Abstract

Introduction. Buckwheat grain has long been used in food technology. However, its aboveground part remains understudied even though it is richer in biologically active substances than grain. The research objective was to evaluate the potential of buckwheat grass as a raw material for functional tea beverages. Study objects and methods. The research featured the lower and upper parts of the stem, leaves, and flowers of common buckwheat, as well as buckwheat tea beverages. The content of polyphenol compounds was determined by the Folin-Ciocalteu method, while the amount of rutin was measured by HPLC analysis. Sensory properties were analyzed by standard methods and quality score, and antioxidant activity – by DPPH radical scavenging method. Results and discussion. The sensory analyses proved that the best tea beverages were made from the upper part of the plant: the samples had a strong smell of meadow grass and honey. The taste of the samples was pleasant, sweetish, with a honey and light floral aftertaste. As the total score (maximum score – 20) increased, the tea samples were arranged in the following order: lower stem (14.3) > upper stem (16.8) > leaves, (18.5) > blend – mix of leaves, flowers, and upper stem (18.6) > flowers (19.3). Polyphenol compounds were found in all parts of the plant: flowers – 6.67%, leaves – 5.71%, blend – 5.45%, upper and lower stem – 1.92 and 1.32%, respectively. Only 30–40% of buckwheat grass polyphenol compounds were found in tea beverages. Most of them were in the samples prepared from leaves and flowers – 1.78 %. Rutin made up most of the polyphenol compounds found in the leaves (5.05%), but its content was lower in other parts of the plant: 3.43% in the blend, 3.03% in the flowers, 1.08 and 0.76% in the upper and lower stem. Except for the lower stem samples, the tea contained from 15 to 75% of the daily rutin intake. All the tea samples showed antioxidant activity: flowers – 66.7%, leaves – 62.3%, and blend – 52.5%. In terms of ascorbic acid, it was 69, 64, and 52 μmol/g dry matter, respectfully. The same samples demonstrated antiradical activity. Conclusion. Common buckwheat grass can serve as a raw material for tea beverages. Buckwheat tea is a natural functional food product with zero caffeine. They have a pleasant taste and aroma. They owe their high biological activity to the high content of rutin and other polyphenol compounds.

Keywords

Buckwheat, buckwheat grass, beverages, polyphenol compound, rutin, antioxidant activity

