Phenol In Water Research Articles

Comparative study of the topochemistry on delignification of Japanese beech (Fagus crenata) in subcritical phenol and subcritical water

Abstract The delignification of Japanese beech (Fagus crenata) has been evaluated under conditions of subcritical phenol (230°C/1.2 MPa) and subcritical water (230°C/2.9 MPa). In the former, more than 90% of the original lignin was decomposed and removed, while in subcritical water, around half of the original lignin was left as insoluble residue. Ultraviolet (UV) microscopic images of the insoluble residues showed that the lignin in the secondary walls is decomposed and removed under both conditions. These images also revealed that the lignin in the compound middle lamella (CML) is resistant to subcritical water, but not to subcritical phenol. Results of alkaline nitrobenzene oxidation of the residual lignin confirmed these observations. Lignin in Japanese beech wood was phenolated by subcritical phenol, which was efficiently removed due to its high solubility in the reactant. It is obvious that CML is rich in condensed-type linkages facilitating rapid solvolysis by phenol. The topochemistry of the plant has a pronounced impact on its delignification behavior.

Community Analysis and Recovery of Phenol-degrading Bacteria from Drinking Water Biofilters.

Phenol is a ubiquitous organic contaminant in drinking water. Biodegradation plays an important role in the elimination of phenol pollution in the environment, but the information about phenol removal by drinking water biofilters is still lacking. Herein, we study an acclimated bacterial community that can degrade over 80% of 300 mg/L phenol within 3 days. PCR detection of genotypes involved in bacterial phenol degradation revealed that the degradation pathways contained the initial oxidative attack by phenol hydroxylase, and subsequent ring fission by catechol 1,2-dioxygenase. Based on the PCR denatured gradient gel electrophoresis (PCR-DGGE) profiles of bacteria from biological activated carbon (BAC), the predominant bacteria in drinking water biofilters including Delftia sp., Achromobacter sp., and Agrobacterium sp., which together comprised up to 50% of the total microorganisms. In addition, a shift in bacterial community structure was observed during phenol biodegradation. Furthermore, the most effective phenol-degrading strain DW-1 that correspond to the main band in denaturing gradient gel electrophoresis (DGGE) profile was isolated and identified as Acinetobacter sp., according to phylogenetic analyses of the 16S ribosomal ribonucleic acid (rRNA) gene sequences. The strain DW-1 also produced the most important enzyme, phenol hydroxylase, and it also exhibited a good ability to degrade phenol when immobilized on granular active carbon (GAC). This study indicates that the enrichment culture has great potential application for treatment of phenol-polluted drinking water sources, and the indigenous phenol-degrading microorganism could recover from drinking water biofilters as an efficient resource for phenol removal. Therefore, the aim of this study is to draw attention to recover native phenol-degrading bacteria from drinking water biofilters, and use these native microorganisms as phenolic water remediation in drinking water sources.

Elucidation of a masked repeating structure of the O-specific polysaccharide of the halotolerant soil bacteria Azospirillum halopraeferens Au4.

An O-specific polysaccharide was obtained by mild acid hydrolysis of the lipopolysaccharide isolated by the phenol–water extraction from the halotolerant soil bacteria Azospirillum halopraeferens type strain Au4. The polysaccharide was studied by sugar and methylation analyses, selective cleavages by Smith degradation and solvolysis with trifluoroacetic acid, one- and two-dimensional 1H and 13C NMR spectroscopy. The following masked repeating structure of the O-specific polysaccharide was established: →3)-α-L-Rhap2Me-(1→3)-[β-D-Glcp-(1→4)]-α-D-Fucp-(1→2)-β-D-Xylp-(1→, where non-stoichiometric substituents, an O-methyl group (~45%) and a side-chain glucose residue (~65%), are shown in italics.

