Effect of Dietary Conjugated Linoleic Acid on Lipid Characteristics of Egg Yolk

  • Hur, Sun-Jin ;
  • Kang, Geun-Ho ;
  • Jeong, Jin-Yeun ;
  • Yang, Han-Sul ;
  • Ha, Yeong-Lae ;
  • Park, Gu-Boo ;
  • Joo, Seon-Tea
  • Received : 2002.12.09
  • Accepted : 2003.03.04
  • Published : 2003.08.01


A total of 250 laying hens were fed a diet containing 0, 1, 2.5 or 5% conjugated linoleic acid (CLA), and 5% Safflower seed oil (SSO) for 5 weeks, and eggs were collected by week to analyse lipid characteristics of egg yolk. Egg yolk from CLA-fed groups showed significant increase in CLA content with increased CLA in the diet. Dietary CLA also increased the ratio of saturated fatty acids and decreased unsaturated fatty acids in the egg yolk. The proportion of myristic, palmitic, stearic and CLA were increased, while those of oleic, linoleic, linolenic and arachidonic acid were decreased. The cholesterol content in egg yolk was significantly decreased by dietary CLA for 5 weeks feeding. After 7 days of feeding, 5% CLA-fed group showed the lowest cholesterol content in egg yolk. CLAfed groups showed significantly lower 2-thiobarbituric acid-reactive substances (TBARS) values compared to control and SSO-fed group after 14 days of storage. No significant differences in TBARS values among CLA-fed groups were observed at the 28 days of storage. Results suggested that lipid oxidation of egg yolk during cold storage could be inhibited by dietary CLA due not only to changes in fatty acid composition but also to the high concentration of CLA in egg yolk.


