Headspace analysis of buttermilk

ABSTRACT

The volatile flavor compounds of commercially cultured buttermilk were analyzed by head space gas chromatography to study the flavor changes occurring during 2 weeks of storage at 8 degree. Separation of acetaldehyde, acetic acid, diacetyl, acetoin and 2,3-butylene glycol was achieved by using a 100/150 mesh Porapak-Q column in a gas chromatograph equipped with a flame ionization detector. The column was programmed to operate at the rate of 10 degree per minute from 100 to 200 degree with a nitrogen carrier gas flow of 45 ml per minute. Tentative identification of the resultant peaks was made by comparing the retention of the peaks on the chromatograms of the samples and known mixed standards. Large variations in concentrations of volatile compounds were apparent. Moreover, the ratio of diacetyl to acetaldehyde in the samples showed considerable variation. An increase in acetaldehyde and acetic acid with a decrease in diacetyl, acetoin and 2, 3-butylene glycol occurred during storage. The increase in acetaldehyde and acetic acid and the decrease in diacetyl, acetoin and 2, 3-butylene glycol were closely related to the rapid decrease in product acceptability during storage