The study concentrated on the changes in caseins during the ripening of a semisoft goat's milk cheese [mixed coagulation (4% acid bacteria starter plus 0.05% calf rennet), 60 days ripened]. Samples of milk and cheeses at 1, 21, 42, and 63 days of ripening were compared for the densitometric profile of the electrophoretic analyses of the nonsoluble protein fraction at pH 4.6. Experiments were also carried out on αs1-and β-caseins of goats in isolation, and the action of rennet on these proteins was detected. The appearance of the degradation peptides αs1-I, β-I, β-II, β-III, and β-IV was observed in these experiments. These experiments allowed identification, in the tests undertaken on cheese, of the degradation products αs1-I, β-I, and β-II, previously identified in the bibliography of cow's milk cheese. Vigorous activity of microbial enzymes on αs1-caseins was also observed. The resistance of β-casein to hydrolysis was illustrated by the 50% of 0-casein remaining unaltered at the end of ripening. © 1994, American Chemical Society. All rights reserved.
- Goat's cheese
- casein breakdown