Toxic and nutrient elements in yerba mate (Ilex paraguariensis)

Leaves, Infusion, and Grounds-A Three-Stage Assessment of Element Content in Yerba Mate (Ilex paraguariensis) Based on the Dynamic Extraction and Mineralization of Residues

The more yerba mate infusions that are consumed, the larger the amount of grounds generated. What is more, both the infusion and the residues after brewing remain rich elements. Therefore, a strategy for the three-stage assessment of the element content was presented. A new brewing method was based on dynamic extraction, ensuring both the ease of preparing the infusion and recovering the grounds. In turn, microwave-assisted acid mineralization was used to decompose the leaves and twigs of yerba mate before and after brewing. In total, 30 products were analyzed by ICP OES in three fractions each, i.e., dry yerba mate, infusion, and grounds, to determine up to 25 elements. The elemental composition was considered in terms of the country of origin, type, or composition of yerba mate. The extraction percentages obtained with dynamic extraction were comparable to previously used ultrasound-assisted extraction, as well as data from the literature. The three-stage strategy is a novel approach in yerba mate studies, and it may be a model procedure for the laboratory preparation of yerba mate grounds (waste that can be re-used, e.g., a natural fertilizer).

Assessment on Solubility and Solid Phase Chemical Fractionation of Manganese in Hot Infusions of Green and Roasted Mate

A solid phase chemical fractionation (SPCF) of the Mn in hot infusions prepared from commercial samples of roasted (RM) and green mate (GM) using a chelating resin Chelex 100 (NH4+ form) was performed to assess the relative lability of this essential trace element (ETE). In addition, total Mn contents in the RM and GM samples and their infusions were determined by flame atomic absorption spectrometry. Total polyphenol (TP) contents and the presence of soluble melanoidins (SM) were correlated with the Mn solubility in the RM and GM infusions. From the SPCF study, it was possible to observe that the soluble Mn forms in the mate infusions were essentially associated with relatively noninert chemical species (98.4-99.7%), suggesting that they may be potentially bioavailable. In addition, the soluble Mn contents in the GM infusions were 20.5% higher than those found in the RM. Mn solubility in the (RM) infusions was highly and directly correlated (r = 0.99) with the soluble TP, while in the GM infusions, it was high and inversely correlated with soluble TP (r =  -0.87). On the other hand, Mn solubility in the RM and GM infusions was weakly correlated with the SM. It should be stressed that GM infusions can contribute with 57 and 44% more than the RM infusions to the recommended adequate intake of Mn established for females and males, respectively. Moreover, this work is the first to evaluate and compare the relative lability of Mn and its solubility in the RM and GM infusions.

Accumulation Capacity of Nickel and Zinc in Yerba Mate Cultivated in Soils with Contrasting Parent Materials

Yerba mate (Ilex paraguariensis St. Hill.) has shown a relatively high capacity for micronutrient absorption and could be a candidate for biofortification and combating a lack of micronutrients. To further evaluate the accumulation capacity of Ni and Zn, yerba mate clonal seedlings were grown in containers under five rates of Ni or Zn (0, 0.5, 2, 10, and 40 mg kg-1) with three soils originating from different parent material (basalt, rhyodacite, and sandstone). After 10 months, plants were harvested, divided into component parts (leaves, branches, and roots), and evaluated for 12 elements. The use of Zn and Ni enhanced seedling growth under rhyodacite- and sandstone-derived soils at the first application rate. Application of Zn and Ni resulted in linear increases based on Mehlich I extractions; recovery of Ni was smaller than Zn. Root Ni concentration increased from approximately 20 to 1000 mg kg-1 in rhyodacite-derived soil and from 20 to 400 mg kg-1 in basalt- and sandstone-derived soils; respective increases in leaf tissue were ~ 3 to 15 mg kg-1 and 3 to 10 mg kg-1. For Zn, the maximum obtained values were close to 2000, 1000, and 800 mg kg-1 for roots, leaves, and branches for rhyodacite-derived soils, respectively. Corresponding values for basalt- and sandstone-derived soils were 500, 400, and 300 mg kg-1, respectively. Although yerba mate is not a hyperaccumulator, this species has a relatively high capacity to accumulate Ni and Zn in young tissue with the highest accumulation occurring in roots. Yerba mate showed high potential to be used in biofortification programs for Zn.