Phenolic compounds as indicators of drought resistance in shrubs from Patagonian shrublands (Argentina)

SummaryPlants exposed to drought stress, as usually occurs in Patagonian shrublands, have developed different strategies to avoid or tolerate the lack of water during their development. Production of phenolic compounds (or polyphenols) is one of the strategies used by some native species of adverse environments to avoid the oxidative damage caused by drought. In the present study the relationship between phenolic compounds content, water availability and oxidative damage were evaluated in two native shrubs: Larrea divaricata (evergreen) and Lycium chilense (deciduous) of Patagonian shrublands by their means and/or by multivariate analysis. Samples of both species were collected during the 4 seasons for the term of 1 year. Soil water content, relative water content, total phenols, flavonoids, flavonols, tartaric acid esters, flavan-3-ols, proanthocyanidins, antioxidant capacity and lipid peroxidation were measured. According to statistical univariate analysis, L. divaricata showed high production of polyphenols along the year, with a phenolic compound synthesis enhanced during autumn (season of greatest drought), while L. chilense has lower production of these compounds without variation between seasons. The variation in total phenols along the seasons is proportional to the antioxidant capacity and inversely proportional to lipid peroxidation. Multivariate analysis showed that, regardless their mechanism to face drought (avoidance or tolerance), both shrubs are well adapted to semi-arid regions and the phenolic compounds production is a strategy used by these species living in extreme environments. The identification of polyphenol compounds showed that L. divaricata produces different types of flavonoids, particularly bond with sugars, while L. chilense produces high amount of non-flavonoids compounds. SynthesisThese results suggest that flavonoid production and accumulation could be a useful indicator of drought tolerance in native species.

HRP Immobilization on Activated Carbon/Polyvinyl Formal Composite Materials for Degradation of Phenolic Wastewater

A novel method was developed for degradation of phenolic waste water using horseradish peroxidase (HRP) immobilization on activated carbon/polyvinyl formal (AC/PVFM) composite materials in this study. The materials were black-sponge-like, soft and elastic, and had three-dimensional porous network structure. Optimum conditions of immobilized HRP carrier preparation technology was selected by orthogonal experiment. The enzymatic properties were explored and compared between immobilized and free enzyme. The optimum pH of immobilized HRP and free HRP were both 4, nevertheless, the immobilization of HRP increased the enzyme activity. The optimum temperature of immobilized HRP was 20°C which was lower than that of free HRP (25°C), therefore the immobilized HRP could resist to lower temperature. The Km of immobilized HRP and free HRP were 0.23 mmol/L and 0.40 mmol/L, respectively. The lower Km value of immobilized HRP indicated higher affinity to the substrate. These results show that HRP immobilized on AC/PVFM composite materials is promising in phenolic wastewater degradation.

Synthesis of iron-based nanoparticles and comparison of their catalytic activity for degradation of phenolic waste water in a small-scale batch reactor

In the present work, iron-based nanoparticles were synthesized by sol–gel method (iron oxide I), modified co-precipitation method (iron oxide II), reduction of FeSO4 by NaBH4 (nano zero-valent iron I, nZVI I), and reduction of FeSO4 by NaBH4 in presence of chelating ligand EDTA (nZVI II) for use as a catalyst for degradation of phenol. Particle characterization was performed for each set of samples by UV–vis spectra, X-ray diffraction, Fourier transformed infrared spectroscopy (FTIR), dynamic light scattering (DLS), and field emission scanning electron microscopy (FESEM). FESEM was performed with iron oxide II and particle size was found to be 36.5 nm. The average particle diameter obtained for nZVI was in the range of 141–150 nm. nZVI(II) has been found to be most efficient with respect to high percentage degradation of phenol in an hour under optimum operating condition at room temperature which were as follows: catalyst concentration = 0.05 g/l, pH 3, phenol:hydrogen peroxide (50%) concentration = 1:14 (stoichiometric ratio), temperature = ambient. Brunauer–Emmett–Teller (BET) surface area measurement also showed higher surface area for nano zero-valent iron (nZVI) particles than compared to other iron oxides. The initial phenol concentration was varied in the range of 50–400 mg/l. Degradation efficiency was found decreasing with increasing initial concentration of phenol. Iron oxide I and II can be successfully recovered and reused.

Genistein suppresses Prevotella intermedia lipopolysaccharide-induced inflammatory response in macrophages and attenuates alveolar bone loss in ligature-induced periodontitis

