Valorization of a by-product of the yerba mate industry by assembling with cassava starch adhesive for packaging material production.

Yerba mate industrial processing produces tons of powder as a by-product, this yerba mate powder (YMP) is an excellent source of biomass to develop biodegradable materials. Cassava starch modified with 1,2,3,4-butane tetracarboxylic acid (BA) in the presence of sodium propionate as a catalyst is an eco-friendly option to obtain bioadhesives. This work aimed to develop sustainable laminates from starch-based adhesives and yerba mate powder and to study their physico-chemical, structural, and mechanical properties. Blends of bioadhesive and YMP were prepared (1:1, adhesive:YMP). Monolayer materials were obtained by thermo-compression and later assembled with adhesive to obtain bilayer laminates. Bioadhesive was able to bind the yerba mate by-product fibers, as evidenced by SEM microstructure analysis, the interactions of adhesive:substrate were elucidated by ATR-FTIR and supported by chemometrics analysis. The incorporation of the catalyst decreased the rugosity of materials and their mechanical performance was improved by the action of both acid concentration and catalyst presence, requiring higher energy for puncture. Thus, it was feasible to obtain mono and bilayer laminates as an eco-compatible alternative for the design of sustainable tray-like materials based on the industrial by-product of yerba mate.

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).

Volatilome, Microbial, and Sensory Profiles of Coffee Leaf and Coffee Leaf-Toasted Maté Kombuchas.

Kombucha is a fermented beverage traditionally made from the leaves of Camelia sinensis. The market has drastically expanded recently, and the beverage has become more elaborated with new, healthy food materials and flavors. Pruning and harvesting during coffee production may generate tons of coffee leaves that are discarded although they contain substantial amounts of bioactive compounds, including those found in maté tea and coffee seeds. This study characterized the changes in volatilome, microbial, and sensory profiles of pure and blended arabica coffee leaf tea kombuchas between 3-9 days of fermentation. Acceptance was also evaluated by consumers from Rio de Janeiro (n = 103). Kombuchas (K) were prepared using black tea kombucha starter (BTKS) (10%), sucrose (10%), a symbiotic culture of Bacteria and Yeasts (SCOBY) (2.5%), and a pure coffee leaf infusion (CL) or a 50:50 blend with toasted maté infusion (CL-TM) at 2.5%. The RATA test was chosen for sensory profile characterization. One hundred volatile organic compounds were identified when all infusions and kombucha samples were considered. The potential impact compounds identified in CL K and CL-TM K were: methyl salicylate, benzaldehyde, hexanal, nonanal, pentadecanal, phenylethyl-alcohol, cedrol, 3,5-octadien-2-one, ß-damascenone, α-ionone, ß-ionone, acetic acid, caproic acid, octanoic acid, nonanoic acid, decanoic acid, isovaleric acid, linalool, (S)-dihydroactinidiolide, isoamyl alcohol, ethyl hexanoate, and geranyl acetone. Aroma and flavor descriptors with higher intensities in CL K included fruity, peach, sweet, and herbal, while CL-TM K included additional toasted mate notes. The highest mean acceptance score was given to CL-TM K and CL K on day 3 (6.6 and 6.4, respectively, on a nine-point scale). Arabica coffee leaf can be a co-product with similar fingerprinting to maté and black tea, which can be explored for the elaboration of potentially healthy fermented beverages in food industries.

Gut Microbiota Modulation by Bioactive Compounds from Ilex paraguariensis: an In Vivo Study.

