Comparative Analysis of Catechins and Antioxidant Capacity in Various Grades of Organic Green Teas Grown in Boseong, Korea

보성산 유기농 녹차의 품질에 따른 카테킨 함량과 항산화능 비교 분석

  • Park, Kyung-Ryun (Department of Food Science and Technology and Institute of Life Science and Resources, Kyung Hee University) ;
  • Lee, Sang-Gil (Department of Food Science and Technology and Institute of Life Science and Resources, Kyung Hee University) ;
  • Nam, Tae-Gyu (Department of Food Science and Technology and Institute of Life Science and Resources, Kyung Hee University) ;
  • Kim, Young-Jun (Department of Food and Biotechnology, Korea University) ;
  • Kim, Young-Rok (Department of Food Science and Technology and Institute of Life Science and Resources, Kyung Hee University) ;
  • Kim, Dae-Ok (Department of Food Science and Technology and Institute of Life Science and Resources, Kyung Hee University)
  • 박경련 (경희대학교 식품공학과 및 생명자원과학연구원) ;
  • 이상길 (경희대학교 식품공학과 및 생명자원과학연구원) ;
  • 남태규 (경희대학교 식품공학과 및 생명자원과학연구원) ;
  • 김영준 (고려대학교 식품생명공학과) ;
  • 김영록 (경희대학교 식품공학과 및 생명자원과학연구원) ;
  • 김대옥 (경희대학교 식품공학과 및 생명자원과학연구원)
  • Published : 2009.02.28


The objective of this study was to evaluate the effect of various solvents on extraction of bioactive phenolics and to analyze the antioxidant capacity and contents of individual catechins in various grades of green teas organically grown in Boseong, Korea. The organic green teas, based on their harvest seasons, were categorized into five grades such as Woo-Jeon, Se-Jak, Jung-Jak, Dae-Jak, and coarse tea. Solvents used to extract phenolics from these teas included water at $23^{\circ}C$ and $70^{\circ}C$ as well as 80% (v/v) aqueous methanol and ethanol. In general, aqueous organic solvents of methanol and ethanol led to higher extraction yields of phenolics than water at $23^{\circ}C$ and $70^{\circ}C$. Total phenolics and antioxidant capacity of the teas extracted with the aqueous organic solvents were approximately 1.5 to 3.2 and 1.8 to 3.8 times higher than those with water at $23^{\circ}C$ and $70^{\circ}C$, respectively. Coarse tea, the lowest grade of green tea, showed approximately 30-60% lower total phenolics and antioxidant capacity compared with the higher grade ones. Reversed-phase HPLC analysis was performed quantitatively to identify individual catechins, gallic acid, and caffeine in teas extracted with 80% (v/v) aqueous methanol. Based on their dry weights, the organic green teas contained about 1.7 to 2.9% of caffeine. Content (mg/g dry weight) of tea catechins decreased in the following order: Woo-Jeon (155.4) > Se-Jak (147.7) > Jung-Jak (143.2) > coarse tea (135.1) > Dae-Jak (130.5). (-)-Epigallocatechin gallate was the most abundant among the catechins analyzed. The highest grade of green tea, Woo-Jeon, had the highest amount of (-)-epigallocatechin gallate at 77.4 mg/g dry weight. Overall, the higher grade of organic green teas tended to have the higher level of antioxidant capacity and catechins.


