Detection of Lard in Binary Animal Fats and Vegetable Oils Mixtures and in Some Commercial Processed Foods

Authors: H. A. Al-Kahtani, A. A. Abou Arab, M. Asif

Abstract:

Animal fats (camel, sheep, goat, rabbit and chicken) and vegetable oils (corn, sunflower, palm oil and olive oil) were substituted with different proportions (1, 5, 10 and 20%) of lard. Fatty acid composition in TG and 2-MG were determined using lipase hydrolysis and gas chromatography before and after adulteration. Results indicated that, genuine lard had a high proportion (60.97%) of the total palmitic acid at 2-MG. However, it was 8.70%, 16.40%, 11.38%, 10.57%, 29.97 and 8.97% for camel, beef, sheep, goat, rabbit and chicken, respectively. It could be noticed also the position-2-MG is mostly occupied by unsaturated fatty acids among all tested fats except lard. Vegetable oils (corn, sunflower, palm oil and olive oil) revealed that the levels of palmitic acid esterifies at 2-MG position was 6.84, 1.43, 9.86 and 1.70%, respectively. It could be observed also the studied oils had a higher level of unsaturated fatty acids in the same position, compared with animal fats under investigation. Moreover, palmitic acid esterifies at 2-MG and PAEF increased gradually as the substituted levels increased among all tested fat and oil samples. Statistical analysis showed that the PAEF correlated well with lard level. The detection of lard in some commercial processed foods (5 French fries, 4 Butter fats, 5 processed meat and 6 candy samples) was carried out. Results revealed that 2 samples of French fries and 4 samples of processed meat contained lard due to their higher PAEF, while butter fat and candy were free of lard.

Keywords: Lard, adulteration, PAEF, goat, triglycerides.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1326830

References:

[1] J.M.N. Marikkar, H.M. Ghazali, Y.B. Che Man, T.S.G. Peiris, and O.M. Lai, “Distinguishing lard from other animal fats in admixtures of some vegetable oils using liquid chromatographic data coupled with multivariate data analysis,” Food Chem., vol. 9, pp.5-14, 2005.
[2] A. Rohman, and Y.B. Che Man, “Fourier transform infrared (FTIR) spectroscopy for analysis of extra virgin olive oil adulterated with palm oil,” Food Res. International, vol. 43, pp.886-892, 2010.
[3] J. M. Regenstein, M. M. Chaudry, and C. E. Regenstein, “The kosher and halal food laws,” Comprehensive Reviews in Food Science and Food Safety, vol. 2, pp. 111–127, 2003.
[4] F.H .Mattson, R.A. Volpenhein, and E.S. Lutton, “The distribution of fatty acids in the triglycerides of the Artiodactyla (even-toed animals),” J. Lipid Res., vol. 5, pp. 3636-365, 1964.
[5] R.S. Hal, L. Elaine, H.T. Raymond, S.D. Cavol, and V.M. George, “Lipid in raw and cooked beef,” J. Food composition and Analysis, pp.26-37, 1987; International Union of pure and Applied Chem., Applied Chem. Division, Commission on Oils, Fats and Derivates, 6th Ed. part 1 (section I and II), 1979. Pergamon Press, New York.
[6] G.K. Chacko, and E.G. Perkins, “Anatomical variation in fatty acid composition and triglyceride distribution in animal depot fats,” J. Am. Oil Chem. Soc., vol. 42, pp.1121-1124, 1964.
[7] B. Jayme, M.N. Reddy, and R.G. Alssa, “A simple method for the separation of triacylglycerols from fatty acids released in lipase assays,” J. Lipid Res., vol.29, pp.1549-1552, 1988.
[8] IUPAC, “International Union of Pure Applied Chemistry. Commission on Oils, Fats and Derivatives, Standard Methods for the Analysis of Oils,” 6th edn. Pergamon, New York, Method 2.210, 1979.
[9] A.H. Bayoumy, “Studies on the detection pork products in some foods,” M.Sc. Thesis, Faculty of Agri., Moshtohor, Zagazig Univ., Egypt, 1982.
[10] Y.M. Youssef, M.B. Omer, A. Skulberg, and M. Rashwan, “Detection and evaluation of lard in certain locally proceeded and imported meat products,” J. Food Chem., vol.30, pp.167-180, 1988.
[11] K.A. Al-Rashood, R.R.A. Abu-Shaaban, E.M. Abdel-Moety, and Abdul- Rauf, “Compositional and thermal characterization of genuine and randomized lard: A comparative study,” AOCS, vol.73, no.3, pp.303- 309, 1996.
[12] T. Dourtoglou, E. Stefanou, S. Lalas, V. Dourtoglou, and C. Poulos, “Quick regiospecific analysis of fatty acids in triacylglycerols with GC using 1, 3-specific lipase in butanol, Analyst, vol.126, pp.1032–1036, 2001.
[13] W. W. Christie, “The positional distributions of fatty acids in triglycerides. In R. J. Hamilton & J. B. Rossell (Eds.), “Analysis of oils and fats, pp. 313–339, 1986, Essex: Elsevier Applied Science.
[14] W. W. Christie, “The positional distributions of fatty acids in triglycerides. In R. J. Hamilton & J. B. Rossell (Eds.), “Analysis of oils and fats, pp. 313–339, 1986, Essex: Elsevier Applied Science.
[15] T. Saeed, S. G .Ali, H. A. A. Rahman, and W. N. Sawaya, “Detection of pork and lard as adulterants in processed meat: Liquid chromatographic analysis of derivatized triglycerides,” J. of the Association of Official Analytical Chemists, vol.72, pp.921–925, 1989.
[16] M. A. Soliman, and N. A. Younes, “Adulterated butterfat: Fatty acid composition of triglycerides and 2-monoglycerides,” J. of the American Oil Chemists Society, vol. 63, pp.248–250, 1986.
[17] E. Dister, and F.J. Baur, “The determination of mono, di- and triglycerides concentrates by column chromatography,” J. Assoc. Agric. Chem., vol. 48, no.2, pp.444-448, 1965.
[18] W.R. Morrison, and L.M. Smith, “Preparation of fatty acid methyl esters and dimethylacetals from lipids with boron fluoride-methanol,” J. Lipid Res., vol. 53, pp.600-608, 1964.
[19] IUPAC, “International Union of Pure Applied chemistry. Determination of fatty acid in the 2-position in the triglycerides of oils and fats," In Standard Methods for the Analysis of oils, fats and derivatives, edited by C. Paquoec and A. Hautfenne. Blockwell Scientific publishers Ltd. P.111. 1987.
[20] F. E. Luddy, R.A. Barford, S.F. Herb, and P. Magidman, “A rapid and quantitative procedure for the preparation of methyl esters of butter oil and other fats,” J. Am. Oil Chem. Soc., vol. 45, pp. 549-553, 1968.
[21] W.W. Christie, and J.H. Moore, “Structures of triglycerides isolated from various sheep tissues,” J. Sci. Food. Agric., vol. 22, pp.120-124, 1971.
[22] A.M.F. Abou-Hadeed, and A.R. Kotb, “Detection of small amounts of lard in other animal fats,” Qatar Univ. Sci. J., vol.13, no. 1, pp. 30-39, 1993
[23] A. Uzzan, “Oleaginous Fruits and their oils, In: Oils and Fats Manual, A Comprehensive Treatise,” Vol.1.Karleskind, A. (Ed), pp. 225-233. 1996, Lavoisier Publishing, ISBN: 1-898298-08-4.Paris, France.
[24] A.A. Abou Arab, “Identification of the sort of fats and oils in different foods,” M.Sc. Thesis, faculty of agric. Ain shams Univ., Cairo, Egypt, 1980.
[25] J. Folch, M. Lees, and G.H. Sloane-Stanley, “A simple method for the isolation and purification of total lipids from animal tissues,” Biol. Chemist's, vol. 226, pp.497. 1957.
[26] W.W. Christie, B. Nikolova-Damyanova, P. Laakso, and B. Herslof, “Stearospecific analysis of triacyl-sn-glycerols via resolution of diasteromeric diacyleglycerol derivatives by high-performance liquid chromatography on silica,” J. Am. Oil Chemist's Soc., vol.68, pp.695- 701, 1991.
[27] P. Angers, and J. Arul, “A simple method for regiospecific analysis of triacylglycerols by gas chromatography,” J. AOCS, vol. 76, no.4, pp.481-484, 1999.
[28] M.I. Abdel-kawy, “Analysis of some edible fats and fatty foods for the detection of pig fat,” Ph.D. Thesis (Pharm. Sci., analytical Chemistry), faculty of Pharmacy, Cairo University, 1987.
[29] P.L. Zock, H.M. Jeanne, J. Nanneke, and B.K. Martijn, “Positional distribution of fatty acids in dietary triglycerides: effects on fasting blood lipoprotein concentrations in humans,” Am. J. Clin. Nut., vol. 61, pp.48-55, 1995.
[30] L.Z. Cheong, H. Zhang, L. Nersting, K. Jensen, J.A.J. Haagensen, and X. Xu, “Physical and sensory characteristics of pork sausages from enzymatically modified blends of lard and rapeseed oil during storage,” Meat Sci., vol. 85, pp. 691–699, 2010.
[31] I. Foubert, P.A. Vanrolleghem, O. Thas, and K. Dewettinck, “Influence of Chemical Composition on the Isothermal Cocoa Butter Crystallization,” J. Food Sci., vol.69, no. 9, pp.478-487, 2004.
[32] A. Neri, M.S. Simonetti, L. Cossignani, and P. Damiani, “Identification of cocoa butter equivalents added to cocoa butter I. An approach by fatty acid composition of the triacylglycerol sub-fractions separated by Ag+-HPLC,” Zeitschrift Fur Lebensmittelunterschung und Forsschung A., vol.206, no. 6, pp.387-392, 1998.
[33] A.R. Nasyrah, J.M.N. Marikkar, and M.H. Dzulkifly, “Discrimination of plant and animal derived MAG and DAG by principal component analysis of fatty acid composition and thermal profile data,” Inter. Food Res. J., vol. 19, no.4, pp.1497-1501, 2012.
[34] H.L. Mansson, “Fatty acid in bovine milk fat,” Food Nutr. Res., vol. 52, pp.10-34, 2008.
[35] L.E. Abdel-Fattah, “Analysis study of some food and pharmacutica lipids products,” Ph.D. thesis, Faculty of Pharmacy, Cairo Univ., 1974.
[36] L. El-Sayed, A.K.S. Ahmed, and M.N. Amer, “The detection of lard in hydrogenated fats,” La Riv. Ital. Della Sostanze Grasse, vol.62, pp.553, 1985.
[37] A. Thielemans, H .De-Brabander, and D.L Massar, “Class definition and mixture class definition by means of construction of convex hull boundaries application to analysis for animal fat adulteration,” J. Assoc. Off. Anal. Chem., vol.72, pp.41-47, 1989.