Ezgi DEMİR, Münevver SÖKMEN, Gönül SERDAR

Recycling of Tea Waste: Simple and Effective Separation of Caffeine and Catechins by Microwave Assisted Extraction (MAE)

This study was designed to develop a cost effective green extraction method to separate valuable chemicals from black tea waste (BTW) and tea dust called “caffeine dust” (CD). These materials are totally unwanted residue and treated as rubbish. Two extraction methods were used for extraction of waste materials obtained in three collection periods. In conventional extraction method, material was subjected to hot water extraction at 80 oC for 40 minutes. In microwave assisted extraction (MAE) method, different eco-friendly aqueous solvents (water, citric acid-water or ethanol-water) were used under a controlled 600 W microwave power at 80 oC for only 4 minutes treatment in a close microwave system. MAE and conventional method gave similar extract yields for both waste materials but MAE was more successful and economical completing the extraction in shorter time. Using citric acid-water solvent in MAE significantly increased the extraction of individual catechins such as epicatechin (EC) and epigallocatechin gallate (EGCG). This study showed that tea waste could be utilized for production of valuable chemicals using nontoxic solvents at extremely short extraction periods.

Anahtar Kelimeler:

Tea waste, caffeine, catechins, microwave assisted extraction

Recycling of Tea Waste: Simple and Effective Separation of Caffeine and Catechins by Microwave Assisted Extraction (MAE)

Keywords:

Tea waste, caffeine, catechins, microwave assisted extraction,

PDF

___

Serpen, A., Pelvan, E., Alaşalvar, C., Mogol, B.A., Yavuz, H.T., Gökmen, V., Özcan, N. & Özçelik, B. (2012). Nutritional and Functional Characteristics of Seven Grades of Black Tea Produced in Turkey. Journal Agriculturel of Food Chemistry, 60 (31), p. 7682–7689
Pan, X., Niu, G. & Liu, H. (2003). Microwave-assisted extraction of tea polyphenols and tea caffeine from green tea leaves. Chemical Engineering and Processing, 42, p. 129-133.
Wang, L., Qin, P. & Hu, Y. (2010). Study on the microwave-assisted extraction of polyphenols from tea. Frontiers of Chemical Engineering in China, 4(3): 307–313.
Vuong, Q.V., Golding, J.B., Nguyen, M. & Roach, P.D. (2010). Extraction and isolation of catechins from tea. Journal separation of science, 33(21) p. 3415-3428.
Vuong, Q.V, Stathopoulos, C.E., Nguyen, M.H., Golding, J.B. & Roach, P.D. (2011). Isolation of Green Tea Catechins and Their Utilization in the Food Industry. Taylor & Francis, 27(3), p.227-24.
Row, K.H. & Jin, Y. (2006). Recovery of Catechin Compounds From Korean Tea by Solvent Extraction. Bioresource Technology, 97, p. 790-793.
Karadeniz, B. & Koca, İ. (2009). Phenolic Profiles and Antioxidant Properties of Turkish Black Tea Manufactured with Orthodox Method. Asian Journal of Chemistry, 21, p. 6803-6810.
Bronner, W.E. & Beecher, G.R. (1998). Method for determining the content of catechins in tea infusions by high-performance liquid chromatograp. Journal of Chromatography A, 805, p. 137-142
Wang, K., Liu, Z., Huang, J., Fu, D., Liu, F., Gong, Y. & Wu, X. (2009). TLC seperation of catechins and theaflavins on polyamide plates. Journal of Planar Chromatography, 22(2), p. 97-100.
Vovk, I., Simonovska, B. &Vuorela, H. (2005). Separation of Eight Selected Flavan-3-ols on Cellulose Thin-Layer Chromatographic Plates. Journal of Chromatography A, 1077, p. 188-194.
Goodarznia, I. & Govar, A.A. (2009). Superheated Water Extraction of Catechins from Green Tea Leaves: Modeling and Simulation Transactions C. Chemistry and Chemical Engineering, 16(2), p. 99-107.
Gürü, M. & İçen, H. (2004). Obtaining of caffeine from Turkish tea fiber and stalk wastes. Bioresource Technology, 94, p. 17–19.
Spigno, G. & De Faveri, D.M. (2009). Microwave-assisted extraction of tea phenols: a phenomenological study. Journal Food Engineering, 93, p. 210–217.
Deng, C.H., Ji, J., Li, N., Yu, Y.J., Duan, G.L., & Zhang, X.M. (2006). Fast determination of curcumol, curdione and germacrone in three species of curcuma rhizomes by microwave assisted extraction followed by headspace solid-phase microextraction and gas chromatography–mass spectrometry. Journal Chromatography A, 1117, p.115-120.
Nkhili, E., Tomao, V., Hajji, H.E., Boustani, E.S.E., Chemat, F. & Dangles, O. (2009). Microwave-assisted water extraction of green tea polyphenols. Phytochemical Analysis, 20(5), p. 408-415.
Wang, K., Liu, F., Liu, Z., Huang, J., Xu, Z., Li, Y., Chen, J., Gong, Y. & Yang, X. (2011). Comparison of catechins and volatile compounds among different types of tea using high performance liquid chromatograph and gas chromatograph mass spectrometer. International Journal of Food Science and Technology, 46 (7), p. 1406-1412.
İçen, H. & Gürü, M. (2009). Extraction of caffeine from tea stalk and fiber wastes using supercritical carbon dioxide. Journal Supercritical Fluids, 50 (3), p. 225–228.
İçen, H. & Gürü, M. (2010). Effect of ethanol content on supercritical carbon dioxide extraction of caffeine from tea stalk and fiber wastes. Journal Supercritical Fluids, 55 (1), p. 156-160.
Shalmashi, A., Abedi, M., Golmohammad, F. & Eikani, M.H. (2010). Isolation of caffeine from tea waste using subcritical water extraction. Journal of Food Process Engineering, 33 (4), p. 701-711.
Oliveira, M.E.C., & Franca, A.S. (2002). Microwave heating of foodstuffs. Journal of Food Engineering, 53 (4), p. 347-359.