REFERENCES

1. Dannye FAO po sboru zerna grechikhi v 2019 g [FAO data on buckwheat grain harvest in 2019] [Internet]. [cited 2021 Apr 30]. Available from: https://www.fao.org/faostat/en/#data/QC.
2. Tomotake H, Shimaoka I, Kayashita J, Nakajoh M, Kato N. Physicochemical and functional properties of buckwheat protein product. Journal of Agricultural and Food Chemistry. 2002;50(7):2125–2129. https://doi.org/10.1021/jf011248q.
3. Krkoskova B, Mrazova Z. Prophylactic components of buckwheat. Food Research International. 2005;38(5):561–568. https://doi.org/10.1016/j.foodres.2004.11.009.
4. Giménez-Bastida JA, Zieliński H. Buckwheat as a functional food and its effects on health. Journal of Agricultural and Food Chemistry. 2015;63(36):7896–7913. https://doi.org/10.1021/acs.jafc.5b02498.
5. Ahmed A, Khalid N, Ahmad A, Abbasi NA, Latif MSZ, Randhawa MA. Phytochemicals and biofunctional properties of buckwheat: A review. Journal of Agricultural Science. 2014;152(3):349–369. https://doi.org/10.1017/S0021859613000166.
6. Arendt E, Bello FD. Gluten-free cereal products and beverages. Amsterdam: Academic Press; 2008. 464 p.
7. Ikeda K. Buckwheat composition, chemistry, and processing. Advances in Food and Nutrition Research. 2002;44:395–434. https://doi.org/10.1016/s1043-4526(02)44008-9.
8. Kayashita J, Shimaoka I, Akajyoh M. Hypocholesterolemic effect of buckwheat protein extract in rats fed cholesterol-enriched diets. Nutrition Research. 1995;15(5):691–698. https://doi.org/10.1016/0271-5317(95)00036-I.
9. Tomotake H, Kayashita J, Kato N. Hypolipidemic activity of common (Fagopyrum esculentum Moench) and tartary (Fagopyrum tataricum Gaertn.) buckwheat. Journal of the Science of Food and Agriculture. 2015;95(10):1963–1970. https://doi.org/10.1002/jsfa.6981.
10. Liu Z, Ishikawa W, Huang X, Tomotake H, Kayashita J, Watanabe H, et al. A buckwheat protein product suppresses 1,2-dimethylhydrazine-induced colon carcinogenesis in rats by reducing cell proliferation. Journal of Nutrition. 2001;131(6):1850–1853. https://doi.org/10.1093/jn/131.6.1850.
11. Sharma A, Yadav BS. Resistant starch: Physiological roles and food applications. Food Reviews International. 2008;24(2):193–234. https://doi.org/10.1080/87559120801926237.
12. Qin P, Wang Q, Shan F, Hou Z, Ren G. Nutritional composition and flavonoids content of flour from different buckwheat cultivars. International Journal of Food Science and Technology. 2010;45(5):951–958. https://doi.org/10.1111/j.1365-2621.2010.02231.x.
13. Bonafaccia G, Marocchini M, Kreft I. Composition and technological properties of the flour and bran from common and tartary buckwheat. Food Chemistry. 2003;80(1):9–15. https://doi.org/10.1016/S0308-8146(02)00228-5.
14. Ikeda S, Yamashita Y, Tomura K, Kreft I. Nutritional comparison in mineral characteristics between buckwheat and cereals. Fagopyrum. 2006;23:61–65.
15. Wijngaard HH, Arendt EK. Buckwheat. Cereal Chemistry. 2006;83(4):391–401. https://doi.org/10.1094/CC-83-0391.
16. Jiang P, Burczynski F, Campbell C, Pierce G, Austria JA, Briggs CJ. Rutin and flavonoid contents in three buckwheat species Fagopyrum esculentum, F. tataricum, and F. homotropicum and their protective effects against lipid peroxidation. Food Research International. 2007;40(3):356–364. https://doi.org/10.1016/j.foodres.2006.10.009.
17. Kreft M. Buckwheat phenolic metabolites in health and disease. Nutrition Research Reviews. 2016;29(1):30–39. https://doi.org/10.1017/S0954422415000190.
18. Zhang Z-L, Zhou M-L, Tang Y, Li F-L, Tang Y-X, Shao J-R, et al. Bioactive compounds in functional buckwheat food. Food Research International. 2012;49(1):389–395. https://doi.org/10.1016/j.foodres.2012.07.035.
19. Anisimova MM, Kurkin VA, Ezhkov VN. Qualitative and quantitative analysis of flavonoids in buckwheet sowing grass. Izvestia of Samara Scientific Center of the Russian Academy of Sciences. 2010;12(1–8):2011–2014. (In Russ.).
20. Anisimova MM, Kurkin VA, Ryzhov VM. Research the possibility of using high effective liquid chromatography for standardization of Fagopyrum sagittatum herbs raw materials. Izvestia of Samara Scientific Center of the Russian Academy of Sciences. 2011;13(1–4):767–769. (In Russ.).
