Trans Fat Analysis by 300 MHz 1H NMR

This topic has become pertinent again with the interest of FDA in trans-fat content in processed foods – more information here.Back in 2006 we performed a cursory analysis of trans fat reference materials that we purchased from AOCS. We performed a series of 1H NMR analysis and performed a chemometric PLS analysis correlating the 1H NMR spectral variability to trans fat content, PUFA (polyunsaturated fatty acid content), SAFA (saturated fatty acid content), and MONO (monounsaturated fatty acid content). Excellent correlations were obtained between wt% values obtained by GC analysis and the rapid 1H NMR analysis (2 minutes on a 300 MHz NMR).

1H NMR spectra on the standard samples are shown in the figures below as well as the GC data that was used in the regressions.

A PCA analysis of  the NMR data nicely categorized the various types of samples as well as the trans fat contents of the samples with nice separation being shown in the PC1 vs PC2 score plot.

The various correlations for trans fat, SAFA, PUFA, and MONO are shown below.