ObjectiveGenistein is a major isoflavone subclass of flavonoids found in soybean and a potent tyrosine kinase inhibitor. The present study aimed to assess the effect of genistein on the production of proinflammatory mediators in murine macrophages stimulated with lipopolysaccharide (LPS) isolated from Prevotella intermedia, a pathogen associated with different forms of periodontal disease, and to evaluate its possible influence on alveolar bone loss in ligature-induced periodontitis using micro-computed tomography (micro-CT) analysis as well. DesignLPS was isolated from P. intermedia ATCC 25611 by using the standard hot phenol–water method. Culture supernatants were analyzed for nitric oxide (NO) and interleukin-6 (IL-6). Inducible NO synthase (iNOS) protein expression was evaluated by immunoblot analysis. Real-time PCR was carried out to measure iNOS and IL-6 mRNA expression. In addition, effect of genistein on alveolar bone loss was evaluated in a rat model of experimental periodontitis using micro-CT analysis. ResultsGenistein significantly attenuated P. intermedia LPS-induced production of iNOS-derived NO and IL-6 with attendant decrease in their mRNA expression in RAW264.7 cells. In addition, when genistein was administered to rats, decreases in alveolar bone height and bone volume fraction induced by ligature placement were significantly inhibited. Genistein administration also prevented ligature-induced alterations in the microstructural parameters of trabecular bone, including trabecular thickness, trabecular separation, bone mineral density and structure model index. ConclusionsWhile additional studies are required, we suggest that genistein could be utilized for the therapy of human periodontitis in the future.

Comparison of Biological and Immunological Characterization of Lipopolysaccharides From Brucella abortus RB51 and S19.

Background:Brucella abortus RB51 is a rough stable mutant strain, which has been widely used as a live vaccine for prevention of brucellosis in cattle instead of B. abortus strain S19. B. abortus lipopolysaccharide (LPS) has unique properties in comparison to other bacterial LPS.Objectives:In the current study, two types of LPS, smooth (S-LPS) and rough (R-LPS) were purified from B. abortus S19 and RB51, respectively. The aim of this study was to evaluate biological and immunological properties of purified LPS as an immunogenical determinant.Materials and Methods:Primarily, S19 and RB51 LPS were extracted and purified by two different modifications of the phenol water method. The final purity of LPS was determined by chemical analysis (2-keto-3-deoxyoctonate (KDO), glycan, phosphate and protein content) and different staining methods, following sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). C57BL/6 mice were immunized subcutaneously three times at biweekly intervals with the same amount of purified LPSs. The humoral immunity was evaluated by measuring specific IgG levels and also different cytokine levels, such as IFN-γ, TNF-α, IL-4 and IL-10, were determined for assessing T-cell immune response.Results:Biochemical analysis data and SDS-PAGE profile showed that the chemical nature of S19 LPS is different from RB51 LPS. Both S and R-LPS induce an immune response. T-cell immune response induced by both S and R-LPS had almost the same pattern whereas S19 LPS elicited humoral immunity, which was higher than RB51 LPS.Conclusions:Purified LPS can be considered as a safe adjuvant and can be used as a component in prophylactic and therapeutic vaccines targeting infectious disease, cancer and allergies.

Performance Evaluation of Anaerobic Biodegradation of Synthetic Phenolic Waste Water in Single Stage Fixed Bed Bio- Reactor

Performance Evaluation of Anaerobic Biodegradation of Synthetic Phenolic Waste Water in Single Stage Fixed Bed Bio- Reactor

Effects of Types of Metal Oxides on Hydrothermal Gasification of Phenol over Novel Metal Oxide–carbon Composite Supported Ni Catalysts Prepared by Sol-gel Method

Novel carbon and oxide-supported Ni (Ni/C/TiO2, SiO2 or ZrO2) catalysts were prepared by the sol-gel method and investigated for hydrothermal gasification of aqueous solution of phenol (phenol water) as a model of wastewater, and compared with carbon and Al2O3 supported Ni catalysts. Catalysts were prepared by the combination of titanium tetraisopropoxide (TIP), tetraethylorthosilicate (TEOS) or zirconium tetrabutoxide (ZB) and polyethylene glycol (PEG) as an organic template, with the addition of active metal, nickel nitrate hexahydrate, at the preparation of catalysts. After calcination under a nitrogen atmosphere, larger amounts of active metal species were deposited on the carbon skeleton in the catalysts. The introduction of PEG dispersed metal Ni with high loading on carbon derived from PEG. Hydrothermal gasification was performed under the following conditions: 350 °C, pressure 20 MPa, phenol water 2-20 g/L, catalyst 5 mL, LHSV 48 h−1. 16N11C73Z catalyst, which represents 16 wt% Ni, 11 wt% carbon in PEG, and 73 wt% ZrO2 at the preparation of the catalyst, showed the highest activity among the 16N11C73Oxide catalysts (Oxide: TiO2, SiO2, ZrO2 or Al2O3). The conversion of phenol decreased in the order 16N11C73Z>16N11C73A>16N11C73T>16N11C73S (16N: 16 wt% Ni; 11C: 11 wt% carbon in PEG; 73Z, A, T or S: 73 wt% ZrO2, Al2O3, TiO2 or SiO2). As the amount of PEG added was increased, TiO2, ZrO2 and Al2O3 containing catalysts showed 100 % of conversion whereas the yields of carbon and methane decreased in the order 16N63C21A>16N53C31Z>16N53C31T (16N: 16 wt% Ni; 53 or 63C: 53 or 63 wt% carbon in PEG; 21 or 31A, Z or T: 21 or 31 wt% Al2O3, ZrO2 or TiO2). 16N53C31Z and 16N53C31T did not show change in pore structure after the reaction, although the sizes of Ni species increased.

