ORGANOLEPTIC PROPERTIES AND GAS CHROMATOGRAPHY PATTERNS OF STEAM DISTILLATES FROM FRESH AND STALE MILK FAT

We have examined the chromatographic patterns as well as the flavor characteristics of steam distillates of milk fat to obtain a more objective procedure than that given solely by taste panel evaluation for following the development of stale flavor during the storage of fat-containing dairy products. Both fresh and stale milk fats were steam deodorized at 50 and 75 C at 1 mm. Stale milk fat was also steam deodorized at 100 (1 mm) and at 50 C (3 mm). One-millimeter pressure is preferable to higher pressures. Distillation at 75 C or higher produces artifacts, volatile compounds generated from precursors, undesirable for following the formation of stale-flavor compounds during storage. Volatiles are recovered less completely at 50 C than at higher temperatures, but artifact generation is low. Moreover, the flavor of volatiles recovered at 50 C is characteristic of stale fat, and the chromatographie patterns of the 11 most prominent peaks correlate well with the flavor intensity and with the expected relative concentrations of the pertinent off-flavor compounds produced by storage of fats at various temperatures. © 1969, American Dairy Science Association. All rights reserved.