933 resultados para Ethanol concentrations


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Neste trabalho, avaliou-se a fermentação da cana-de-açúcar queimada, ensilada com ou sem uso de aditivo seco. Os tratamentos (seis no total) consistiram da silagem de cana crua ou queimada, adicionada de 0, 50 ou 100 g/kg de milho desintegrado com palha e sabugo (MDPS), com base no peso verde da forragem. Foram determinados os teores de MS, PB, nitrogênio insolúvel em detergente ácido (NIDA), FDN, FDA, celulose, hemicelulose e lignina. Na avaliação das características fermentativas, foram determinados os valores de carboidratos solúveis, o poder tamponante, o pH e as concentrações de nitrogênio amoniacal e etanol. Como características microbiológicas, avaliou-se o desenvolvimento de leveduras. A inclusão de MDPS elevou os teores de MS e reduziu discretamente os teores de N-NH3 e etanol das silagens, não ocasionando efeito nos valores de pH e na população de leveduras. A presença do fogo reduziu a concentração de MS das silagens, elevou os teores de etanol e leveduras e diminuiu os teores de N-NH3. A fermentação etanólica durante a ensilagem não foi controlada com a inclusão de aditivo seco ou com o uso do fogo.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The effect of four extracts from neem seeds (Azadirachta indica) containing 2000, 5000, 9000 and 10,000 ppm of azadirachtin A (AZA), quantified by high-performance liquid chromatography (HPLC) and diluted to 1.25%; 2.5%; 5.0%; 10.0% and 12.8% was verified by in vitro tests with engorged females and larvae of the cattle tick Rhipicephalus micro plus. The results from the bioassays with the engorged females showed that the main toxic effect of the extracts was reduction of the reproductive parameters, with a sharp drop in the number of eggs laid and the hatching rate, mainly when the extracts were diluted to 10.0% and 12.8%. The product effectiveness (PE) calculations for all the solutions tested showed that the AZA solution at 10,000 ppm (N10) was the most effective. However, statistical analysis of the PE data obtained for the proportional AZA concentrations in the different diluted extracts showed significance (P<0.05) of the effects included in the model (extract dilution, principle effect (classificatory) of the assay (extract) and the interaction between the two), indicating significant variations due to the dilution, the test and the interaction between the two factors in the tests with engorged females. For solutions N2, N5, and N9, it was not possible to estimate LC(90) values in the dilution range tested. The lowest LC(50) was observed for extract N5, and although extract N10 was the only extract for which the LC(90) could be estimated within the range tested, the LC(50) was higher than for N5 and N9. These results suggest that substances other than AZA present in the extracts influenced the efficacy, especially up to a certain LC range. In the tests with larvae, no mortality was observed, indicating zero effectiveness of all the extracts tested. The results of the tests with engorged females showed that the neem extracts had acaricide activity, inhibiting egg laying and the larval hatching rate. Complementary studies are necessary to develop new methods to isolate and/or identify other substances besides AZA contained in this plant, to enable using products made from it as acaricides. (C) 2011 Elsevier B.V. All rights reserved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The plants belonging to Pfaffia genus are used in folk medicine to treat gastric disturbances. This study examined the effects of an aqueous extract of Pfaffia glomerata (Spreng) Pedersen (AEP) on the gastrointestinal tract. Wistar rats were pretreated orally (p.o.) with the AEP (125, 250, 500 and 1000 mg.kg(-1)) before induction of ulcers by hypothermic restraint stress (HRS, 3 h restraint stress at 4 degreesC), ethanol (ET, 