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Evaluating acid and base catalysts in the methylation of milk and rumen fatty acids with special emphasis on conjugated dienes and total trans fatty acids

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Lipids

Abstract

Milk analysis is receiving increased attention. Milk contains conjugated octadecadienoic acids (18∶2) purported to be anticarcinogenic, low levels of essential fatty acids, and trans fatty acids that increase when essential fatty acids are increased in dairy rations. Milk and rumen fatty acid methyl esters (FAME) were prepared using several acid-(HCl, BF3, acetyl chloride, H2SO4) or base-catalysts (NaOCH3, tetramethylguanidine, diazomethane), or combinations thereof. All acid-catalyzed procedures resulted in decreased cis/trans (Δ9c, 11t-18∶2) and increased trans/trans (Δ9t, 11t-18∶2) conjugated dienes and the production of allylic methoxy artifacts. The methoxy artifacts were identified by gas-liquid chromatography (GLC)-mass spectroscopy. The base-catalyzed procedures gave no isomerization of conjugated dienes and no methoxy artifacts, but they did not transesterify N-acyl lipids such as sphingomyelin, and NaOCH3 did not methylate free fatty acids. In addition, reaction with tetramethylguanidine coextracted material with hexane that interfered with the determination of the short-chain FAME by GLC. Acid-catalyzed methylation resulted in the loss of about 12% total conjugated dienes, 42% recovery of the Δ9c,11t-18∶2 isomer, a fourfold increase in Δ9t,11t-18∶2, and the formation of methoxy artifacts, compared with the base-catalyzed reactions. Total milk FAME showed significant infrared (IR) absorption due to conjugated dienes at 985 and 948 cm−1. The IR determination of total trans content of milk FAME was not fully satisfactory because the 966 cm−1 trans band overlapped with the conjugated diene bands. IR accuracy was limited by the fact that the absorptivity of methyl elaidate, used as calibration standard, was different from those of the other minor trans fatty acids (e.g., dienes) found in milk. In addition, acid-catalyzed reactions produced interfering material that absorbed extensively in the trans IR region. No single method or combination of methods could adequately prepare FAME from all lipid classes in milk or rumen lipids, and not affect the conjugated dienes. The best compromise for milk fatty acids was obtained with NaOCH3 followed by HCl or BF3, or diazomethane followed by NaOCH3, being aware that sphingomyelins are ignored. For rumen samples, the best method was diazomethane followed by NaOCH3.

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Abbreviations

ATR:

attenuated total reflection

FTIR:

Fourier transform infrared

GLC:

gas-liquid chromatography

HPLC:

high-performance liquid chromatography

IR:

infrared

MS:

mass spectrometry

TLC:

thin-layer chromatography

References

  1. Christie, W.W. (1981) The Effects of Diet and Other Factors on the Lipid Composition of Ruminant Tissues and Milk, in Lipid Metabolism in Ruminant Animals (Christie, W.W., ed.) pp. 193–226, Pergamon Press, Oxford.

    Google Scholar 

  2. Sutton, J.D., and Morant, S.V. (1989) A Review of the Potential of Nutrition to Modify Milk Fat and Protein, Livest. Prod. Sci. 23, 219–237.

    Article  Google Scholar 

  3. Henninger, M., and Ulberth, F. (1994) Trans Fatty Acid Content of Bovine Milk Fat, Milkwissenschaft 49, 555–558.

    CAS  Google Scholar 

  4. Wolff, R.L. (1994) Contribution of trans-18:1 Acids from Dairy Fat to European Diets, J. Am. Oil Chem. Soc. 71, 277–283.

    CAS  Google Scholar 

  5. Chen, Z.-Y., Pelletier, G., Hollywood, R., and Ratnayake, W.M.N. (1995) Trans Fatty Acid Isomers in Canadian Human Milk, Lipids 30, 15–21.

    PubMed  CAS  Google Scholar 

  6. Wolff, R.L. (1995) Content and Distribution of trans-18:1 Acids in Ruminant Milk and Meat Fats. Their Importance in European Diets and Their Effect on Human Milk, J. Am. Oil Chem. Soc. 72, 259–272.