Optimization of the Spray‐Drying Process for Developing Jabuticaba Waste Powder Employing Response Surface Methodology

AbstractThe objective of this work was to obtain spray‐dried extract from seeds and peels jabuticaba (Myrciaria cauliflora) with optimized properties. To optimize the spray‐drying process, a 33 Box–Behnken design was used, in which the independent variables were the inlet drying air temperature (x1, 100–120C), feed flow rate (x2, 3–5 mL/min) and spray nozzle air flow rate (x3, 40–50 L/min). The dependent variables were ellagic acid content, total flavonoid content, total phenolic content, antioxidant activity, water activity and moisture content. Only flavonoid content and moisture content were influenced by none of the independent variables in the ranges studied. Using the desirability function, the optimum conditions for obtaining spray‐dried extracts for the responses (with significant effects) were inlet drying air temperature of 120C, feed flow rate of 3 mL/min and spray nozzle air flow rate of 50 L/min. Under these conditions, the results from the verification were 0.0844 ± 0.0013% for ellagic acid content, 16.27 ± 0.63 % for total phenolic content, 0.176 ± 0.02 for water activity and 54.45 ± 0.92% for antioxidant activity, which were in good agreement with the predicted values.Practical ApplicationsThis paper gives a report on the reuse of the vegetal wastes obtained from jabuticaba fruits – Myrciaria cauliflora (peels and seeds), which can be considered a raw material with several chemical compounds with biological activities. So, this work aims to arrive at the possible industrial application in the spray‐drying process to obtain an intermediary product from jabuticaba wastes. Furthermore, surface response methodology (SRM) was employed to determine the influence of the most important spray dryer parameters on the physicochemical properties of M. cauliflora spray‐dried extracts. Based on the results obtained from SRM and in biological activities known for this species, the spray‐dried extracts exhibited a great potential for use in pharmaceutical and nutraceutical fields.

Application of concrete surfaces as novel substrate for immobilization of TiO2 nano powder in photocatalytic treatment of phenolic water.

BackgroundIn this study, concrete application as a substrate for TiO2 nano powder immobilization in heterogeneous photocatalytic process was evaluated. TiO2 immobilization on the pervious concrete surface was done by different procedures containing slurry method (SM), cement mixed method (CMM) and different concrete sealer formulations. Irradiation of TiO2 was prepared by UV-A and UV-C lamps. Phenolic wastewater was selected as a pollutant and efficiency of the process was determined in various operation conditions including influent phenol concentration, pH, TiO2 concentration, immobilization method and UV lamp intensity.FindingsThe removal efficiency of photocatalytic process in 4 h irradiation time and phenol concentration ranges of 25–500 mg/L was more than 80 %. Intermediates were identified by GC/Mass and spectrophotometric analysis.ConclusionsAccording to the results, photocatalytic reactions followed the pseudo-first-order kinetics and can effectively treate phenol under optimal conditions.

