Rapid Quantitative Profiling of Lipid Oxidation Products in a Food Emulsion by ¹H NMR

Abstract

Lipid oxidation is one of the most important reasons for the compromised shelf life of food emulsions. A major bottleneck in unravelling the underlying mechanisms is the lack of methods that provide a rapid, quantitative, and comprehensive molecular view on lipid oxidation in these heterogeneous systems. In this study, the unbiased and quantitative nature of H NMR was exploited to assess lipid oxidation products in mayonnaise, a particularly oxidation-prone food emulsion. An efficient and robust procedure was implemented to produce samples where theH NMR signals of oxidation products could be observed in a well resolved and reproducible manner. H NMR signals of hydroperoxides were assigned in a fatty acid and isomer specific way. Band-selectiveH NMR pulse excitation allowed immediate and precise (RSD = 5.9%) quantification of both hydroperoxides and aldehydes with high throughput and large dynamic range at levels of 0.03 mmol/kg. Explorative multivariate data modeling of the quantitative H NMR profiles revealed that shelf life temperature has a significant impact on lipid oxidation mechanisms.

1H–13C HMBC NMR experiments as a structural and analytical tool for the characterization of elusive trans/cis hydroperoxide isomers from oxidized unsaturated fatty acids in solution

“…The low hydroperoxide values in the case of olive oils compared with the NMR values were attributed to the high content of specific phenolic compounds that exhibit strongly deshielded 1 H NMR chemical shifts in the region of hydroperoxide signals . Recently, 1D band selective NOESY and TOCSY sequences were employed to obtain assignments specific for hydroperoxide positions . 1D NOESY experiments were used for the transfer of magnetization from the hydroperoxide proton to the neighboring allylic CH proton.…”

Nuclear Magnetic Resonance (NMR) Spectroscopy in Food Science: A Comprehensive Review

“…NMR has the ability to serve as an invaluable tool for the compositional analysis of foods, not only due to its ability to provide important information for structural elucidation, but also for its quantitative nature. NMR has been effectively used for the analysis of several classes of compounds including lipids (Dais & Hatzakis, ; Monakhova & Diehl, , ; Siddiqui et al., ; Tsiafoulis et al., ), carbohydrates (Kazalaki et al., ; Merkx, Hong, Ermacora, & van, ; Singh, Kumar, Srivastava, Deepak, & Singh, ; Spraul et al., , ), amino acids (Belton et al., ), alcohols (Hatzakis, Archavlis, & Dais, ; Nilsson et al., ), organic acids (Berregi, del Campo, Caracena, & Miranda, ), polyphenols (Agiomyrgianaki & Dais, , ; Charisiadis, Exarchou, Troganis, & Gerothanassis, ), vitamins (Ackermann et al., ; Dais et al., ; Shumilina, Ciampa, Capozzi, Rustad, & Dikiy, ; Vaysse et al., ), terpenes (Dais, Plessel, Williamson, & Hatzakis, ), phospholipids (Hatzakis, Koidis, Boskou, & Dais, ; Kaffarnik, Ehlers, Gröbner, Schleucher, & Vetter, ), colorants (Englert, ; Scotter, ; Venkatachalam et al., ; Berké, Chèze, Vercauteren, & Deffieux, ), and contaminants (Lachenmeier et al., ) in a variety of foods, such as oils (Dais & Hatzakis, ; Siddiqui et al., ), beverages (Kidrič, ; Ryu, Koda, Miyaka, & Tanokura, ; Santos, Fonseca, Lião, Alcantara, & Barison, ; Zurriarrain et al., 2015), meats (García‐García et al., ), dairy products (Gangwar, Singh, & Deepak, ; Hu, Furihata, Ito‐Ishida, Kaminogawa, & Tanokura, ; Maher & Rochfort, ; Murgia, Mele, & Monduzzi, ; Scano et al., ; Tociu et al., ), and infant formula (Zhao et al., ). For the structural characterization of various food components, the application of 2D techniques is often required.…”

“…However, because of their high molecular weight, polysaccharides are expected to have long correlation times, τ c (the time required for a molecule to rotate by one radian) and thus long T 1 relaxation time, which would extend the time of the analysis. The quantification of polysaccharides in foods using 1 H NMR combined with Saeman hydrolysis quantum mechanical total line shape (QMTLS) fitting has been recently described (Merkx et al., ). This is a very promising methodology because it utilizes the rapid and sensitive 1 H NMR analysis, although conversion of polysaccharides into the corresponding monosaccharide units via hydrolysis is required.…”

NMR and Computational Studies as Analytical and High-Resolution Structural Tool for Complex Hydroperoxides and Diastereomeric Endo-Hydroperoxides of Fatty Acids in Solution-Exemplified by Methyl Linolenate

“…1 H- and 13 C-NMR have also been extensively utilized to elucidate the structures of primary and secondary oxidation products both in model compounds and in edible oils, which were subjected to a variety of degradative conditions [ 18 , 19 , 20 , 21 , 22 , 23 , 24 ]. More recently, 1 H-NMR of hydroperoxide (-OOH) chemical shifts and 1D band selective Nuclear Overhauser Enhancement Spectroscopy (NOESY) and TOCSY experiments were utilized for the specific assignments of various hydroperoxide positions [ 25 ].…”