Analytical methods for determination of trans-C18 fatty acid isomers in milk fat. A review

Abstract

This review describes analytical methods developed for the separation, identification and quantitation of trans-isomers of unsaturated fatty acids. Although these methods am applicable to a wide variety of food matrices, we have particularly emphasised the analysis of trans unsaturated fatty acids in milk fat. Various methods are described such as infrared spectroscopy, direct gas chromatography, gas chromatography in combination with either thin-layer chromatography or liquid chromatography both impregnated with silver nitrate and gas chromatography coupled with mass spectrometry. The field of application, the advantages and the drawbacks of each method are evaluated and discussed.