The consumption of medicinal herbs, in the form of infusions, such as chamomile (Matricaria chamomilla), rosemary (Rosmarinus officinalis), wormwood (Artemisia absinthium), mint (Mentha piperita) and muña-muña (Clinopodium gilliesii) is widespread in the region. The determination of toxic and essential elements is relevant to evaluate their incorporation into the human organism. Although the study of elemental levels in different herbs and their infusions is quite widespread, information on plants from Argentina is scarce. In the present work, Cd, Pb, As, Fe, Cu, Ca, Mg, Na and K were quantified in the five commercially available medicinal herbs and in their infusions by atomic absorption and emission spectrometry. In general, the nutrient levels obtained in the herbs studied followed the sequence: K > Ca > Mg > Fe > Na > Cu while in the infusions the order was: K > Mg > Na > Ca > Fe > Cu. Pb was found in the chamomile and wormwood infusions at levels below 10 µg.L-1, whereas Cd and As were not detected (LOD= 0.07 μg.L-1 and 7 μg.L-1 respectively). The estimated daily intake (EDI) values calculated for the essential elements in the infusions were lower than the recommended daily intake (RDI) levels suggested by the World Health Organization (WHO) and did not provide the diet with significant nutritional values. As for to the toxic elements Pb, Cd and As, the EDI values obtained in the infusions were below the provisional maximum tolerable daily intake (PMTDI), indicating that they do not entail a health risk.

In this study, the antioxidant activity values of infusions at different temperatures of the commercially sold rosehip tea bag. To determine the effect of different infusion temperatures on antioxidant activity, 7 different temperatures (0, 15, 30, 45, 60, 75, 90°C) also including cold infusions temperatures were selected. Infusions of the rosehip tea bags were prepared with packaged drinking water for 5 minutes (recommended time in tea bag packaging) at these temperatures. Antioxidant activity values of the infused extracts were determined by antioxidant activity determination methods: TPC (Total Phenolic Compound), CUPRAC (Cu (II) Ion Reducing Antioxidant Capacity), FRAP (Iron (III) Ion Reducing Antioxidant Power) and ABTS•+ (2.2-azinobis- (3-ethylbenzothiazoline-6-sulphonic acid)) radical scavenging assay. According to the results obtained by the antioxidant determination methods, the highest and lowest activity values for TPC, FRAP and ABTS were measured at 90°C and 0°C, respectively, and a positive correlation was found between temperature and antioxidant activity values. Contrary to the activity values determined in these methods, in the CUPRAC method, the highest and the lowest activity value was measured at 45°C and 90 °C, respectively. As determined in the CUPRAC method, infusions of rosehip tea at low temperatures may provide an advantage in terms of the solubility of some phenolics that can be denatured at high temperatures. In addition, rosehip tea infusions at lower temperatures will contribute to lower energy costs.