Yerba-mate (Ilex paraguariensis) is recognized for its biocompounds and bioactive properties. This study aimed to assess the potential of yerba-mate extract to modulate the intestinal microbiota in rats. After the ethical committee approval (CEUA - UPF, number 025/2018), the Wistar rats were given a daily dose of 3.29 mg of phenolic compounds per animal for 45 days. The antioxidant activity of the extract was assessed by ABTS and FRAP assays and the total phenolic compounds was measured at different pH levels. Identification and quantification of chlorogenic acid isomers were carried out using high-performance liquid chromatography (HPLC). Intestinal microbiota modulation was evaluated by administering the yerba-mate extract or water (control) to Wistar rats via intragastric gavage and its efficiency was measured through PCR. The antioxidant capacity of the yerba-mate extract was 64.53 ± 0.26 µmol Trolox/mL (ABTS) and 52.96 ± 0.86 µmol Trolox/mL (FRAP). The total phenolic compounds showed higher levels at pH 7.5 compared to pH 2.0. Chlorogenic acid isomers were found in greater abundance, with a concentration of 14.22 g/100 g. The administration of the extract resulted in positive modulation of the intestinal microbiota, specifically for the genera Lactobacillus sp. and Prevotella sp. The increase of these genera is related to the promotion of homeostasis of the gut microbiota. Therefore, these findings indicate that yerba-mate extract possesses significant antioxidant activity and can effectively modulate the intestinal microbiota in rats. These results support the potential use of yerba-mate as an alternative for controlling and preventing diseases associated with intestinal dysbiosis.

Yerba Maté (Ilex paraguariensis) Supplement Exerts Beneficial, Tissue-Specific Effects on Mitochondrial Efficiency and Redox Status in Healthy Adult Mice.

Yerba maté, a herbal tea derived from Ilex paraguariensis, has previously been reported to be protective against obesity-related and other cardiometabolic disorders. Using high-resolution respirometry and reverse-phase high-performance liquid chromatography, the effects of four weeks of yerba maté consumption on mitochondrial efficiency and cellular redox status in skeletal muscle, adipose, and liver, tissues highly relevant to whole-body metabolism, were explored in healthy adult mice. Yerba maté treatment increased the mitochondrial oxygen consumption in adipose but not in the other examined tissues. Yerba maté increased the ATP concentration in skeletal muscle and decreased the ATP concentration in adipose. Combined with the observed changes in oxygen consumption, these data yielded a significantly higher ATP:O2, a measure of mitochondrial efficiency, in muscle and a significantly lower ATP:O2 in adipose, which was consistent with yerba maté-induced weight loss. Yerba maté treatment also altered the hepatic glutathione (GSH)/glutathione disulfide (GSSG) redox potential to a more reduced redox state, suggesting the treatment's potential protective effects against oxidative stress and for the preservation of cellular function. Together, these data indicate the beneficial, tissue-specific effects of yerba maté supplementation on mitochondrial bioenergetics and redox states in healthy mice that are protective against obesity.

Phytochemical and functional characterization of fermented Yerba mate using Rhizopus oligosporus.

Solid-state fermentation (SSF) was used to enhance the bioactive compounds and biological properties of food materials, such as buckwheat, turmeric, and ginseng. This study was investigated the effects of SSF for up to 10 days using Rhizopus oligosporus on Yerba mate (Ilex paraguariensis St. Hilaire). The total phenolic content of Yerba mate rose to 20% after 1 day fermentation. The saponin contents of Yerba mate rose to 38% after 7 day fermentation. Furthermore, chlorogenic acid, caffeic acid, and caffeine levels were increased up to 27.74% by fermentation, as determined by UPLC-MS analysis. ORAC and FRAP assays showed that the antioxidant activities of Yerba mate were enhanced 1.9- and 1.14-fold after 1 day fermentation. In addition, its inhibitory activities against yeast α-glucosidase and nitric oxide release in LPS-stimulated RAW264.7 cells were higher than in the unfermented Yerba mate. Moreover, taste sensory analysis using an electronic tongue sensory system showed that the flavor of Yerba mate after 1 day fermentation was similar to that of the unfermented Yerba mate. These results suggested that solid fermentation using R. oligosporus is conducive to producing Yerba mate with enhanced biological properties.

Use of Bio-Waste of Ilex paraguariensis A. St. Hil. (Yerba mate) to Obtain an Extract Rich in Phenolic Compounds with Preservative Potential.

