Effects of partial substitution of caprine for ovine milk on the volatile compounds of fresh and mature Urfa cheeses

Fresh Urfa cheeses were produced from ovine and caprine milk mixed in ratios of 100:0; 90:10; 80:20; 70:30 (ovine:caprine). They were preserved by two methods: (1) dry salted for 12 h, and (2) scalded in boiling whey for 5 min and ripened for 240 days. The basic composition of ovine cheese did not significantly differ from cheese, in which part of the sheep milk was replaced by goat's milk. The composition of dry salted cheese was in general similar with scalded cheese for chemical compositions and volatile compounds. Alcohols were quantitatively the most abundant chemical family found in the Urfa cheese, and their concentration were 37.91-53.48 μg 100 g−1 fresh cheese, especially more marked in the mature cheeses (56.21-121.54 μg 100 g−1 cheese). After 3 months, the concentration of volatile compounds and their contents of Urfa cheese generally decreased. Thus, Urfa cheese could be matured until 90 days in brine without affecting the concentration of volatile compounds. The partial substitution of ovine milk with caprine milk by up to 10 and 20% did not generally change volatile characteristics of the cheese. However, 30% substitution of ovine milk with caprine milk increased hexanoic, octanoic, decanoic acids, 2-methyl-pentanal, 2-butanone, 2-heptanone, 2-nonanone, methyl butanoate, and decreased acetic acid, 3-methyl-butanal, heptanal, 3-hydroxy-2 butanone, and methyl-2-methyl-butanoate.