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Journal of the American Oil Chemists' Society

, Volume 76, Issue 1, pp 73–81 | Cite as

Deodorization of vegetable oils. Part I: Modelling the geometrical isomerization of polyunsaturated fatty acids

  • G. Hénon
  • Zs. Kemény
  • K. Recseg
  • F. Zwobada
  • K. Kovari
Article

Abstract

Laboratory-scale treatments of canola oils similar to deodorization were carried out by applying the following conditions: reduced pressure with nitrogen or steam stripping at different temperatures ranging from 210 to 270°C for 2–65 h. The formation of the group of trans linolenic acid isomers follows a first-order reaction and the kinetic constant varies according to the Arrhenius’ law. Similar results were observed for the trans isomerization of linoleic acid. Based on these experiments, a mathematical model was developed to describe the isomerization reaction steps occurring in linoleic and linolenic acids during deodorization. The calculated degrees of isomerization are independent of the composition of the oil but related to both time and temperature of deodorization. The degree of isomerization of linolenic acid is unaffected by the decrease of this acid content observed during the deodorization. Deodorization at about 220–230°C appears to be a critical limit beyond which the linolenic isomerization increases very strongly. The newly established model can be a tool for manufacturers to reduce the total trans isomer content of refined oils, and was applied to produce a special selectively isomerized oil for a European Nutritional Project.

Key words

Deodorization isomerization kinetics linoleic acid linolenic acid modelling trans isomer fatty acids 

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References

  1. 1.
    Ackman, R.G., and S.N. Hooper, Linolenic Acid Artifacts from the Deodorization of Oils, J. Am. Oil Chem. Soc. 51:42–49 (1973).Google Scholar
  2. 2.
    Wolff, R.L., Further Studies on Artificial Geometrical Isomers of α-Linolenic Acid in Edible Linolenic Acid-Containing Oils, J. Am. Oil Chem. Soc. 70:219–224 (1993).CrossRefGoogle Scholar
  3. 3.
    Wolff, R.L., Trans-Polyunsaturated Fatty Acids in French Edible Rapeseed and Soybean Oils. Ibid.:106–110 (1992).CrossRefGoogle Scholar
  4. 4.
    Devinat, G., L. Svamaroni, and M. Naudet, Isomerisation de l’Acide Linolénique durant la Désodorisation des Huiles de Colza et de Soja, Rev. Frse Corps Gras 6:283–287 (1980).Google Scholar
  5. 5.
    Wolff, R.L., Heat-Induced Geometrical Isomerization of α-Linolenic Acid: Effect of Temperature and Heating Time on the Appearance of Individual Isomers, J. Am. Oil Chem. Soc. 70:425–430 (1993).CrossRefGoogle Scholar
  6. 6.
    O’Keefe, S.F., V.A. Wiley, and D. Wright, Effect of Temperature on Linolenic Acid Loss and 18:3 Δ9-cis, Δ12-cis, Δ15-trans Formation in Soybean Oil, J. Am. Oil Chem. Soc. 70:915–917 (1993).CrossRefGoogle Scholar
  7. 7.
    Wolff, R.L., Ubiquité et Caractéristiques des Isomères trans de l’Acide Linolénique: une Revue, OCL 2:391–400 (1995).Google Scholar
  8. 8.
    Doc. ISO/TC 34/SC 11N611-2nd ISO/CD 15304:1996: Animal and Vegetable Fats and Oils. Determination of trans Fatty Acid Isomer Content of Refined Fats and Oils. GLC method.Google Scholar
  9. 9.
    Hénon, G., Zs. Kémény, K. Recseg, F. Zwobada, and K. Kovari, Degradation of α-Linolenic Acid During Heating, J. Am. Oil Chem. Soc. 74:1615–1617 (1997).CrossRefGoogle Scholar
  10. 10.
    Bertoli, C., A. Delvecchio, P. Durand, and D. Gumy, Formation of trans Fatty Acids During Deodorization of Low Erucic Acid Rapeseed Oil, Poster presented during the “World Conference on Oilseed and Edible Oils Processing,” Istanbul, October 6–10, 1996.Google Scholar
  11. 11.
    O’Keefe, S.F., S. Gaskins-Wright, V. Wiley, and I.-C. Chen, Levels of trans Geometrical Isomers of Essential Fatty Acids in Some Unhydrogenated U.S. Vegetable Oils, Journal of Food Lipids 1:165–176 (1994).CrossRefGoogle Scholar
  12. 12.
    Wolff, R.L., Trans Isomers of α-Linolenic Acid in Deodorized Oils, Lipid Technology Newsletter, (April):36–39, (1997).Google Scholar
  13. 13.
    Pudel, F., and P. Denecke, Influences on the Formation of trans Fatty Acids During Deodorization of Rapeseed Oil, OCL 1:58–61 (1997).Google Scholar
  14. 14.
    Wolff, R.L., Analysis of α-Linolenic Acid Geometrical 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 (1994).CrossRefGoogle Scholar
  15. 15.
    Chardigny, J.M., J.L. Sebedio, and O. Berdeaux, Trans Polyunsaturated Fatty Acids: Occurrence and Nutritional Implications, Lipid Research 2:1–33 (1996).Google Scholar

Copyright information

© AOCS Press 1999

Authors and Affiliations

  • G. Hénon
    • 1
  • Zs. Kemény
    • 2
  • K. Recseg
    • 2
  • F. Zwobada
    • 1
  • K. Kovari
    • 2
  1. 1.Eridiana Béghin-Say Group, Lesieur Recherche & DéveloppementCoudekerque-BrancheFrance
  2. 2.Eridiana Béghin-Say Group, Cereol Group Research CentreBudapestHungary

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