Solubility of Cd, Cr, Cu, Ni, and Pb and Its Correlation with Total Polyphenols and Soluble Melanoidins in Hot Infusions of Green and Roasted Mate

The total and soluble contents of three potentially toxic elements (PTEs) (Cd, Cr, and Pb) and two essential elements (Cu and Ni) in commercial green and roasted mate (Ilex paraguariensis St. Hil.) and their hot infusions were accessed by inductively coupled plasma mass spectrometry. Total polyphenolic (TP) contents in the infusions were accessed by Folin-Ciocalteu method, and the presence of soluble melanoidins (SM) was evaluated by measuring absorbances at 420 nm. The soluble element contents in hot infusions of green mate were present in the following increasing order: Pb < Cd < Cr < Cu, and Ni. For hot infusions of roasted mate, the increasing order was: Cu < Pb < Cd < Cr < Ni. Except for Cr, hot infusions of roasted mate supply lower contents of the soluble PTEs than hot infusions of green mate. Cadmium was the only of evaluated trace element found in hot infusions of green and roasted mate as well as in some of their mate samples above the maximum allowed contents established by Brazilian legislation. Despite this, polyphenol and melanoidin contents in green and roasted mate infusions may reduce Cd bioavailability. The soluble trace elements that correlated directly with total polyphenols in hot infusions of green or roasted mate are indirectly correlated with the presence of soluble melanoidins. Moreover, this is the first study to evaluate the correlations of soluble forms of Cd, Cr, Cu, Ni, and Pb with the presence of SM and TP contents in hot infusions of green and roasted mate.

Novel ICP-OES-Based Method for the Reliable Determination of the Total Content of 15 Elements in Yerba Mate Drinks along with the Determination of Caffeine and the In Vitro Bioaccessibility of the Compounds

A fully validated inductively coupled plasma optical emission spectrometry (ICP-OES)-based method combined with a simplified sample preparation procedure for the determination of up to 15 elements (Al, Ba, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Sr, and Zn) in caffeinated yerba mate (YM) drinks was proposed. Various "green" treatments (acidification or dilution with a HNO₃ solution and direct analysis of untreated YM with or without sonication (US)) that could replace the traditional total sample decomposition before spectrometric measurements were tested and compared. The key selection parameter was the analytical performance of the ICP-OES method obtained with each sample preparation procedure in terms of the precision and the trueness of results and limits of detection (LODs) of elements. It was found that the acidification of YMs with concentrated HNO₃ to 5%, supported by US (10 min, room temperature (RT)), provided the best results, i.e., LODs at 0.11-8.5 ng g^-1, precision below 5%, and trueness better than 5% (97.0%-105% as recoveries). Eleven YM drinks, commercially available on the Polish market, were analyzed with the proposed method. In addition to the mineral content, the concentration of caffeine in all analyzed YMs was determined and compared. Finally, the studies were completed by determining the bioaccessible fraction of selected elements and caffeine in YMs using in vitro gastrointestinal digestion (GID) in order to evaluate the nutritional value/risk assessment of these drinks. Accordingly, the bioaccessibility of nutritious elements (Ca, Fe, Mg, Mn, Zn) and caffeine was within 40%-59%. Except for Mn, it was established that by drinking daily 1 L of YMs, the recommended dietary intakes (RDIs) of the aforementioned essential elements were covered to a low degree (<4.5%). Hence, they are not an important source of these elements in the human diet. On the other hand, potentially toxic elements (Al, Ba, Sr) were found in a relatively inert form. Opposite to minerals, YMs can supply human organisms with quite high amounts of natural caffeine in bioaccessible form (31-70 mg per serving).

