Low Ethanol Research Articles

Perspectives on using ethanol as an internal standard for the quantification of volatile compounds in alcoholic products by headspace SPME–GC/FID without sample preparation

For the first time, the beneficial “Ethanol as Internal Standard (IS)” method developed for the analysis of alcoholic products was tested in headspace mode of solid-phase microextraction gas chromatography with flame ionization detector (SPME-GC/FID) and compared with the traditional IS method. The extraction and separation conditions were optimized for the analysis of 10 volatile congeners prescribed in European legislation: acetaldehyde, methyl acetate, ethyl acetate, methanol, butan-2-ol, propan-1-ol, 2-methylpropan-1-ol (isobutanol), butan-1-ol, 1,1-diethoxyethane (acetal), and 3-methylbutan-1-ol (isoamylol). To evaluate the accuracy of the compared methods, three real alcoholic product samples with ethanol content of 20%, 40%, and 80% v/v were spiked with gravimetrically prepared standard solutions to calculate recoveries. The obtained data indicates that the suggested method can be employed as a robust and accurate tool for SPME analysis of alcoholic products with low ethanol content, such as wines. It was also observed that an increase in ethanol content in the matrix affects the accuracy of the “Ethanol as IS” method, potentially due to non-linearity of analyte extraction. However, in the case of wine sample, the “Ethanol as IS” method showed significantly better results compared to the traditional approach. The precision of the suggested method, evaluated using relative standard deviations (RSD) of obtained concentrations was found to be comparable to that of the traditional method.Graphical abstract

Green recovery optimization of phenolic compounds from “Spinoso sardo” globe artichoke by-products using response surface methodology

The reuse and valorization of agri-food by-products is a pivotal activity in the pursuit of a circular model that can improve sustainability and efficiency of agri-food production. During artichoke processing, 60–80% of the biomass produced by the plant consists of inedible fractions, which nevertheless represent a natural source of high value-added compounds, such as phenolics. In this study, response surface methodology was applied to investigate and optimize the amount of ethanol and the reduction of extraction time to achieve the maximum yield of polyphenols and flavonoids from artichoke stems, leaves, and bracts, by using two extraction methods, namely maceration and ultrasound-assisted extraction. Overall, phenolic compounds were most concentrated in extracts obtained from the stems, followed by those derived from the bracts and leaves, with the percentage of ethanol being the most influential factor. After applying the optimization criteria, the best factor setting to achieve maximum extraction yields and strong antioxidant capacities was: 53% ethanol for stems, 45% for leaves, and 50% for bracts and 60 min for all by-products in the case of maceration; 10 min for stems and leaves with 42 and 20% of ethanol, respectively, and 41 min and 64% ethanol for bracts in the case of ultrasound-assisted extraction. Comparison between the two techniques evidenced that maceration was significantly more efficient, but similar recoveries were obtained with ultrasound-assisted extraction in shorter extraction time and lower ethanol consumption. Therefore, using this unconventional method to convert Spinoso Sardo artichoke by-products into bioactive ingredients with interesting industrial applications could be a viable strategy to reduce food losses and mitigate related environmental impacts.

Microwave Grooved SRR Sensor for Detecting Low Concentration Ethanol-Blended Petrol

The rise in global energy demand due to economic development and an increase in population, have posed major concerns regarding energy security and environmental impact. Ethanol-blended petrol is an emerging alternative fuel that is considered cost-effective and environmentally friendly. However, the detection of low concentrations of ethanol in petrol is a significant challenge, especially as most nations mandate the blending of petrol with 5%-25% ethanol. This paper proposes a microwave sensor operating at 2.4GHz ISM band frequency to detect low concentrations of ethanol in petrol. The change in the magnitude of the reflection coefficient is adopted as the main sensing parameter. A single-frequency sensor composed of a square-shaped monopole loop antenna embedded with an SRR is proposed, which avoids the need for a wideband interrogation signal. The proposed design utilizes a filter paper wetted with the ethanol-petrol solution, placed along the split edge of the SRR, thus the use of complex and costly fluidic channels and space-consuming sample holders is avoided, bringing down the cost and complexity. The device dimensions are small, 4.2cm x 4.5cm. The sensitivity achieved in terms of amplitude change of the reflection coefficient is 2.83dB/5 % change of ethanol concentration in petrol, at a fixed frequency. In terms of the received power at 2.4GHz, the sensitivity is 2dBm/5 % change of ethanol concentration. Overall, this proposed sensor offers a simple, cost-effective, and efficient solution for detecting low concentrations of ethanol in petrol, which can aid in the adoption of ethanol-blended petrol as a viable alternative fuel.

