Deep-Frying with Thermoxidized Groundnut Oil Is a Potential Source of Free Radicals with Health Hazards
Abstract
Groundnut oil is one of the most commonly used vegetable oils in the household and industry in Nigeria for deep frying purposes. This research work was aimed at evaluating the effects of thermoxidized and fresh groundnut oils on lipid peroxidation, in vitro radical scavenging and in vivo antioxidant activities. The study comprised thirty-five (35) wistar albino rats divided into seven (7) groups of five (5) rats each. The different groups excluding group one (1) were fed with animal feeds containing various doses of the oils in their feed for six (6) weeks. Different methods of analyses, ranging from colorimetric, titrimetric, spectrophotometric, and hyphenated mass-spectroscopy were employed to obtain the results. The study showed that the peroxide and acid values (responsible for the off-flavour due to rancidity), DPPH and FRAP (which give a measure of the pro-oxidant capacity) were significantly (p<0.05) increased in the thermoxidized oils when compared to the fresh edible oils. Also, SOD, CAT (responsible for the antioxidant activity) and MDA values (a measure of peroxidation of a sample) increased significantly (P<0.05) in the thermoxidized groups. The GC-MS analyses also revealed that the thermoxidized oil samples produced compounds which are toxic or carcinogenic, like Butane, 1-[(2-methyl-2-propenyl)oxy]-, 4-n-Hexylthiane, (R)-,1,6-Octadiene, 5,7-dimethyl-, (R)- and Cyclododecanol, 1-aminomethyl and (R)-(-)-14-Methyl-8-hexadecyn-1-ol. The above findings suggest that there are potential health hazards associated with the consumption of oxidized products resulting from these oils used repeatedly in frying processes. In light of these findings, it is recommended that consumption of groundnut oils subjected to heating for long periods of time should be discouraged in Nigeria and other Low and Medium Income Countries (LMIC) where such practices are common.
Keywords: Edible oils, Deep-frying, Antioxidants, Radical scavenging, Lipid peroxidation.
References
Abdullah, A., Shahrul, S., Chan, X.S., Noorhazliza, A.P., Khairunnisak, M., Qodriyah, H.M.S.,Kamisah, Y., Nur Azlina, M.F. and Kamsiah J (2010) Level of awareness amongst the general public regarding usage of repeatedly heated cooking oil in Kuala Lumpur, Malaysia. Inter. Med. J. 17(4): 310-311.
Abdullah, K., Bunyami, O., Mehmet, I., Ismayil, Y., Ismail, D., Sabri, S. A., Ebubekir, B. and Halis, S. (2014). Damage induced by paracetamol compared with N-acetylcysteine. Journal of the Chinese Medical Association. (77): 463-468.
Awney, H.A. (2011). The effects of Bifidobacteria on the lipid profile and oxidative stress biomarkers of male rats fed thermally oxidized soybean oil. Biomarkers. 16(5): 445-452.
Beers, R. and Sizer, I. (1952). A Spectrophotometric Method for Measuring the Breakdown of Hydrogen Peroxide by Catalase, J Biol Chem (23) 195, 133.
Belakhdar, G. Benjouad, A. and Abdennebi, E.H. (2015). Determination of some bioactive chemical constituents from Thesium humile Vahl.J. Mater. Environ. Sci. 6 (10): 2778-2783.
Benedetti, P.C., Benedetti, M., D'Aquino, M., Di Felice, V., Centili, B. and Tagliamonte, G. (1987). Effects of a fraction of thermally oxidized soybean oil on growing rats. Nutr Rep Int, 36 (2), 387-401
Benzie, I.F and Strain, J.J. (1996). The ferric reducing ability of plasma (FRAP) as a measure of ‘‘antioxidant power’’: the FRAP assay. Analytical Biochemistry; 239, 70–76.
Chacko, C. and Rajamohan, T. (2011). Repeatedly heated cooking oils alter platelet functions in cholesterol fed Sprague dawley rats. Int J Biol Med Res. 2: 991 – 997.
Choe, E. (1997). Effects of heating time and storage temperature on the oxidative stability of heated palm oil. Korean J Food Sci Technol 29:407–11.
Chong, Y.H. and Ng, T.K. (1991). Effects of Palm Oil on Cardiovascular Risk. Palm Oil Research Institute of Malaysia; Division of Human Nutrition: Med. J. Malaysia Vol. 46: pp 34-67.
Codex Alimentarius Commission (1987). Report of the thirteenth session of the Codex committee on fats and oils, 23-27 February, London, UK.
Deepa, B., Prema, G., Krishna, B. and Cherian, K. M. (2013). Antioxidant and free radical scavenging activity of triphala determined by using different in vitro models Journal of Medicinal Plant Research. 7(39), 2898-2905.
Ekwu, F.C. and Nwagu, A. (2004). Effect of processing on the quality of cashew nut oils. J. Sci. Agric. Food Tech. Environ; 4, 105–110.
Frankel, E. (1998) Frying Fats. In: Frankel E (ed.). Lipids Oxidation. The Oily Press, Dundee, Scotland, pp. 227–248
Gao, H., Shupe, T., Hse, C. and Eberhardt, T. (2006). Antioxidant activity of extracts from the bark of Chamaecyparis lawsoniana (A. Murray) Parl. Holzforschung 60:459–462
Garcıa-Pe´rez, M.E., Diouf, P.N. and Stevanovic, T. (2008). Comparative study of antioxidant capacity of yellow birch twigs extracts at ambient and high temperatures. Food Chem 107:344–351.