  1. Khan N, Mukhtar H. Tea polyphenols for health promotion. Life Sci. 81: 519–533 (2007)
  2. Coimbra S, Castro E, Rocha-Pereira P, Rebelo I, Rocha S, Santos-Silva A. The effect of green tea in oxidative stress. Clin. Nutr.25: 790-796 (2006)
  3. Bursill CA, Abbey M, Roach PD. A green tea extract lowers plasma cholesterol by inhibiting cholesterol synthesis and upregulating the LDL receptor in the cholesterol-fed rabbit. Atherosclerosis 193: 86-93 (2007)
  4. Ryu OH, Lee J, Lee KW, Kim HY, Seo JA, Kim SG, Kim NH, Baik SH, Choi DS, Choi KM. Effects of green tea consumption on inflammation, insulin resistance and pulse wave velocity in type 2 diabetes patients. Diabetes Res. Clin. Pr. 71: 356-358 (2006)
  5. Kim D-O, Heo HJ, Kim YJ, Yang HS, Lee CY. Sweet and sour cherry phenolics and their protective effects on neuronal cells. J. Agr. Food Chem. 53: 9921-9927 (2005)
  6. Turkmen N, Sari F, Velioglu YS. Effects of extraction solvents on concentration and antioxidant activity of black and black mate tea polyphenols determined by ferrous tartrate and Folin-Ciocalteu methods. Food Chem. 99: 835-841 (2006)
  7. Chen C, Tang H-R, Sutcliffe LH, Belton PS. Green tea polyphenols react with 1,1-diphenyl-2-picrylhydrazyl free radicals in the bilayer of liposomes: Direct evidence from electron spin resonance studies. J. Agr. Food Chem. 48: 5710-5714 (2000)
  8. Wang H, Helliwell K. Epimerisation of catechins in green teainfusions. Food Chem. 70: 337-344 (2000)
  9. Yoshida Y, Kiso M, Goto T. Efficiency of the extraction of catechins from green tea. Food Chem. 67: 429-433 (1999)
  10. Kim D-O, Lee KW, Lee HJ, Lee CY. Vitamin C equivalent antioxidant capacity (VCEAC) of phenolic phytochemicals. J. Agr. Food Chem. 50: 3713-3717 (2002)
  11. Perva-Uzunali\acute{c} A, \check{S}kerget M, Knez \check{Z}, Weinreich B, Otto F, Grüner S. Extraction of active ingredients from green tea (Camellia sinensis): Extraction efficiency of major catechins and caffeine. Food Chem. 96: 597-605 (2006)
  12. Singleton VL, Rossi JA, Jr. Colorimetry of total phenolics with phosphomolybdic-phosphotungstic acid reagents. Am. J. Enol. Viticult. 16: 144-158 (1965)
  13. Yasuda M, Kondo M, Sonda T, Takedomi K, Eguchi S, Eguchi A. The effects of tea manufacturing methods on the contents of chemical components and antioxidative activity in tea infusions. Food Sci. Biotechnol. 13: 156-161 (2004)
  14. Kondo K, Kurihara M, Miyata N, Suzuki T, Toyoda M. Scavenging mechanisms of (-)-epigallocatechin gallate and (-)-epicatechin gallate on peroxyl radicals and formation of superoxide during the inhibitory action. Free Radical Biol. Med. 27: 855-863 (1999)
  15. Kim D-O, Lee CY. Extraction and isolation of polyphenolics. ppI1.2.1-I1.2.12. In: Current Protocols in Food Analytical Chemistry. Wrolstad RE (ed). John Wiley & Sons, Inc., New York, NY,USA (2002)
  16. Koiwai H, Masuzawa N. Extraction of catechins from green tea using ultrasound. Jpn. J. Appl. Phys. 46: 4936-4938 (2007)
  17. Lee MJ, Kwon DJ, Park OJ. The comparison of antioxidant capacities and catechin contents of Korean commercial green, oolong, and black teas. Korean J. Food Culture 22: 449-453 (2007)
  18. Rasheed A, Haider M. Antibacterial activity of Camellia sinensis extracts against dental caries. Arch. Pharm. Res. 21: 348-352 (1998)
  19. Kang S-K, Shon M-Y. Changes of bioactive compounds and antioxidant activities in Korean green tea (Camellia sinensis) with different harvestig periods. Korean J. Food Pres. 14: 709-715 (2007)
  20. Coyle CH, Philips BJ, Morrisroe SN, Chancellor MB, Yoshimura N. Antioxidant effects of green tea and its polyphenols on bladder cells. Life Sci. 83: 12-18 (2008)
  21. Peterson J, Dwyer J, Bhagwat S, Haytowitz D, Holden J, Eldridge AL, Beecher G, Aladesanmi J. Major flavonoids in dry tea. J. Food Compos. Anal. 18: 487–501 (2005)
  22. Suganuma M, Okabe S, Sueoka N, Sueoka E, Matsuyama S, Imai K, Nakachi K, Fujiki H. Green tea and cancer chemoprevention. Mutat. Res.-Fund. Mol. M. 428: 339-344 (1999)
  23. Kim S-H, Han D, Park J-D. Changes of some chemical compounds of Korean (Posong) green tea according to harvest periods. Korean J. Food Sci. Technol. 36: 542-546 (2004)
  24. Dobashi Y, Hirano T, Hirano M, Ohkatsu Y. Antioxidant and photo-antioxidant abilities of catechins. J. Photoch. Photobio. A 197: 141-148 (2008)