the water-soluble fraction displayed increasing n umbers of bands throughout ripening, an observation that is consistent with the increase in the ratio of water-soluble nitrogen to total nit rogen.