Ghidurus, M., Turtoi1, M., Boskou, G., Niculita, P. and stan, V. (2011): Nutritional and health aspects related to frying. Romanian Biotechnological Letters. 16(5): 6467-6472.
Gupta, M.K. (2005). Frying oil. in: Edible Oil and Food Products: Products and Applications (ed. F. Shahidi). John Wiley & Sons, Hoboken, NJ, USA, pp. 1–31.
Halvorsen, B.L. and Blomhoff, R. (2011): Determination of lipid oxidation products in vegetable oils and marine omega-3 supplements. Food Nutr Res.55; 1-231.
Izaki, Y., Yoshikawa, S. and Uchiyam, M. (1984). Effect of ingestion of thermally oxidized frying oil on peroxidative criteria in rats Lipids, 19 (5) (1984), pp. 324-331
Koh, E. and Surh, J. (2015). Food types and frying frequency affect the lipid oxidation of deep frying oil for the preparation of school meals in Korea. Journal of Food Chemistry, 174, 467–472.
Min, D.B. and Bradley, G.D. (1992). Fats and Oils: Flavors. In: Hui, Y.H. (Ed.), Wiley Encyclopedia of Food Science and Technology, John Wiley & Sons, New York, pp. 828–832.
Mukherjee, S. and Mitra, A. (2009). Health effects of palm oil. J. Hum. Ecol; 26 (3), 197–203.
Nsimba, R.Y., Kikuzaki, H. and Konishi, Y. (2008). Antioxidant activity of various extracts and fractions of Chenopodium quinoa and Amaranthus spp. seeds. Food Chem 106:760–766
Nwanguma, B.C. Nwanguma, A.C., Achebe, L.U. and Ezeanyika, L.C. (1999). EzeToxicity of oxidized fats II: tissue levels of lipid peroxides in rats fed a thermally oxidized corn oil diet. Food Chem Toxicol, 37 (4) (1999), pp. 413-416.
OECD (2005), OECD Economic Globalisation Indicators, OECD, Paris.
Ohkawa, H., Ohishi, N. and Yagi, k. (1979). Assay for lipid peroxides in animal tissues by thiobarbituric acid reaction. Anal biochem. (95) 351-358.
Owu, D.U., Osim, E.E. and Ebong, P.E. (1998). Serum liver enzymes profile of wistar rats following chronic consumption of fresh or oxidized palm oil diets Acta Trop, 69 (1) (1998), pp. 65-73
Quiles, J.L., Huertas, J.R., Battino, M., Tortosa, M.C., Cassinello, M. and Mataix, J. (2002). The intake of fried virgin olive or sunflower oils differentially induces oxidative stress in rat liver microsomes. Br J Nutr; 88(1): 57-65.
Radhakrishnan, K., Mohan, A., Shanmugavadivelu, C. and Velavan S. (2016). A Comparison of Chemical Composition, Antioxidant and Antimicrobial Studies of Abutilon indicum Leaves and Seeds.Research Journal of Phytochemistry. 51; 1223 -1279.
Ramachandran, H.D., Narasimhamurthy, K. and Raina, P.L. (2002). Effect of oxidative stress on serum and antioxidant enzymes in liver and kinder of rats and their modulation through dietary factors. Ind J Experi Biol; 40: 1010-5.
Sarumathy, K., Dhana, M.S.R., Vijay, T. and Jayakanthi, J. (2011). Evaluation of phytoconstituents, nephro-protective and antioxidant activities of Clitoria ternatea. Journal of Applied Pharmaceutical Science. 01 (05): 164-172.
Shastry, C.S., Patel, N.A., Joshi, H. and Aswathanarayana, B.J. (2011). Evaluation of effect of reused edible oils on vital organs of wistar rats. Nitte University J. Health Sci., 1 (4), 10–15.
Sayon-Orea, C., Bes-Rastrollo, M., Basterra-Gortari, F.J., Beunza, J.J., Guallar-Castillon, P., Fuente-Arrillaga, C. and Martinez-Gonzalez, M.A. (2012). Consumption of fried foods and weight gain in a Mediterranean cohort: The SUN project. Nutr. Metab. Cardiovasc. Dis. (in press).
Sermakkani, M. and Thangapandian, V. (2012). GC-MS analysis of Cassia italica leaf methanol extract. Asian Journal of Pharmaceutical and Clinical Research. 5(2) 974-2441.
Stein, S.E. (1999). “An integrated method for spectrum extraction and compound identification from gas chromatography/mass spectrometry data,” Journal of the American Society for Mass Spectrometry, vol. 10, no. 8, pp. 770–781.
Sushma, B.J., Nagarajappa, C.R. and Mallikarjuna, N.U. (2013). Serum paraoxonase-1 activity, oxidative stress and lipid profile in patients with chronic liver disease. Int J Pharm Biol Sci, 3 (1) (2013), pp. 1-6
WHO. (2015). Determination of Acid Value. The International Pharmacopoeia, 5th Edition, World Health Organization (WHO) Department of Essential Medicine and Health Products. [http://apps.who.int/phint/en/p/docf/](accessed January 2016).
