Content of lutein in aqueous extracts of yerba mate (Ilex paraguariensis St. Hil)

Lutein is the main carotenoid in green leafy vegetables. It has been associated to reduction of risks of progression of macular degeneration, therefore, the consumption of lutein through diet is essential to help prevention of blindness and cataract. In this study, we investigated lutein in aqueous extracts of yerba mate by ultra high performance liquid chromatoraphy and mass spectrometry. Different commercial types of yerba mate for chimarrão (smooth, traditional and coarse-ground) and terere were analyzed. The effect of temperature on the amount of lutein extracted was also investigated. We observed that terere extracts presented lutein content higher (17 μg) than chimarrão extracts, and among chimarrão commercial types, coarse-ground presented the highest lutein content (in average 9.5 μg). We also verified that water temperature incremental favored the lutein migration to aqueous extract. The levels of lutein found in the yerba mate infusions investigated in this study were superior to others tea drinks, showing that aqueous extracts of yerba mate can contribute significantly to the ingestion of lutein.     

In vitro antimicrobial and anti-inflammatory effects of herbs against Propionibacterium acnes

Propionibacterium acnes play an important role in the pathogenesis of acne by inducing certain inflammatory mediators and comedogenesis. The objective of this study was to evaluate the antimicrobial and anti-inflammatory effects of herbal extracts against P. acnes. Among the ten tested herbs, methanolic extracts of rose (Rosa damascene), duzhong (Eucommia ulmoides Oliv.), and yerba mate (Ilex paraguariensis) were found to inhibit the growth of P. acnes with respective minimum inhibitory concentrations of 2, 0.5, and 1 mg/ml. In addition, duzhong and yerba mate extracts reduced the secretion of pro-inflammatory cytokines such as tumour necrosis factor-α, interleukin (IL)-8, and IL-1β by human monocytic THP-1 cells pretreated with heat-killed P. acnes at a concentration of 0.1 mg/ml. Our results suggested that duzhong and yerba mate extracts possess both antimicrobial and anti-inflammatory effects against P. acnes and can possibly be used as therapeutic agents for acne.     

Increasing the antioxidant power of tea extracts by biotransformation of polyphenols

Green tea (Camellia sinensis) and yerba mate (Ilex paraguariensis) are rich in polyphenolic compounds, which are thought to contribute to the health benefits of tea. The aim of this study was to evaluate the potential antioxidant properties of green tea and yerba mate extracts before and after the enzymatic biotransformation reaction catalysed by the Paecilomyces variotii tannase. The antiradical properties of the tea extracts, as well as the standards of chlorogenic acid and EGCG, were assessed using the ORAC and DPPH assays before and after the tannase biotransformation. The antioxidant power of enzyme-treated green tea and yerba mate increased by 55% and 43%, respectively, compared with that of untreated teas. The antioxidant power of the standards was also highly increased by enzyme treatment. These results provide relevant data about the potential of the tannase application on various polyphenol sources and to increase the antioxidant power of two widely consumed beverages.     

Polyphenol input to the antioxidant activity of yerba mate (Ilex paraguariensis) extracts

Industrial processing modified the polyphenol content, composition and antioxidant activity of the yerba mate extracts. Pre-dried leaves were the most appropriate raw material combining maximum activity with high polyphenol content. Chlorogenic acid and its derivatives were the major components of the phenolic fraction but we also identified caffeic, rutin and quercetin.Yerba mate extracts inhibited malonedialdehyde formation in sunflower oil (20 μmol/kg) and conjugated dienes production in oil/water emulsions (60 μmol/kg). Enhancing the dose to 60 μmol/kg reduced 27.8% the extract’s activity in oil.The relationship between polyphenol composition and antioxidant activity of a mixture of caffeic, chlorogenic, kaempferol, quercetin and rutin was satisfactorily predicted with a polynomial model. Results showed that quercetin was the highest contributor to the linear term followed by kaempferol and caffeic acid while rutin and chlorogenic acid inputs were the lowest. The model detected five synergistic and six antagonistic effects.     