Influence of Brewing Method on the Content of Selected Elements in Yerba Mate (Ilex paraguarensis) Infusions

In this paper, the effect of the extraction method on the concentrations of selected elements in yerba mate (Ilex paraguariensis) infusions is presented. Seven pure yerba mate samples (without additives) were selected, representing various types and countries of origin. An extensive sample preparation procedure was proposed: ultrasound-assisted extraction using two types of extractants (deionized and tap water) at two different temperatures (room and 80 °C). In parallel, the above extractants and temperatures were carried out for all samples by the classical brewing method (without ultrasound). In addition, microwave-assisted acid mineralization was carried out to determine the total content. All the proposed procedures were thoroughly investigated with certified reference material (tea leaves, INCT-TL-1). For the total content of all the determined elements, acceptable recoveries (80-116%) were obtained. All digests and extracts were analyzed by simultaneous ICP OES. For the first time, it was assessed how tap water extraction affects the percentage of extracted element concentrations.

Effects of La2O3 nanoparticles and bulk-La2O3 on the development of Pfaffia glomerata (Spreng.) Pedersen and respective nutrient element concentration

Nanoparticles (NPs) have been progressively applied in the last decades, which may impact the environment. Synthesis of pigments, growing, and nutrient element uptake by plants can also be affected by NPs. The influence of lanthanum oxide nanoparticles (La₂O₃ NPs) on growth, pigment synthesis, and nutrient element uptake by Pfaffia glomerata (Spreng.) Pedersen, a medicinal plant native in South America, was evaluated in the present study. P. glomerata plantlets were cultivated for 28 days in the absence (control) and presence of 100, 200, and 400 mg L^-1 of La₂O₃ NPs or bulk-La₂O₃ (b-La₂O₃) at the same cultivation conditions. Root development, aerial part growth, and pigment concentration in plants were affected by b-La₂O₃ and La₂O₃ NPs, mainly by La₂O₃ NPs. In spite of alteration of nutrient element concentration observed for the 100 and 200 mg L^-1 of La₂O₃ NPs or b-La₂O₃ treatments, Ca, Cu, Fe, K, La, Mg, Mn, Mo, P, S, and Zn determination in stems and leaves revealed drastically and similar decrease of these elements in plants cultivated in the presence of 400 mg L^-1 of La₂O₃ NPs or b-La₂O₃. Element distribution (mapping) determined by using laser ablation inductively coupled plasma mass spectrometry in leaves of plants submitted to treatment with 400 mg L^-1 of b-La₂O₃ or La₂O₃ NPs showed differences in the distribution of elements, indicating distinct effects of b-La₂O₃ and La₂O₃ NPs on P. glomerata. As such, this study demonstrated that La₂O₃ NPs may impact plant growth. However, more investigations are necessary for better understanding of the effect of La₂O₃ on plants, including a broader range of concentration.

Analysis of Mercury Content in Various Types of Tea (Camellia sinensis) and Yerba Mate (Ilex paraguariensis)

Due to the content of active ingredients, teas can be used prophylactically, but most of all they are consumed for taste reasons. As with food or water, these products can be contaminated with heavy metals, including mercury. Mercury (Hg) is a toxic element, it causes many side effects in the human body depending on the form of Hg, which can include respiratory failure, kidney damage, neurological disorders. At the cellular level, Hg and its compounds lead to a disturbance of metabolism and cell death. The aim of the study was to evaluate the mercury concentration of tea (Camellia sinensis) and Yerba Mate (Ilex paraguariensis). Eighty-six samples were collected and analyzed, including the following kinds: black, green, white, Pu-erh, and Yerba Mate. The samples came from Poland. The Hg concentration was determined with an AMA 254 atomic absorption spectrometer. The study showed that the Hg content in each tea sample averaged 2.47 μg/kg. The Hg concentration in the tested types of tea differed significantly statistically (p = 0.000). It was the largest in Yerba Mate, followed by green, Pu-erh, and white tea, and was the smallest in black tea. Statistically significant differences in the Hg content (p = 0.004) were also dependent on the form of the product; in leaf tea samples, the concentration of Hg (2.54 µg/kg) was higher than in tea bags (1.16 µg/kg). The Hg concentration determined in the tested samples does not exceed the permitted EU standard. Consuming these teas poses no health risk in terms of the amount of Hg.

