FNS  Vol.6 No.15 , November 2015
Effect of Seasons on Theanine Levels in Different Kenyan Commercially Released Tea Cultivars and Its Variation in Different Parts of the Tea Shoot
Abstract: A study was conducted to determine the effect of seasons in 23 different Kenyan commercially released tea cultivars. This was done for three seasons viz: cold and wet, cold and humid, hot and dry. The cold and wet season was shown to be the best for obtaining high levels of theanine while the hot and dry season resulted in decrease in theanine levels in most of the test cultivars thus showing seasonal variation on the levels of theanine. Theanine content was determined using High Performance Liquid Chromatography (HPLC). On average, TRFK 31/8 contained 1.20% dw of theanine and highest in green tea while TRFK 56/89 contained 0.97% dw of theanine and highest in black tea. Green tea contained higher theanine levels than black tea and this has been shown in most of the test cultivars. To achieve the health benefits of theanine, one should drink 4 cups of tea brewed from cultivars with 0.63% dw and more of theanine. Also theanine levels were determined in the different partitions of the tea shoot (4 leaves + bud) and the internode contained the highest theanine levels up to 3.26% dw for both cultivars compared to the leafy partitions.
Cite this paper: Janet, T. , John, W. , Thomas, K. , Kelvin, M. and Francis, W. (2015) Effect of Seasons on Theanine Levels in Different Kenyan Commercially Released Tea Cultivars and Its Variation in Different Parts of the Tea Shoot. Food and Nutrition Sciences, 6, 1450-1459. doi: 10.4236/fns.2015.615149.

[1]   Andlauer, W. and Héritier, J. (2011) Rapid Electrochemical Screening of Antioxidant Capacity (RESAC) of Selected Tea Samples. Food Chemistry, 125, 1517-1520.

[2]   Chen, C., Yu, R., Owuor, E.D. and Kong, A.N.T. (2000) Activation of Antioxidant-Response Element (ARE), Mitogen-Activated Protein Kinases (MAPKs) and Caspases by Major Green Tea Polyphenol Components during Cell Survival and Death. Archives of Pharmacal Research, 23, 605-612.

[3]   Higdon, J.V. and Frei, B. (2003) Tea Catechins and Polyphenols: Health Effects, Metabolism, and Antioxidant Functions. Critical Reviews in Food Science and Nutrition, 43, 89-143.

[4]   Leung, L.K., Su, Y., Chen, R., Zhang, Z., Huang, Y. and Chen, Z.Y. (2001) Theaflavins in Black Tea and Catechins in Green Tea Are Equally Effective Antioxidants. Journal of Nutrition, 131, 2248-2251.

[5]   Stewart, A.J., Mullen, W. and Crozier, A. (2005) On-Line High Performance Liquid Chromatography Analysis of the Antioxidant Activity of Phenolic Compounds in Green and Black Tea. Molecular Nutrition & Food Research, 49, 52-60.

[6]   Maki, K.C., Reeves, M.S., Farmer, M., Yasunaga, K., Matsuo, N., Katsuragi, Y., Komikado, M., Tokimitsu, I., Wilder, D., Jones, F., Blumberg, J.B. and Cartwright, Y. (2009) Green Tea Catechin Consumption Enhances Exercise-Induced Abdominal Fat Loss in Overweight and Obese Adults. Journal of Nutrition, 139, 264-270.

[7]   Shrubsole, M.J., Lu, W., Chen, Z., Shu, X.O., Zheng, Y., Dai, Q., Gu, K., Ruan, Z.X., Gao, Y.T. and Zheng, W. (2009) Drinking Green Tea Modestly Reduces Breast Cancer Risk. Journal of Nutrition, 139, 310-316.

[8]   Higdon, G.E.J., Ruxton, C.H.S. and Leed, A.R. (2007) Black Tea—Helpful or Harmful? A Review of the Evidence. European Journal of Clinical Nutrition, 61, 3-18.

[9]   Duffy, S.J., Keaney Jr., J.F., Holbrook, M., Gokce, N., Swerdloff, P.L., Frei, B. and Vita, J.A. (2001) Short- and Long-Term Black Tea Consumption Reverses Endothelial Dysfunction in Patients with Coronary Artery Disease. Circulation. Journal of the American Heart Association, 104, 151-156.

[10]   Bolling, B.W. and Chen, C.Y (2009) Tea and Health: Preventive and Therapeutic Usefulness in the Elderly. Current Opinion in Clinical Nutrition & Metabolic Care, 12, 42-48.

[11]   Sakato, Y. (1949) The Chemical Constituents of Tea: A New Amide Theanine. Journal of Agricultural and Food Chemistry, 23, 262-267.

[12]   Syu, K.Y., Lin, C.L., Huang, H.C. and Lin, J.K. (2008) Determination of Theanine, GABA, and Other Amino Acids in Green, Oolong, Black, and Puerh Teas with Dabsylation, and High Performance Liquid Chromatography. Journal of Agricultural and Food Chemistry, 56, 7637-7643.

