Yerba maté extracts have in vitro antioxidant capacity attributed to the presence of polyphenolic compounds, mainly chlorogenic acids and dicaffeoylquinic acid derivatives. DPPH is one of the most used assays to measure the antioxidant capacity of pure compounds and plant extracts. It is difficult to compare the results between studies because this assay is applied in too many different conditions by the different research groups. Thus, in order to assess the antioxidant capacity of yerba maté extracts, the following procedure is proposed: 100 µL of an aqueous dilution of the extracts is mixed in duplicate with 3.0 mL of a DPPH 'work solution in absolute methanol (100 µM.L-1), with an incubation time of 120 minutes in darkness at 37 ± 1 °C, and then absorbance is read at 517 nm against absolute methanol. The results should be expressed as ascorbic acid equivalents or Trolox equivalents in mass percentage (g% dm, dry matter) in order to facilitate comparisons. The AOC of the ethanolic extracts ranged between 12.8 and 23.1 g TE % dm and from 9.1 to 16.4 g AAE % dm. The AOC determined by the DPPH assay proposed in the present study can be related to the total polyphenolic content determined by the Folin-Ciocalteu assay.

Purpose – The purpose of this study was to evaluate in vivo the bioavailability of the Ilex paraguariensis polyphenols due to total polyphenols and changes in antioxidant capacity (AOC) in human plasma after an acute intake of 300 ml of an infusion of yerba maté (YM) for 120 minutes. Also, we evaluated the variation of plasma protein or plasma uric acid after the acute intake of YM infusion. Design/methodology/approach – Seventeen healthy young volunteers participated in the determining plasma of total polyphenols concentration (TPC, Folin-Ciocalteu method), plasma AOC for ferric reducing antioxidant power (FRAP) and 2,2′-azinobis-3-ethylbenzothiazoline-6-sulfonic acid diammonium salt [ABTS] methods), plasmatic uric acid and plasma total protein over the 120 minutes test. Findings – It was found that the bioavailability of YM polyphenols during 120 minutes was 49.3 ± 11.9 per cent, the TPC was increased to 6.0 ± 1.5 per cent, the plasma AOC was increased by FRAP 8.3 ± 3.3 per cent and by ABTS 6.0 ± 2.0 per cent and no significant variation of plasma protein or plasma uric acid was found. Practical implications – Maté polyphenols has a thrifty effect on the natural antioxidant defenses of the body, which are beneficial to human health. Originality/value – There was no information on the bioavailability of polyphenols in YM infusions prepared in its traditional form as “hot mate”.

Yerba maté (Ilex paraguariensis) is a native plant of South America widely consumed as hot infusion. It is a vegetable that has many bioactive compounds, such as caffeine, theobromine theophylline and saponins, phenolic compounds, mainly chlorogenic acids and dicaffeoylquinic acids, and minerals as Fe, Ca, K y Mg, which have many beneficial properties for the health. Polyphenols have the property of chelating the transition metals, as iron and magnesium, decreasing their bioavailability. Iron deficiency anaemia and subclinical hypomagnesemia is observed in the American population. Women at childbearing age belong to a specially vulnerable group. The aim of this work was to evaluate the "in vivo" effect of the polyphenols from yerba maté infusions, consumed in their traditional form, on the bioavailability of Fe and Mg in the diet. Eleven healhty young female volunteers participated in the magnesium and iron study. After the first blood sample was taken (time 0), the volunteers ingested 300 mL of yerba maté infusions, ferrous sulfate or yerba maté infusions plus ferrous sulfate at50 °C in no more than 5 minutes. They remained seated at a comfortable temperature throughout the study. Blood samples were taken 20, 40, 50, 60, 80, 100 and 120 minutes after ingestion.The yerba maté infusions prepared in their traditional form of "hot maté", which containining an average of 4.68 ± 0.54 GAE/L of polyphenols, have an inhibitory effect on the bioavailability of the magnesium and mainly on non-heminic Fe consumed as ferrous sulphate of the 76 ± 10 % .In Argentina, Paraguay, Brazil and Uruguay Yerba mate consumption is very high, either in the traditional form of hot mate, tea mate in tea bags or cold mate (tereré ). Hot mate consists of putting between 30 and 50 g of yerba mate in a gourd, and a device similar to a straw (bombilla) with a filter on its end is inserted into the yerba mate. Then fractions of approximately 30 mL of hot water (70 º C to 85 º C) are poured repeatedly on the yerba mate, to extract the infusion through the "bombilla". Yerba mate infusions contain a high amount of polyphenols, mainly caffeoylquinic acids.Units and reference values: 1 Globular sedimentation rate (GSR): 0 -15 mm/ 1 er h; 2 Hematocrito: 37 -47 %; 3 Hemoglobin: 11,5 16, 5 g/dL;

Women in the fertile age are target group for some functional food addressed to improve Iron (Fe) nutritional status since they are prone to suffer Fe marginal deficiency. In Argentina and other MERCOSUR countries people drinks mate, a Yerba Mate (Ilex Paraguariensis) (YM) infusion which contains 12 mg Fe/100g dw of low bioavailability (BA). We are presenting results of a first step in the biochemical assessment of the effectiveness of a YM with technologically improved Fe bioavailability (BA+). Voluntary healthy women 25–47 years old (n=50) were instructed to drink mate twice daily according the traditional use; half of then received BA+ at blind. Blood samples were obtained at cero time (To) and monthly during 6 m. Hematocrit (Ht) and Hemoglobin (Hb) were determined. At To, Ht and Hb were 38.1±2,8 and 12,6±0,9 respectively. In those women who have complete 180 days, significant changes were found in Ht and Hb regarding To in the B+ group (Durbin Watson p< 0,0001) whereas control group remains constant. In BA+, deltas (Δ) intersampling fit, as a function of time (x), equations with positive slope being: ΔHt=0,037x – 0,069 and ΔHb=0,0044x – 0,0044. Results of changes in traditional hematological values support effectiveness of the YM with increased BA. However, to confirm this conclusion, indicators of Iron stores are in progress. 2. MS Thesis. Fellow from Molinos Río de La Plata. 3. PIP N° 02306.