Rooibos tea, scientific name Aspalathus linearis, is a popular tea grown in South Africa and consumed worldwide for its unique taste and presumed health benefits. There is a growing interest in using rooibos tea as a supplement for the deficiency of metallic nutrients in South Africa. In this study, the total concentrations of manganese (Mn) and zinc (Zn) in acid-digested tea leaves and the corresponding tea infusions were determined by inductively coupled plasma-mass spectrometry (ICP-MS) to estimate the contribution of rooibos tea consumption to the recommended daily allowance (RDA) of Mn and Zn in consumers. The accuracy of microwave-assisted acid digestion and tea infusion methods were checked by analyzing INCT-TL-1 tea leaves certified reference material (CRM) and samples spiked with standards, respectively. Both methods yielded quantitative percentage recoveries for Mn and Zn. Rooibos tea leaves and the corresponding infusions are composed of higher levels of Mn than Zn where 40.9 to 85.7 μg Mn/g and 4.15 to 12.2 μg Zn/g were found in digested tea leaves and 11.8 to 30.2 μg Mn/g and 1.51 to 4.59 μg Zn/g in tea infusions. These results indicate the contribution of about 1.0 to 3.2% Mn and 0.03 to 0.08% Zn in males approximately ≥ 9 years of age and 1.3 to 3.8% Mn and 0.04 to 0.11% Zn in females of the same age group as males of the RDA from drinking a cup of tea obtained by infusing a 2-g bag of rooibos tea.
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Joubert EB (2008) South African herbal teas: Aspalathus linearis, Cyclopia spp. and Athrixia phylicoides. J Ethnopharm 119:376–412
White PJ, Broadley MR (2009) Biofortification of crops with seven mineral elements often lacking in human diets - iron, zinc, copper, calcium, magnesium, selenium and iodine. New Phytol 182:49–84
Van Wyk BE, Van Oudtshoorn B, Gericke N (2009) Medicinal plants of South Africa. Briza Publications, Pretoria
Simpson D (1998) Buchu—South Africa’s amazing herbal remedy. Scottish Med J 43(6):189–191
De Beer D, Joubert E, Viljoen M, Manley M (2012) Enhancing aspalathin stability in rooibos (Aspalathus linearis) ready-to-drink iced teas during storage: the role of nano-emulsification and beverage ingredients, citric and ascorbic acids. J Sci Food Agric 92(2):274–282
Raynolds LT, Ngcwangu SU (2010) Fair Trade rooibos tea: connecting South African producers and American consumer markets. Geoforum 41(1):74–83
Michalski R (2006) Simultaneous determination of common inorganic anions in black and herbal tea by suppressed ion chromatography. J Food Quality 29:607–616
Posthumus MA, Van Beek TA, Collins NF, Graven EH (1996) Chemical composition of the essential oils of Agathosma betulina, A. crenulata and an A. betulina x crenulata hybrid (Buchu). J Essent Oil Res 8(3):223–228
Patrickson S, Malgas R, Oettlé N (2008) Environmental threat or conservation opportunity? Veld Flora 94:8–11
Olivier J, Symington EA, Jonker CZ, Rampedi IT, Van Eeden TS (2012) Comparison of the mineral composition of leaves and infusions of traditional and herbal teas. SA J Sci 1(2):108
Korn MA, Das Graças M, da Boa M, Santos E, dos Santos B, Muniz DC, Teixeira J, Pereira JT, Paixão A, Pires FA, Welz B, dos Santos WPC, dos Santos N, Guimarães EB, Korn M (2008) Sample preparation for the determination of metals in food samples using spectroanalytical methods—a review. J Appl Spectrosc Rev 43(2):67–92
Szymczycha-Madeja A, Welna M, Pohl P (2015) Determination of essential and non-essential elements in green and black teas by FAAS and ICP OES simplified – multivariate classification of different tea products. Microchem J 121:122–129
Conor R (2002) Metal contamination of food: its significance in food quality and human health. Blackwell science, Oxford
Matsuura H, Hokura A, Katsuki F, Itoh A, Haraguchi H (2001) Multielement determination and speciation of major-to-trace elements in black tea leaves by ICP-AES and ICP-MS with the aid of size exclusion chromatography. Anal Sci 17(3):391–398
