Abstract
Four methods were evaluated for detecting adulteration of butter fat with vegetable fats. The procedures involve GLC determination of free or combined β-sitosterol after isolation of the sterols by either preparative GLC or digitonin precipitation. Each of the methods was sensitive enough to detect about 1 mg added β-sitosterol/100 g butter fat. Also studied was the free and combined β-sitosterol content of a number of crude and refined vegetable oils. The TLC-GLC method for determining cholesterol in fats and oils, which was collaboratively studied in 1968, is being recommended for official first action status. The GLC portion of this procedure replaces the obsolete one in methods 26.065–26.070 for detecting vegetable fats in butter fat.
