Recovery of volatile compounds from butter oil

Three methods for the isolation of volatile compounds from oils and fats were compared using small concentrations (approximately 1 ppm) of added C_3-12 n-alkan-2-ones and C_2-10 n-alkan-1-ols in commercial butter oil. These were : high vacuum degassing, cold-finger molecular distillation and reduced pressure steam distillation. Several modifications were incorporated. The highest yields of all compounds were obtained by cold-finger molecular distillation but difficulties were encountered in subsequent analysis. It was more convenient to recover compounds boiling below 150C by either high vacuum degassing or reduced pressure steam distillation. The latter was more efficient for the higher boiling compounds. Extraction with organic solvents was not required in any of these techniques. The combination of high vacuum degassing and cold-finger molecular distillation was found to be the best method of analyzing the complete range of model compounds.