Carbon monoxide-releasing molecule-3 suppresses Prevotella intermedia lipopolysaccharide-induced production of nitric oxide and interleukin-1β in murine macrophages

This study was performed to analyze the effect of carbon monoxide (CO)-releasing molecule-3 (CORM-3) in alleviating the production of proinflammatory mediators in macrophages treated with lipopolysaccharide (LPS) from Prevotella intermedia, a pathogen associated with periodontal disease, and its possible mechanisms of action. LPS was isolated using the hot phenol–water method. Culture supernatants were assayed for nitric oxide (NO) and interleukin-1β (IL-1β). Gene expression was quantified by real-time PCR, and protein expression by immunoblotting. DNA-binding activities of NF-κB subunits were determined using an ELISA-based kit. CORM-3 suppressed the production of inducible NO synthase (iNOS)-derived NO and IL-1β at both gene transcription and translation levels in P. intermedia LPS-activated RAW264.7 cells. CORM-3 enhanced heme oxygenase-1 (HO-1) expression in cells stimulated with P. intermedia LPS, and inhibition of HO-1 activity by SnPP notably reversed the suppressive effect of CORM-3 on LPS-induced production of NO. LPS-induced phosphorylation of p38 and JNK was not affected by CORM-3. CORM-3 did not influence P. intermedia LPS-induced degradation of IκB-α. Instead, nuclear translocation of NF-κB p65 and p50 subunits was blocked by CORM-3 in LPS-treated cells. In addition, CORM-3 reduced LPS-induced p65 and p50 binding to DNA. Besides, CORM-3 significantly suppressed P. intermedia LPS-induced phosphorylation of STAT1. Overall, this study indicates that CORM-3 suppresses the production of NO and IL-1β in P. intermedia LPS-activated murine macrophages via HO-1 induction and inhibition of NF-κB and STAT1 pathways. The modulation of host inflammatory response by CORM-3 would be an attractive therapeutic approach to attenuate the progression of periodontal disease.

Structure of fructans from three strains of Cronobacter dublinensis

Partially O-acetylated fructan was isolated by phenol—water extraction of cells of Cronobacter dublinensis G2732 followed by anion-exchange chromatography on DEAE-Toyopearl 650M. Structure of the isolated fructan was established by 2D 1H and 13C NMR spectroscopy. The same fructan but lacking O-acetyl groups was isolated from two other C. dublinensis strains, G3947 and G4061. Genes for the fructan biosynthesis were not found at the typical Cronobacter O-antigen gene cluster located between the conserved genes galF and gnd and are evidently located elsewhere on the chromosome.

Continuous Treatment of Phenol over an Fe2O3/γ-Al2O3 Catalyst in a Fixed-Bed Reactor

Fe2O3/γ-Al2O3 catalysts were prepared using the wet impregnation method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and nitrogen adsorption–desorption. The continuous catalytic wet hydrogen peroxide oxidation of an aqueous phenol solution over Fe2O3/γ-Al2O3 was studied in a fixed-bed reactor. The effects of several factors, such as the weight hourly space velocity (WHSV), particle size, reaction temperature, H2O2 concentration, and initial pH, were studied to optimize the operation conditions for phenol mineralization. For a 1 g L−1 phenolic aqueous solution, the phenol was nearly completely removed and chemical oxygen demand (COD) removal was approximately 92 % at steady-state conditions with a WHSV of 2.4 × 10−2 gPhOH h−1 gcat −1 at 80 °C with 5.1 g L−1 H2O2. The long-term stability of the Fe2O3/γ-Al2O3 catalyst was also investigated for the continuous treatment of phenolic water. The removal of phenol and COD exhibited a slowly decreasing trend, which was primarily due to the complexation of active sites with acid organic compounds and the adsorption of intermediate products. The deposition of organic carbon and Fe leached from the catalyst had a small role in the partial deactivation of the catalyst. The Fe leached from the catalyst partially contributed to the phenol removal during a short run. However, this contribution could be neglected after 36 h because the Fe leached from the catalyst decreased to approximately 5 mg L−1.

Structure elucidation of the capsular polysaccharide of Acinetobacter baumannii AB5075 having the KL25 capsule biosynthesis locus

Capsular polysaccharide was isolated by the phenol–water extraction of Acinetobacter baumannii AB5075 and studied by 1D and 2D 1H and 13C NMR spectroscopy. The following structure of the linear trisaccharide repeating unit was established:→3)-β-d-ManpNAcA-(1→4)-β-d-ManpNAcA-(1→3)-α-d-QuipNAc4NR-(1→where R indicates (S)-3-hydroxybutanoyl or acetyl in the ratio∼2.5:1. The genes in the polysaccharide biosynthesis locus designated KL25 are appropriate to the established CPS structure.

Infrared spectroscopy of warm and neutral phenol-water clusters.

