Kinetics of the formation of trans linoleic acid and trans linolenic acid were compared. Pilot plant-scale tests on canola oils were carried out to validate the laboratory-scale kinetic model of geometrical isomerization of polyunsaturated fatty acids described in our earlier publication. The reliability of the model was confirmed by statistical calculations. Formation of the individual trans linoleic and linolenic acids was studied, as well as the effect of the degree of isomerization on the distribution of the trans fatty acid isomers. Oil samples were deodorized at temperatures from 204 to 230°C from 2 to 86 h. Results showed an increase in the relative percentage of isomerized linolenic and linoleic acid with an increase in either the deodorization time or the temperature. The percentage of trans linoleic acid (compared to the total) after deodorization ranged from <1 to nearly 6%, whereas the percentage of trans linolenic acid ranged from <1 to >65%. Applying this model, the researchers determined the conditions required to produce a specially isomerized oil for a nutritional study. The practical applications of these trials are as follows: (i) the trans fatty acid level of refined oils can be predicted for given deodorization conditions, (ii) the conditions to meet increasingly strict consumer demands concerning the trans isomer content can be calculated, and (iii) the deodorizer design can be characterized by the deviation from the theoretical trans fatty acid content of the deodorized oil.
This is a preview of subscription content, access via your institution.
Buy single article
Instant access to the full article PDF.
Price excludes VAT (USA)
Tax calculation will be finalised during checkout.
Wolff, R.L., Trans Isomers of α-Linolenic Acid in Deodorized Oils, Lipid Technol. Newsletter (April):36–39 (1997).
Wolff, R.L., Heat-Induced Geometrical Isomerization of α-Linolenic Acid: Effect of Heating Time on the Appearance of Individual Isomers, J. Am. Oil Chem. Soc. 70:425–430 (1993).
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, —Ibid. 70:915–917 (1993).
Hénon, G., Z. Kemény, K. Recseg, F. Zwobada, and K. Kővári, Deodorization of Vegetable Oils. Part I: Modeling the Geometrical Isomerization of Polyunsaturated Fatty Acids, —Ibid. 76:73–81 (1999).
American Oil Chemists' Society, Preparation of Methyl Esters of Long-Chain Fatty Acids, in Official Methods and Recommended Practices of the American Oil Chemists' Society, 4th edn., Champaign, 1993, Ce 2-26.
Document ISO 9936: 1997, Animal and Vegetable Fats and Oils—Determination of Tocopherols and Tocotrienols Contents—Method Using High-Performance Liquid Chromatography.
Hénon, G., Z. Kemény, K. Recseg, F. Zwobada, and K. Kővári, Degradation of α-Linolenic Acid During Heating, J. Am. Oil Chem. Soc. 74:1615–1617 (1997).
Wolff, R.L., Trans-Polyunsaturated Fatty Acids in French Edible Rapeseed and Soybean Oils, —Ibid. 69:106–110 (1992).
Wolff, R.L., Further Studies on Artificial Geometrical Isomers of α-Linolenic Acid in Edible Linolenic Acid-Containing Oils, —Ibid. 70:219–224 (1993).
De Greyt, W., O. Radanyi, M. Kellens, and A. Huyghebaert, Contribution of trans Fatty Acids from Vegetable Oils and Margarines to the Belgian Diet, Fett/Lipid 98:30–33 (1996).
Devinat, G., L. Scamaroni, and M. Naudet, Isomérisation de l'Acid Linoléique Durant la Désodorisation des Huiles de Colza et de Soja, Rev. Franc. Corps Gras 27:283–287 (1980).
About this article
Cite this article
Kemény, Z., Recseg, K., Hénon, G. et al. Deodorization of vegetable oils: Prediction of trans polyunsaturated fatty acid content. J Amer Oil Chem Soc 78, 973–979 (2001). https://doi.org/10.1007/s11746-001-0374-0