Extraction of Antioxidants and Caffeine from Green Tea (Camelia sinensis) Leaves: Kinetics and Modeling

Abstract

The effects of temperature (50, 60, 70, 80, 90 °C) and time (5, 10, 20, 40, 80 min) on catechins and caffeine solubility in water from Iranian green tea were investigated, The best combinations of temperature and time extraction with water were 20—40 min, 80 °C for epigallocatechin (EGC), epicatechin (EC) and caffeine (Caff), and 80 min, 90 °C for catechin (C), epicatechin gallate (ECG) and epigallocatechin gallate (EGCG). A mathematical model derived from Fick’s second law was then used to calculate the diffusivity of the components, and to monitor the effect of temperature on the diffusivities. The extraction of these components is governed by two diffusion processes: fast and slow. The results showed that the intra-particle diffusion was the rate-governing step of the extraction process. The slow stage diffusivities of these components at their optimum extraction temperatures were calculated as: 1.94e-9 (EGC), 8.1e-10 (EC), 3.9e-10 (Caff), 1.34e-8 (C), 4.2e-9 (ECG) and 4.63e-9 (EGCG).

Keywords

green tea catechins caffeine diffusivity coefficients mass transfer

Get full access to this article

View all access options for this article.

References

Bauzinet L. , Labbe D. and Tremblay A. ( 2007). Production of green tea EGC- and EGCG- enriched fractions by a two-step extraction procedure. Separation and Purification Technology 56: 53-56.

Cacace J. E. and Mazza G. ( 2003). Mass transfer process during extraction of phenolic compounds from milled berries. Journal of Food Engineering 59: 379-389.

Chalmerchat Y. , Fincan M. and Dejmek P. ( 2004). Pulsed electric fields treatment for solid-liquid treatment of red beetroot pigment: mathematical modeling of mass transfer. Journal of Food Engineering 64: 229-236.

Crank J. ( 1975). The Mathematics of Diffusion. Oxford : Oxford University Press.

Doulia D. , Tzia K. and Gekas V. ( 2000). A knowledge base for the apparent mass diffusion coefficient (DEff) of foods. International Journal of Food Properties 3: 1-14.

Gekas V. ( 2001). Mass transfer modeling. Journal of Food Engineering 49: 97-102.

Herodez S.S. , Hadolin M. , Skerget M. and Knez Z. ( 2003). Solvent extraction study of antioxidants from Balm (Melissa officinalis L.) leaves. Food Chemistry 80: 275-282.

Hojnik M. , Skerget M. and Knez Z. ( 2008). Extraction of Lutein from Marigold flower petals-experimental kinetics and modeling. LWT-Food Science and Technology 40(10): 2008-2016.

Labbe D. , Tetu B. , Trudel D. and Bazinet L. ( 2008). Catechin stability of EGC and EGCG - enriched tea drinks produced by a two step extraction procedure. Food Chemistry 111: 139-143.

10.

Labbe D. , Tremblay A. and Bazinet L. ( 2006). Effect of brewing temperature and duration on green tea catechin solubilization: basis for production of EGC and EGCG enriched fractions . Separation and Purification Technology 49: 1-9.

11.

Liang Y. and Xu Y. ( 2002). Effect of extraction temperature on cream and extractability of black tea [Camellia Sinensis (L.) O. Kuntze]. International Journal of Food Science and Technology 38(1): 37-45.

12.

Martinez S. , Valek L. , Petrovic Z. , Metikos-Hukovic M. and Piljac J. ( 2005). Catechin antioxidant action at various pH studied by cyclic voltammetry and PM3 semi-empirical calculations. Journal of Electroanalytical Chemistry 584(2): 92-99.

13.

Nishitani E. and Sagesaka Y.M. ( 2004). Simultaneous determination of catechins, caffeine and other phenolic compounds in tea using new HPLC method. Journal of Food Composition and Analysis 17: 675-685.

14.

Nwuha V. , Nakajima M. , Tong J. and Ichikawa S. ( 1999). Solubility of green tea extracts in pure solvents and edible oils. Journal of Food Engineering 40: 161-165.

15.

Osburn J.O. and Katz D.L. ( 1944). Structure as a variable in the application of diffusion theory to extraction. Transactions of the American Institute of Chemical Engineers 40: 511-531.

16.

Suematsu S. , Hisanobu Y. , Saigo H. , Matsuda R. and Komatsu Y. ( 1995). A new extraction procedure for determination of caffeine and catechins in green tea. Journal of Japanese Society of Food Science and Technology 42: 419-424.

17.

Uzunalic A.P. , Skerget M. , Knez Z. , Weinreich B. , Otto F. and Gruner S. ( 2006). Extraction of active ingredients from green tea (Camellia sinensis): extraction efficiency of major catechins and caffeine. Food Chemistry 96(4): 597-605.

18.

Wang H. and Helliwell K. ( 2001). Determination of flavanols in green and black tea leaves and green tea infusions by high-performance liquid chromatography. Food Research International 34: 223-227.

19.

Wang H. , Helliwell K. and You X. ( 2000a). Isocratic elution system for the determination of catechins, caffeine and gallic acid in green tea using HPLC. Food Chemistry 68: 115-121.

20.

Wang H. , Provan G.J. and Helliwell K. ( 2000b). Tea flavonoids: their functions, utilization and analysis . Trends in Food Science and Technology 11: 152-160.

21.

Yushida Y. , Kiso M. and Goto T. ( 1999). Efficiency of the extraction of catechins from green tea. Food Chemistry 67: 429-433.