Malaysian Journal of Analytical Sciences Vol 25 No 5 (2021): 740 - 750

 

 

 

 

SPECTROPHOTOMETRIC DETERMINATION OF TOTAL FLAVONOID CONTENTS IN TEA PRODUCTS AND THEIR LIQUORS UNDER VARIOUS BREWING CONDITIONS

 

(Penentuan Spektrofotometrik bagi Kandungan Jumlah Flavonoid di dalam Produk Teh dan Arak di Bru pada Keadaan Berbeza)

 

Nguyen Cong-Hau¹, Le-Thi Anh-Dao¹, Le Nhon-Duc², Nguyen Thanh-Nho¹*

 

¹Faculty of Environmental and Food Engineering,

Nguyen Tat Thanh University, Ho Chi Minh City, Vietnam

²Warrantek Joint Stock Company-Testing Center, Can Tho City, Vietnam

 

^*Corresponding author:  ntnho@ntt.edu.vn

 

 

Received: 31 July 2021; Accepted: 7 September 2021; Published:  25 October 2021

 

 

Abstract

Tea (Camellia sinensis L.) has been considered among the most common beverages consumed worldwide, primarily due to its medical properties and sensory attributes. Flavonoids are the most abundant type of phenolic compounds found in tea leaves, and the flavonoid contents vary according to tea variety and processing method. In this study, we proposed and validated a spectrophotometric method for determining the total flavonoid contents (TFCs) in tea products and their liquors. Quercetin was used as the standard to build the calibration curve with AlCl₃ as the color reagent, to measure the absorbance of the formed complex at 510 nm for quantification purposes. The reaction time in the colorimetric assay was investigated, and immediate spectrophotometric measurement after adding enough reagent was applied. The linear range was from 50 to 700 milligrams of quercetin equivalents per liter (mg QE L^–1), and the regression equation was y = 0.0013x + 0.0872 (R² = 0.9981). Repeatability and reproducibility (RSD_r = 1.1 and RSD_R = 1.2%) were favorable regarding Appendix F. AOAC (2016). Trueness was assessed through the spiked samples, and recoveries ranged from 98 to 102%. The analytical method was applied to determine the TFCs in several tea products collected from tea plantation regions in the North and South of Vietnam. The TFCs in tea products followed the descending order of green (140.1-155.3 mg QE g^–1) > Pu’erh (108.5-141.8 mg QE g^–1) > white (95.3-99.0 mg QE g^–1) > black (60.8-89.7 mg QE g^–1) > oolong (42.0 to 59.8 mg QE g^–1). Moreover, the effect of brewing conditions on the release of TFCs into tea liquors was assessed. The results indicate that the highest extraction percentage of flavonoid for most tea products was recorded at 90 °C within the infusion time of 40 minutes.

 

Keywords:  Camellia sinensis L., flavonoids, quercetin, tea products, tea liquors 

 