Study of the bioactive compounds variation during yerba mate (Ilex paraguariensis) processing

Ilex paraguariensis St. Hil. (Aquifoliaceae) (yerba mate) is one of the most used plant species in South America due to its nutritional and medicinal properties. The industrial processing involves different stages (green leaves, zapecado, drying, forced or natural aging) which can modify the qualitative and quantitative composition and the pharmacological activities. In this work, the main compounds, caffeoyl derivatives (caffeic acid, mono- and dicaffeoylquinic acids), methylxanthines (caffeine and theobromine) and flavonoids (rutin, quercetin and kaempferol) were studied by HPLC in extracts obtained by decoction of samples of a large amount of I. paraguariensis during its industrial process stages. The comparative quantitative analysis of all the samples indicated that those obtained after the zapecado, drying and aging stages possess higher content of biologically active principles when compared with green leaves. No differences were found between the natural and forced aging processes. This is the first complete report on the quantitative variation of the bioactive compounds of I. paraguariensis during each step of the industrial processing. The results obtained in this work provide a guideline for the obtention of extracts enriched in biological principles for the pharmaceutical, food and cosmeceutical industry.     

Authentication of yerba mate according to the country of origin by using Fourier transform infrared (FTIR) associated with chemometrics

This study deals with the development of a method for classification of yerba mate (Ilex paraguariensis) using attenuated total-reflectance Fourier transform infrared (ATR-FTIR) and multivariate analysis. Fifty-four brands of yerba mate from southern South America were analysed in order to classify the commercialised yerba mate according to the respective country of yerba mate processing. The yerba mate was ground in a cryogenic mill, and the reflectance was directly measured in the region ranging from 4000 to 650 cm^?1. Different pre-processing algorithms and three methods of multivariate analysis were investigated, including principal component analysis (PCA), partial least square discriminant analysis (PLS-DA) and support vector machine discriminant analysis (SVM-DA). The yerba mate classification was 100% correct when the reflectance spectra were pre-treated (derived at first order, normalised by standard normal variation, smoothed and mean centred) and analysed using the SVM-DA method.     

Aqueous extracts of yerba mate (Ilex paraguariensis) as a natural antimicrobial against Escherichia coli O157:H7 in a microbiological medium and pH 6.0 apple juice

Ilex paraguariensis is popularly used in the preparation of a tea infusion (yerba mate), most commonly produced and consumed in the South American countries of Uruguay, Paraguay, Argentina, and Brazil. In this study, aqueous extracts of commercial tea, derived from the holly plant species I. paraguariensis were evaluated for their ability to inhibit or inactivate Escherichia coli O157:H7 in a microbiological medium and modified apple juice. Dialyzed, lyophilized aqueous extracts were screened for antimicrobial activity against E. coli O157:H7 strains ATCC 43894 and 'Cider' in tryptic soy broth (TSB) and apple juice (adjusted to pH 6.0 to allow for growth of the bacterium). A mixture of the two strains was used as the inoculum when apple juice was used as the medium. MBCs were determined to be ca. 5 and 10 mg/ml for ATCC 43894 and 'Cider', respectively, in TSB. Higher concentrations of the extract were required to inactivate E. coli O157:H7 in pH-adjusted apple juice. An approximate 4.5-log reduction was observed for E. coli O157:H7 treated with 40 mg/ml extract. It was concluded that aqueous extracts from commercial yerba mate have potential to be used as antimicrobials in foods and beverages against pathogenic E. coli O157:H7.     

Consumer perceptions,attitudes and acceptance of new and traditional mate tea products

Consumption of teas has been increasing around the world. In Brazil, mate tea, prepared from yerba mate (Ilex paraguariensis), is the most popular tea and its popularity is increasing due to the development of new mate-based products and the increasing health consciousness of the Brazilian population. Further development of the mate market in Brazil requires accurate consumer profiling, focusing on tea drinking behavior, preferences and perceptions. We applied a questionnaire to mate tea consumers to assess their beliefs, consumption behavior, and taste preferences. We also explored the acceptability of tea made from yerba mate processed in different ways: immediately after harvest and after eight months of storage, varying the percentage of leaves and sticks. One hundred consumers evaluated six experimental samples and two commercial mate teas. Results indicated that mate was most consumed in tea bag form, followed by ice teas. The preferred flavors were natural and lemon. Most of the consumers (61%) consumed mate with sugar, drinking it at home before bedtime. Product quality, brand and price were the most important aspects taken into account when purchasing mate. The majority of consumers were not satisfied with the products currently offered in the market, and the main criticism was poor quality and packaging. Consumers accepted all tasted samples, except the tea prepared with 100% sticks. Commercial teas were less preferred than the experimental teas, indicating that there are opportunities for further development of commercially viable mate products.     

