A 1H NMR-Linked PCR Modelling Strategy for Tracking the Fatty Acid Sources of Aldehydic Lipid Oxidation Products in Culinary Oils Exposed to Simulated Shallow-Frying Episodes

Authors: Martin Grootveld, Benita Percival, Sarah Moumtaz, Kerry L. Grootveld

Abstract:

Objectives/Hypotheses: The adverse health effect potential of dietary lipid oxidation products (LOPs) has evoked much clinical interest. Therefore, we employed a ¹H NMR-linked Principal Component Regression (PCR) chemometrics modelling strategy to explore relationships between data matrices comprising (1) aldehydic LOP concentrations generated in culinary oils/fats when exposed to laboratory-simulated shallow frying practices, and (2) the prior saturated (SFA), monounsaturated (MUFA) and polyunsaturated fatty acid (PUFA) contents of such frying media (FM), together with their heating time-points at a standard frying temperature (180 ^oC). Methods: Corn, sunflower, extra virgin olive, rapeseed, linseed, canola, coconut and MUFA-rich algae frying oils, together with butter and lard, were heated according to laboratory-simulated shallow-frying episodes at 180 ^oC, and FM samples were collected at time-points of 0, 5, 10, 20, 30, 60, and 90 min. (n = 6 replicates per sample). Aldehydes were determined by ¹H NMR analysis (Bruker AV 400 MHz spectrometer). The first (dependent output variable) PCR data matrix comprised aldehyde concentration scores vectors (PC1* and PC2*), whilst the second (predictor) one incorporated those from the fatty acid content/heating time variables (PC1-PC4) and their first-order interactions. Results: Structurally complex trans,trans- and cis,trans-alka-2,4-dienals, 4,5-epxy-trans-2-alkenals and 4-hydroxy-/4-hydroperoxy-trans-2-alkenals (group I aldehydes predominantly arising from PUFA peroxidation) strongly and positively loaded on PC1*, whereas n-alkanals and trans-2-alkenals (group II aldehydes derived from both MUFA and PUFA hydroperoxides) strongly and positively loaded on PC2*. PCR analysis of these scores vectors (SVs) demonstrated that PCs 1 (positively-loaded linoleoylglycerols and [linoleoylglycerol]:[SFA] content ratio), 2 (positively-loaded oleoylglycerols and negatively-loaded SFAs), 3 (positively-loaded linolenoylglycerols and [PUFA]:[SFA] content ratios), and 4 (exclusively orthogonal sampling time-points) all powerfully contributed to aldehydic PC1* SVs (p 10^-3 to < 10^-9), as did all PC1-3 x PC4 interaction ones (p 10^-5 to < 10^-9). PC2* was also markedly dependent on all the above PC SVs (PC2 > PC1 and PC3), and the interactions of PC1 and PC2 with PC4 (p < 10^-9 in each case), but not the PC3 x PC4 contribution. Conclusions: NMR-linked PCR analysis is a valuable strategy for (1) modelling the generation of aldehydic LOPs in heated cooking oils and other FM, and (2) tracking their unsaturated fatty acid (UFA) triacylglycerol sources therein.

Keywords: Frying oils, frying episodes, lipid oxidation products, cytotoxic/genotoxic aldehydes, chemometrics, principal component regression, NMR Analysis.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.3299355

References:

[1] A. J. S. Angelo. “Lipid oxidation in foods,” Critical Rev. Food Sci. Nutr., vol. 36, pp. 175-224, 1996.
[2] Choe, E. and Min, DB. “Mechanisms and factors for edible oil oxidation.” Comprehen. Rev. Food Sci. Food Safety, vol. 5, no. 4, pp. 169–186 ,2006.
[3] Grootveld, M., Ruiz-Rodado, V. and Silwood C. J. L. “Detection, monitoring and deleterious health effects of lipid oxidation products generated in culinary oils during thermal stressing episodes.” Inform, Am Oil Chem Soc., vol. 25, no. 10, pp. 614-624, 2014.
[4] Frankel, E. N. “Volatile lipid oxidation-products.” Prog. Lipid Res., vol. 22, pp. 1-33, 1983.
[5] Dobarganes, M.C. and Perez-Camino, M. C. “Fatty acid composition: a useful tool for the determination of alteration level in heated fats.” Rev. Franc. Corps Gras., vol. 35, pp. 67-70, (1988).
[6] Claxson, A. W. D., Hawkes, G. E., Richardson, D. P., Naughton, D. P., Haywood, R. M., Chander, C. L., Atherton, M., Lynch, E. J., and Grootveld, M. C. “Generation of lipid peroxidation products in culinary oils and fats during episodes of thermal stressing: a high field 1H NMR study.” FEBS Lett., vol. 355, pp. 81-90, 1994.
[7] Haywood, R. M., Claxson, A. W. D., Hawkes, G. E., Richardson, D. P., Naughton, D. P., Coumbarides, G., Hawkes, J., Lynch, E. J., and Grootveld, M. C. “Detection of aldehydes and their conjugated hydroperoxydiene precursors in thermally-stressed culinary oils and fats: investigations using high resolution proton NMR spectroscopy.” Free Rad Res vol. 22, pp. 441-482, 1995.
[8] Silwood, C. J. L. and Grootveld, M. “Application of high-resolution two-dimensional 1H and 13C nuclear magnetic resonance techniques to the characterization of lipid oxidation products in autoxidized linoleoyl/linolenoyglycerols.” Lipids, vol. 34, pp. 741–756, 1999.
[9] Martınez-Yusta, A., Goicoechea, E. and Guillen, M. D. “A Review of thermo-oxidative degradation of food lipids studied by 1H NMR spectroscopy: influence of degradative conditions and food lipid nature.” Comprehensive Rev. Food Sci. Food Safety, vol. 13, pp. 838-859, 2014.
[10] Guillan, M. D. and Ruiz, A. “Formation of hydroperoxy‐ and hydroxyalkenals during thermal oxidative degradation of sesame oil monitored by proton NMR.” Eur J Lipid Sci Technol, vol. 106, pp. 680-687, 2004.
[11] Guillan, M. D. and Ruiz, A. “Monitoring the oxidation of unsaturated oils and formation of oxygenated aldehydes by proton NMR.” Eur J Lipid Sci Technol, vol. 107: pp. 36-47, 2005.
[12] Grootveld, M., Percival, B. C. and Grootveld, K. L. “Chronic non-communicable disease risks presented by lipid oxidation products in fried foods.” HepatoBiliary Surg. Nutr. vol. 7, no. 4, 305-312, 2018. doi: 10.21037/hbsn.2018.04.01.
[13] Moumtaz, S., Percival, B., Parmar, D., Grootveld, K. L., Jansson, P. and Grootveld, M. “Generation of toxic α,β-unsaturated and saturated aldehydes during simulated shallow frying episodes: comparisons of common frying oils with a novel high-stability algae oil product. Sci. Rep. 2019 (in press).
[14] Knothe, G. and Kenar, J. A. “Determination of the fatty acid profile by 1H-NMR spectroscopy.” Eur. J. Lipid Sci. Technol. Vol. 106, pp. 88–96, 2004.
[15] Cortinas, L., Galobart, J., Barroeta, A. C., Baucells, M. D. & Grashorn M. A. “Change in α-tocopherol contents, lipid oxidation and fatty acid profile in eggs enriched with linolenic acid or very long-chain w-3 polyunsaturated fatty acids after different processing methods.” J. Sci. Food Agr. 83, pp. 820-829, 2003.
[16] Young, S. C., et al. “DNA damage induced by trans,trans-2,4-decadienal (tt-DD), a component of cooking oil fume, in human bronchial epithelial cells.” Environ. Mol. Mutagen. vol. 51, pp. 315–321, 2010.
[17] Grootveld, M., et al. “In vivo absorption, metabolism, and urinary excretion of α,β-unsaturated aldehydes in experimental animals. Relevance to the development of cardiovascular diseases by the dietary ingestion of thermally-stressed polyunsaturate-rich culinary oils.” J. Clin. Invest., vol. 101, pp. 1210–1218, 1998.
[18] Penumetcha, M., Khan, N. and Parthasarathy, S. “Dietary oxidized fatty acids: an atherogenic risk?” J. Lipid Res. vol. 41, pp. 1473-1480, 2000.
[19] Kritchevsky, D. and Tepper, S. A. “Cholesterol vehicle in experimental atherosclerosis. 9. Comparison of heated corn oil and heated olive oil.” J Atheroscler Res. vol. 7, pp. 647-651, 1967.
[20] Staprãns, I., Rapp, J. H., Pan, x-M., Hardman, D. A. and Feingold, K. R. “Oxidized lipids in the diet accelerate the development of fatty streaks in cholesterol-fed rabbits.” Arterioscler Thromb Vasc Biol. vol. 16, pp. 533–538, 1996.
[21] Soffritti, M. et al. “Results of long-term experimental studies on the carcinogenicity of formaldehyde and acetaldehyde in Rats.” Ann. N.Y. Acad. Sci., vol. 982, pp. 87-105, 2003.
[22] Stavridis, J. C. “Toxicity and carcinogenicity of aldehydes.” In: Oxidation: The Cornerstone of Carcinogenesis. Oxidation and Tobacco Smoke Carcinogenesis. A Relationship Between Cause and Effect. (Stavridis, J. C., Ed.). pp. 161-173. Springer Science & Business Media. DOI 10.1007/978-1-4020-6704-4_11 (2007).
[23] Benigni, R., Passerini, L. and Rodomonte, A. Structure–activity relationships for the mutagenicity and carcinogenicity of simple and α-β unsaturated aldehydes.” Environ. Mol. Mutagen. vol. 42, pp. 136-143, 2003. doi:10.1002/em.10190
[24] Lee, T. & Gany, F. Cooking oil fumes and lung cancer: a review of the literature in the context of the U.S. population. J. Immigr. Minor Health vol. 15, pp. 646-652, 2013.
[25] Indart, A. et al. “Teratogenic actions of thermally-stressed culinary oils in rats.” Free Rad Res. vol. 36, pp. 1051–1058, 2002.
[26] Benedetti, A., Ferrali, A., Casini, A. F., Peiri, S. & Comporti, M. Foot edema induced by carbonyl compounds originating from the peroxidation of microsomal lipids. Biochem Pharmacol. Vol. 29, pp. 121-124, 1980.
[27] Grootveld, M. et al. “Health effects of oxidised heated oils.” Foodservice Res. Internat. vol. 13, pp. 39-53, 2001.
[28] Jayaraj, A. P., Rees, K. R., Tovey, F. E. I. and White, J. S. “A molecular basis of peptic ulceration due to diet.” Brit. J. Exp. Path. Vol. 67, pp. 149-155, 1986.
[29] Long, E. K. et al. “Trans-4-hydroxy-2-hexenal is a neurotoxic product of docosahexaenoic (22:6; n-3) acid oxidation.” J. Neurochem. vol. 105, pp. 714-724, 2008.
[30] Leong, X-F., Mustafa, M. R., Das, S. and Jaarin, K. “Association of elevated blood pressure and impaired vasorelaxation in experimental Sprague-Dawley rats fed with heated vegetable oil.” Lipids Health Dis. Vol. 9, pp. 66 http://www.lipidworld.com/content/9/1/66 (2010).