Abstrak

Teh (Camellia sinensis L.) merupakan minuman yang sering kali diambil di seluruh dunia, terutama disebabkan sifat perubatannya dan aromanya. Flavonoids merupakan jenis sebatian fenolik yang sering dijumpai di dalam daun teh, dan kandungan flavonoids berbeza mengikut varieti teh dan kaedah pemprosesan. Melalui kajian ini, kami mencadangkan dan validasi kaedah spektrofotometrik bagi penentuan kandungan jumlah flavonoids (TFCs) di dalam produk teh dan arak. Quercetin telah di guna sebagai piawai dalam penghasilan lengkung piawai Bersama AlCl₃ sebagai reagen warna, untuk mengukur serapan yang membentuk kompleks pada 510 nm bagi tujuan kuantifikasi. Masa tindak balas ujian kolorimetrik telah dikaji, dan pengukuran spektrofotometrik segera dilakukan selepas penambahan reagen dilakukan. Julat kelinearan dari 50 hingga 700 miligram quertin setiap liter (mg QE L^–1), dan pekali persamaan diperolehi ialah y = 0.0013x + 0.0872 (R² = 0.9981). Kebolehulangan dan kebolehasilan semula (RSD_r = 1.1 dan RSD_R = 1.2%) adalah baik berdasarkan Appendix F. AOAC (2016). Ketepatan kaedah diuji menggunakan sampel yang dipaku, dan perolehan semula pada julat 98 hingga 102%. Kaedah analisis telah digunapakai bagi penentuan TFCs di dalam pelbagai produk teh yang di ambil dari kawasan ladang teh terletak di utara dan selatan Vietnam. TFCs di dalam produk teh mengikut tertib menurun seperti berikut hijau (140.1-155.3 mg QE g^–1) > Pu’erh (108.5-141.8 mg QE g^–1) > putih (95.3-99.0 mg QE g^–1) > hitam (60.8-89.7 mg QE g^–1) > oolong (42.0-59.8 mg QE g^–1). Tambahan lagi, kesan bru yang pelbagai terhadap TFCs di dalam teh arak juga telah dikaji. Hasil menunjukkan peratus kesan pengekstrakan flavonoids bagi kebanyakkan teh telah direkod pada 90 °C dengan masa rendaman ialah 40 minit.

 

Kata kunci:  Camellia sinensis L., flavonoids, quercetin, produk teh, teh arak

 

References

1.      Yan, Z., Zhong, Y., Duan, Y., Chen, Q. and Li, F. (2020). Antioxidant mechanism of tea polyphenols and its impact on health benefits. Animal Nutrition, 6(2): 115-123.

2.      Zhang, L., Li, N., Ma, Z.-Z. and Tu, P.-F. (2011). Comparison of the chemical constituents of aged pu-erh tea, ripened pu-erh tea, and other teas using HPLC-DAD-ESI-MS. Journal of Agricultural and Food Chemistry, 59 (16): 8754-8760.

3.      Kosińska, A. and Andlauer, W. (2014). Antioxidant capacity of tea: Effect of processing and storage. Processing and impact on antioxidants in beverages. Elsevier: pp. 109-120.

4.      Ahmed, S., Unachukwu, U., Stepp, J. R., Peters, C. M., Long, C. and Kennelly, E. (2010). Pu-erh tea tasting in Yunnan, China: correlation of drinkers' perceptions to phytochemistry. Journal of Ethnopharmacology, 132 (1): 176-185.

5.      Chen, S., Li, M., Zheng, G., Wang, T., Lin, J., Wang, S., Wang, X., Chao, Q., Cao, S. and Yang, Z. (2018). Metabolite profiling of 14 Wuyi Rock tea cultivars using UPLC-QTOF MS and UPLC-QqQ MS combined with chemometrics. Molecules, 23(2): 104.

6.      Kodama, D. H., Gonçalves, A. E. d. S. S., Lajolo, F. M. and Genovese, M. I. (2010). Flavonoids, total phenolics and antioxidant capacity: comparison between commercial green tea preparations. Food Science and Technology, 30: 1077 – 1082.

7.      Tao, W., Zhou, Z., Zhao, B. and Wei, T. (2016). Simultaneous determination of eight catechins and four theaflavins in green, black and oolong tea using new HPLC–MS–MS method. Journal of Pharmaceutical and Biomedical Analysis, 131: 140-145.

8.      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(1): 89-143.

9.      Yokozawa, T., Dong, E., Nakagawa, T., Kashiwagi, H., Nakagawa, H., Takeuchi, S. and Chung, H. Y. (1998). In vitro and in vivo studies on the radical-scavenging activity of tea. Journal of Agricultural and Food Chemistry, 46(6): 2143- 2150.

10.   Ahmad, N., Cheng, P. and Mukhtar, H. (2000). Cell cycle dysregulation by green tea polyphenol epigallocatechin-3-gallate. Biochemical and Biophysical Research Communications, 275(2): 328-334.