    CAS  Google Scholar 

  7. Precht, D. (1995) Variation of trans Fatty Acids in Milk Fats, Z. Ernährungswiss. 34, 27–29.

    Article  PubMed  CAS  Google Scholar 

  8. Chardigny, J.-M., Wolff, R.L., Mager, E., Bayard, C.C., Sébédio, J.-L., Martine, L., and Ratnayake, W.M.N. (1996) Fatty Acid Composition of French Infant Formulas with Emphasis on the Content and Detailed Profile of trans Fatty Acids, J. Am. Oil Chem. Soc. 73, 1595–1601.

    Article  CAS  Google Scholar 

  9. Fogerty, A.C., Ford, G.L., and Svoronos, D. (1988) Octadeca-9,11-dienoic Acid in Foodstuffs and in the Lipids of Human Blood and Breast Milk, Nutr. Rep. Internat. 38, 937–944.

    CAS  Google Scholar 

  10. Ha, Y.L., Grimm, N.K., and Pariza, M.W. (1989) Newly Recognized Anticarcinogenic Fatty Acids: Identification and Quantitation in Natural and Processed Cheeses, J. Agr. Food Chem. 37, 75–81.

    Article  CAS  Google Scholar 

  11. Shantha, N.C., Decker, E.A., and Ustunol, Z. (1992) Conjugated Linoleic Acid Concentration in Processed Cheese, J. Am. Oil Chem. Soc. 69, 425–428.

    CAS  Google Scholar 

  12. Werner, S.A., Luedecke, L.O., and Shultz, T.D. (1992) Determination of Conjugated Linoleic Acid and Isomer Distribution in Three Cheddar-Type Cheeses: Effects of Cheese Cultures, Processing, and Aging, J. Agric. Food Chem. 40, 1817–1821.

    Article  CAS  Google Scholar 

  13. Shantha, N.C., Ram, L.N., O’Leary, J., Hicks, C.L., and Decker, E.A. (1995) Conjugated Linoleic Acid Concentrations of Dairy Products as Affected by Processing and Storage, J. Food Sci. 60, 695–697, 720.

    CAS  Google Scholar 

  14. Banni, S., Gianfranca, C., Contini, M.S., Angioni, E., Deiana, M., Dessì, M.A., Melis, M.P., and Corongiu, F.P. (1996) Characterization of Conjugated Diene Fatty Acids in Milk, Dairy Products, and Lamb Tissues, Nutr. Biochem. 7, 150–155.

    Article  CAS  Google Scholar 

  15. Jiang, J., Bjoerck, L., Fondén, R., and Emanuelson, M. (1996) Occurrence of Conjugated cis-9, trans-11-Octadecadienoic Acid in Bovine Milk: Effects of Feed and Dietary Regimen, J. Dairy Sci. 79, 438–445.

    PubMed  CAS  Google Scholar 

  16. Ha, Y.L., Storkson, J., and Pariza, M.W. (1990) Inhibition of Benzo(a)pyrene-induced Mouse Forestomach Neoplasia by Conjugated Dienoic Derivatives of Linoleic Acid, Cancer Res. 50, 1097–1101.

    PubMed  CAS  Google Scholar 

  17. Ip, C., Chin, S.F., Scimeca, J.A., and Pariza, M.W. (1991) Mammary Cancer Prevention by Conjugated Dienoic Derivative of Linoleic Acid, Cancer Res. 51, 6118–6124.

    PubMed  CAS  Google Scholar 

  18. Belury, M.A. (1995) Conjugated Dienoic Linoleate: A Polyunsaturated Fatty Acid with Unique Chemoprotective Properties, Nutr. Rev. 53, 83–89.

