LEVELS OF TRANS GEOMETRICAL ISOMERS OF ESSENTIAL FATTY ACIDS IN SOME UNHYDROGENATED U. S. VEGETABLE OILS1
SEAN. O'KEEFE
Food Science and Human Nutrition Department Institute of Food and Agricultural Sciences University of Florida Gainesville, FL 32611–0370
Search for more papers by this authorSARA. GASKINS-WRIGHT
Food Science and Human Nutrition Department Institute of Food and Agricultural Sciences University of Florida Gainesville, FL 32611–0370
Search for more papers by this authorVIRGINIA. WILEY
Food Science and Human Nutrition Department Institute of Food and Agricultural Sciences University of Florida Gainesville, FL 32611–0370
Search for more papers by this authorI-CHEN. CHEN
Food Science and Human Nutrition Department Institute of Food and Agricultural Sciences University of Florida Gainesville, FL 32611–0370
Search for more papers by this authorSEAN. O'KEEFE
Food Science and Human Nutrition Department Institute of Food and Agricultural Sciences University of Florida Gainesville, FL 32611–0370
Search for more papers by this authorSARA. GASKINS-WRIGHT
Food Science and Human Nutrition Department Institute of Food and Agricultural Sciences University of Florida Gainesville, FL 32611–0370
Search for more papers by this authorVIRGINIA. WILEY
Food Science and Human Nutrition Department Institute of Food and Agricultural Sciences University of Florida Gainesville, FL 32611–0370
Search for more papers by this authorI-CHEN. CHEN
Food Science and Human Nutrition Department Institute of Food and Agricultural Sciences University of Florida Gainesville, FL 32611–0370
Search for more papers by this authorFlorida Agricultural Experimentation Station Journal Series No. R03212.
ABSTRACT.
Concentrations of trans isomers of 18:2w6 and 18:3w3 were measured in soybean and canola oils purchased in the U. S. Fatty acid methyl esters were prepared by BF3 catalyzed transesterification and separated using gas chromatography with Omegawax and CPSil88 capillary columns. Fatty acids were identified by comparing retention times with standards and with isomers of 18:2w6 and 18:3w3 in elaidinized linseed oil. Isomers identified included 18:2ct, 18:2tc, 18:3tct+ctt, 18:3cct, 18:3ctc, and 18:3tcc. The degree of isomerizations of 18:2w6 and 18:3w3 ranged from 0.3% to 3.3% and 6.6% to 37.1%, respectively. The trans contents were between 0.56% and 4.2% of the total fatty acids. Consumers will obtain isomerized essential fatty acids from vegetable oils currently marketed in the U. S.
REFERENCES
- ACKMAN, R. G., HOOPER, S. N. and HOOPER, D. L. 1974. Linolenic acid artifacts from deodorization of oils. J. Amer. Oil Chem. Soc. 51, 42–49.
- ANDERSON, R. L., FULLMER, JR. C. S. and HOLLENBACH, E. J. 1975. Effects of the trans isomers of linoleic acid on the metabolism of linoleic acid in rats. J. Nutr. 105, 393–400.
- BEYERS, E. G. and EMKEN, E. A. 1991. Metabolites of cis, trans, and trans, cis isomers of linoleic acid in mice and incorporation into tissue lipids. Biochim. Biophys. Acta 1082, 275–284.
- CHARDIGNY, J. M., SEBEDIO, J. L. and GRANDGIRARD, A. 1992. Possible physiological effects of trans polyunsaturated fatty acids. In Essential Fatty Acids and Eicosanoids, ( A. Sinclair and R. Gibson, eds.) pp. 148–152, American Oil Chemists Society, Champaign , IL .
- GRANDGIRARD, A. and JUILLIARD, F. 1987. Influence de divers paramètres sur la dégradation d'huiles végétales au cours du chauffage: Nature de l'huile, température et durée du chauffage. Rev. Francais Corps Gras 34, 213–219.
- GRANDGIRARD, A., PICONNEAUX, A., SEBEDIO, J. L., O'KEEFE, S. F., SEMON, E. and LEQUÉRE, J. L. 1989. Occurrence of geometrical isomers of eicosapentaenoic and docosahexaenoic acids in liver lipids of rats fed heated linseed oil. Lipids 24, 799–804.