Natural allelic variation modifies acute ethanol response phenotypes in wild strains of C. elegans.

Genetic variation contributes to the likelihood that an individual will develop an alcohol use disorder (AUD). Traditional laboratory studies in animal models have elucidated the molecular pharmacology of ethanol, but laboratory-derived genetic manipulations rarely model the naturally occurring genetic variation observed in wild populations. Rather, these manipulations are biased toward identifying genes of central importance in the phenotypes. Because changes in such genes can confer selective disadvantages, they are not ideal candidates for carrying AUD risk alleles in humans. We sought to exploit Caenorhabditis elegans to identify allelic variation existing in the wild that modulates ethanol response behaviors. We tested the acute ethanol responses of four strains recently isolated from the wild (JU1511, JU1926, JU1931, and JU1941) and 41 multiparental recombinant inbred lines (mpRILs) derived from them. We assessed locomotion at 10, 30, and 50 min on low and high ethanol concentrations. We performed principal component analyses (PCA) on the different phenotypes, tested for transgressive behavior, calculated heritability, and determined the correlations between behavioral responses. We observed a range of responses to ethanol across the strains. We detected a low-concentration locomotor activation effect in some of the mpRILs not seen in the laboratory wild-type strain. PCA showed different ethanol response behaviors to be independent. We observed transgressive behavior for many of the measured phenotypes and found that multiple behaviors were uncorrelated. The average broad-sense heritability for all phenotypes was 23.2%. Genetic variation significantly affects multiple acute ethanol response behaviors, many of which are independent of one another. This suggests that the genetic variation captured by these strains likely affects multiple biological mechanisms through which ethanol acts. Further study of these strains may allow these distinct mechanisms to be identified.

Comparison of marine and rushton impeller in high solid loading of two-step pretreated oil palm trunk using simultaneous saccharification and fermentation for ethanol production

Substrate loading enhancement in fermenter generates difficulty in mixing that results in low ethanol yield owing to insufficient mass transfer. Thus, this study evaluated the efficiency of a six-blade Rushton turbine and a three-blade marine type propeller in a 3 L stirred tank bioreactor (STBR) by using steam exploded and alkaline pretreated oil palm trunk (OPT) fibers in a unique batch and fed-batch strategy. The fed-batch began with 5% (w/v) solid loading and after 12 h of simultaneous saccharification and fermentation (SSF) reaction, 2.5% (w/v) solid was added in the bioreactor with 6 h interval. The marine and Rushton impellers were compared at 5% (w/v) batch and 20% (w/v) fed-batch SSF, using agitation rate of 100 rpm. At 5% (w/v) solid loading, the highest ethanol concentration and theoretical yield were 15.66 ± 1.71 g/L and 61.69 ± 2.34%, and 12.10 ± 0.98 g/L and 54.01 ± 3.52%, respectively for marine and Rushton impeller. At high solid loading (20% w/v), the marine impeller achieved maximum ethanol concentration of 41.33 ± 2.02 g/L at 72 h of fermentation, with a low power consumption of 54.73 kW. The Rushton impeller resulted in ethanol concentration of 39.08 ± 1.47 g/L at 96 h of fermentation with relatively higher power consumption of 83.62 kW. The marine impeller is therefore efficient with the fed-batch strategy.