[13]   Deng, W.W., Shinjiro, O. and Hiroshi, A. (2010) Distribution and Biosynthesis of Theanine in Theaceae Plants. Plant Physiology and Biochemistry, 47, 70-72.

[14]   Palva, S. and Palva J.M. (2007) New Vistas for Alpha-Frequency Band Oscillations. Trends in Neurosciences, 30, 150-158.

[15]   Hideyuki, S., Shunsuke, I., Nobukazu, M. and Hidehiko, K. (2002) Enzymatic Production of Theanine, an “Umami” Component of Tea, from Glutamine and Ethylamine with Bacterial γ-Glutamyl Trans Peptidase. Enzyme and Microbial Technology, 31, 884-889.

[16]   DeMejia, E.G., Ramirez-Mares, M.V. and Puangpraphant, S. (2009) Bioactive Components of Tea: Cancer, Inflammation and Behavior. Brain, Behavior, and Immunity, 23, 721-731.

[17]   Boris, K., Nir, G., Amos, D. and Korczyn, H. (2009) Smoking and Tea Consumption Delay Onset of Parkinson’s Disease. Parkinsonism and Related Disorders, 15, 41-46.

[18]   Sugiyama, T. and Sadzuka, Y. (2003) Theanine and Glutamate Transporter Inhibitors Enhance the Antitumor Efficacy of Chemotherapeutic Agents. Biochimica et Biophysica Acta, 5, 47-59.

[19]   Popkin, B.M. (2010) Recent Dynamics Suggest Selected Countries Catching up to US Obesity. American Journal of Clinical Nutrition, 91, 1284S-1288S.

[20]   Van der Pijl, P.C., Chen, L. and Mulder, T.P.J. (2010) Human Disposition of L-Theanine in Tea or Aqueous Solution. Journal of Functional Foods, 2, 239-244.

[21]   Wan, X., Zhang, Z. and Li, D. (2009) Chemistry and Biological Properties of Theanine. In: Ho, C.T., Lin, J.K. and Shahidi, F., Eds., Tea and Tea Products, CRC Press, Boca Raton, 255-274.

[22]   Chu, D.C. and Juneja, L.R. (1997) General Chemical Composition of Green Tea and Its Infusion. In: Yamamoto, T., Juneja, L.R., Chu, D.C. and Kim, M., Eds., Chemistry and Applications of Green Tea, CRC Press, Boca Raton, 13-22.

[23]   Engelhardt, U.H. and Simonides, M. (2007) Schnellmethode zur Bestimmung von Theanin in Tee. Lebensmittelchemie (im Druck).

[24]   Too, J.C., Kinyanjui, T., Wanyoko, J.K. and Wachira, F.N. (2015) Effect of Sunlight Exposure and Different Withering Durations on Theanine Levels in Tea (Camellia sinensis). Food and Nutrition Sciences, 6, 1014-1021.

[25]   Wachira, F.N., Kamunya, S.M., Chalo, R., Maritim, T. and Kinyangi, T. (2012) TRFK Clonal Catalogue. Tea Research Foundation of Kenya (TRFK), 15-140.

[26]   Chen, H.Y., Lin-Shiau, S.Y. and Lin, J.K. (2009) Pu-erh Tea: Its Manufacturing and Health Benefits. In: Ho, C.T., Lin, J.K. and Shahidi, F., Eds., Tea and Tea Products: Chemistry and Health-Promoting Properties, CRC Press, Boca Raton, 9-15.

[27]   Chen, Y.L., Jiang, Y.M., Duan, J., Shi, J., Xue, S. and Kakuda, Y. (2010) Variation in Catechin Contents in Relation to Quality of “Huang Zhi Xiang” Oolong Tea (Camellia sinensis) at Various Growing Altitudes and Seasons. Food Chemistry, 119, 648-652.

[28]   Li, Q., Huang, J., Liu, S., Li, J., Yang, X., Liu, Y. and Liu, Z. (2011) Proteomic Analysis of Young Leaves at Three Developmental Stages in an Albino Tea Cultivar. Proteome Science, 9, 44-49.

[29]   Kilel, E.C., Faraj, A.K., Wanyoko, J.K., Wachira, F.N. and Mwingirwa, V. (2013) Green Tea from Purple Leaf Coloured Tea Clones in Kenya—Their Quality Characteristics. Journal of Food Chemistry, 141, 769-775.

[30]   Lin, J.K., Lin, C.L., Liang, Y.C., Lin-Shiau, S.Y. and Juan, I.M. (1998) Survey of Catechins, GA, and Methylxanthines in Green, Oolong, Pu-erh and Black Teas. Journal of Agricultural and Food Chemistry, 46, 3635-3642.

[31]   Jeng, K.C., Chen, C.S., Fang, Y.P., Hou, R.C.W. and Chen Y.S. (2007) Effect of Microbial Fermentation on Content of Statin, GABA, and Polyphenols in Pu-erh Tea. Journal of Agricultural and Food Chemistry, 55, 8787-8792.