Regiospecific analysis of natural mixtures of triglycerides using quantitative 13C nuclear magnetic resonance of acyl chain carbonyl carbons
✍ Scribed by Giovanna Vlahov
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 167 KB
- Volume
- 36
- Category
- Article
- ISSN
- 0749-1581
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✦ Synopsis
High-resolution 13C NMR spectroscopy of the carbonyl carbons of triglyceride acyl chains was used as a quantitative method for the regiospeciÐc analysis of the triglyceride fraction of vegetable oils of di †erent botanical origins. The carbonyl carbon resonances of saturated, oleyl and linoleyl chains were baseline resolved. Moreover, the chains attached at the 1,3-position were shifted by 0.4 ppm at higher frequencies than those of the corresponding chains attached at the 2-position. This quantitative NMR method was adopted after demonstrating that proton decoupling a †ected the carbonyl intensities to the same extent, no signiÐcant di †erences being found among the NOE factors of di †erent acyl chains. The proton-decoupled spectra were measured for quantitative purposes with full NOE enhancement. As a result, the spectrum signal-to-noise ratios were signiÐcantly improved in shorter experiment times. The 13C NMR method was used to determine the acyl chain composition of vegetable oil triglycerides, the composition of the two acyl chain pools which entered the glycerol 1,3-and 2-positions and the speciÐcity of each chain for the 2-position.