Analysis of positional distribution of fatty acids in palm oil by¹³C NMR spectroscopy

Abstract

The13C NMR spectrum of the carbonyl carbons of the acyl groups of triacylglycerols of palm oil has been shown to give the composition of saturated, oleic and linoleic acyl groups at the 1,3‐positions and at the 2‐position of the glycerol moiety. Except for the lack of differentiation of the saturated fatty acids, the13C NMR technique provides the same information as the tedious enzymatic hydrolysis cum fatty acid analysis. The carbonyl carbon of the linolenic acyl group (18∶3,[cis, cis, cis]‐9, 12, 15) has a chemical shift which is only 0.005 ppm to low frequency of that of the linoleic acyl group (18∶2,[cis, cis]‐9, 12), so that the two resonances may not be distinguishable (or resolved) even at a high magnetic field.

Recognition and quantitation of cis‐vaccenic and eicosenoic fatty acids in olive oils by 13C nuclear magnetic resonance spectroscopy

“…The general rules that apply to the resonances of triacylglycerols in vegetable oils and animal fats and the assignments reported in the literature (1,3,4,9,14,15) on similar systems suggest that these peaks belong to monoenoic cis-11 fatty acids, mainly in sn-1,3 position. This hypothesis was verified by the addition of a small amount of eicosenoic triacylglycerol to one of the olive oil samples.…”

Lipid analysis of Neochloris oleoabundans by liquid state NMR

“…Liquid state NMR has been used in many studies to analyze lipids (Gunstone, 1991a(Gunstone, ,b, 1993(Gunstone, , 1994Lie Ken Jie and Mustafa, 1997;Mannina et al, 1999;Meneses and Glonek, 1988;Ng, 1985;Sacchi et al, 1997;Schiller et al, 2007;Sotirhos et al, 1986;Vlahov, 1996;Vlahov and Angelo, 1996;Vlahov et al, 2002). There have also been studies published for the application of liquid state NMR to evaluate algal lipid extracts (Boyle-Roden et al, 2003;Meneses et al, 1993;Pollesello et al, 1992Pollesello et al, , 1993 and ''bio-oil'' produced from the liquefaction of algae (Zou et al, 2009).…”

High‐resolution nuclear magnetic resonance spectroscopy —Applications to fatty acids and triacylglycerols

“…The 13 C NMR spectral analysis of the carbonyl carbon atoms of the acyl groups of triacylglycerols of palm oil allowed the composition of saturated, oleic, and linoleic acyl groups at the 1,3-position and at the 2-position of the glycerol moiety to be established. The report indicated that, except for the lack of differentiation of the saturated fatty acids, the 13 C NMR technique provided the same information as the tedious enzymatic hydrolysis cum fatty acid analysis (88). The chemical shift difference of the olefinic carbon atoms in the fatty acid chain of triacylglycerols in palm oil was found to be characteristic of the chain's glycerol position and can therefore be used to identify the glycerol position of an unsaturated fatty acid in the triacylglycerol molecule (89).…”