THE COMPOSITION OF HYDROGENATED FATS BY HIGH-RESOLUTION C-13 NUCLEAR-MAGNETIC-RESONANCE SPECTROSCOPY

The high-resolution C-13 nuclear magnetic resonance spectra of twelve hydrogenated fats have been examined. Each spectrum contains 50-100 si gnals and reveals much about the nature of the acyl chains of both dou ble-bond position and configuration. The signals for the omega1, omega 2 and omega3 carbon atoms give information on the cis and trans isomer s of the DELTA15, DELTA14, DELTA13 and DELTA12 18:1 esters, respective ly. Allylic signals distinguish between cis and trans esters, and the proportion of total cis to total trans isomers can be obtained from th ese. Olefinic signals are the most informative, and most of these have been assigned. This leads to a semi-quantitative estimate of the vari ous 18:1 isomers present. Assignments are based mainly on information already in the literature, but some were confirmed after urea fraction ation of the acids from a hydrogenated oil in which cis and trans mono ene acids were separately concentrated.