Multi-elemental Analysis and Health Risk Assessment of Commercial Yerba Mate from Brazil

Consumption of yerba mate occurs mostly in the form of hot infusion (chimarrão). Water solubility of elements found in commercialized yerba mate is needed to establish nutritional value and risks associated with potentially toxic elements. In this study, yerba mate products marketed in three Brazilian states (Paraná, Santa Catarina, and Rio Grande do Sul) for chimarrão were analyzed. Total (dry product) and hot water-soluble concentrations of Al, As, B, Ba, Ca, Cd, Co, Cs, Cu, Fe, K, Li, Mg, Mn, Mo, Ni, P, Pb, Rb, S, Se, Sr, Ti, V, and Zn were determined by inductively coupled plasma mass spectroscopy (ICP-MS). Total concentrations of the ten top elements followed the order of K>Ca>Mg>Mn>P>S>Al>Fe>Ba>Zn. The most soluble elements were B, Cs, Ni, Rb, and K, with values greater than 80%. The lowest water-soluble elements were V, Fe, and Ti (values <10%), followed by Ba, Cd, Al, As, Sr, Ca, and Pb with solubility between 10 and 20%. Although total Cd levels in yerba mate products were often above those permitted by South America legislation, estimated daily consumption intake indicated no risk associated with the chimarrão beverage. Manganese was the micronutrient with the highest total and soluble levels in yerba mate, which surpassed recommended daily intake values when considering a consumption amount of 50 g day^-1 of yerba mate as chimarrão. The consumption of yerba mate is safe and contributes to intake of nutrients. The Cd and Pb reference values of yerba mate products sold in South America should be revised.

Effect of Processing on the Nutritional Quality of Ilex paraguariensis

Ilex paraguariensisA.St.-Hil. (IP) is a South American plant. IP-dried leaves have been consumed in the form of infusion by indigenous peoples since pre-Hispanic times. In recent years, IP has gained many beverage markets and new ways of consumption, reaching the category of a global consumer product. A side consequence is the increase in IP crops for the specification of human consumption. This situation is the driving force for the investigation of new uses of IP, including feed supplements for livestock and functional food for human consumption. A deep understanding of the influence of processing on the nutritional value of IP is crucial for the development of these alternative products. It is known that the quality and quantity of nutritional compounds occurring in IP depend on the origin, plant condition, and harvest time. However, the effects of the drying method of the leaves and the ageing time of dried leaves on the final IP products deserve further investigation. The present work presents the variation of the nutritional, digestibility, energy, and mineral assets of IP submitted to three different processes: open-air dried and crushed; dried under direct fire and grounded; and dried under direct fire, grounded, and aged for 6 months under controlled conditions. The presence of agrochemical residues and antinutritional factors were also studied. Processing widely influenced the nutritional and digestibility assets of IP leaves. The inorganic content (K, Mg, Ca, P, Zn, B and Fe) significantly varied among leaves treated using different processes. IP samples dried in open air resulted in the highest % of crude protein, Mg, K, S, and Mn. IP samples dried under direct fire resulted in the highest % of carbohydrates and Fe. IP samples dried under direct fire and aged for 6 months resulted in the highest % of digestible matter, Ca, P, Zn, and B. The results also showed quality protein levels between 10.03 and 19.06% of dry matter. The digestibility values showed that IP leaves are suitable for human functional foods and for enriched supplements for livestock feeds. No traces of agrochemicals or antinutritional factors were found.

Elemental and Speciation Analyses of Different Brands of Yerba Mate (Ilex paraguariensis)

In this work, a methodology for determination of As(III), As(V), dimethylarsinic acid (DMA), Fe(II) and Fe(III) in fifty-eight samples (forty-nine products of thirteen brands from three countries) commercial yerba mate (Ilex paraguariensis) was performed. The hyphenated high performance liquid chromatography inductively coupled plasma optical emission spectrometry (HPLC-ICP OES) technique was used. Arsenic was determined below the quantification limit in 38 samples of yerba mate. As(III) was found at the level 0.09 and 0.08 mg kg⁻¹. The As(V) content was in the range: 0.21 to 0.28 mg kg⁻¹. The content of DMA was found the highest of the three arsenic species in the range: 0.21 to 0.47 mg kg⁻¹. The content of Fe(II) and Fe(III) was found in the range: 0.61 to 15.4 mg kg⁻¹ and 0.66 to 43.1 mg kg⁻¹, respectively and the dominance of Fe(III) was observed. Moreover, total and extractable content of 16 elements were determined. The results have been subjected to statistical analysis in order to establish relationships between samples of the same origin (country), kind (type) and composition (purity).

