Short communication Aluminium and other elements in selected herbal tea plant species and their infusions Jan Malik a,⇑ , Adela Frankova b , Ondrej Drabek b , Jirina Szakova c , Christopher Ash a , Ladislav Kokoska d a Department of Zoology and Fisheries, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, 129 Kamycka, 165 21 Prague 6-Suchdol, Czech Republic b Department of Soil Science and Geology, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, 129 Kamycka, 165 21 Prague 6-Suchdol, Czech Republic c Department of Agroenvironmental Chemistry and Plant Nutrition, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, 129 Kamycka, 165 21 Prague 6-Suchdol, Czech Republic d Department of Crop Sciences and Agroforestry, Institute of Tropics and Subtropics, Czech University of Life Sciences Prague, 129 Kamycka, 165 21 Prague 6-Suchdol, Czech Republic article info Article history: Received 2 October 2012 Received in revised form 31 January 2013 Accepted 2 February 2013 Available online 16 February 2013 Keywords: Al Leaching Hibiscus sabdariffa Decoction ICP-OES abstract The determination of Al, B, Cu, Fe, Mn, Ni, P, Zn and Ca, K, Mg by inductively coupled plasma optical emis- sion spectrometry (ICP-OES) and flame atomic absorption spectroscopy (FAAS), respectively, in digests and infusions of Hibiscus sabdariffa (petals), Rosa canina (receptacles), Ginkgo biloba (leaves), Cymbopogon citratus (leaves), Aloe vera (leaves) and Panax ginseng (roots) was carried out in this study. Particular attention has been given to Al and heavy metals for the identification of possible raw material contam- inants, their transformation into the infusion and for predicting their eventual role in the human diet dur- ing daily consumption. Additionally, Ion Chromatography (IC) speciation of Al in the leachates was carried out. In dry herbs, hibiscus and ginkgo appeared to contain the greatest contents of Al, Fe, K, Mn, Ni, Zn and B, Mg, P, respectively. A. vera contained the highest amount of Ca and highest values of Cu and P were observed in ginseng. In infusions, the topmost concentrations of Al, B, Cu, Fe, P, K, Mn, Ni, Zn were detected in those prepared from hibiscus petals, Ca from aloe leaves and Mg from leaves of ginkgo. According to a possible daily consumption exceeding 1 L, hibiscus decoction was identified as potentially dietetically significant in the content of certain elements. It seems to be possibly one of the top contrib- utors of B from food (up to 5.5 ± 0.2 mg/L). The Mg contained in the infusion (up to 106 ± 5 mg/L) may be a contributor in the attenuation of blood pressure. A high amount of accessible Mn (up to 17.4 ± 1.1 mg/L) can probably have an adverse effect in humans. The total Al allowance (up to 1.2 ± 0.1 mg/L) suggests that no more than 1 L of the hibiscus infusion should be consumed per day by sensitive individuals including pregnant women and should be completely excluded from the diet of children under 6 months of age and children with chronic renal failure. Ó 2013 Elsevier Ltd. All rights reserved. 1. Introduction Since ancient times, the consumption of hot watery infusions prepared from collected or later cultivated plants has been gradu- ally replacing fresh water drinking. A number of herbal tea plant species – those for consumption prepared similarly to tea (Camellia sinensis L.) leaves as hot watery infusion – have been found in hu- man cultures all around the world (van der Vossen & Wessel, 2000). Due to its acidic taste and natural colourant content, Hibis- cus sabdariffa L. (Malvaceae), commonly known as Roselle, is one of the most economically important herbal tea plant species. Its dark red petals are used as a basic constituent of fruit teas, which are commonly composed of hibiscus by 50% or more. Due to a lack of caffeine, these mixtures are also recommended to caffeine sen- sitive individuals (including pregnant women or infants) instead of common tea. The cooled pure hibiscus infusion, known as karkade, is very popular in Turkey and Arabic countries due to its refreshing properties (Prenesti, Berto, Daniele, & Toso, 2007). The dry pulp of receptacles (enlarged floral cups) from Rosehip (Rosa canina L., Ros- aceae) is also used for preparing a mildly refreshing infusion. As well as hibiscus, it is a frequent constituent of fruit tea mixtures. Infusion from leaves of Ginkgo biloba L. (Ginkgoaceae) has been mainly consumed for its biological activities. Additionally, in re- cent years, dried ginkgo leaves are being commonly added to tea mixtures which are consumed on a daily basis for their stimulant properties (Goh, Barlow, & Yong, 2003). Cymbopogon citratus (DC. ex Nees) Stapf. (Poaceae), known as East Indian lemongrass, is a 0308-8146/$ - see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.foodchem.2013.02.013 ⇑ Corresponding author. Tel.: +420 606450754; fax: +420 224381829. E-mail address: malikj@af.czu.cz (J. Malik). Food Chemistry 139 (2013) 728–734 Contents lists available at SciVerse ScienceDirect Food Chemistry journal homepage: www.elsevier.com/locate/foodchem