Egg Yolk;Conjugated Linoleic Acid;Fatty Acid;Cholesterol;Lipid Oxidation


  1. Ahn, D. U., J. L. Sell, C. Jo, M. Chamruspollert and M. Jeffrey. 1999. Effect of dietary conjugated linoleic acid on the quality characteristics of chicken eggs during refrigerated storage. Poult. Sci. 78:922-928.
  2. Ha, Y. L., N. K. Grimm and M. W. Pariza. 1989. Newly recognized anticarcinogenic fatty acid: Identification and quantification in natural and processed cheeses. J. Agric. Food Chem. 37: 75-81.
  3. Joo, S. T., J. I. Lee, Y. L. Ha, and G. B. Park. 2002a. Effects of dietary conjugated linoleic acid on fatty acid composition, lipid oxidation, color, and water-holding capacity of pork loin. J. Anim. Sci., 801: 108-112
  4. Joo, S. T., S. J. Lee, S. J. Hur, J. K. Ha, Y. L. Ha and G. B. Park. 2002b. Effects of dietary conjugated linoleic acid on the egg quality. Korean J. Food Sci. Anim. Res. 22:252-258.
  5. Li, Y. and B. A. Watkins. 1998. Conjugated linoleic acids alter bone fatty acid composition and reduce ex vivo prostaglandin E-2 biosynthesis in rats fed n-6 or n-3 fatty acid. Lipids. 33:417-425.
  6. NRC. 1994. Nutrient requirements of poultry. 9th. Rev. Ed Washington DC. National Academy Press.
  7. Shantha, N. C., L. N. Ram, J. O'Leary, C. L. Hicks and E. A. Decker. 1995. Conjugated linoleic acid concentrations in dairy products as affected by processing and storage. J. Food Sci. 60: 695-697.
  8. Elkin, R. G., Yan, Z., Buhman, K. K., Story, J. A., Turek, J. J., Anderson, M., Homan, R. and Newton, R. S. 1997. Reduction of egg yolk cholesterol content through inhibition of hepatic cholesterol biosynthesis and alteration of plasma VLDL composition in laying hens: Comparative effects of atorvastatin, lovastatin, and simvastatin. Atherosclerosis. 134: 123.
  9. Ip, C., J. A. Scimeca and H. Thompson. 1995. Effect of timing and duration of dietary conjugated linoleic acid on mammary cancer prevention. Nutrition and Cancer. 24: 241-247.
  10. Du, M., D. U. Ahn, K. C. Nam and J. L. Sell. 2000a. Influence of dietary conjugated linoleic acid on volatile profiles, color and lipid oxidation of irradiated raw chicken meat. Meat Sci. 56: 387-395.
  11. Stangl, G. I., H. Mueller and M. Kirchgessner. 1999. Conjugated linoleic acid effects on circulating hormones, metabolites and lipoproteins, and its proportion in fasting serum and erythrocyte membranes of swine. European J. Nutr. 38:271-277.
  12. Kim, Y. R., Y. H. Lee, K. A. Park, J. O. Kim and Y. L. Ha. 2000. A simple method for the preparation of highly pure conjugated linoleic acid (CLA) synthesized from safflower seed oil. J. Food Sci. & Nutr. 5:10-14.
  13. Nicolosi, R. J., E. J. Rogers, D. Kritchevsky, J. A. Scimeca and P. J. Huth. 1997. Dietary conjugated linoleic acid reduces plasma lipoproteins and early aortic atherosclerosis in hypercholesterolemic hamsters. Artery. 22:266-277.
  14. Lv, C., Y. Tang, L. Wang, W. Ji, Y. Chen, S. Yang and W. Wang. 2002. Bioconversion of yolk cholesterol by extracellular cholesterol oxidase from Brevibacterium sp. Food Chem. 77: 457-463.
  15. Stangl, G. I. 2000. High dietary levels of a conjugated linoleic acid mixture alter hepatic glycerophospholipid class profile and cholesterol-carrying serum lipoproteins of rats. J. Nutritional Biochem. 11:184-191.
  16. Du, M., D. U. Ahn and J. L. Sell. 1999. Effect of dietary conjugated linoleic acid on the composition of egg yolk lipids. Poult. Sci. 78:1639-1645.
  17. Folch, J., M. Lees and G. H. Sloane-Stanley. 1957. A simple method for the isolation and purification of total lipids from animal tissues. J. Biol. rnChem. 226: 497-507.
  18. SAS. (1996). SAS/STAT Software for PC. Release 6.11, SAS Institute, Cary, NC. USA.
  19. Chin, S. F., J. M. Storkson, K. Albright, M. E. Cook and M. W. Pariza. 1994. Conjugated linoleic acid is a growth factor for rats as shown by enhanced weight gain and improved feed efficiency. J. Nutr. 124: 2344-2349.
  20. Ha, Y. L., J. Storkson and M. W. Pariza. 1990. Inhibition of benzo(a)pyrene-induced mouse forestomach neoplasia by conjugated dienoic derivatives of linoleic acid. Cancer Res. 50: 1097-1101.
  21. Bretillon, L., J. M. Chardigny, S. Gregoire, O. Berdeaux and J. L. Sebedio. 1999. Effect of conjugated linoleic acid isomers on the hepatic microsomal desaturation activities in vitro. Lipids. 34: 965-969.
  22. Du, M., D. U. Ahn and J. L. Sell. 2000b. Effect of dietary conjugated linoleic acid (CLA) and linoleic/linolenic acid ratio on polyunsaturated fatty acid status in laying hens. Poult. Sci. 79:1749-1756.
  23. Lee, K. N., D. Kritchevsky and M. W. Pariza. 1994. Conjugated linoleic acid and atherosclerosis in rabbits. Atherosclerosis. 108:19-25.
  24. Lee, K. N., J. M. Storkson and M. W. Pariza. 1995. Dietary conjugated linoleic acid changes fatty acid composition in different tissues by decreasing monounsaturated fatty acids. Page 183 in: Institute of Food Technology Annual Meeting. Book of Abstracts (Abstr).
  25. de-Deckere, E. A. M., J. M. M. van Amelsvoort, G. P. McNeill and P. Jones. 1999. Effects of conjugated linoleic acid (CLA) isomers on lipid levels and peroxisome proliferation in the hamster. Br. J. Nutr. 82:309-317.

Cited by

  2. Nutritional significance and health benefits of designer eggs vol.74, pp.02, 2018,


Supported by : Ministry of Education