Browse > Article

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

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)
Publication Information
Korean Journal of Food Science and Technology / v.41, no.1, 2009 , pp. 82-86 More about this Journal
Abstract
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.
Keywords
organic green teas; catechins; HPLC; total phenolics; antioxidant capacity;
Citations & Related Records
Times Cited By KSCI : 3  (Citation Analysis)
Times Cited By SCOPUS : 1
연도 인용수 순위
1 Yoshida Y, Kiso M, Goto T. Efficiency of the extraction of catechins from green tea. Food Chem. 67: 429-433 (1999)   DOI   ScienceOn
2 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)   DOI   ScienceOn
3 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)   DOI   ScienceOn
4 Khan N, Mukhtar H. Tea polyphenols for health promotion. Life Sci. 81: 519–533 (2007)   DOI   ScienceOn
5 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)   DOI   ScienceOn
6 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)   DOI   ScienceOn
7 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)   DOI   ScienceOn
8 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)   DOI   ScienceOn
9 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)   DOI   ScienceOn
10 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)   DOI   ScienceOn
11 Wang H, Helliwell K. Epimerisation of catechins in green teainfusions. Food Chem. 70: 337-344 (2000)   DOI   ScienceOn
12 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)
13 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)   DOI   ScienceOn
14 Singleton VL, Rossi JA, Jr. Colorimetry of total phenolics with phosphomolybdic-phosphotungstic acid reagents. Am. J. Enol. Viticult. 16: 144-158 (1965)
15 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)
16 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)
17 Koiwai H, Masuzawa N. Extraction of catechins from green tea using ultrasound. Jpn. J. Appl. Phys. 46: 4936-4938 (2007)   DOI
18 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)   DOI   ScienceOn
19 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)
20 Rasheed A, Haider M. Antibacterial activity of Camellia sinensis extracts against dental caries. Arch. Pharm. Res. 21: 348-352 (1998)   DOI   ScienceOn
21 Dobashi Y, Hirano T, Hirano M, Ohkatsu Y. Antioxidant and photo-antioxidant abilities of catechins. J. Photoch. Photobio. A 197: 141-148 (2008)   DOI   ScienceOn
22 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)   DOI   ScienceOn
23 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)   DOI   ScienceOn
24 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)