- GRANDGIRARD, A., SEBEDIO, J. L. and FLEURY, J. 1984. Geometrical isomerization of linolenic acid during heat treatment of vegetable oils. J. Amer. Oil Chem. Soc. 61, 1563–1568.
- MORRISON, W. R. and SMITH, L. M. 1964. Preparation of fatty acid methyl esters and dimethyl acetals from lipids with boron trifluoride-methanol. J. Lipid Res. 5, 600–608.
- NORRIS, F. A. 1985. Deodorization. In Bailey's Industrial Oil and Fat Products, Vol. 3, ( T. H. Applewhite, ed.) pp 127–165, John Wiley & Sons, New York .
- O'KEEFE, S. F., LAGARDE, M., GRANDGIRARD, A. and SEBEDIO, J. L. 1990. Trans n-3 eicosapentaenoic and docosahexaenoic acid isomers exhibit different inhibitory effects on arachidonic acid metabolism in human platelets compared to the respective cis fatty acids. J. Lipid Res. 31, 1241–1246.
- O'KEEFE, S. F., WILEY, V. A. and GASKINS, S. 1994. Geometrical isomers of essential fatty acids in liquid infant formulas. Food Res. Internat. 27, 7–13.
- O'KEEFE, S. F., WILEY, V. A. and WRIGHT, D. 1993. Effect of temperature on linolenic acid loss and 18:3 Δ9-cis, Δ12-cis, Δ15-trans formation in soybean oil. J. Amer. Oil Chem. Soc. 70, 915–917.
- PERKINS, E. G. and SMICK, S. 1987. Octadecatrienoic fatty acids of partially hydrogenated soybean oil. J. Amer. Oil Chem. Soc. 64, 1150–1155.
- PICONNEAUX, A., GRANDGIRARD, A. and SEBEDIO, J. L. 1985. Identification d'un acide gras polyunsaturé atypique présent dans le foie de rats ayant ingéré de l'huile de lin chauffée. C. R. Acad. Sc. Paris 300, 353–358.
- PRIVETT, O. S., STEARNS, JR. E. M. and NICKELL, E. C. 1967. Metabolism of the geometric isomers of linoleic acid in the rat. J. Nutr. 92, 303–310.
- RATNAYAKE, W. M. N., HOLLYWOOD, R. and O'GRADY, E. 1991. Fatty acids in Canadian margarines. Can. Inst. Food Sci. Technol. J. 24, 81–86.
- RATNAYAKE, W. M. N., HOLLYWOOD, R., O'GRADY, E. and BEAREROGERS, J. L. 1990. Determination of cis and trans-octadecenoic acids in margarines by gas liquid chromatography-infrared spectrophotometry. J. Amer. Oil Chem. Soc. 67, 804–810.
- SEBEDIO, J.-L., GRANDGIARD, A., SEPTIER, C. and PREVOST, J. 1987. Etat d'altération de quelques huiles de friture prélevées en restauration. Rev. Francas Corps Gras 34, 15–18.
- WOLFF, R. L. 1992a. Trans-polyunsaturated fatty acids in French edible rapeseed and soybean iols. J. Amer. Oil Chem. Soc. 69, 106–110.
- WOLFF, R. L. 1992b. Resolution of linolenic acid geometrical isomers by gas-liquid chromatography on a capillary column coated with a 100% cyanopropyl polysiloxane film (CPTMSil88). J. Chromatogr. Sci. 30, 17–22.
- WOLFF, R. L. 1993a. Further studies on artificial geometrical isomers of α-linolenic acid in edible linolenic acid-containing oils. J. Amer. Oil Chem. Soc. 70, 219–224.
- WOLFF, R. L. 1993b. Heat-induced geometrical isomerization of α-linolenic acid: Effect of temperature and heating time on the appearance of individual isomers. J. Amer. Oil Chem. Soc. 70, 425–430.
- WOLFF, R. L. 1993c. Occurrence of artificial trans-polyunsaturated fatty acids in refined (deodorized) walnut oils. Sci. Aliments 13, 155–163.
- WOLFF, R. L. and SEBEDIO, J.-L. 1991. Geometrical isomers of α linolenic acid in low-calorie spreads marketed in France. J. Amer. Oil Chem. Soc. 68, 719–725.