Surface plasmon resonance imaging for analyzing the local variation of evaporation flux of multiple binary mixture droplets

This study investigates the local variation of concentration and selective evaporation flux affected by the droplet-to-droplet distance during the evaporation of multiple-binary mixture droplets (M-BMDs). Surface plasmon resonance imaging (SPRi) is used to measure the local liquid concentration of the binary mixture droplets and to analyze the spatial distributions of liquid concentration with the estimated local changes of surface tension during evaporation. In addition, we conduct three-dimensional numerical simulations to predict the ethanol vapor distributions and the local ethanol evaporation flux for single- and multiple-binary mixture droplets. It was found that the total evaporation time of M-BMDs is delayed due to vapor accumulation in the region adjacent to the neighboring droplets for M-BMDs, which significantly reduces the local evaporation flux. Also, the local liquid concentration of M-BMDs was found to vary, showing a lower ethanol concentration far away from the adjacent region due to vapor shielding and selective evaporation. Moreover, the scaled lifetime, which is the ratio of evaporation time between multiple droplets and a single droplet, shows good agreement with the previously reported experiments and theoretical models.

Development of invaethosomes and invaflexosomes for dermal delivery of clotrimazole: optimization, characterization and antifungal activity

The objective of this study was to develop novel invaethosomes (I-ETS) and invaflexosomes (I-FXS) to enhance the dermal delivery of clotrimazole (CZ). Twenty model CZ-loaded I-ETS and I-FXS formulations were created according to a face-centered central composite experimental design. CZ-loaded vesicle formulations containing a constant concentration of 0.025% w/v CZ and various amounts of ethanol, d-limonene, and polysorbate 20 as penetration enhancers were prepared using the thin film hydration method. The physicochemical characteristics, skin permeability, and antifungal activity were characterized. The skin permeability of the experimental CZ-loaded I-ETS/I-FXS was significantly higher than that of conventional ethosomes, flexosomes, and the commercial product (1% w/w CZ cream). The mechanism of action was confirmed to be skin penetration of low ethanol base vesicles through the disruption of the skin microstructure. The optimal I-ETS in vitro antifungal activity against C. albicans differed significantly from that of ETS and the commercial cream (control). The response surface methodology predicted by Design Expert® was helpful in understanding the complicated relationship between the causal factors and the response variables of the 0.025% w/v CZ-loaded I-ETS/I-FXS formulation. Based on the available information, double vesicles seem to be promising versatile carriers for dermal drug delivery of CZ.

Physicochemical parameters, sensory profile and concentration of volatile compounds and anthocyanins in beers brewed using potato variety with purple flesh

In the recent years, beer brewers are experimenting with using various substrates, other than traditional barley malt, water, hops, and yeast for beer production, because new adjuncts to the beer brewing can add new sensory and functional properties to this beverage. Novel potatoes with purple or red-colour flesh are a good and cheap starch source and are rich in bioactive components, which could increase the nutritive value of the produced beer. The aim of the study was to determine whether some part of barley malt can be replaced by the potatoes of purple-colour flesh and assessment of properties of such beer. Beer samples showed increased antioxidant activity, higher concentration of anthocyanins and polyphenol compounds, as well as modified composition of volatiles and lower ethanol content. Beer produced with the addition of 30% of purple potatoes showed acceptable organoleptic qualities in the sensory analysis.

The Impact of Nigella sativa Essential Oil on T Cells in Women with Hashimoto's Thyroiditis.

Hashimoto's thyroiditis (HT) is an autoimmune disease mediated by T cells. It is characterized by the presence of thyroid autoantibodies in the serum, such as anti-thyroid peroxidase antibodies (TPO-Ab) and anti-thyroglobulin antibodies (TG-Ab). The essential oil extracted from Nigella sativa seeds is rich in bioactive substances, such as thymoquinone and cymene. Therefore, we examined the effect of essential oil from Nigella sativa (NSEO) on T cells from HT patients, especially their proliferation capacity, ability to produce cytokines, and susceptibility to apoptosis. The lowest ethanol (EtOH) dilution (1:10) of NSEO significantly inhibited the proliferation of CD4+ and CD8+ T cells from HT patients and healthy women by affecting the percentage of dividing cells and the number of cell divisions. In addition, 1:10 and 1:50 NSEO dilutions induced cell death. Different dilutions of NSEO also reduced the concentration of IL-17A and IL-10. In healthy women, the level of IL-4 and IL-2 significantly increased in the presence of 1:10 and 1:50 NSEO dilutions. NSEO did not influence the concentration of IL-6 and IFN-γ. Our study demonstrates that NSEO has a strong immunomodulatory effect on the lymphocytes of HT patients.