    Article  PubMed  CAS  Google Scholar 

  19. Jensen, R.G., Ferris, A.M., and Lammi-Keefe, C.J. (1991) The Composition of Milk Fat, J. Dairy Sci. 74, 3228–3243.

    PubMed  CAS  Google Scholar 

  20. Jensen, R.G. (1996) The Lipids in Human Milk, Prog. Lipid Res. 35, 53–92.

    Article  PubMed  CAS  Google Scholar 

  21. Harfoot, C.G. (1981) Lipid Metabolism in the Rumen, in Lipid Metabolism in Ruminant Animals (Christie, W.W., ed.) pp. 21–55, Pergamon Press, Oxford.

    Google Scholar 

  22. Ratnayake, W.M.N., and Beare-Rogers, J.L. (1990) Problems of Analyzing C18 cis- and trans-Fatty Acids of Margarine on the SP-2340 Capillary Column, J. Chromatogr. Sci. 28, 633–639.

    CAS  Google Scholar 

  23. Ratnayake, W.M.N., and Pelletier, G. (1992) Positional and Geometric Isomers of Linoleic Acid in Partially Hydrogenated Oils. J. Am. Oil Chem. Soc. 69, 95–105.

    CAS  Google Scholar 

  24. Wolff, R.L., Bayard, C.C., and Fabien, R.J. (1995) Evaluation of Sequential Methods for the Determination of Butterfat Fatty Acid Composition with Emphasis on trans-18:1 Acids. Application of the Study of Seasonal Variations in French Butters, J. Am. Oil Chem. Soc. 72, 1471–1483.

    CAS  Google Scholar 

  25. Molkentin, J., and Precht, D. (1995) Optimized Analysis of trans-Octadecenoic Acids in Edible Oils, Chromatographia 41, 267–272.

    CAS  Google Scholar 

  26. Christie, W.W. (1982) Lipid Analysis, 2nd edn., Pergamon Press, Oxford.

    Google Scholar 

  27. Shantha, N.C., Decker, E.A., and Hennig, B. (1993) Comparison of Methylation Methods for the Quantitation of Conjugated Linoleic Acid Isomers, J. AOAC Internat. 76, 644–649.

    CAS  Google Scholar 

  28. van den Berg, J.J.M., Cook, N.E., and Tribble, D.L. (1995) Reinvestigation of the Antioxidant Properties of Conjugated Linoleic Acid, Lipids 30, 599–605.

    PubMed  Google Scholar 

  29. Koritala, S., and Rohwedder, W.K. (1972) Formation of an Artifact During Methylation of Conjugated Fatty Acids, Lipids 7, 274.

    CAS  Google Scholar 

  30. Bannon, C.D., Craske, J.D., and Hilliker, A.E. (1985) Analysis of Fatty Acid Methyl Esters with High Accuracy and Reliability. IV. Fats with Fatty Acids Containing Four or More Atoms, J. Am. Oil Chem. Soc. 62, 1501–1507.

    CAS  Google Scholar 

  31. Craske, J.D., Bannon, C.D., and Norman, L.M. (1988) Limitations of Ambient Temperature Methods for the Methanolysis of Triacylglycerols in the Analysis of Fatty Acid Methyl Esters with High Accuracy and Reliability. J. Am. Oil Chem. Soc. 65, 262–266.

    CAS  Google Scholar 

  32. Wolff, R.L., and Fabien, R.J. (1989) Utilisation de l’isopropanol pour l’extraction de la matière grasse de produits laiters et pour l’estérification subséquente des acides gras, Le Lait 69, 33–46.

    CAS  Google Scholar 

  33. Stoffel, W., Chu, F., and Ahrens, E.H. (1959) Analysis of Long-Chain Fatty Acids by Gas-Liquid Chromatography. Micromethod for Preparation of Methyl Esters, Anal. Chem. 31, 307–308.

    Article  CAS  Google Scholar 

  34. Morrison, W.R., and Smith, L.M. (1964) Preparation of Fatty Acid Methyl Esters and Dimethylacetals from Lipids with Boron Fluoride-Methanol, J. Lip. Res. 5, 600–608.

    CAS  Google Scholar 

  35. Lepage, G., and Roy, C.C. (1986) Direct Transesterification of all Classes of Lipid in a One-Step Reaction, J. Lip. Res. 27, 114–120.