Although many studies have been reported on structures of neutral water clusters, most of experimental information has been restricted to their most stable structures. With elevation of temperature, however, transient structures as well as higher energy stable structures can be formed, as recently demonstrated in small-sized neat water clusters (Zischang, J.; Suhm, M. A. J. Chem. Phys. 2014, 140, 064312). In the present study, we performed infrared spectroscopy of warm phenol-(H2O)2, which is an analogue of (H2O)3 concerning the hydrogen-bond structure, in order to overcome the size uncertainty in the neat water cluster study. The strict size selection was achieved by infrared-ultraviolet double-resonance spectroscopy combined with mass spectrometry. The temperature control of the cluster was accomplished by the reduction of the stagnation pressure of the jet expansion and the internal energy selective detection of the cluster. A remarkable shift to higher frequency of the phenolic OH stretch band was observed with elevation of temperature, suggesting deformation of the cluster from the most stable cyclic structure to the transient chain-type structure.

Determination of binding energy in molecular clusters by ion imaging methods: A test on the phenol–water 1:1 cluster

In this paper we present a test on the velocity mapping imaging approach for the experimental direct determination of the binding energy in clusters formed by strongly interacting polyatomic molecules. The method is applied to the phenol–water cluster, a system for which the binding energies were already determined in different experiments. The binding energy values that we obtained, 1975cm−1 in the S0 state, 2327cm−1 in the S1 state and 6586cm−1 in the ionic D0 state, are in very good agreement with the previous determinations. We report our results and we discuss advantages and limitations resulting from our experience.

Two Binary Liquid Critical Mixtures Belong to Class of Universality

The dynamic shear viscosity of a binary liquid mixture phenol–water has been measured at different temperatures (50.0°C ≤ T ≤ 75.0°C) and different concentrations (0.00% up to 100.00% by weight of phenol). The critical temperature Tc and critical concentration xc are found to be 67.0°C and 33.90% by weight of phenol respectively, the critical mass density ρc is measured to be 0.8952 g/cm3. The critical and background amplitudes of specific heat at constant pressure are calculated to be 78.12 J/kg.K and 85.29 J/kg.K respectively. The pressure derivative of the critical temperature along the critical line ' cT T is calculated to be 9.722 ×10-6 K/Pa. In addition, dynamic shear viscosity of binary liquid mixture phenol–cyclohexane has been measured at different temperatures (14.0°C ≤ T ≤ 30.0°C) and different concentrations (2.00% up to 39.70% by weight of phenol). The critical temperature Tc and critical concentration xc are found to be 17.0°C and 2.70% by weight of phenol respectively; the critical mass density ρc is measured to be 0.7627 g/cm3. The critical and background amplitudes of isobaric thermal expansion coefficient αpc and αpb are calculated to be 8×10-6 K-1, 6×10-4 K-1 respectively. The pressure derivative of the critical temperature ' cT for the binary is calculated to be 2.8572 × 10-8 K/Pa. The universal quantity R+ ξ for the binary liquid critical mixture phenol–water is calculated to be 0.2716 ± 0.0005. In addition, the universal quantity R+ ξ for the binary liquid critical mixture phenol–cyclohexane is calculated to be 0.2699 ± 0.0001. The calculated values of the universal quantity R+ ξ are in a good agreement with the theoretical value of R+ ζ which is equal 0.2710. The two binary liquid critical mixture belong to the class of universality Two–Scale–Factor Universality.

Microencapsulation of freeze concentrated Ilex paraguariensis extract by spray drying

Concentrated extract of mate leaves obtained from the third stage of the freeze concentration process was microencapsulated with maltodextrin by spray drying. The effect of maltodextrin concentration (20%, 30%, and 40%) on the phenolic compounds, antioxidant activity, microencapsulation yield, morphology, particle size, moisture content, water activity, dissolution, hygroscopicity, color and thermal properties were investigated. The retention of phenolic compounds after microencapsulation by spray drying and the stability of the microcapsules at 4°C for 45days were also determined. It was possible to note an enhancement of the total phenolic content and antioxidant activity of mate leaves aqueous extract obtained through freeze concentration. The high concentrations of maltodextrin in the microcapsules promoted higher phenolic compounds microencapsulation yield, higher particle size and longer time required for the powders to dissolve in water, while moisture content, water activity and hygroscopicity decreased. The color parameters indicated that maltodextrin protected the microcapsules against heat during spray drying. The results of the thermoanalyses suggested an increase in the stability of the microcapsules. Besides, the microcapsules produced with maltodextrin showed better retention and enhanced stability at 4°C for 45days.