A comparison on the binding mechanisms of zein and gliadin with curcumin to guide the self-assembly of nanoparticles for delivery purpose

Using prolamins to prepare delivery systems is promising for pharmaceutical and food industries. It is very necessary to find a reliable strategy to probe the assembly-release mechanisms of prolamin-based delivery systems, which could accelerate the screening of fabrication conditions. In this study, interactions of zein and gliadin with curcumin at different temperatures and ethanol concentrations was investigated by fluorescence quenching and other spectroscopic methods. It was found that the binding affinity between curcumin and gliadin gradually decreased with increasing ethanol concentration, but that of curcumin-zein gradually increased with increasing ethanol concentration. Zein and gliadin showed highest binding constant values (Ka) of 2.29 × 105 L mol−1 at 80% ethanol and 293K, 2.0 × 105 L mol−1 at 60% ethanol and 293 K, respectively. The temperature-dependent thermodynamic parameters were calculated. And the main driven forces were determined to be electrostatic interactions for gliadin-curcumin complexation, while van der Waals forces and hydrogen bonding were also involved in the binding of zein with curcumin in low ethanol conditions (60–70%). The curcumin-encapsulated zein/gliadin nanoparticles were prepared at various conditions, and their physicochemical properties were compared. The highest EE and LC values of zein nanoparticles were observed at 80% ethanol (95.8% and 19.2 μg/mg), while those of gliadin were observed at 60% ethanol (95.7% and 19.1 μg/mg). The change of encapsulation efficiency and loading capacity of nanoparticles was basically consistent with the binding affinity tendency between curcumin and zein/gliadin, confirming that the fluorescence quenching method is applicable to guide the screening of encapsulants and fabrication conditions.

Effect of a low ethanol concentration during in vitro maturation of bovine oocytes and subsequent embryo development

The present study investigated the effects of low ethanol exposure on bovine oocytes. Cumulus-oocyte complexes (COCs) were aspirated for the antral follicles of slaughterhouse-derived ovaries. These COCs were incubated in maturation medium containing 0, 0.1, and 0.2% ethanol for 21 h and subjected to fertilization and in vitro development, and then the rates of nuclear maturation, mitochondrial DNA copy number (Mt-cn) and protein (TOMM40), ATP content and lipid content in oocyte, fertilization, and blastulation were examined. Furthermore, COCs were incubated with 0 or 0.1% ethanol and then mitochondrial membrane potential (MMP) and the glucose consumption of COCs was determined. In addition, gene expression in oocytes was examined by RNA sequencing. Ethanol (0.1 and 0.2%) increased Mt-cn and Mt-protein levels whereas 0.2% ethanol increased the blastulation rate and ATP content in oocytes and decreased lipid content in oocytes. Ethanol (0.1%) increased MMP in oocytes and decreased glucose consumption of COCs. Eight stage embryos derived from 0.1% ethanol treated oocytes had higher levels of trimethyl-H3K9 compared with that of nontreated counterpart. RNA sequencing revealed that differentially expressed genes were associated with glycolysis/gluconeogenesis, carbon metabolism, sphingolipid metabolism, amino acid metabolism, and fatty acid degradation pathways. In conclusion, even 0.1% concentrations of ethanol during in vitro maturation considerably affects oocyte metabolism and histone configuration of embryos.

Binary Mixture Droplet Evaporation on Microstructured Decorated Surfaces and the Mixed Stick-Slip Modes.