70%; 0.5 ml/animal; p.o.) or indomethacin (IND, 20 mg.kg(-1); s.c.). Control animals received water (C) or ranitidine (60 mg.kg(-1)) p.o. The AEP protected rats against HRS and ET-induced ulcers, but was not able to protect the gastric mucosa against IND-induced ulcers. When injected into the duodenal lumen, the AEP reduced total acidity and both basal and histamine-stimulated acid secretion in pylorus-ligated rats. In addition, gastric secretion from AEP-treated animals exhibited increased concentrations of nitrite and nitrate. Treatment of animals with L-NAME (120 mg.kg(-1), p.o.) prevented both the reduction of total acidity and the increase in NO, levels promoted by AEP treatment. In conclusion, AEP effectively protected the gastric mucosa and inhibited gastric acid secretion in rats, probably by involving the histaminergic pathway and an enhanced production of nitric oxide in the stomach. (C) 2003 Elsevier B.V. All rights reserved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Agaricus blazei Murill is a medicinal mushroom native to Brazil. The present work assessed the clastogenic and anticlastogenic potential of organic extracts (ethanol and chloroform/methanol) from the lineage AB97/11 in chinese hamster CHO-K-1 (wild type) and CHO-xrs5 (repair deficient) cells using the chromosome aberration (CA) and sister chromatid exchange (SCE) assays. In these experimental conditions were observed: (a) anticlastogenic effect at concentrations of 0.06 and 0.09% of the EtOH extract and at the 0.03 and 0.06% concentrations of the C/MetOH extract in CHO-K-1; (b) absence of protector effect on CHO-xrs5 cells; and (c) absence of protector effect in the SCE assay. These results indicate that organic extracts of A. blazei lineage AB97/11 present bio-antimutagenic type protective activity. (C) 2003 Elsevier B.V. B.V. All rights reserved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The liquid of the rind of green coconut (LCCV), an effluent stream from the industrial processing of green coconut rind, is rich in sugars and is a suitable feedstock for fermentation. The first step of this study was to evaluate the potential of natural fermentation of LCCV. As the literature did not provide any information about LCCV and due to the difficulty of working with such an organic effluent, the second step was to characterize the LCCV and to develop a synthetic medium to explore its potential as a bioprocess diluent. The third step was to evaluate the influence of initial condensed and hydrolysable tannins on alcoholic fermentation. The last step of this work was divided into several stages: in particular to evaluate (1) the influence of the inoculum, temperature and agitation on the fermentation process, (2) the carbon source and the use of LCCV as diluent, (3) the differences between natural and synthetic fermentation of LCCV, in order to determine the best process conditions. Characterization of LCCV included analyses of the physico-chemical properties as well as the content of DQO, DBO and series of solids. Fermentation was carried out in bench-scale bioreactors using Saccharomyces cerevisiae as inoculum, at a working volume of 5L and using 0.30% of soy oil as antifoam. During fermentations, the effects of different initial sugars concentrations (10 - 20%), yeast concentrations (5 and 7.5%), temperatures (30 - 50°C) and agitation rates (400 and 500 rpm) on pH/sugars profiles and ethanol production were evaluated. The characterization of LCCV demonstrated the complexity and variability of the liquid. The best conditions for ethanol conversion were (1) media containing 15% of sugar; (2) 7.5% yeast inoculum; (3) temperature set point of 40°C and (4) an agitation rate of 500 rpm, which resulted in an ethanol conversion rate of 98% after 6 hours of process. A statistical comparison of results from natural and synthetic fermentation of LCCV showed that both processes are similar