In this work, a comparison between the extracts of dehydrated yerba mate (Ilex paraguariensis) and bio-waste of yerba mate leaves from the Brazilian industry was made. The incorporation of the functional extract as a preservative/functional ingredient in a pastry product (pancakes) was tested. The individual profile of phenolic compounds was determined by HPLC-DAD-ESI/MS, and the bioactive potential was assessed using in vitro assays for antioxidant, anti-inflammatory, antimicrobial, and cytotoxic activities. The yerba mate extracts revealed a high antimicrobial potential against the tested strains and a very promising antioxidant and anti-inflammatory action. Additionally, revealed a cytotoxic capacity for MCF-7, CaCo and AGS tumor cell-lines. In the three types of pancakes, after 3 days of storage, the chemical and nutritional characteristics remain unchanged, proving the preservative efficiency of the extract. This study showed the benefits of the use bio-waste from agro-industrial sector, focusing on sustainable production and the development of circular economy.

Analytical and chemometric strategies for elucidation of yerba mate composition.

Yerba mate, a popular plant consumed mainly as an infusion, possesses nutritional and medicinal properties attributed to its secondary metabolites. This study aimed to develop strategies to elucidate the phenolic composition of yerba mate samples from Brazil, Argentina, Uruguay, and Paraguay. Optimization of ultrasonic-assisted extraction (UAE) was performed, and the extracted compounds were characterized using ultra-high-pressure liquid chromatography coupled with quadrupole/time-of-flight mass spectrometry (UHPLC-QTOF-MS), molecular fluorescence and high-pressure liquid chromatography with diode-array detection (HPLC-DAD). Chemometric analysis, including parallel factor analysis (PARAFAC) and principal component analysis (PCA) explored metabolite profiles and identify patterns. PARAFAC modelling of the molecular fluorescence results revealed higher pigment content in Brazilian samples, while other countries' samples exhibited higher phenolic content. PCA modeling of HPLC-DAD results indicated that cultivated yerba mate contained higher chlorogenic acids levels, and samples from Argentina, Paraguay, and Uruguay exhibited higher concentrations of chlorogenic acids and flavonoids.

Dietary Supplementation with Yerba Mate (Ilex paraguariensis) Infusion Increases IRS-1 and PI3K mRNA Levels and Enhances Insulin Sensitivity and Secretion in Rat Pancreatic Islets.

"Yerba mate" (YM), an aqueous extract of Ilex paraguariensis, has antioxidant, diuretic, cardio-protective and hypoglycaemic properties. Since its effect on the pancreatic islets remains unclear, we evaluated insulin sensitivity and glucose-stimulated insulin secretion (GSIS) in rats consuming YM or tap water (C) for 21 days. Glucose tolerance, glycemia, triglyceridemia, insulinemia, TBARS and FRAP serum levels were evaluated. GSIS and mRNA levels of insulin signaling pathway and inflammatory markers were measured in isolated pancreatic islets from both groups. In C rats, islets were incubated with YM extract or its phenolic components to measure GSIS. YM improved glucose tolerance, enhanced GSIS, increased FRAP plasma levels and islet mRNA levels of IRS-1 and PI3K (p110), and decreased TBARS plasma levels and islet gene expression of TNF-α and PAI-1. Islets from C rats incubated with 100 µg/mL dry YM extract, 1 µM chlorogenic acid, 0.1 and 1 µM rutin, 1 µM caffeic acid or 1 µM quercetin showed an increase in GSIS. Our results suggest that YM enhances glucose tolerance because of its positive effects on GSIS, oxidative stress rate and insulin sensitivity in rat islets, suggesting that long-term dietary supplementation with YM may improve glucose homeostasis in pre-diabetes or type 2 diabetes.

Utilization of different by-products to produce nutritionally rich gelled products.