The interactions between liquid droplets and solid surfaces during wetting and phase change are important to many applications and are related to the physicochemical properties of the substrate and the fluid. In this work, we investigate experimentally the evaporation of pure water, pure ethanol, and their binary mixture droplets, accessing a wide range of surface tensions, on hydrophobic micro-pillared surfaces varying the spacing between the pillars. Results show that on structured surfaces, droplets evaporate following three classical evaporative behaviors: constant contact radius/pinning, stick-slip, or mixed mode. In addition, we report two further droplet evaporation modes, which are a mixed stick-slip mode where the contact angle increases while the contact radius decreases in a stick-slip fashion and a mixed stick-slip mode where both the contact angle and the contact radius decrease in a stick-slip fashion. We name these evaporation modes not yet reported in the literature as the increasing and decreasing contact angle mixed stick-slip modes, respectively. The former ensues because the fluid surface tension increases as the most volatile fluid evaporates coupled to the presence of structures, whereas the latter is due to the presence of structures for either fluid. The duration of each evaporation mode is dissimilar and depends on the surface tension and on the spacing between structures. Pure water yields longer initial pinning times on all surfaces before stick-slip ensues, whereas for binary mixtures and pure ethanol, initial pinning ensues mainly on short spacing structures due to the different wetting regimes displayed. Meanwhile, mixed stick-slip modes ensue mainly for high ethanol concentrations and/or pure ethanol independent of the solid fraction and for low ethanol concentrations on large spacing. Contact line jumps, changes in contact angle and pinning forces are also presented and discussed. This investigation provides guidelines for tailoring the evaporation of a wide range of surface tension fluids on structured surfaces for inkjet printing, DNA patterning, or microfluidics applications.

Enhancing electrochemical performance and membrane stability evaluation of carrageenan/polyvinyl alcohol-graphene oxide membrane in passive DEFCs

A good electrochemical performance of polymer electrolyte membranes (PEMs) is achieving high membrane selectivity, which is a result of low ethanol permeability and high proton conductivity. Reducing the thickness of PEMs is beneficial for high proton conductivity due to the short distance of proton diffusion. Unfortunately, it results in high ethanol permeability. Thus, achieving high membrane selectivity for good electrochemical performance by balancing the requirements of ethanol permeability and proton conductivity is a critical parameter of PEMs. In this paper, the thickness of the carrageenan/polyvinyl alcohol-graphene oxide membrane was varied from 15 μm – 30 μm to identify the optimum thickness for good electrochemical performance. With a 25 μm membrane thickness, the highest membrane selectivity was performed at 1.609 × 104 S s cm−3, and maximum power density in passive direct ethanol fuel cells was achieved at 14.5 mW cm−2, using 2.0 mg cm−2 anode catalyst loading and 2 M ethanol concentration at 70 °C, respectively. Furthermore, this membrane has sustained electrochemical performance for 1000 h at 70 °C without degrading the membrane stability.

Elevated O2 alleviated anaerobic metabolism in postharvest winter jujube fruit by regulating pyruvic acid and energy metabolism

Over-accumulation of anaerobic metabolites is a typical characteristic of postharvest senescence in winter jujube fruit. Here, elevated O2 was applied during cold storage to investigate its regulation on anaerobic respiration. The results found 60 % O2 was the optimal concentration to inhibit anaerobic respiration, which showed 83.82 % lower acetaldehyde and 57.13 % lower ethanol compared with control. Elevated O2 maintained energy status by activating succinate dehydrogenase and cytochrome C oxidase, with 1.11-fold higher energy charge observed as compared with the control. In addition, activated aerobic respiration also accelerated the consumption of pyruvic acid, and pyruvic acid content was reduced by 63 % in elevated O2-treated fruit. Sufficient energy supply and reduced pyruvic acid content in elevated O2-treated fruit induced the alleviation of anaerobic respiration, leading to attenuating the accumulation of ethanol and acetaldehyde as a result. The study proved elevated O2 repressed anaerobic metabolism by regulating pyruvic acid level and energy metabolism.