Smith RF (1968) Studies on the formation and composition of ‘cream’ in tea infusions. J Sci Food Agric 9(19):530–534
Welna M, Szymczycha-Madeja A, Pohl P (2013) A comparison of samples preparation strategies in the multi-elemental analysis of tea by spectrometric methods. Food Res Int 53(2):922–930
Szymczycha-madeja A, Welna M, Pohl P (2016) Comparison and validation of different alternative sample preparation procedures of tea infusions prior to their multi-element analysis by FAAS and ICP OES. Food Anal Methods 9:1398–1411
Millaleo R, Reyes-Diaz M (2010) Manganese as essential and toxic element for plants: transport, accumulation and resistance mechanisms. J Soil Sci Plant Nutr 10(4):476–494
Gupta N, Ram H, Kumar B (2016) Mechanism of zinc absorption in plants: uptake, transport, translocation and accumulation: a review. Rev Environ Sci Biotechnol 15:89–109
Munns DN, Johnson CM, Jacobson L (1963) Uptake and distribution of manganese in oat plants III: an analysis of biotic and environmental effects. Plant Soil 19(3):285–295
Caldelas C, Weiss DJ (2017) Zinc homeostasis and isotopic fractionation in plants: a review. Plant Soil 411:17–46
Szymczycha-Madeja A, Welna M, Pohl P (2012) Elemental analysis of teas and their infusions by spectrometric methods. Trends Anal Chem 35:165–181
World Health Organization (WHO) (1996) Trace elements in human nutrition and health. WHO, Geneva
Mokgalaka NS, McCrindle RI, Botha BM (2004) Multielement analysis of tea leaves by inductively coupled plasma optical emission spectrometry using slurry nebulization. J Anal Atom Spectrom 19(10):1375–1378
Szymczycha-Madeja A, Welna M, Zyrnicki W (2013) Multi-element analysis, bioavailability and fractionation of herbal tea products. J Braz Chem Soc 24(5):777–787
Brzezicha-Cirocka J, Grembecka M, Szefer P (2016) Monitoring of essential and heavy metals in green tea from different geographical origins. Environ Monit Assess 188:183
Bonga MW (2005) An overview of the South African iron, manganese and steel industry during the period 1984–2003. Directorate: Mineral economics. The department of minerals and energy, Republic of South Africa, report R45/2005
Powell JJ, Burden TJ, Thompson PH (1998) In vitro mineral availability from digested tea: a rich dietary source of manganese. Analyst 123:1721–1724
Shotyk W, Javed MB, Noernberg T (2020) Trace elements in Labrador tea (Rhododendron groenlandicum): how the predominant sources of trace elements to the plants affect the chemical composition of hot water extracts. Environ Res 183:109272
Institute of Medicine (2006) Dietary reference intakes: the essential guide to nutrient requirements. The National Academies Press, Washington, DC. https://doi.org/10.17226/11537
Wenhold F, Faber M (2008) Nutritional status of South Africans: links to agriculture and water. Water Research Commission, WRC Report No TT 362/P/08, ISBN 978-1-77005-756-2.
Wessells KR, Brown KH (2012) Estimating the global prevalence of zinc deficiency: results based on zinc availability in national food supplies and the prevalence of stunting. PLoS One 7(11):1–13
The authors are grateful to the University of Johannesburg Spectrum for the facility. We thank Mr. Johan Brand of Rooibos Ltd. for giving us permission to collect tea leaves and assigning a field guide to the selected farms.
This work was based on the research supported in part by the National Research Foundation of South Africa (Grant number: 106895 and reference: AEMD160602167326). Nombuzo Mabuza greatly acknowledges the financial support from the National Research Foundation.
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Mabuza, N., Kinfe, H.H., Godeto, T.W. et al. Estimated Contributions of Rooibos Tea to the Daily Manganese and Zinc Intakes Determined in Tea Leaves and Tea Infusions by Inductively Coupled Plasma-Mass Spectrometry. Biol Trace Elem Res (2020). https://doi.org/10.1007/s12011-020-02211-x
- Infusion method
- Metal deficiency
- Recommended daily allowance
- South Africa