21. Ganeshpurkar A, Saluji AK. The pharmacological potential of rutin. Saudi Pharmaceutical Journal. 2017;25(2):149–164. https://doi.org/10.1016/j.jsps.2016.04.025.
22. Azevedo MI, Pereira AF, Nogueira RB, Rolim FE, Brito GAC, Wong DVT. The antioxidant effects of the flavonoids rutin and quercetin inhibit oxaliplatin-induced chronic painful peripheral neuropathy. Molecular Pain. 2013;9(1). https://doi.org/10.1186/1744-8069-9-53.
23. Machado DG, Bettio LEB, Cunha MP, Santos ARS, Pizzolatti MG, Brighente IMC, et al. Antidepressant-like effect of rutin isolated from the ethanolic extract from Schinus molle L. in mice: Evidence for the involvement of the serotonergic and noradrenergic systems. European Journal of Pharmacology. 2008;587(1–3):163–168. https://doi.org/10.1016/j.ejphar.2008.03.021.
24. Baza dannykh po fenolʹnym soedineniyam rasteniy [Database on phenolic compounds of plants] [Internet]. [cited 2021 Apr 30]. Available from: https://phenol-explorer.eu/.
25. Pérez-Jiménez J, Neveu V, Vos F, Scalbert A. Identification of the 100 richest dietary sources of polyphenols: an application of the Phenol-Explorer database. European Journal of Clinical Nutrition. 2010;64:S112–S120. https://doi.org/10.1038/ejcn.2010.221.
26. Dziadek K, Kopec A, Piatkowska E, Leszczynska T, Pisulewska E, Witkowicz R, et al. Identification of polyphenolic compounds and determination of antioxidant activity in extracts and infusions of buckwheat leaves. European Food Research and Technology. 2018;244(2):333–343. https://doi.org/10.1007/s00217-017-2959-2.
27. Vachirapatama N, Chamnankid B, Kachonpadungkitti Y. Determination of rutin in buckwheat tea and Fagopyrum tataricum seeds by high performance liquid chromatography and capillary electrophoresis. Journal of Food and Drug Analysis. 2011;19(4):463–469. https://doi.org/10.38212/2224-6614.2214.
28. Aliakbarlu J, Khalili S, Mohammadi S, Naghili H. Physicochemical properties and antioxidant activity of Doshab (a traditional concentrated grape juice). International Food Research Journal. 2014;21(1):367–371.
29. Bystricka J, Vollmannova A, Kupecsek A, Musilova J, Polakova Z, Cicova I, et al. Bioactive compounds in different plant parts of various buckwheat (Fagopyrum esculentum Moench.) cultivars. Cereal Research Communications. 2011;39(3):436–444. https://doi.org/10.1556/CRC.39.2011.3.13.
30. Zielińska D, Turemko M, Kwiatkowski J, Zielinski H. Evaluation of flavonoid contents and antioxidant capacity of the aerial parts of common and tartary buckwheat plants. Molecules. 2012;17(8):9668–9682. https://doi.org/10.3390/molecules17089668.
31. Drazic S, Glamoclija D, Ristic M, Dolijanovic Z, Drazic M, Pavlovic S, et al. Effect of environment of the rutin content in leaves of Fagopyrum esculentum Moench. Plant, Soil and Environment. 2016;62(6):261–265. https://doi.org/10.17221/233/2016-PSE.
32. Kreft I, Fabjan N, Yasumoto K. Rutin content in buckwheat (Fagopyrum esculentum Moench) food materials and products. Food Chemistry. 2006;98(3):508–512. https://doi.org/10.1016/j.foodchem.2005.05.081.
33. Borovaya SA, Klykov AG. Some aspects of flavonoid biosynthesis and accumulation in buckwheat plants. Plant Biotechnology Reports. 2020;14(2):213–225. https://doi.org/10.1007/s11816-020-00614-9.
34. Luthar Z, Germ M, Likar M, Golob A, Vogel-Mikus K, et al. Breeding buckwheat for increased levels of rutin, quercetin and other bioactive compounds with potential antiviral effects. Plants. 2020;9(12). https://doi.org/10.3390/plants9121638.
35. Klykov AG, Moiseenko LM, Gorovoy PG. Biological resources of species of the genus Fagopyrum Mill. (buckwheat) in the Russian Far East. Vladivostok: Dalʹnauka; 2018. 302 p. (In Russ.).
36. Polehina NN, Pavlovskaya NE. Dynamics of accumulation of biochemical compounds antioxidant action in different organs of buckwheat during ontogeny. Fundamental research. 2013;(10–2):357–361. (In Russ.).
37. Park CH, Kim YB, Choi YS, Heo K, Kim SL, Lee KC, et al. Rutin content in food products processed from groats, leaves, and flowers of buckwheat. Fagopyrum. 2000;17:63–66.