Triglyceride gas chromatography as a means of detecting butterfat adulteration

Abstract

Gas chromatography was used for the separation and quantitative estimation of triglycerides by carbon number from native and adulterated butterfats. When the triglyceride type composition of the native butter was known, adulteration with vegetable fat could be detected at the 1% level, and with lard at the 3% level, as these adulterants added significantly to only a few of the butterfat triglyceride peaks resulting in a noticeable distortion of the chromatographic elution pattern of this fat. Due to considerable variations observed in the elution patterns with butterfats of different origin, the lower limit for the detectio of adulteration of an unknown butter sample with lard or vegetable fat was of the order of 5–10%. The ease of detection and identification of the adulterant varied with the type of fat added. It was demonstrated that mixtures of coconut oil and lard could be made which matched the gas chromatograms of butterfat closely and remained undetected even when added in relatively large amounts. Despite this, the simplicity of the technique and its rapid and relatively reliable applicability to the widest variety of problems of natural fat characterization recommends it as one of the methods in any fat test or control laboratory.