983 resultados para Ultrasound-assisted enzymatic hydrolysis
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Pós-graduação em Química - IBILCE
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Recently there is a great quest of producing alcohol from starchy resources, replacing the sugar cane. The most common starchy sources are cassava, maize and sweet potatoes and a lot of research are been realized with excellent results. In this work it was evaluated the influence of the concentration of dry matter on the enzymatic hydrolysis process of starch from sweet potato for ethanol production. Through the sweet potato was produced a flour using a low-cost method and easy operation equipments. The sweet potato flour was characterized physical and chemically and from these results was prepared the treatments for enzymatic hydrolysis. The experimental design considered as independent variable the dry matter concentration of the sweet potato flour in 3 levels; 10, 15 and 20% in the formulation of suspensions. The other variables were keeping constant being: temperature in the 1° hydrolysis step of 90°C and time of 2 hours; temperature in the 2° saccharification step of 60°C and time of 17 hours. The hydrolysates obtained at the three assays were transferred to six liter enlerynmeyer and inoculated with a biologic catalyst, Saccharomyces, dehydrated yeasts of Saccharomyces cerevisiae CAT 1, at a rate of 5% in weight. The flasks were placed in a shaker type orbital with controlled temperature of 30°C during a time of 15 hours. The initial reducer sugars concentration and respective ethanol concentrations in wine were: 11.2% glucose and 2.16% ethanol in the suspension with 10% of dry matter; 13.5% glucose and 4.39% ethanol with 15% and 17.5% glucose and 6.03% ethanol in suspension with 20% of dry matter. ix The results showed that the higher percentage of dry matter carried out to higher sugar yield in hydrolyzed. It was possible observed that products quality improved with a higher concentration of dry matter
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New patterns from replaceable sources have been searched by scientific community to ethanol produce. The seed of avocado has thereabout 20% of starch. The starch hydrolysis results fermentable sugars by Saccharomyces cerevisiae, and the ethanol is the major product of fermentation. The starch can be hydrolysed by acids, basis and enzymes. Previous studies showed that enzymatic hydrolysis can produce 26,01 liter of ethanol per ton of seed. At the present work, we analyzed the chemistry hydrolysis efficiency before the enzymatic hydrolysis and the use of dormant seed consequence. The Brix rate variation at each stage was evaluated and the ethanol concentration was determined with gas chromatograph technique. The chemistry hydrolysis with subsequent enzymatic hydrolysis was effective, producing until 61,8 L.ton-1. The use of dormant seeds wasn’t significative to raise the Brix rate. The seed of avocado demonstrated to be an alternative replaceable source to ethanol produce
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Hydrogen is known as a clean energy resource. The biological production of hydrogen has been attracting attention as an environmentally friendly processs that does not consume fossil fuels. Cellulosic plant and waste materials are potential resources for fermentative hydrogen production. Cellulose is a linear biopolymer of glucose molecules, connected by β-1,4-glycosidic bonds. Enzymatic hydrolysis of cellulose requires the presence of cellulase. The present study aimed to investigate the efficiency of acid pretreatment on ruminal fluid in order to enrich H2 producing bacteria consortia to enhance biohydrogen rate and substrate removal efficiency. In this study, fermentative hydrogen producers were enriched on cellulose (2g/L) in a modificated Del Nery medium (DNM) at 37ºC and initial pH 7.0 using rumen fluid (10% v/v) as inoculum. To increase the hydrogen production it was added cellulose (10mL) to the medium. The gas products (mainly H2 and CO2) was analyzed by gas chromatography (Shimadzu GC 2010) using a thermal conductivity detector. The volatile fatty acids and ethanol were also detected by GC using a flame ionization detector. Cellulose degradation was quantified by using the phenolsulfuric acid method. Analysis showed that the biogas produced from the anaerobic fermentation contained only hydrogen and carbon dioxide, without detectable methane after acid pretreatment test. On DNM the hydrogen production started with 4 h (5,3 x 105 mmol H2/L) of incubation, and the maximum H2 concentration was observed with 34 h (7,1 x 106 mmol H2/L) of incubation. During the process, it was observed a predominance of acetic acid and butyric acid as well as a low production of acetone, ethanol and nbutanol in all experimental phases. Butyrate accounted for more than 77% of total. As a result of the accumulation of volatile fatty acids (VFAs), the pH value in anaerobic digestion system was reduced to 4,0. On microscopy analyses there were observed rods with endospores. The batch anaerobic fermentation assays performed on anaerobic mixed inoculum from rumen fluid demonstrated the feasibility of H2 generation utilizing cellulose as substrate. Based on the results, it can be concluded that the acid treatment was efficient to inhibit the methanogenic archaea cells present in rumen fluid. The rumen fluid cells present a potential route in converting renewable biomass such as cellulose into hydrogen energy.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Vinegar is a food of condiments group that have great use in the food industry. This study aimed to evaluate the effects of parameters of the acetic fermentation process in the production of ginger vinegar. A suspension of ginger rhizomes with 12% of starch was subjected to enzymatic hydrolysis process to obtain hydrolyzed with 85.6% of glucose. After the alcoholic fermentation the wine was obtained with 40.3% ethanol. The acetic fermentation process of ginger alcoholic solution followed a completely randomized design in a factorial for three factors at two levels. The independent variables were: temperature, nutrients and proportion of "strong vinegar" and alcoholic solution (initial acidity). Results showed variation from 2.74 to 3.70% for dry extract and 2.13 to 2.83% for ash in vinegars. The profile of organic acids of ginger vinegars showed the presence of acetic, citric, malic and succinic acids in all treatments. The condition of 20 degrees C, initial acidity 1:1, with addition of nutrients allow obtaining good quality vinegars and higher GK yields.
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A sample preparation method based on ultrasound assisted-extraction (UAE) of Ca, Mg and P from swine feed has been described. The experiment was performed to cover the variables influencing the sonication process and, the method validation using standard reference material. Final solutions obtained upon sonication were analyzed by flame atomic absorption spectrometry (for Ca and Mg) and by UV-vis spectrophotometry (for P). The best conditions for metal extraction were as follows: sample mass: 100 mg in 20 mL 0.10 mol/L HCl, a particle size: <60 μm, sonication time: 5 cycles of 10 s and ultrasound power: 102 W. The UAE method was applied in digestibility assays in different piglet feeds and their results showed that it is highly comparable (P > 0.05) to the other methods used for such purposes, as block digestion, and offered a Ca, Mg and P method of quantification limit of 10.6, 12.4 and 14 mg/kg, respectively. The major advantages of the UAE method compared to other methods are the high treatment rate, low reagent usage in the extracts and, it does not generate toxic residues that might negatively affect human health and the environment, accompanied by good precision and accuracy.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)