Fatty acid and volatile compounds from salami manufactured with yerba mate (Ilex paraguariensis) extract and pork back fat and meat from pigs fed on diets with partial replacement of maize with rice bran

Four batches of salami were manufactured. Back fat and meat from pigs fed on diets with maize or maize partially substituted with rice bran (maize/rice bran, 62/38, w/w) were used to prepare two different batches, M and M/RB, respectively. The other two batches (M-YM or M/RB-YM) were prepared as batch M or M/RB, added a yerba mate (Ilex paraguariensis) extract. Salamis did not show differences in percentual general composition, texture analysis or sensory features. The TBAR values were affected by the storage time. The use of yerba mate extract controlled the lipid oxidation.     

Methylxanthines,phenolic composition,and antioxidant activity of bark from residues from mate tree harvesting (Ilex paraguariensis A. St. Hil.)

Leaves and products made from them are the major focus of research on bioactive compounds of mate (Ilex paraguariensis). However, studies on other parts of the plant, are scarce. The aim of this study was to determine the methylxanthines, phenolic compounds, and antioxidant activity of mate bark (residual biomass) and compare with those of mate leaves. The high antioxidant activity of mate bark and its high concentration of total polyphenols were apparent in both the aqueous and the methanolic extracts, the values of which were greater than those detected in the leaves. Of the phenolic acids identified, the levels of chlorogenic acid and 4,5-dicaffeoylquinic acid in the samples were significantly higher in the methanolic bark extract. With regard to methylxanthines, considerable concentrations were detected in the samples. The results obtained contribute to the viability of exploiting this residue, broadening the use of the mate plant.     

Flavour characteristics of Ilex paraguariensis infusion,a typical Argentine product,assessed by sensory evaluation and electronic nose

Sensory evaluation and electronic nose (E‐nose) technology were applied to study two formulations of a new product intended to have organoleptic characteristics similar to those of Ilex paraguariensis (Saint Hilaire) infusions. Infusions prepared from I paraguariensis, called ‘yerba mate’ in South America, possess distinct sensory properties that were described by trained panellists using a lexicon of 17 terms. The two commercial products were formulated by combining various flavour components and processed as instant powders for infusion. Results from the sensory panel showed that it would be necessary to change the product formulation in order to achieve desirable yerba mate characteristics. Odour, mouthfeel and sweetness intensities would have to be improved. The E‐nose had an array of 32 sensors which were able to discriminate between infusions prepared from yerba mate and from the instant powders. Using stepwise discriminant analysis, the group of sensors that contributed to this classification was identified. The response of these sensors correlated (P < 0.05) with yerba mate odour, mouthfeel and sweetness attributes. Comparison of the results obtained by the two methodologies enabled the E‐nose procedure to be improved and showed that this methodology is suitable for food product development and is a good complement to sensory evaluation. Copyright © 2004 Society of Chemical Industry     

Dihydrocaffeic acid,a major microbial metabolite of chlorogenic acids,shows similar protective effect than a yerba mate phenolic extract against oxidative stress in HepG2 cells

The hepatoprotective effect of a yerba mate phenolic extract (YMPE), rich in chlorogenic acids, and its main circulating metabolites dihydrocaffeic (DHCA) and dihydroferulic (DHFA) acids were assessed in human hepatoma HepG2 cells subjected to oxidative damage induced by tert-butylhydroperoxide (t-BOOH). Direct treatment of HepG2 cells with realistic concentrations of YMPE (1, 10 and 50 μg/mL), DHCA or DHFA (0.2, 1, 10 μM) for 20 h was not cytotoxic and significantly decreased ROS generation. Pre-treatment with YMPE and DHCA prevented the cytotoxicity and macromolecular damage induced by t-BOOH. Moreover, decreased levels of reduced glutathione (GSH), and increased ROS levels and antioxidant enzyme activity induced by t-BOOH were dose-dependently recovered. DHFA only showed a slight protection against cell cytotoxicity, lipid oxidation and GSH depletion. In conclusion, YMPE and one of its major microbial metabolites, DHCA, confer significant protection against oxidative damage, adding evidences to the beneficial health effects associated with mate intake.     