Yerba Mate-A Long but Current History

Bearing in mind the growing interest in Yerba Mate, a comprehensive study has been prepared containing the most important aspects and possibilities of its use. The introduction of the work contains the species characteristics of Yerba Mate, as well as information about the origin and places of cultivation. The next part focuses on the analysis of the composition, pointing to purine alkaloids, polyphenols, saponins, and minerals as groups of active compounds responsible for the clinical activity of Yerba Mate. The review of the results of preclinical and clinical studies indicates activity in relation to the stimulating effect, reducing weight by stimulating lipolysis, cardioprotective, anti-diabetic, and anti-inflammatory effects. The information about the action of Yerba Mate is supplemented by the characteristics of its potential toxicity in terms of PAHs content (in particular benzo[α]pyrene) and preparation as a determinant of increased irritation. The current data on the effects of Yerba Mate and the wide safety margin of its use position this raw material as a valuable component of functional food. The growing frequency of consuming Yerba Mate, conditioned by the availability resulting from the globalization of the market and the information provided about it's the pro-health effects, will position Yerba Mate's popularity among wider population groups.

Iron species determination by high performance liquid chromatography with plasma based optical emission detectors: HPLC-MIP OES and HPLC-ICP OES

The paper presents an independent application of two hyphenated techniques, wherein an identical chromatographic system i.e. high performance liquid chromatography (HPLC) was coupled to microwave induced plasma optical emission spectrometry (MIP OES) or inductively coupled plasma optical emission spectrometry (ICP OES). A cation-exchange column and a mobile phase based on pyridine-2,6-dicarboxylic acid (PDCA) were employed to separate Fe(II) and Fe(III) within 300 s. Additionally, two methods of sample preparation were employed. Optimization and validation of both methods were conducted parallel. The applicability was presented with different sample matrix types: post-glacial sediments, archaeological pottery, soils located in the proximity of industry wastes disposal site, river sediments and yerba mate (Ilex paraguariensis). Obtained results were compared in terms of the excitation source (microwave induced or inductively coupled) and supplied gas (nitrogen or argon). The research introduces HPLC-MIP OES for iron speciation analysis and its applicability were critically evaluated with HPLC-ICP OES.

Multi-mode Sample Introduction System (MSIS) as an interface in the hyphenated system 2 HPLC-MSIS-ICP-OES in simultaneous determination of metals and metalloids species

The paper presents a usage of a new hyphenated technique, wherein a Multi-mode Sample Introduction System (MSIS) was applied as an interface of two high pressure liquid chromatography units and inductively coupled plasma optical emission spectrometry (2 HPLC-MSIS-ICP-OES). Simultaneous separation and detection of non-hydride forming and hydride forming elements was possible due to the application of two different HPLC column, cation-exchange and anion-exchange respectively. The method was able to determine 15 elements quantitatively with a distinction of three arsenic and two iron species and it was validated obtaining acceptable LODs (2.67-28.7 μg L^-1) and recoveries (80-120%). The method applicability was presented and confirmed on 5 varied sample matrix types i.e. post-glacial sediments, yerba mate (Ilex paraguariensis), soil samples located in the proximity of industry wastes disposal site, river sediments, and archaeological pottery. In addition to the above, unknown Cu, Fe, Mn and Zn species were detected in real samples (qualitative speciation analysis) and the identification was attempted according to the literature.

