Antioxidative effect of ethanol tea extracts on oxidation of canola oil

  • Z. Y. Chen
  • P. T. Chan
  • H. M. Ma
  • K. P. Fung
  • J. Wang
Article

Abstract

There is an increasing interest in the biological effects of natural antioxidants present in teas on formation ofin vivo free radicals, carcinogenesis, and atherogenesis. Teas are traditionally classified into six major groups, namely, green, yellow, white, black, dark-green, and oolong teas. The present study examined the antioxidative activity of ethanol extracts from these six major groups of teas against oxidation of heated canola oil. The oxidation was conducted at 100°C by monitoring oxygen consumption and changes in linoleic and linolenic acids in canola oil. The ethanol extracts of green, yellow, and white teas strongly inhibited oxidation of canola oil compared to butylated hydroxytoluene, probably due to the presence of natural polyphenols. In contrast, oolong teas examined exhibited only moderate antioxidative activity because of the partial destruction of natural polyphenols by semifermentation. The ethanol extracts of black, dark-green, and ginseng teas studied showed little or no protection to canola oil from lipid oxidation, probably due to the complete destruction of natural polyphenols by fermentation during manufacturing processes.

Key Words

Antioxidants black teas canola oil dark-green teas ginseng teas green teas oolong teas tea 

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References

  1. 1.
    Chen, Z.P.,Encyclopedia of Chinese Teas, Shanghai Culture Press, Shanghai, 1992, p. 386.Google Scholar
  2. 2.
    Stagg, G.V., and D.J. Millin, Nutritional and Therapeutic Value of Tea,J. Sci. Food. Agric. 26:1439–1459 (1975).CrossRefGoogle Scholar
  3. 3.
    Graham, H.N., The Plant and Its Manufacture, inMethyl Xanthine Beverage and Foods: Chemistry, Consumption, and Health Effects, edited by G. Spiller, Alan R. Liss, New York, 1984, pp. 29–74.Google Scholar
  4. 4.
    Zhu, M., P.G. Qiao, P.P. Zhang, and W.H. Lu, Catechins in Green and Black Teas,J. Chinese Trad. Med. 17:677–678 (1992).Google Scholar
  5. 5.
    Hertog, M.G.L., E.J.M. Feskens, P.C.H. Hollman, M.B. Katan, and D. Kromhout, Dietary Antioxidant Flavonoids and Risk of Coronary Heart Disease,Lancet 342:1007–1011 (1993).CrossRefGoogle Scholar
  6. 6.
    Renaud, S., and M. de Lorgeril, Wine, Alcohol, Platelets and French Paradox for Coronary Heart Disease,339:1523–1526 (1992).CrossRefGoogle Scholar
  7. 7.
    Addis, P.B., Coronary Heart Disease, An Update with Emphasis on Dietary Lipid Oxidation Products,Nutrition Quarterly 14:43–47 (1990).Google Scholar
  8. 8.
    Kinsella, J.E., E. Frankel, B. German, and J. Kanner, Possible Mechanism for the Protective Role of Antioxidants in Wine and Plant Foods,Food Technology:85–89 (1993).Google Scholar
  9. 9.
    Frankel, E.N., J. Kanner, J.B. German, E. Parks, and J.E. Kinsella, Inhibitionin vitro of Oxidation of Human Low-Density Lipoproteins by Phenolic Substance in Wine,Lancet 341:1–4 (1993).CrossRefGoogle Scholar
  10. 10.
    Stocks, P., Cancer Mortality in Relation to National Consumption of Cigarettes, Solid Fuel, Tea and Coffee,Br. J. Cancer 24:215–225 (1970).Google Scholar
  11. 11.
    Kono, S., M. Ikeda, S. Tokudome, and M. Kuratsune, A Case-Control Study of Gastric Cancer and Diet in Northern Kyushu, Japan,Jpn. J. Cancer Res. 79:1067–1074 (1988).Google Scholar
  12. 12.
    Oguni, I., K. Nasu, S. Yamamoto, and T. Nomura, The Antitumour Activity of Fresh Green Tea Leaf,Agric. Bio. Chem. 52:1879–1880 (1988).Google Scholar
  13. 13.
    Kinlen, L.J., A.N. Willows, P. Goldblatt, and J. Yudkin, Tea Consumption and Cancer,Br. J. Cancer 58:397–401 (1988).Google Scholar
  14. 14.