Phenolic Acids and Methylxanthines Composition and Antioxidant Properties of Mate (Ilex paraguariensis) Residue

ABSTRACT: Ilex paraguariensis is known to contain compounds with antioxidant properties, such as phenolic acids, and its stimulant properties are attributed to methylxanthines, such as caffeine. The aims of this study were to evaluate the phenolic, methylxanthinic, and tannin composition of a mate residue (mate powder), to compare the quali-quantitative phenolic composition and the antioxidant potential of extracts obtained from distinct solvent systems. Among the extracts prepared with different solvents, the 80% methanol extract showed the highest total polyphenol content (11.51 g/100 g) and antioxidant activity. HPLC analysis showed that 4,5 dicaffeoylquinic acid is the major component of the phenolic fraction of mate powder. The caffeine, theobromine, and tannin contents in mate powder were 1.01, 0.10, and 0.29 g/100 g, respectively. Consumption of mate powder would significantly contribute to antioxidant and stimulant intake, providing high amounts of phenolic acids, tannins, and methylxanthines with biological effects potentially beneficial for human health. Practical Application: This article contributes to the minimization of residues in yerba-mate processing.     

Toxic and nutrient elements in yerba mate (Ilex paraguariensis)

Toxic and nutrient elements were investigated in yerba mate (Ilex paraguariensis) from South America. Fifty-four brands of commercialised yerba mate from Argentina, Brazil, Paraguay and Uruguay were analysed for Al, Ba, Ca, Cu, Fe, K, Mg, Mn, P, Sr, and Zn, using inductively coupled plasma optical emission spectrometry (ICP-OES), and Li, Be, Ti, V, Cr, Ni, Co, As, Se, Rb, Mo, Ag, Cd, Sb, La, Ce, Pb, Bi and U using inductively coupled plasma mass spectrometry (ICP-MS). Antimony, Se, Ag and Bi were not detected in any sample whereas the limits of detection (LODs) of these elements were 0.19, 0.40, 0.003 and 0.001 μg g^?1, respectively. Analysis of variance (ANOVA) revealed that the concentrations of Cd, Ti, Ni, As, Mo, U, Li and Be in yerba mate were not statistically different with regard to the country of origin, while those of the other investigated elements differed.     

Characterization of aroma-impact compounds in yerba mate (Ilex paraguariensis) using GC–olfactometry and GC–MS

The volatile compounds of 18 yerba mate (YM) commercial brands from Argentina, Brazil, P.araguay and Uruguay were extracted using a Likens–Nickerson simultaneous distillation–extraction (SDE) apparatus, and analyzed by gas chromatography–mass spectrometry (GC–MS). Results showed that a total of 35 major volatile compounds were identified by GC–MS; among them, norisoprenoid compounds. A principal component analysis (PCA) was carried out in order to ascertain the degree of differentiation between samples and which compounds were involved. The results showed three main groups of YM corresponding to the places where they are commercialized. The first group (samples from Paraguay and Argentina) correlated positively with 6-methyl-5-hepten-2-one, octanal and 1-octanol. The second group (YM marketed in Uruguay but produced in Brazil) correlated positively with α- and β-ionone, linalool, nerol, α-terpineol, (Z)-linalool oxide and the aliphatic hydrocarbons undecane, dodecane and heptadecane. The third group (YM produced and marketed in Brazil) correlated positively with 2,4-heptadienal isomers, (E)-linalool oxide and β-cyclocitral. Through a preference test, one commercial brand was selected to be analyzed by gas chromatography–olfactometry (GC–O). Sixteen odor active compounds were perceived by GC–O analysis. It seems that the norisoprenoid compounds and components produced by fatty acid degradation play a vital role in the special aroma of yerba mate.     