Callus culture as a new approach for the production of high added value compounds in Ilex paraguariensis: genotype influence, medium optimization and compounds identification

Ilex paraguariensis (yerba mate) is a native species from South America and is a rich source of bioactive compounds. There is a lack of research efforts on the phytochemical investigation of callus culture from this species. In the present study, an effort was made to optimize callus culture conditions and to identify secondary compounds. Calli were induced from 10 genotypes using leaf explants and the best genotype was selected to evaluate the effects of cytokinin types and concentrations on callus induction and biomass accumulation. The best genotype and cytokinin treatment were used to conduct one last experiment with sucrose concentrations in culture media and its effects on calli biomass, antioxidant activity and secondary compounds accumulation. Callus initiation was genotype dependent, and the 6-156-6 line had the best response. Zeatin supplemented medium showed higher callus induction rate (82%) and higher biomass accumulation after 120 days (328.2 mg). Higher biomass and secondary compounds accumulation were observed for calli on 3% sucrose medium. Antioxidant activity was not affected by sucrose concentrations. Yerba mate callus culture allowed the accumulation of chlorogenic acid, cryptochlorogenic acid, neochlorogenic acid, 3,4-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid, 4,5-dicaffeoylquinic acid, theobromine and caffeine.

Elemental composition of yerba mate (Ilex paraguariensis A.St.-Hil.) under low input systems of southern Brazil

Elemental composition of food can be used to determine nutritional potential as well as guiding legislation for establishing maximum acceptable limits (MAL) of metals in consumption products. This study aimed to determine the elemental background levels of yerba mate (Ilex paraguariensis A.St.-Hil.) under varied geologic formations in southern Brazil. Mature leaves were randomly collected from four wild-grown plants at thirty native sites in three states and analyzed for 32 elements. Since yerba mate is not washed to obtain the final product, leaves were analyzed with and without washing to assess foliar deposition. Concentration values of As, Ag, Be, Cs, Cr, Li, Se, Tl, U, and V were near detection limits, indicating low potential as a source and/or toxicity to the consumer. Washing decreased concentrations of Fe, Ti, As, Mo, Li, V, and Pb, suggesting atmospheric contributions/dust deposition. Concentrations of Mn (very high), Zn (high), and Ni (high) demonstrated that leaves could be an important source of these elements. Soil parent material affected elemental composition with basalt providing higher concentrations of Mn, P, and Co while Rhyodacite provided higher concentrations of K and Na. All samples exhibited Pb values below the MAL of 0.6 mg kg^-1, but 23% of washed leaves and 20% of unwashed leaves had Cd concentrations close to or above the MAL value of 0.4 mg kg^-1. Study results indicated that Cd MAL values for yerba mate in southern Brazil should be reassessed.

Macroelement, trace element, and toxic metal levels in leaves and infusions of yerba mate (Ilex paraguariensis)

Mate is an infusion made from the dried leaves of yerba mate (Ilex paraguariensis). Yerba mate may be an important source of essential elements but could contain toxicologically relevant metals. Macroelements (Ca, Mg, Na, K), trace elements (B, Ba, Sr, V, Li, Ni, Fe, Zn, Cu, Cr, Co, Mn, Mo), and toxic metals (Al, Cd, Pb) content have been determined in 32 samples of yerba mate by ICP-OES (inductively coupled plasma-optical emission spectrometry) with the aim of determining the element content of yerba mate leaves and the influence of temperature in the extraction of these elements from the plant to the infusion, and estimating the dietary intake for each element studied. The highest element contents have been found in infusions prepared with hot distilled water (70-75 °C); the most noteworthy are K (303 mg/L), Mn (4.85 mg/L), and Al (4.52 mg/L). The consumption recommended by the producers (500 mL infusion/day) contributes significantly to the daily intake of essential elements such as Mn, Mg, and Cu. This consumption does not pose a health risk, although it is necessary to assess the risk/benefit of Ni intake from mate consumption for people with impaired renal function (500 mL/day accounts for 52.2% of the TDI).