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The decontamination of the materials has been subject of some studies. One of the factors that it increases the pollution is the lack of responsibility in the discarding of toxic trash, as for example the presence of PCB (Polychlorinated Biphenyls) in the environment. In the Brazilian regulations, the material contaminated with PCB in concentrations higher than 50 ppm must be stored in special places or destroyed, usually by incineration in plasma furnace with dual steps. Due to high cost of the procedure, new methodologies of PCBs removal has been studied. The objective of this study was to develop an experimental methodology and analytical methodology for quantification of removal of PCBs through out the processes of extractions using supercritical fluid and Soxhlet method, also technical efficiency of the two processes of extraction, in the treatment of contaminated materials with PCBs. The materials studied were soils and wood, both were simulated contamination with concentration of 6.000, 33.000 and 60.000 mg of PCB/ kg of materials. Soxhlet extractions were performed using 100 ml of hexane, and temperature of 180 ºC. Extractions by fluid supercritical were performed at conditions of 200 bar, 70°C, and supercritical CO2 flow-rate of 3 g/min for 1-3 hours. The extracts obtained were quantified using Gas chromatography-mass spectrometry (GC/MS). The conventional extractions were made according to factorial experimental planning technique 22, with aim of study the influence of two variables of process extraction for the Soxhlet method: contaminant concentration and extraction time for obtain a maximum removal of PCB in the materials. The extractions for Soxhlet method were efficient for extraction of PCBs in soil and wood in both solvent studied (hexane and ethanol). In the experimental extraction in soils, the better efficient of removal of PCBs using ethanol as solvent was 81.3% than 95% for the extraction using hexane as solvent, for equal time of extraction. The results of the extraction with wood showed statistically it that there is not difference between the extractions in both solvent studied. The supercritical fluid extraction in the conditions studied showed better efficiency in the extraction of PCBs in the wood matrix than in soil, for two hours extractions the obtain percentual of 43.9 ± 0.5 % for the total of PCBs extracted in the soils against 95.1 ± 0,5% for the total of PCBs extracted in the wood. The results demonstrated that the extractions were satisfactory for both technical studied