Effects of extraction solvents on concentration and antioxidant activity of black and black mate tea polyphenols determined by ferrous tartrate and Folin–Ciocalteu methods

Effect of the use of water and different organic solvents such as acetone, N,N-dimethylformamide (DMF), ethanol or methanol at various concentrations on the total polyphenol content and antioxidant activity was studied for the black tea and mate tea. Polyphenol contents of extracts were determined using ferrous tartrate (method # 1) and Folin–Ciocalteu (method # 2) assays. For black tea, 50% DMF extract showed the highest polyphenol content of 131.9 mg/g and 99.8 mg GAE/g by method # 1 and method # 2, respectively. For mate tea, 50% acetone showed the highest polyphenol content of 132.5 mg/g and 120.4 mg GAE/g by method # 1 and method # 2, respectively. Fifty percent ethanol extract from mate tea and 50% acetone from black tea had the greatest antioxidant activity. The results showed that solvent with different polarity had significant effect on polyphenol content and antioxidant activity. A high correlation between polyphenol content and antioxidant activity of tea extracts was observed.     

Discrimination of yerba mate (<Emphasis Type="Italic">Ilex paraguayensis</Emphasis> St. Hil.) samples according to their geographical origin by means of near infrared spectroscopy and multivariate analysis

Near infrared reflectance (NIR) spectroscopy combined with multivariate data analysis was used to discriminate between the geographical origins of yerba mate (Ilex paraguayensis St. Hil.) samples. Samples were purchased from the local market and scanned in the NIR region (1100–2500 nm) in a monochromator instrument in reflectance. Principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA) and linear discriminant analysis (LDA) were used to classify the samples based on their NIR spectra according to their geographical origin. Full cross validation was used as validation method when classification models were developed. The overall classification rates obtained were 76 and 100% using PLS-DA and LDA, respectively. The results demonstrated the usefulness of NIR spectra combined with multivariate data analysis as an objective and rapid method to classify yerba mate samples according to their geographical origin. Nevertheless, NIR spectroscopic might provide initial screening in the food chain and enable costly methods to be used more productively on suspect specimens.     

Modeling yerba mate aqueous extraction kinetics: Influence of temperature

A new kinetics model, a combined second-order-diffusional kinetics model, was developed and compared with a pseudo first-order model for the aqueous extraction of total water soluble solids (WSS) from yerba mate leaves. The model that coupled two mechanisms fits the experimental data more satisfactorily (E% = 1.2 to 2.2) than the pseudo first-order model (E% = 3.9 to 4.4). The second-order-diffusional model could explain the first seconds of the WSS extraction and how the different mechanisms contributed to the concentration of the extract. Temperature influenced the kinetics parameters, but the equilibrium concentrations and the extraction yield were not significantly influenced in a temperature range between 40 and 70 °C.     

The in vitro and in vivo effects of yerba mate (Ilex paraguariensis) extract on adipogenesis

The aim of this study was to evaluate the effects of yerba mate extract and its principal bioactive compounds on adipogenesis. The anti-adipogenic effects of yerba mate, chlorogenic acid, quercetin and rutin were evaluated in 3T3-L1 cells using a PCR array. The results obtained in vitro were validated in vivo in a high-fat diet-induced model of obesity. The in vitro and in vivo results demonstrated that yerba mate extract down-regulated the expression of genes that regulate adipogenesis, such as Creb-1and C/EBPα, and the extract up-regulated the expression of genes related to the inhibition of adipogenesis, including Dlk1, Gata2, Gata3, Klf2, Lrp5, Pparγ₂, Sfrp1, Tcf7l2, Wnt10b, and Wnt3a. In summary, it was demonstrated that yerba mate and its bioactive compounds regulate the expression of genes related to in vitro adipogenesis. Furthermore, yerba mate might regulate adipogenesis through the Wnt pathway.     

Antioxidant activity of Agaricus sp. mushrooms by chemical,biochemical and electrochemical assays

The antioxidant activity of five Agaricus sp. mushrooms was screened through chemical, biochemical and electrochemical techniques. The chemical assays allowed an evaluation of their reducing power and radical scavenging activity, while biochemical assays evaluated the lipid peroxidation inhibition capacity, using erythrocytes and brain cells as models; the electrochemical characterization of the mushrooms extracts were performed by cyclic voltammetry and differential pulse voltammetry. All the species proved to have antioxidant activity and particularly, by the electrochemical techniques, it has been shown that mushroom extracts revealed similar electrochemical responses, suggesting similar electroactive chemical composition, and oxidation potentials more positive than those of the standards (ascorbic and gallic acids). Agaricus silvaticus was the most efficient species presenting the lowest EC₅₀ values in the chemical and biochemical assays, and the highest “antioxidant power” in the electrochemical assays.