La2O3 Nanoparticles: Study of Uptake and Distribution in Pfaffia glomerata (Spreng.) Pedersen by LA-ICP-MS and μ-XRF

The production and use of nanoparticles (NPs) in different fields increased in the last years. However, some NPs have toxicological properties, making these materials potential emerging pollutants. Therefore, it is important to investigate the uptake, transformation, translocation, and deposition of NPs in plants. In this work, laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) and micro X-ray fluorescence (μ-XRF) were used to investigate the uptake and translocation of La₂O₃ NPs to stem and leaves of Pfaffia glomerata (Spreng.) Pedersen after in vitro cultivation of plants in the presence of 400 mg L^-1 of La₂O₃ NPs. By using LA-ICP-MS and μ-XRF, image of the spatial distribution of La in the leaves was obtained, where higher concentration of La was observed in the main veins. Differences in the signal profile of La in leaves of plants cultivated in the presence of bulk La₂O₃ (b-La₂O₃) and La₂O₃ NPs were observed. Sharp peaks of La indicated that NPs were transported to the stems and leaves of plants treated with La₂O₃ NPs. Both LA-ICP-MS and μ-XRF techniques have shown to be useful for detecting NPs in plants, but LA-ICP-MS is more sensitive than μ-XRF and allowed better detection and visualization of La distribution in the whole leaf.

Lead contamination in food consumed and produced in Brazil: Systematic review and meta-analysis

This systematic review (SR) evaluated evidence of lead (Pb) levels in foods consumed or produced in Brazil. Seventy-seven publications were included in this review, corresponding to a total of 8466 food samples that were grouped into 12 food categories with similar characteristics (infant food; sugar; beverages; meat and meat products; nuts, cocoa and products; fruits and fruit products; grains, cereals and products; milk and milk products; eggs; oil and fat spreads; vegetables and vegetable products and other foods). The random model was used to establish levels of Pb in food categories. We used the software R® to perform the meta-analysis. The overall occurrence of Pb was estimated at 0.0541 mg/kg, and ranged from 0.0004 mg/kg to 0.4842 mg/kg. The SR and meta-analysis presented relevant results about Pb contamination on foods, despite the high heterogeneity. They were understood as a viable strategy to answer questions regarding prevalence of Pb which is necessary for the risk assessment of Pb intake in foods.

Maté consumption association with upper aerodigestive tract cancers: A systematic review and meta-analysis

Maté is a beverage regularly consumed by Latin American populations. Upper aerodigestive tract (UADT) cancers are frequent in this region and are suspected to be associated with maté consumption. The aim of this systematic review and meta-analysis was to answer a focused question: "Is there an association between maté consumption and occurrence of the UADT cancer?". Studies investigating any association between maté consumption and occurrence of UADT cancer were included. Out of the 569 studies, 18 met the inclusion criteria for qualitative and 15 for quantitative analysis. An increased odds was observed regarding maté consumption and overall occurrence of UADT cancer (OR = 2.24; 95%CI = 1.74-2.87). Consistent evidence of a positive association was found for all UADT subsites, oral, pharynx, esophagus and larynx. No differences in effect were found between consumption of cold/warm and hot/very hot mate (OR = 1.08; 95%CI = 0.83-1.41). Consumption of more than one liter of maté per day was associated with increased odds of having UADT cancer compared to an intake of less than one liter per day (OR = 1.72; 95%CI = 1.47-2.01). According to published data, regardless of the temperature, maté consumption significantly increased the odds of occurrence of UADT cancer.

Plant growth, nutrients and potentially toxic elements in leaves of yerba mate clones in response to phosphorus in acid soils

Native to subtropical region of South America, yerba mate is responsive to P under some conditions, but the degree of influence of genetic and soil on the growth and composition of the leaf is unknown. The aim of study was to evaluate plant growth, nutrients and potentially toxic elements in leaves of yerba mate clones in response to P application in acid soils. In greenhouse condition, two yerba mate clone seedlings were grown (210 days) in pots, each clone in a completely randomized design in factorial scheme (with and without P; four acid soils). The elemental composition of leaves and the growth of plants were determined. Phosphorus promoted plant growth, but this was not accompanied by increased P in leaf tissue in all conditions tested. The P effect on the elemental composition varied: decrease/null (N, K, Mg, Mn, Cu, Ni, B, Mo, Al, Cd); increase/null (C/N, C, Ca, Fe, V); increase/decrease/null (Zn, Ba, Pb) and; null (Cr). The soils affect the elemental composition of the leaves, especially Mn, with accumulation greater than 1000 mg kg-1. The Ba, Pb, Al and Zn in the leaves varied among clones. Yerba mate response to P was affected by edaphic and plant factors.