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Polymer particles in the nanometer range are of fundamental interest today, especially when used as carrier systems in the controlled release of drugs, cosmetics and nutraceuticals, as well as in coating materials with magnetic properties. The main objective of the present study concerns the production of submicron particles of poly (methyl methacrylate) (PMMA) by crystallization of a polymer solution by thermally controlled cooling. In this work, PMMA solutions in ethanol and 1-propanol were prepared at different concentrations (1% to 5% by weight) and crystallized at different cooling rates (0.2 to 0.8 ° C / min) controlled linearly. Analysis of particle size distribution (DLS / CILAS) and scanning electron microscopy (SEM) were performed in order to evaluate the morphological characteristics of the produced particles. The results demonstrated that it is possible to obtain submicron polymer perfectly spherical particles using the technique discussed in this study. It was also observed that, depending on the cooling rate and the concentration of the polymer solution, it is possible to achieve high yield in the formation of submicron particles. In addition, preliminary tests were performed in order to verify the ability of this technique to form particulated carrier material with magnetic properties. The results showed that the developed technique can be an interesting alternative to obtain polymer particles with magnetic properties

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Recently, global demand for ethanol fuel has expanded very rapidly, and this should further increase in the near future, almost all ethanol fuel is produced by fermentation of sucrose or glucose in Brazil and produced by corn in the USA, but these raw materials will not be enough to satisfy international demand. The aim of this work was studied the ethanol production from cashew apple juice. A commercial strain of Saccharomyces cerevisiae was used for the production of ethanol by fermentation of cashew apple juice. Growth kinetics and ethanol productivity were calculated for batch fermentation with different initial sugar (glucose + fructose) concentration (from 24.4 to 103.1 g.L-1). Maximal ethanol, cell and glycerol concentrations (44.4 g.L-1, 17.17 g.L-1, 6.4 g.L-1, respectively) were obtained when 103.1 g.L-1 of initial sugar concentration were used, respectively. Ethanol yield (YP/S) was calculated as 0.49 g (g glucose + fructose)-1. Pretreatment of cashew apple bagasse (CAB) with dilute sulfuric acid was investigated and evaluated some factors such as sulfuric acid concentration, solid concentration and time of pretreatment at 121°C. The maximum glucose yield (162.9 mg/gCAB) was obtained by the hydrolysis with H2SO4 0.6 mol.L-1 at 121°C for 15 min. Hydrolysate, containing 16 ± 2.0 g.L-1 of glucose, was used as fermentation medium for ethanol production by S. cerevisiae and obtained a ethanol concentration of 10.0 g.L-1 after 4 with a yield and productivity of 0.48 g (g glucose)-1 and 1.43 g.L-1.h-1, respectively. The enzymatic hydrolysis of cashew apple bagasse treated with diluted acid (CAB-H) and alkali (CAB-OH) was studied and to evaluate its fermentation to ethanol using S. cerevisiae. Glucose conversion of 82 ± 2 mg per g CAB-H and 730 ± 20 mg per g CAB-OH was obtained when was used 2% (w/v) of solid and loading enzymatic of 30 FPU/g bagasse at 45 °C. Ethanol concentration and productivity was achieved of 20.0 ± 0.2 g.L-1 and 3.33 g.L-1.h-1, respectively when using CAB-OH hydrolyzate (initial glucose concentration of 52.4 g.L-1). For CAB-H hydrolyzate (initial glucose concentration of 17.4 g.L-1), ethanol concentration and productivity was 8.2 ± 0.1 g.L-1 and 2.7 g.L-1.h-1, respectively. Hydrolyzates fermentation resulted in an ethanol yield of 0.38 g/g glucose and 0.47 g/g glucose, with pretreated CABOH and CAB-H, respectively. The potential of cashew apple bagasse as a source of sugars for ethanol production by Kluyveromyces marxianus CE025 was evaluated too in this work. First, the yeast CE025 was preliminary cultivated in a synthetic medium containing glucose and xylose. Results showed that it was able to produce ethanol and xylitol at pH 4.5. Next, cashew apple bagasse hydrolysate (CABH) was prepared by a diluted sulfuric acid pre-treatment. The fermentation of CABH was conducted at pH 4.5 in a batch-reactor, and only ethanol was produced by K. marxianus CE025. The influence of the temperature in the kinetic parameters was evaluated and best results of ethanol production (12.36 ± 0.06 g.L-1) was achieved at 30 ºC, which is also the optimum temperature for the formation of biomass and the ethanol with a volumetric production rate of 0.25 ± 0.01 g.L-1.h-1 and an ethanol yield of 0.42 ± 0.01 g/g glucose. The results of this study point out the potential of the cashew apple bagasse hydrolysate as a new source of sugars to produce ethanol by S. cerevisiae and K. marxianus CE025. With these results, conclude that the use of cashew apple juice and cashew apple bagasse as substrate for ethanol production will bring economic benefits to the process, because it is a low cost substrate and also solve a disposal problem, adding value to the chain and cashew nut production

Relevância:

20.00% 20.00%

Publicador:

Resumo:

O assentamento de células de leveduras no fundo das dornas e perdas de células nas centrífugas podem ser causadas por bactérias floculantes, contaminantes naturais da fermentação alcoólica industrial. Estes problemas levam a queda no rendimento e produtividade do etanol. O presente trabalho visa a caracterização da floculação de Saccharomyces cerevisiae por Lactobacillus fermentum CCT 1396. As células de leveduras e bactérias foram misturadas e a floculação das células quantificadas por espectrofotometria. Concentrações de bactérias numa faixa de 0,4 a 3,8g/L (biomassa seca) foram testadas a fim de determinar a ótima concentração de bactérias necessária para provocar a floculação das leveduras. O efeito de pH na floculação das células de leveduras e bactérias foi determinado. 1,38g/L de bactéria foi necessário para a floculação, de 65,4g/L de células de levedura com tempo de contato entre as células (sob agitação) de 15 minutos e repouso de 20 minutos. No pH 3,0 pouco efeito na floculação celular foi detectado e as células continuaram floculadas, mas na faixa de pH 2,0 -- 2,5 a floculação foi próxima de zero. Esta técnica pode ser utilizada para o controle da floculação de leveduras de indústrias de produção de álcool, para determinar a origem desta floculação, já que trata-se de uma técnica fácil, econômica e rápida.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The release of reactive oxygen specie (ROS) by activated neutrophil is involved in both the antimicrobial and deleterious effects in chronic inflammation. The objective of the present investigation was to determine the effect of therapeutic plasma concentrations of non-steroidal anti-inflammatory drugs (NSAIDs) on the production of ROS by stimulated rat neutrophils. Diclofenac (3.6 µM), indomethacin (12 µM), naproxen (160 µM), piroxicam (13 µM), and tenoxicam (30 µM) were incubated at 37ºC in PBS (10 mM), pH 7.4, for 30 min with rat neutrophils (1 x 10(6) cells/ml) stimulated by phorbol-12-myristate-13-acetate (100 nM). The ROS production was measured by luminol and lucigenin-dependent chemiluminescence. Except for naproxen, NSAIDs reduced ROS production: 58 ± 2% diclofenac, 90 ± 2% indomethacin, 33 ± 3% piroxicam, and 45 ± 6% tenoxicam (N = 6). For the lucigenin assay, naproxen, piroxicam and tenoxicam were ineffective. For indomethacin the inhibition was 52 ± 5% and diclofenac showed amplification in the light emission of 181 ± 60% (N = 6). Using the myeloperoxidase (MPO)/H2O2/luminol system, the effects of NSAIDs on MPO activity were also screened. We found that NSAIDs inhibited both the peroxidation and chlorinating activity of MPO as follows: diclofenac (36 ± 10, 45 ± 3%), indomethacin (97 ± 2, 100 ± 1%), naproxen (56 ± 8, 76 ± 3%), piroxicam (77 ± 5, 99 ± 1%), and tenoxicam (90 ± 2, 100 ± 1%), respectively (N = 3). These results show that therapeutic levels of NSAIDs are able to suppress the oxygen-dependent antimicrobial or oxidative functions of neutrophils by inhibiting the generation of hypochlorous acid.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Special diets are used to mitigate many human diseases. When these diets require changes in carbohydrate content, then sweetness becomes an important characteristic. The range of low-calorie sweeteners available to the food industry is expanding. It is essential to have an exact knowledge of the relative sweetness of various sweeteners in relation to different sucrose concentrations. The objective of this study was to determine the variation on the relative sweetness of aspartame (APM), stevia [Stevia rebaudiana (Bert.) Bertoni] leaf extract (SrB) and the mixture cyclamate/saccharin - two parts of cyclamate and one part of saccharin - (C/S) with the increase in their concentrations, and in neutral and acid pH in equi-sweet concentration to 10% sucrose, using magnitude estimation. Sweetness equivalence of SrB in relation to sucrose concentrations of 20% or higher and of APM and C/S to sucrose concentrations of 40% or higher could not be determined, because a bitter taste predominated. The potency of all sweeteners decreased as the level of sweetner increased. In equi-sweet concentration of sucrose at 10%, with pH 7.0 and pH 3.0, the potency was practically the same for all sweeteners evaluated.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A preparation, enriched with malate dehydrogenase (MDH), alcohol dehydrogenase (ADH), glycerol -3- P dehydrogenase (GPDH) and glycerol kinase (GK), was obtained from dry baker's yeast. This preparation was used to assay glycerol, ethanol and malate measuring the variations in absorbance (NADH formation) at 340 nm. Good degrees of recoveries were obtained when glycerol was added to red wine and fermenting sugar-cane juice and when L-malate was added to commercial apple juice samples. Good results were also obtained when ethanol was assayed in fermented sugar-cane juice and wine samples, using both the partially purified preparation obtained from dry yeast and a purified commercial alcohol dehydrogenase.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We evaluated the presence of the melatonin metabolite N-1-acetyl-N-2-formyl-5-methoxykynuramine (AFMK), in cerebrospinal fluid (CSF) of patients with viral meningitis (n = 20) and control samples (n = 8) and correlate AFMK levels with inflammatory markers such as cellularity, protein, tumor necrosis factor (TNF)-alpha, interleukin (IL)-8 and IL-1 beta levels. A portion of the CSF was extracted with dichloromethane (1:5) and analyzed by high-performance liquid chromatography (HPLC) under standardized conditions for AFMK. AFMK was detected in 16 of 20 CSF samples of patients with viral meningitis; the concentration of AFMK was found to be above the quantification limit (50 nmol/L) in six of these samples. AFMK was not detected in any of the eight control samples. The samples were classified into groups according to AFMK levels: undetectable (< 10 nmol/L, group I), detectable but below the quantification limit (< 50 nmol/L, group II), and quantified (> 50 nmol/L, group III). Group II presented the highest levels of proteins and IL-8, whereas group III showed the lowest levels of the inflammatory parameters. This study supports our hypothesis that inflammation favors the formation of AFMK and that this compound has immunomodulatory activity in vivo.