Volume 20 (1979) Issue 5 Pages 328-331
A gas liquid chromatographic (GLC) method for the determination of methyl butyrate and methyl caproate was developed, and the established method was used to analyze pure milk fat and 18 kinds of fat samples extracted from milk and dairy products, in comparison with the results obtained by the current official methods of Japan. Butyrate and caproate contents in milk fat should be within the range of 2.5-5.0 and 1.7-3.5% as the methyl esters, respectively, and accordingly, the C4/C6 ratio must not exceed 3.0. From the results of GLC of butyrate and caproate, five samples were judged not to be genuine butterfat which were not thus judged by the current official methods of Japan. On the other hand, there were several samples which GLC of butyrate and caproate failed to show as adulterated, but which the classical analytical techniques (GLC of sterols and semimicro butyric acid (SBA) value) did detect. We conclude that all three methods are necessary for the effective discrimination of adulteration of milk fat.