Identification and assessment of non-conventional yeasts in mixed fermentations for brewing bioflavored beer

The increasing demand for more flavored and complex beers encourages the investigation of novel and non-conventional yeasts with the ability to provide a combination of bioflavoring and low ethanol yields. The present study identified 22 yeasts isolated from different brewing sources, including the fermentation by-products known as yeast sludges, and characterized a selection of strains to find the more suitable for the aforementioned aims. HPLC and GC-FID analysis of its brewing products were performed.The most promising results were obtained with the non-conventional yeasts Pichia kudriavzevii MBELGA61 and Meyerozyma guilliermondii MUS122. The former, isolated from a Belgian wheat beer sludge, was capable of growing in wort (17.0°Bx., 20 °C) with very low ethanol yields (1.19 % v/v). Besides, upon mixed fermentations with Saccharomyces cerevisiae, was suitable to produce volatile compounds such as ethyl acetate, 2-phenyl ethanol and isoamyl alcohol, with characteristic fruity notes. M. guilliermondii MUS122, isolated from a golden ale beer sludge, partially attenuated the wort with low production of ethanol and biomass. In addition, provided some fruity and floral nuances to the aroma profile of mixed fermentations with brewer's yeast.The results suggest that these strains favor the development of more fruity-flowery aroma profiles in beers. Furthermore, they are suitable for use in mixed fermentations with Saccharomyces brewer's strains, although the ethanol level did not decrease significantly.

Self-Polarization Triggered Multiple Polar Units Toward Electrochemical Reduction of CO2 to Ethanol with High Selectivity.

Electrochemical conversion of CO2 to highly valuable ethanol has been considered a intriguring strategy for carbon neutruality. However, the slow kinetics of coupling carbon-carbon (C-C) bonds, especially the low selectivity ethanol than ethylene in neutral conditions, is a significant challenge. Herein, the asymmetrical refinement structure with enhanced charge polarization is built in the vertically oriented bimetallic organic frameworks (NiCu-MOF) nanorod array with encapsulated Cu2 O (Cu2 O@MOF/CF), which can induce an intensive internal electric field to increase the C-C coupling for producing ethanol in neutral electrolyte. Particularly, when directly employed Cu2 O@MOF/CF as the self-supporting electrode, the ethanol faradaic efficiency (FEethanol ) could reach maximum 44.3 % with an energy efficiency of 27 % at a low working-potential of -0.615 V versus the reversible hydrogen electrode (vs. RHE) using CO2 -saturated 0.5 M KHCO3 as the electrolyte. Experimental and theoretical studies suggest that the polarization of atomically localized electric fields derived from the asymmetric electron distribution can tune the moderate adsorption of *CO to assist the C-C coupling and reduce the formation energy of H2 CCHO*-to-*OCHCH3 for the generation of ethanol. Our research offers a reference for the design of highly active and selective electrocatalysts for reducing CO2 to multicarbon chemicals.

Self‐Polarization Triggered Multiple Polar Units Toward Electrochemical Reduction of CO2 to Ethanol with High Selectivity

AbstractElectrochemical conversion of CO2 to highly valuable ethanol has been considered a intriguring strategy for carbon neutruality. However, the slow kinetics of coupling carbon‐carbon (C−C) bonds, especially the low selectivity ethanol than ethylene in neutral conditions, is a significant challenge. Herein, the asymmetrical refinement structure with enhanced charge polarization is built in the vertically oriented bimetallic organic frameworks (NiCu‐MOF) nanorod array with encapsulated Cu2O (Cu2O@MOF/CF), which can induce an intensive internal electric field to increase the C−C coupling for producing ethanol in neutral electrolyte. Particularly, when directly employed Cu2O@MOF/CF as the self‐supporting electrode, the ethanol faradaic efficiency (FEethanol) could reach maximum 44.3 % with an energy efficiency of 27 % at a low working‐potential of −0.615 V versus the reversible hydrogen electrode (vs. RHE) using CO2‐saturated 0.5 M KHCO3 as the electrolyte. Experimental and theoretical studies suggest that the polarization of atomically localized electric fields derived from the asymmetric electron distribution can tune the moderate adsorption of *CO to assist the C−C coupling and reduce the formation energy of H2CCHO*‐to‐*OCHCH3 for the generation of ethanol. Our research offers a reference for the design of highly active and selective electrocatalysts for reducing CO2 to multicarbon chemicals.