Yellow corn cooking water with yerba mate (Ilex paraguariensis) extract, obtained as a by-product of snack manufacture, was combined with whey protein concentrate (7 g/100 g), flaxseed (Linum usitatissimum L.) flour (2 g/100 g), and honey (8 g/100 g) to obtain different gelled products. The effect of the composition on the physicochemical parameters was analyzed. Flaxseed flour was added directly or with a previous pre-heating, and, in both cases, it increased the solid behavior of gels. On the contrary, honey increased the gel liquid-like behavior, and both ingredients modified the color of the gels. Elastic and loss modulus decreased after storage for 7 and 14 days. Some of the textural parameters also changed during storage. Principal component analysis and cluster analysis revealed three groups of formulations according to their composition, and those samples containing only flaxseed flour were best described with the textural and rheological parameters. Yerba mate extract, mainly, flaxseed flour, and honey increased the phenolic composition of gels but decreased the sensory acceptability, despite the sweetness of honey. A variety of gelled products with different textures and flavors was obtained using by-products of the food industry. These gels could be used either for dessert formulations or as a matrix for gelled products.

Binding of Iron (II) Ions by Aqueous Extractions from Yerba Mate (Ilex paraguariensis).

We studied the ability of an aqueous extract from yerba mate and a dry extract obtained on the basis of this aqueous extract to remove Fe(II) ions from an aqueous medium. Aqueous extracts from mate dose-dependently reduced the concentration of free Fe(II) ions assayed by the reaction with 1,10-phenanthroline. This can be attributed to polyphenolic compounds with iron-chelating properties present in aqueous extracts from mate, namely quercetin, rutin, caffeic and chlorogenic acids. These substances effectively removed Fe(II) ions from the medium (the initial concentration of these ions was 15 µM) in the concentration range of 20-30 µM. Binding of Fe(II) ions by aqueous mate extracts (due to the formation of chelate complexes with the participation of polyphenolic compounds) modified their absorption spectra in the visible region. Binding of Fe(II) ions can be a mechanism of the antioxidant action of yerba mate.

Stability of yerba mate extract, evaluation of its microencapsulation by ionic gelation and fluidized bed drying.

Studies show that yerba mate (Ilex paraguariensis) has high antioxidant capacity occasioned by its high contents of total phenolic compounds. Microencapsulation, specifically ionic gelation, since it does not use heating during process, is considered as an alternative for preserving and applying the extract. The purpose of this study was to evaluate general characteristics and stability of hydroalcoholic extract of yerba mate, conduct the extract microencapsulation by ionic gelation followed by microparticle fluidized bed drying. The extract was evaluated for color stability, total phenolic compounds, and antioxidant activity for nine weeks and at three temperatures (5, 15, and 25 °C). From the extract, a double emulsion (W/O/W), generation of microparticles (ionic gelation by dripping), and fluidized bed drying were conducted. The extract had 32912.55 mg GAE/100 g of phenolic compounds and 2379.49 µmol TE/g of antioxidant activity. The main compound observed was chlorogenic acid (5-CQA) with 0.35 ± 0.01 g/100 mL. In the stability study, the temperature was observed to influence in phenolic compounds reduction, as well as in total color difference of the extract. Double emulsion has shown to be stable and appropriate for use. The values of microparticles total phenolic compounds and antioxidant activity were 423.18 ± 8.60 mg GAE/100 g and 21.17 ± 0.24 µmol TE/g, respectively. After drying, the moisture of microparticles was reduced from 79.2% to 19%. The extract had high total phenolic compound content and high antioxidant activity. Storage at the lowest temperature (5 °C) assured better preservation of extract total phenolic compounds. The dried microparticles showed content of total phenolic compounds and antioxidant activity with potential for commercialization and future application in food matrices.

Rigid Polyurethane Biofoams Filled with Pine Seed Shell and Yerba Mate Wastes.