    CAS  Google Scholar 

  36. Christopherson, S.W., and Glass, R.L. (1970) Preparation of Milk Fat Methyl Esters by Alcoholysis in an Essentially Nonalcoholic Solution, J. Dairy Sci. 52, 1289–1290.

    Google Scholar 

  37. Schuchardt, U., and Lopes, O.C. (1988) Tetramethylguanidine-Catalyzed Transesterification of Fats and Oils: A New Method for Rapid Determination of Their Composition, J. Am. Oil Chem. Soc. 65, 1940–1941.

    CAS  Google Scholar 

  38. Fellner, V., Sauer, F.D., and Kramer, J.K.G. (1995) Steady-State Rates of Linoleic Acid Biohydrogenation by Ruminal Bacteria in Continuous Culture, J. Dairy Sci. 78, 1815–1823.

    Article  PubMed  CAS  Google Scholar 

  39. Fellner, V., Sauer, F.D., and Kramer, J.K.G. (1997) Effect of Ionophores with Different Binding Selectivity for Cations on Fermentation and Lipid Metabolism by a Continuous Culture of Ruminal Bacteria, J. Dairy Sci. 80, 921–928.

    Article  PubMed  CAS  Google Scholar 

  40. Sauer, F.D., Fellner, V., Kinsman, R., Kramer, J.K.G., Jackson, H.A., Lee, A.J., and Chen, S. (1997) Methane Output and Lactation Response in Holstein Cattle with Monensin or Unsaturated Fat Added to the Diet, J. Anim. Sci., in press.

  41. Jensen, R.G. (1989) The Lipids of Human Milk, pp. 30, CRC Press Inc., Boca Raton.

    Google Scholar 

  42. Bligh, E.G., and Dyer, W.J. (1959) A Rapid Method of Total Lipid Extraction and Purification, Can. J. Biochem. Physiol. 37, 911–917.

    PubMed  CAS  Google Scholar 

  43. Official Methods and Recommended Practices of the American Oil Chemists’ Society, (1989) Preparation of Methyl Esters of Long-Chain Fatty Acids (Ce 2-66), 4th edn., American Oil Chemists’ Society, Champaign.

    Google Scholar 

  44. Mossoba, M.M., McDonald, R.E., Armstrong, D.J., and Page, S.W. (1991) Identification of Minor C18 Triene and Conjugated Diene Isomers in Hydrogenated Soybean Oil and Margarine by GC-MI-FT-IR Spectroscopy, J. Chromatogr. Sci., 29, 324–330.

    PubMed  CAS  Google Scholar 

  45. Mossoba, M.M., Yurawecz, P.M., and McDonald, R.E. (1996) Rapid Determination of the Total trans Content of Neat Hydrogenated Oils by Attenuated Total Reflection Spectroscopy, J. Am. Oil Chem. Soc. 73, 1003–1009.

    Article  CAS  Google Scholar 

  46. Ali, L.H., Angyal, G., Weaver, C.M., Rader, J.I., and Mossoba, M.M. (1996) Determination of Total trans Fatty Acids in Foods: Comparison of Capillary-Column Gas Chromatography and Single-Bounce Horizontal Attenuated Total Reflection Infrared Spectroscopy, J. Am. Oil Chem. Soc. 73, 1699–1705.

    Article  CAS  Google Scholar 

  47. Official Methods and Recommended Practices of the American Oil Chemists’ Society, (1996–1997) Isolated trans Isomers—Infrared Spectroscopic Methods (Cd 14d-96), 4th edn. with additions and revisions, American Oil Chemists’ Society, Champaign.

    Google Scholar 

  48. Wolff, R.L. (1994) Analysis of Alpha-Linolenic Acid Geometric Isomers in Deodorized Oils by Capillary Gas-Liquid Chromatography on Cyanoalkyl Polysiloxane Stationary Phases: A Note of Caution, J. Am. Oil Chem. Soc. 71, 907–909.

