title: Evaluation of volatile compounds and free fatty acids in set types yogurts made of ewes', goats' milk and their mixture using two different commercial starter cultures during refrigerated storage.
abstract: Six different types of yogurt were manufactured from Damascus goat milk, Awassi ewe milk and a mixture of equal portions of the 2 species of milk using 2 types of commercial yogurt cultures (CH-1 and YF-3331). Yogurts were chemically analysed at 1, 7, 14 and 21days of storage. Results showed that cultures significantly affected acetaldehyde (P<0.05), acetone (P<0.05) and diacetyl (P<0.001) contents. Type of milk significantly influenced acetaldehyde (P<0.05), diacetyl (P<0.001), acetoin (P<0.001) and ethanol (P<0.05) levels. Significant variations occurred in acetaldehyde (P<0.001) and acetoin (P<0.05) contents during the storage. Short-chain free fatty acids were the highest in ewes' milk yogurt made with culture YF-3331, and increased during storage, while the levels of medium-chain free fatty acids, except for decanoic acid, were unchanged and the amount of long-chain free fatty acids decreased during storage. Cultures used and types of milk had no effect on long-chain free fatty acids in yogurts.
authors.affiliation: Department of Food Engineering, Mustafa Kemal University, 31034-Antakya-Hatay, Turkey. Electronic address: zguler@mku.edu.tr.
authors.forename: Zehra
authors.initials: Z
authors.lastname: Güler
authors.affiliation: Department of Food Engineering, Mustafa Kemal University, 31034-Antakya-Hatay, Turkey.
authors.forename: Alev Canan
authors.initials: AC
authors.lastname: Gürsoy-Balcı
keywords: Ewe milk; Free fatty acids; Goat milk; Mixture; Volatile compounds; Yogurt