Pine seed shells and yerba mate are common wastes leftover from the food and beverage industry. This study presents the development of rigid polyurethane foams (RPUFs) filled with pine seed shells and yerba mate at 5, 10 and 15 wt%. The fillers were characterized for chemical properties using bench chemistry analyses, and the RPUFs were investigated in terms of chemical, morphological, mechanical, thermal and colorimetric characteristics. The main results indicated that yerba mate showed good compatibility with the polyurethane system, probably because its available hydroxyl groups reacted with isocyanate groups to form urethane bonds, producing increases in mechanical and thermal properties. However, pine seed shell did not appear to be compatible. Anisotropy increased slightly, as there was an increase in the percentage of reinforcement. The mechanical properties of the yerba mate reinforced foams proved stable, while there was a loss of overall up to ~50% for all mechanical properties in those reinforced with pine seed shell. Thermal properties were improved up to ~40% for the yerba mate reinforced foams, while those reinforced with pine nuts were stable. It was possible to observe a decrease in the glass transition temperature (Tg) of ~-5 °C for the yerba mate reinforced foams and ~-14 °C for the pine seed shell reinforced ones.

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.

Characterization of Natural Compounds as Inhibitors of NS1 Endonuclease from Canine Parvovirus Type 2.

Canine parvovirus type 2 (CPV-2) has high morbidity and mortality rates in canines. Nonstructural protein 1 (NS1) of CPV-2 has endonuclease activity, initiates viral DNA replication, and is highly conserved. Thus, it is a promising target for antiviral inhibitor development. We overexpressed a 41.9 kDa active recombinant endonuclease in Escherichia coli and designed a nicking assay using carboxyfluorescein and quencher-linked ssDNA as substrates. The optimal temperature and pH of the endonuclease were 37°C and pH 7, respectively. Curcumin, bisdemethoxycurcumin, demethoxycurcumin, linoleic acid, tannic acid, and α-tocopherol inhibited CPV-2 NS1 endonuclease with IC50 values of 0.29 to 8.03 µM. The extracted turmeric, yerba mate, and sesame cake suppressed CPV-2 NS1 endonuclease with IC50 values of 1.48, 7.09, and 52.67 µg/ml, respectively. The binding affinity between curcumin, the strongest inhibitor, and CPV-2 NS1 endonuclease by molecular docking was -6.4 kcal/mol. Curcumin inhibited CPV-2 NS1 endonuclease via numerous hydrophobic interactions and two hydrogen bonds with Lys97 and Pro111 in the allosteric site. These results suggest that adding curcuminoids, linoleic acid, tannic acid, α-tocopherol, extracted turmeric, sesame cake, and yerba to the diet could prevent CPV-2 infection.

Microencapsulation of Yerba mate extract: The efficacy of polysaccharide/protein hydrocolloids on physical, microstructural, functional, and antioxidant properties.

Effects of hydrolyzed whey protein concentrate (WPC) and its combination with polysaccharides as wall material in spray-drying microencapsulation of Yerba mate extract (YME) have not been investigated yet. Therefore, it is hypothesized that the surface-active properties of WPC or WPC-hydrolysate may improve different properties of spray-dried microcapsules (such as physicochemical, structural, functional and morphological properties) compared to neat MD and GA. Thus, the objective of current study was to produce microcapsules loaded with YME by different carrier combinations. Effect of maltodextrin (MD), maltodextrin-gum Arabic (MD-GA), maltodextrin-whey protein concentrate (MD-WPC), and maltodextrin-hydrolyzed WPC (MD-HWPC) as encapsulating hydrocolloids was studied on physicochemical, functional, structural, antioxidant and morphological characteristics of the spray-dried YME. The type of carrier significantly affected spray dying yield. Enzymatic hydrolysis by improving the surface activity of WPC increased its efficiency as a carrier and produced particles with high production yield (about 68 %) and excellent physical, functional, hygroscopicity and flowability indices. Chemical structure characterization by FTIR indicated the placement of phenolic compounds of the extract in the carrier matrix. FE-SEM study showed that the microcapsules produced with polysaccharide-based carriers were completely wrinkled, whereas, the surface morphology of particles was improved when protein-based carriers were applied. Among the produced samples, the highest amount of TPC (3.26 mg GAE/mL), inhibition of DPPH (76.4 %), ABTS (88.1 %) and hydroxyl (78.1 %) free radicals were related to microencapsulated extract with MD-HWPC. The results of this research can be used to stabilize plant extracts and produce powders with appropriate physicochemical properties and biological activity.