    CAS  Google Scholar 

  49. Yurawecz, M.P., Hood, J.K., Roach, J.A.G., Mossoba, M.M., Daniels, D.H., Ku, Y., Pariza, M.W., and Chin, S.F. (1994) Conversion of Allylic Hydroxy Oleate to Conjugated Linoleic Acid and Methoxy Oleate by Acid-Catalyzed Methylation Procedures, J. Am. Oil Chem. Soc. 71, 1149–1155.

    CAS  Google Scholar 

  50. Bitman, J., and Wood, D.L. (1987) Comparison of Direct Transesterification of Fatty Acids with Procedures Applied to Extracts of Human and Cow Milk Fat, J. Am. Oil Chem. Soc. 64, 637.

    Google Scholar 

  51. Smith, G.N., Taj, M., and Braganza, J.M. (1991) On the Identification of a Conjugated Diene Component of Duodenal Bile as 9Z,11E-Octadecadienoic Acid, Free Rad. Biol. Med. 10, 13–21.

    Article  PubMed  CAS  Google Scholar 

  52. Kepler, C.R., Hirons, K.P., McNeill, J.J., and Tove, S.B. (1966) Intermediates and Products of the Biohydrogenation of Linoleic Acid by Butyrivibrio fibrisolvens, J. Biol. Chem. 241, 1350–1354.

    PubMed  CAS  Google Scholar 

  53. Hughes, P.E., Hunter, W.J., and Tove, S.B. (1982) Biohydrogenation of Unsaturated Fatty Acids, J. Biol. Chem. 257, 3643–3649.

    PubMed  CAS  Google Scholar 

  54. Fujimoto, K., Kimoto, H., Shishikura, M., Endo, Y., and Ogimoto, K. (1993) Biohydrogenation of Linoleic Acid by Anaerobic Bacteria Isolated from Rumen, Biosci. Biotech. Biochem. 57, 1026–1027.

    Article  CAS  Google Scholar 

  55. Cawood, P., Wickens, D.G., Iversen, S.A., Braganza, J.M., and Dormandy, T.L. (1983) The Nature of Diene Conjugation in Human Serum, Bile and Duodenal Juice, FEBS Lett. 162, 239–243.

    Article  PubMed  CAS  Google Scholar 

  56. Iversen, S.A., Cawood, P., Madigan, M.J., Lawson, A.M., and Dormandy, T.L. (1984) Identification of a Diene Conjugated Component of Human Lipid as Octadeca-9,11-dienoic Acid, FEBS Lett. 171, 320–324.

    Article  PubMed  CAS  Google Scholar 

  57. Dormandy, T.L., and Wickens, D.G. (1987) The Experimental and Clinical Pathology of Diene Conjugation, Chem. Phys. Lipids 45, 353–364.

    Article  PubMed  CAS  Google Scholar 

  58. Belury, M.A., and Kempa-Steczko, A. (1997) Conjugated Linoleic Acid Modulates Hepatic Lipid Composition in Mice, Lipids 32, 199–204.

    PubMed  CAS  Google Scholar 

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Authors and Affiliations

  1. Center for Food Safety and Applied Nutrition, U.S. FDA, 20204, Washington, DC

    Magdi M. Mossoba & Martin P. Yurawecz

  2. Center for Food and Animal Research, Agriculture and Agri-Food Canada, 4046 Neatby Bldg., K1A 0C6, Ottawa, Ontario, Canada

    John K. G. Kramer, Vivek Fellner, Michael E. R. Dugan & Frank D. Sauer

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  1. John K. G. Kramer
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  2. Vivek Fellner
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  3. Michael E. R. Dugan
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  4. Frank D. Sauer
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  5. Magdi M. Mossoba
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Kramer, J.K.G., Fellner, V., Dugan, M.E.R. et al. Evaluating acid and base catalysts in the methylation of milk and rumen fatty acids with special emphasis on conjugated dienes and total trans fatty acids. Lipids 32, 1219–1228 (1997). https://doi.org/10.1007/s11745-997-0156-3

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