Formation of Volatile Free Fatty Acids During Ripening of Cheddar-like Hard Goat Cheese

to C ~O seem to have a major effect on the flavor of Concentrations of FFA in Cheddar-like hard goat cheeses were all above the threshold concentrations, except for pentanoic, heptanoic, and 10-undecenoic acids.The relative abundance of n-chain FFA in Cheddar-like hard goat cheeses, from greatest to least, were n-Clo, n-Clz, n-Cs, n-Cs, n-C4, n-Cg, and n-(211.Similarly, the relative abundance of branchedchain fatty acids in Cheddar-like hard goat cheeses, from greatest to least, was 4-methyloctanoic, methyldecanoic, 3-methylbutanoic, and 4-ethyloctanoic acids.Branched-chain fatty acids such as 4- ethyloctanoic and 4-methyloctanoic acids have intense aromas, and even minute quantities can affect the flavor of dairy products.Ripening time significantly affected the concentrations of FFA; concentrations increased during the initial 12 wk of aging and remained relatively constant for the rest of the 24-wk ripening period.Therefore, the intensity and sharpness of flavor that originated from o r was enhanced by the presence of these FFA did not change greatly aRer 12 wk of aging.The percentage of NaCl or the ratios of salt to moisture, within the range used in hard goat cheeses, did not affect the concentrations of FFA or, apparently, lipolysis in this study.( K e y words: goat cheese, free fatty acids, salt to moisture ratio, ripening time) cheeses ( 7 , 19, 20, 23, 29, 3 0 ) .Although n-chain fatty acids ( FA) occur in abundance, certain minor volatile branched-chain FA ( BCFA) exhibited characteristic flavors at very low concentrations (11, 12,13,27, 28).Ha and Lindsay (16, 17 i determined that BCFA, such as 4-ethyloctanoic and 4-methyloctanoic acids, contributed goat-like and mutton-like flavor notes t o cheeses made from goat and sheep milk, respectively.3-Methylbutanoic acid provides a sweat-like, fruity flavor note (1, 16).Flavor is a major attribute that influences the selection and consumption of cheeses.With the increased consumption and popularity of cheeses made from goat milk, investigation and resolution of some of these problems have become economically more important.The objectives of this investigation were 1 ) to quantify the volatile n-chain and BCFA with 12 or fewer carbon atoms in 1-d-old cheese and a t 6-wk intervals during an aging period of 24 wk, 2 ) and to examine the relationship between varying percentages of salt in moisture ( S / M ) and the quantity of FFA in cheese. MATERIALS AND METHODS ReagentsAbbreviation key: BCFA = branched-chain FA, FA = fatty acids, MSDE = microsimultaneous distillation extraction, S/M = salt in moisture phase.The purity of all chemical reagents and FA standards that were used have been previously described (5).