Fractionation of Aluminum in Commercial Green and Roasted Yerba Mate Samples (Ilex paraguariensis St. Hil.) and in Their Infusions

Abstract

Different trademarks of green mate and mate tea ( Ilex paraguariensis St. Hil.) were employed in this work, the aim of which was to compare the fractionation of Al from green mate and mate tea (roasted mate) and from their infusions. Using the flame atomic absorption spectrometry technique, contents determined for Al leached to green mate and mate tea infusions varied from 12.8 to 18.1% and from 5.9 to 10.6%, respectively. The concentrations of phenolics in infusions were determined using the Folin-Ciocalteu method, and the presence of melanoidins was also evaluated. The results showed that phenolic compounds are the major contributors to the leached Al in green mate infusions, but melanoidins also contribute in the case of infusions prepared from the mate tea. By employing a chelating resin batch procedure, it was observed that Al was predominantly in relatively inert forms, mainly in the case of mate tea infusions (50-70%).

Trace Elements in Different Brands of Yerba Mate Tea

“…The only data available on this subject in Brazil are the studies carried out in the State of Paraná and in the neighboring State of Rio Grande do Sul, Brazil, where aluminum content was determined in infusions of roasted yerba mate samples. According to these authors, Al concentration in Parana varied from 0.5 to 1.67 mg/L [17,19], which is exactly the same value as determined in the present work. However, in Rio Grande do Sul, aluminum content in the infusions was incredibly high, e.g., 445 mg/L.…”

“…As to mineral composition, several studies have been carried out to determine the content of bioactive metals in I. paraguariensis and its infusions [17][18][19], including a vast review on the matter [2]. These metals can be either toxic like lead or benefic like zinc.…”

Toxic and nutrient elements in yerba mate (Ilex paraguariensis)

“…For most elements, the extraction is in the range of 20-60%. In previous studies carried out by other authors, it was found that Al extraction was 10.6% (Gomes daCosta et al 2009), while that of Fe,Mg, K, Ca, Mn, Zn, and Cu was 12.7, 37.6, 58.7, 13.4, 38.2, 42.4, and 90.2%, respectively (Tenorio Sanz & Torija Isasa …”

“…Polyphenols present in yerba mate can complex with Al. Gomes da Costa et al (2009) observed that Al concentration in the extract increased with decreasing polyphenol concentration. Thus, the low extraction of Al observed in the present work can be related to the high concentration of polyphenols present in the analysed yerba mate, where Al is bound to polyphenols.…”

“…Elements such as Al, Ca, Cu, Fe, K, Mg, Mn, Na and Zn can be determined using flame atomic absorption spectrometry (FAAS) (Tenorio Sanz & Torija Isasa 1991;Garcia et al 1997;Gomes da Costa et al 2009). The determination of K, Na, Mg, Mn and Ca in yerba mate by capillary electrophoresis is also reported (Carducci et al 2000), whose limits of detection (LODs) were at the same level as those of FAAS.…”