11.   Kundu, J. K., Na, H.-K., Chun, K.-S., Kim, Y.-K., Lee, S. J., Lee, S. S., Lee, O. -S., Sim, Y.-C. and Surh, Y.-J. (2003). Inhibition of phorbol ester–induced COX-2 expression by epigallocatechin gallate in mouse skin and cultured human mammary epithelial cells. The Journal of nutrition, 133 (11): 3805S-3810S.

12.   Pękal, A. and Pyrzynska, K. (2014). Evaluation of aluminium complexation reaction for flavonoid content assay. Food Analytical Methods, 7(9): 1776-1782.

13.   Izzreen, N. Q. and Mohd Fadzelly, A. (2013). Phytochemicals and antioxidant properties of different parts of Camellia sinensis leaves from Sabah Tea Plantation in Sabah, Malaysia. International Food Research Journal, 20(1): 307-312.

14.   Bansal, S., Syan, N., Mathur, P. and Choudhary, S. (2012). Pharmacological profile of green tea and its polyphenols: A review. Medicinal Chemistry Research, 21(11): 3347-3360.

15.   Putri, T. (2015). In vitro anti-gout activity and phenolic content of "black tea" soursop (Annona muricata L.) leaves brew. Journal of Chemical and Pharmaceutical Research, 7(11): 735-743.

16.   Kılıç, C., Can, Z., Yılmaz, A., Yıldız, S. and Turna, H. (2017). Antioxidant properties of some herbal teas (green tea, senna, corn silk, rosemary) brewed at different temperatures. International Journal of Secondary Metabolite, 4(3): 142-148.

17.   ISO 1572 (1980). Tea-Preparation of ground sample of known dry matter content.

18.   ISO 14502-1 (2005). Determination of substances characteristic of green and black tea-Part 1: Content of total polyphenols in tea-Colorimetric method using Folin-Ciocalteu reagent.

19.   Kim, D.-O., Jeong, S. W. and Lee, C. Y. (2003). Antioxidant capacity of phenolic phytochemicals from various cultivars of plums. Food Chemistry, 81(3): 321-326.

20.   Appendix F. AOAC (2016). Guidelines for Standard Method Performance Requirements. 

21.   Konieczka, P. and Namiesnik, J. (2016). Quality assurance and quality control in the analytical chemical laboratory: A practical approach, CRC Press.

22.   Shannon, E., Jaiswal, A. K. and Abu-Ghannam, N. (2018). Polyphenolic content and antioxidant capacity of white, green, black, and herbal teas: a kinetic study. Food Research, 2(1): 1-11.

23.   Akbay, P., Basaran, A. A., Undeger, U. and Basaran, N. (2003). In vitro immunomodulatory activity of flavonoid glycosides from Urtica dioica L. Phytotherapy Research: An International Journal Devoted to Pharmacological and Toxicological Evaluation of Natural Product Derivatives, 17(1): 34-37.

24.   Pokorny, J., Yanishlieva, N. and Gordon, M. H. (2001). Antioxidants in food: Practical applications: CRC press.

25.   Abdeltaif, S. A., SirElkhatim, K. A. and Hassan, A. B. (2018). Estimation of phenolic and flavonoid compounds and antioxidant activity of spent coffee and black tea (processing) waste for potential recovery and reuse in Sudan. Recycling, 3(2): 27.

26.   Peterson, J., Dwyer, J., Bhagwat, S., Haytowitz, D., Holden, J., Eldridge, A., Beecher, G. and Aladesanmi, J. (2005). Major flavonoids in dry tea. Journal of Food Composition and Analysis, 18(6): 487-501.

27.   Unachukwu, U. J., Ahmed, S., Kavalier, A., Lyles, J. T. and Kennelly, E. J. (2010). White and green teas (Camellia sinensis var. sinensis): variation in phenolic, methylxanthine, and antioxidant profiles. Journal of Food Science, 75 (6): C541-C548.

28.   Rusak, G., Komes, D., Likić, S., Horžić, D. and Kovač, M. (2008). Phenolic content and antioxidative capacity of green and white tea extracts depending on extraction conditions and the solvent used. Food Chemistry, 110(4): 852- 858.

