Profile of trans Fatty Acids (FAs) Including Trans Polyunsaturated FAs in Representative Fast Food Samples

The content of trans fat in foods is most commonly determined by summing the levels of individual trans fatty acids (FM), analyzed as FA methyl esters (FAME) by gas chromatography. Current Official Methods of the American Oil Chemists Society (AOCS) enable quantitation of total trans fat in foods but were not designed for the determination of trans FA isomeric compositions. In the present study, the content of trans fat in 32 representative fast food samples ranged from 0.1 to 3.1 g per serving, as determined according to AOCS Official Method Ce 1j-07. Further analysis of FAME using the 200 m SLB-IL111 ionic liquid column yielded quantitative results of total, trans, saturated, and cis unsaturated fat that were comparable to those of Method Ce 1j-07 and also allowed for the complementary determination of individual trans 18:1, trans 18:2, and trans 18:3 FA isomeric compositions under conditions suitable for routine sample analysis.