Experimental and in silico simulation of slot-die coating with a polymer electrolyte fuel cell catalyst slurry

The causes of coating irregularities in high-speed slot-die coating of catalyst slurries for polymer electrolyte fuel cells (PEFCs) have not been determined. Accordingly, in this study, slot-die-coating experiments and computer simulations of two-phase gas–liquid flow were conducted to explore coating instability in the high-speed coating of PEFC catalyst slurries applied through slot-die coating. The results obtained from experiments and simulations were consistent. A thinner target layer and a faster coating, causing non-uniform coating. This is caused by movement of the gas–liquid interface on the upstream side and side of the die, which entraps the gas phase. Viscosity and surface tension are important, and a lower ethanol content in the solvent increases surface tension and lowers viscosity, improving coating stability.

Boosting Catalytic Combustion of Ethanol by Tuning Morphologies and Exposed Crystal Facets of α-Mn2O3

Three types of α-Mn2O3 catalysts with different well-defined morphologies (cubic, truncated octahedra and octahedra) and exposed crystal facets have been successfully prepared via hydrothermal processes, and evaluated for ethanol total oxidation with low ethanol concentration at low temperatures. The α-Mn2O3-cubic catalyst shows a superior catalytic reaction rate than that of α-Mn2O3-truncated octahedra and α-Mn2O3-octahedra under high space velocity of 192,000 mL/(g·h). Based on the characterization results obtained from XRD, BET, FE-SEM, HR-TEM, FT-IR, H2-TPR, XPS, ethanol-TPD, and CO-TPSR techniques, the observed morphology-dependent reactivity of α-Mn2O3 catalysts can be correlated to the good low-temperature reducibility, abundant surface Mn4+ and adsorbed reactive oxygen species, which was originated from the exposed (001) crystal planes. Through tuning the morphology and exposed (001) crystal facet of α-Mn2O3, a highly active ethanol oxidation catalyst with high selectivity and excellent stability is obtained. The developed approach may be applied broadly to the development of the design principles for high-performance low-cost and environmentally friendly Mn-based oxidation catalysts.

Impact of yeast on the characteristics of Sauvignon Blanc wines from the Campanha Gaúcha Region

The objective of this work was to evaluate the effect of different commercial strains of Saccharomyces cerevisiae on the characteristics of Sauvignon Blanc wines produced in the Campanha Gaúcha region. The must obtained by mechanical destemming and crushing was treated with 150 mg L of potassium metabisulfite and pectolitic enzymes and subject to enzymatic hidrolisis and débourbage for 24h00 at 4°C. The must was divided into glass fermenters of 4,6 L, in triplicate for each of the four treatments, which were defined by the inoculation of 25g hL-1 of dry yeast: T1 - Zymaflore X5® (Laffort, Bordeaux, France); T2 - AWRI 796 (AB Biotek, Sydney, Australia); T3 - Maurivim PDM (AB Biotek, Sydney, Australia); T4 - 50% Zymaflore X5® + 50% AWRI 796. The wines were analyzed, regarding: ethanol; reducing sugars; total acidity; volatile acidity; pH; dry matter; and ash. The most significant differences were observed in: ethanol; reducing sugars; pH; dry matter. Among the treatments inoculated with single strains, T1 showed higher ethanol and lower reducing sugars content. T3 presented results similar to T1. T2 resulted in higher content of reducing sugars and consequently lower ethanol levels. The mixed fermentation (T4) achieved the lowest levels of reducing sugars among the treatments. It suggests that mixed fermentations could be an alternative to produce drier wines.