29.   Harbowy, M. E., Balentine, D. A., Davies, A. P. and Cai, Y. (1997). Tea chemistry. Critical Reviews in Plant Sciences, 16(5): 415-480.

30.   Graham, H. N. (1992). Green tea composition, consumption, and polyphenol chemistry. Preventive Medicine, 21(3): 334-350.

31.   Chen, M., Zhu, Y., Zhang, H., Wang, J., Liu, X., Chen, Z., Zheng, M. and Liu, B. (2017). Phenolic compounds and the biological effects of Pu-erh teas with long-term storage. International Journal of Food Properties, 20(8): 1715-1728.

32.   Zhou, B., Ma, C., Wu, T., Xu, C., Wang, J. and Xia, T. (2020). Classification of raw Pu-erh teas with different storage time based on characteristic compounds and effect of storage environment. LWT Food Science and Technology, 133: 109914.

33.   Imran, A., Butt, M. S., Sharif, M. K. and Sultan, J. I. (2013). Chemical profiling of black tea polyphenols. Pakistan Journal of Nutrition, 12 (3): 261.

34.   Lee, J.-E., Lee, B.-J., Chung, J.-O., Kim, H.-N., Kim, E.-H., Jung, S., Lee, H., Lee, S.-J and Hong, Y.-S. (2015). Metabolomic unveiling of a diverse range of green tea (Camellia sinensis) metabolites dependent on geography. Food Chemistry, 174: 452-459.

35.   Yang, J. and Liu, R. H. (2013). The phenolic profiles and antioxidant activity in different types of tea. International Journal of Food Science & Technology, 48(1): 163-171.

36.   Pacheco-Coello, F., Peraza-Marrero, M., Orosco-Vargas, C., Ramirez-Azuaje, D. and Pinto-Catari, I. (2020). Determination of total phenolic compounds and evaluation of the antioxidant activity of commercial and artisanal green tea traded in Maracay, Venezuela. Revista Boliviana de Química, 37(1): 28-33.

37.   Hertog, M. G., Hollman, P. C. and Van de Putte, B. (1993). Content of potentially anticarcinogenic flavonoids of tea infusions, wines, and fruit juices. Journal of Agricultural and Food Chemistry, 41(8): 1242-1246.

38.   Zayadi, R. A., Rahim, N. A. and Bakar, F. A. (2016). Determination of flavonoid and caffeine content in black and oolong teas. Journal of Science and Technology, 8(2): 18-24. 

39.   Chang, M.-Y., Lin, Y.-Y., Chang, Y.-C., Huang, W.-Y., Lin, W.-S., Chen, C.-Y., Huang, S.-L. and Lin, Y.-S. (2020). Effects of infusion and storage on antioxidant activity and total phenolic content of black tea. Applied Sciences, 10(8): 2685.

40.   Kelebek, H. (2016). LC-DAD–ESI-MS/MS characterization of phenolic constituents in Turkish black tea: Effect of infusion time and temperature. Food Chemistry, 204: 227-238.

41.   Jamshidpour, S., Faramarzi, E., Mahmoudi, M. and Varmira, K. (2016). The effect of the duration and temperature of infusion on the heavy metal content of green tea. European Online Journal of Natural and Social Sciences, 5 (4): 980-987.

42.   Asil, M. H., Rabiei, B. and Ansari, R. H. (2012). Optimal fermentation time and temperature to improve biochemical composition and sensory characteristics of black tea. Australian Journal of Crop Science, 6(3): 550-558.

43.   Ioannou, I., Chekir, L. and Ghoul, M. (2020). Effect of heat treatment and light exposure on the antioxidant activity of flavonoids. Processes, 8 (9): 1078.

44.   Buchner, N., Krumbein, A., Rohn, S. and Kroh, L. (2006). Effect of thermal processing on the flavonols rutin and quercetin. Rapid communications in mass spectrometry, 20: 3229-3235.