A comprehensive review on clinically proven medicinal plants in the treatment of overweight and obesity, with mechanistic insights.

Background and objectives: Obesity has become a global health issue, more precisely, a pandemic throughout the present world due to its high prevalence in the recent era. Increased risk of morbidity and mortality in obese patients can be attributed to its association with the development of different life-threatening conditions. Plants are considered one of the most important sources of bioactive molecules which are used against a wide range of health disorders. This systematic review explores the efficacy as well as the safety profile of commonly used medicinal plants in the management of obesity that may help people to maintain a healthy weight. Methods: This review is based on comprehensive literature searches from PubMed, Science Direct, Scopus, and Google Scholar databases using the keywords- "plants in obesity", "plants used in weight reduction" or keywords that are similar to those. Medicinal plants which have been clinically proven for their anti-obesity effect have only been selected for this study and attempts to investigate beneficial effects and adverse effects along with their mechanism of action have also been taken in this review. Results: A significant reduction of weight in both human and other animals are exhibited by the extracts of Phaseolus vulgaris, green coffee, Yerba Mate, green tea, Gynostemma pentaphyllum, and the combination of Cissus quadrangularis/Irvingia gabonensis. All of those plant extracts seemed to work on different physiological pathways and none of those extracts showed any notable adverse effects in human or animal models. Conclusion: Our review suggests that the discussed medicinal plants are effective in reducing the weight of obese patients without causing notable adverse reactions. Although further study is necessary to confirm their exact molecular mechanism and safety in human use.

Plasticized Mechanical Recycled PLA Films Reinforced with Microbial Cellulose Particles Obtained from Kombucha Fermented in Yerba Mate Waste.

In this study, yerba mate waste (YMW) was used to produce a kombucha beverage, and the obtained microbial cellulose produced as a byproduct (KMW) was used to reinforce a mechanically recycled poly(lactic acid) (r-PLA) matrix. Microbial cellulosic particles were also produced in pristine yerba mate for comparison (KMN). To simulate the revalorization of the industrial PLA products rejected during the production line, PLA was subjected to three extrusion cycles, and the resultant pellets (r3-PLA) were then plasticized with 15 wt.% of acetyl tributyl citrate ester (ATBC) to obtain optically transparent and flexible films by the solvent casting method. The plasticized r3-PLA-ATBC matrix was then loaded with KMW and KMN in 1 and 3 wt.%. The use of plasticizer allowed a good dispersion of microbial cellulose particles into the r3-PLA matrix, allowing us to obtain flexible and transparent films which showed good structural and mechanical performance. Additionally, the obtained films showed antioxidant properties, as was proven by release analyses conducted in direct contact with a fatty food simulant. The results suggest the potential interest of these recycled and biobased materials, which are obtained from the revalorization of food waste, for their industrial application in food packaging and agricultural films.

Yerba mate: From waste to activated carbon for supercapacitors.

Developing technological solutions that use yerba mate waste as precursors is key to reducing the environmental impact caused by the lack of treatment and its accumulation in landfills. Due to their physicochemical properties, these residues can be used to develop activated carbons. Activated carbon is a versatile material with a high surface area that can be used for energy storage. In this work, yerba mate residues were valued by producing chemically activated carbon to be used as electrode material in supercapacitors. Activated carbons were developed through chemical activation in two steps with KOH. Variables such as impregnation ratio and activation temperature are studied. The developed carbons were characterized by physicochemical and electrochemical techniques. They were found to have high surface areas, up to 1800 m2 g-1, with a hierarchical porous distribution. A maximum specific capacitance of 644 F g-1 at 0.1 A g-1, and power values of ca 32,000 W kg-1, at 33 A g-1 were found. All the synthesized carbons have excellent electrochemical properties and are suitable for use as active material in supercapacitors.