    Kapadia, G.J., B.B. Paul, E.B. Chung, B. Ghosh, and S.N. Pradham, Carcinogenicity of Camellia Sinensis (Tea) and Some Tannin-Containing Folk Medical Herbs Administered Subcutaneously in Rats,J. Natl. Cancer Inst. 57:207–209 (1976).Google Scholar
  15. 15.
    Bogovski, P., N. Day, M. Chvedoff, and F. Lafaverges, Accelerating Action of Tea on Mouse Skin Carcinogenesis,Cancer Letter 3:9–13 (1977).CrossRefGoogle Scholar
  16. 16.
    Shi, S.T., Z.Y. Wang, T.J. Smith, J.Y. Hong, W.F. Chen, C.T. Ho, and C.S. Yang, Effects of Green Tea and Black Tea on 4-(methylnitrosamine)-1-(3-Pyridyl)-1-Butanone Bioactivation, DNA Methylation and Lung Tumorigenesis in A/J Mice,Cancer Res. 54:4641–4647 (1994).Google Scholar
  17. 17.
    Wang, Z.Y., M.T. Huang, Y.R. Lou, J.G. Xie, K.R. Reuhl, H.L. Newmark, C.T. Ho, C.S. Yang, and A.H. Conney, Inhibitory Effects of Black Tea, Green Tea, Decaffeinated Black Tea and Decaffeinated Green Tea on Ultraviolet B Light-induced Skin Carcinogenesis in 7, 12-Dimethylbenz(a) Anthracene-Initiated SKH-1 Mice,54:3428–3435 (1994).Google Scholar
  18. 18.
    Branen, A.L., Toxicology and Biochemistry of Butylated Hydroxyanisole and Butylated Hydroxytoluene,J. Am. Oil Chem. Soc. 52:59–63 (1975).Google Scholar
  19. 19.
    Ito, N., S. Fukushima, A. Hagiwara, M. Shibata, and T. Ogiso, Carcinogenicity of Butylated Hydroxyanisole in F344 Rats,J. Natl. Cancer Inst. 70:343–352 (1983).Google Scholar
  20. 20.
    Altmann, H.J., W. Grunow, U. Mohr, H.B. Richter-Reichhelm, and P.W. Wester, Effects of BHA and Related Phenols on the Forestomach of Rats,Food Chem. Toxic. 24:1183–1188 (1986).CrossRefGoogle Scholar
  21. 21.
    Witschi, H., and C.C. Morse, Enhancement of Lung Tumor Formation in Mice by Dietary Butylated Hydroxytoluene: Dose-Time Relationships and Cell Kinetics,J. Natl. Cancer Inst. 71:859–866 (1983).Google Scholar
  22. 22.
    Linderschmidt, R.C., A.F. Trylka, M.E. Goad, and H.P. Witschi, The Effects of Dietary Butylated Hydroxytoluene on Liver and Colon Tumor Development in Mice,Toxicol. 38:151–160 (1986).CrossRefGoogle Scholar
  23. 23.
    Xie, B., H. Shi, Q. Chen, and C.T. Ho, Antioxidant Properties of Fractions and Polyphenol Constituents from Green, Oolong and Black Teas, Proceedings of the National Science Council, ROC, Part B:Life Science 17:77–84 (1993).Google Scholar
  24. 24.
    Lunder, T.L., Catechins of Green Tea, inPhenolic Compounds in Food and Their Effects on Health II, edited by C-T. Ho, C.Y. Lee, and M.T. Huang, American Chemical Society, Washington, D.C., 1992, pp. 114–120.Google Scholar
  25. 25.
    Bunick, F.J., Lipid Autoxidation in Human Red Blood Cell Membrane, Ph.D. Dissertation, University of Massachusetts at Amberst, Massachusetts, 1984.Google Scholar
  26. 26.
    Chen, Z.Y., W.M.N. Ratnayake, and S.C. Cunnane, Oxidative Stability of Flaxseed Lipids During Baking,J. Am. Oil. Chem. Soc. 71:629–632 (1994).Google Scholar
  27. 27.
    Chen, Z.Y., G. Pelletier, R. Hollywood, and W.M.N. Ratnayake,Trans Fatty Acids in Canadian Human Milk,Lipids 30:15–21 (1995).Google Scholar
  28. 28.
    Duncan, D.B., Multiple Range and F-Tests,Biometrics 11:1–42 (1955).CrossRefGoogle Scholar
  29. 29.
    Balentine, D.A., Manufacturing and Chemistry of Tea, inPhenolic Compounds in Food and Their Effects on Health I, edited by C.-T. Ho, C.Y. Lee, and M.T. Huang, American Chemical Society, Washington, D.C., 1992, pp. 102–117.Google Scholar

Copyright information

© AOCS Press 1996

Authors and Affiliations

  • Z. Y. Chen
    • 1
  • P. T. Chan
    • 1
  • H. M. Ma
    • 1
  • K. P. Fung
    • 1
  • J. Wang
    • 1
  1. 1.Department of BiochemistryThe Chinese University of Hong KongShatin, New TerritoriesHong Kong

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