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

This review describes analytical methods developed for the separation, iden tification and quantitation of trans-isomers of unsaturated fatty acids. Al though these methods are 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, d irect gas chromatography, gas chromatography in combination with either thi n-layer chromatography or liquid chromatography both impregnated with silve r nitrate and gas chromatography coupled with mass spectrometry. The field of application, the advantages and the drawbacks of each method are evaluat ed and discussed.