Apr. is, 1914 
Flavor of Roquefort Cheese 
3 
distilled with steam until 1,000 c. c. of distillate passed over. During 
the distillation a small flame was kept under the Kjeldahl flask and regu¬ 
lated so that the volume of the suspension remained nearly constant. 
The fatty acids which separated from the distillate were filtered off, 
dissolved in alcohol, titrated with decinormal barium hydroxid, and 
reported as insoluble acids. 
The filtrate was neutralized with decinormal barium hydroxid and 
evaporated to about 100 c. c. This solution was then partially decom¬ 
posed with normal sulphuric acid and the liberated acids distilled out. 
The distillate was designated “Fraction I.” The residue was again made 
up to 100 c. c., partially decomposed with normal sulphuric acid, and 
distilled, giving Fraction II. By repeating this process of partial decom¬ 
position followed by distillation the soluble acid portion was divided 
into several fractions containing about equivalent quantities of acid. 
The acids of greater molecular weight occur in the first fractions because 
of their weaker chemical affinity and more rapid rate of volatilization. 
A QUALITATIVE STUDY OF THE VOLATILE ACIDS 
The distillate of a well-ripened cheese was divided into five fractions. 
Fraction I consisted of the insoluble acids adhering to the condenser after 
rinsing with cold water. The remainder of the insoluble acids constituted 
Fraction II. The soluble acids were divided into Fractions III, IV, and 
V by the process of partial decomposition of the barium salts with normal 
sulphuric acid followed by distillation, as previously described. 
The barium salts were prepared by titrating with decinormal barium 
hydroxid, dried to constant weight at 120° C., moistened with dilute 
sulphuric acid, ignited, and weighed as barium sulphate. The results 
are detailed in Table I. 
Table I .—The barium salts of the volatile acids of Roquefort cheese . 
Fraction 
No. 
Decinormal 
equivalent. 
Percentage of barium sulphate found from barium salts. 
Salt. 
Actual. 
Theoretical. 
C. c. 
Per cent. 
Per cent. 
I 
2. 25 
Barium caprate. 
45 - 53 
48. 64 
II 
5. 80 
Barium caprylate... 
47.18 
55 - °8 
III 
I 7-32 
Barium caproate.... 
64.67 
63.48 
IV 
* 7 - 36 
Barium butyrate.... 
76. 07 
74.91 
V 
18. 58 
Barium acetate. 
88.65 
9 i -37 
A study of the above results shows that the distillate from this variety 
of cheese is essentially a mixture of the volatile acids of milk fat. Capric 
acid is the chief constituent of the insoluble-acid portion. The fact that 
no fraction shows the presence of an acid of a molecular weight between 
capric and caproic indicates that the quantity of caprylic acid is small. 
