Table 1.
Chemical shift values, multiplicities and assignments of the major TAG resonances in 1H NMR spectra acquired on culinary oils at an operating frequency of 600 MHz. Coupling patterns are provided in brackets following the chemical shift values provided. The codes correspond to label assignments of the resonances shown in Figure 1. Abbreviations: TMS, tetramethylsilane; 2,5-DTBHQ, 2,5-dibydroxy-tertiary-butyl-hydroquinone (added chain-breaking antioxidant); TCB, 1,3,5-trichlorobenzene (quantitative internal standard); s, singlet; d, doublet; t, triplet; dd, doublet-of-doublets; dt, doublet-of-triplets; m, multiplet.
| Label Code | Chemical Shift (δ/ppm) and Multiplicity | Assignment |
|---|---|---|
| 1 | 0.00 (s) | TMS Si(CH3)4 |
| 2 | 0.84–0.91 (t) | Terminal-CH3 group of all FAs, with the exception of unsaturated Ω-3 FAs |
| 3 | 0.95–0.99 (t) | Terminal-CH3 group of unsaturated Ω-3 FAs |
| 4 | 1.20–1.40 (m) | Bulk-chain acyl–(CH2)n- groups of FA chains |
| 5 | 1.56–1.66 (m) | Acyl-OCO-CH2-CH2- groups of FA chains |
| 6 | 1.95–2.11 (m) | -CH=CH-CH2- protons of FA chains |
| 7 | 2.26–2.36 (m) | -OCO-CH2- group protons of FA chains |
| 8 | 2.75–2.79 (dt) | Bis-allylic-CH=CH-CH2-CH=CH- functions of linoleoylglycerol FA acyl chains |
| 8 | 2.79–2.82 (dt) | Bis-allylic-CH=CH-CH2-CH=CH- functions of linolenoylglycerol FA acyl chains |
| 9 | 4.11–4.32 (dd,dd) | Glycerol backbone-1,3-position-CH2OCOR |
| 10 | 5.23–5.28 | Glycerol backbone-2-position-CH(OH)- |
| 11 | 5.30–5.40 (m) | Vinylic -CH=CH- protons |
| 12 | 6.59 (s) | 2,5-DTBHQ aromatic ring protons |
| 13 | 7.26/7.27(s/s) | 1,3,5-TCB/residual CHCl3 |