452 resultados para Transesterificação enzimática


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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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In heterogeneous catalysis, numerous elements such as titanium and iron have been studied as nanoscale catalysts, but little is known about the use of niobium in nanocatalysis. The nanostructured particles have intrinsic and different physicochemical characteristics with great potential for use in industrial scale. Brazil having the largest known worldwide niobium reserve has the great challenge of creating pioneering technologies with the metal. Biodiesel is an alternative fuel and renewable substitute for regular diesel. Being biodegradable, non-toxic and have CO2 emissions lower than regular diesel, it contributes to the environment and to the independence from oil. The aim of this work was initially synthesize nanoscale particles of niobium pentoxide (Nanospheres, nanorods, nanofibers, nanocubes) from the sol-gel technique. The characterization of different nanoscale structures obtained was performed using different analytical techniques such as x-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). The synthesized nanometer niobium oxide will be used as a heterogeneous catalyst in biodiesel synthesis from commercial soybean oil, checking in detail what the effect of morphology is presented (Nanospheres, nanorods, nanofibers, nanocubes) in the yield of biodiesel synthesis, comparing these results with those already described in literature for the amorphous niobium oxide and other oxide catalysts. The biodiesel obtained was characterized by gas chromatography system equipped with a FID detector

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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There is a great global concern about the depletion and the high cost of fossil fuel reserves exploitation, more than ever, it is necessary to make a profound study and take advantage of alternative sources that can be used as energy efficiency with an appropriate pricing and low environmental impact. Brazil, which has highlighted using alternative energy sources as the use of ethanol and, in recent years, has been encouraging the expansion of its energy matrix in which the biodiesel will have a strategic importance within the agrobusiness area. Biodiesel is a fuel that can replace the diesel, which is a petroleum derivative. It is an ester, produced in the transesterification reaction of vegetable oils and animal greases, in an alcohol with an additional catalyst, are converted into fatty acids and result in esters with glycerol as sub products. The objective of this study was to estimate the final energy balance for the process biodiesel production from oil chicken waste. The energy balance estimation was quantified in calorific value according to the energy expenditure by calorimetric bomb method. The relationship between input and output of energy was around 0.97. In a first evaluation, the procedures adopted should be improved enough, so the process can become energetic and economically viable.

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Ananas erectifolius (curaua) is a fibrous vegetable that can be found in North and Central West regions of Brazil. It is a bromeliaceae family plant which physico-chemical features provides great potential in the automobilistic industry as a source of fibers. As commonly described in other bromeliaceae species, it contains significant levels of bromelain, of high commercial value and wide range of aplications in food, pharmaceutical and cosmetic industry. In this paper, experimental tests were performed to evaluate the extraction of the proteolytic enzymes of the Ananas erectifolius under different pH and temperature conditions to determine in which ones the enzymatic activity would be the maximum for later purification of the bromelain. The two commercially available curaua varieties (white and purple) were used in the experiments and the results showed the same optimal pH of 8,5 for both varieties and different temperatures of 30ºC for the white one, and 10ºC, 20ºC and 35ºC for the purple one.

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The greenhouse production associated with the fertigation management, have established in Brazil as economical alternative for several horticultural species. With this strategy this study had as aim to evaluate possible impacts in the metabolism of plants of bell pepper (Capsicum annuum L.; cv Elisa) in response to the increase of mineral concentration in the soil. During the experiments, the some nutrient concentrations were altered, to obtain high values of electric conductivity (EC) in the soil solution. The EC values commonly observed in the traditional fertigation system were adopted, as control. It was also verified the possibility of reduction of the mineral stress impact by the application of organic matter in the soil. Parameters of the antioxidative response system, as the superoxide dismutase (SOD) and catalase enzyme activities besides the proline content were evaluated to measure the extension of the saline stress and their effects on the plants. The increase of EC of the soil induced to the increase of the proline concentration and the SOD activity. Unexpectedly, it was verified that the saline stress inhibited the activity of the enzyme catalase. It was also concluded that the monitoring of EC of the soil is an indispensable tool to reach success in the fertigation system and that the study of the activity of the enzymes of the antioxidative response system, and the proline contents can be assumed as indicators in of the levels of stress in bell pepper plants (Capsicum annuum L.; cv Elisa).

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Vinegar is a food product that has a great market potential and beneficial health properties. Each type of vinegar has its taste, since the transformation of alcoholic into acetic acid preserves the raw materials fragrancesand other organic acids can be formed. This study produced and characterized vinegars from ginger and cassava starch. The raw materials were first hydrolyzed by an enzymatic process, thenthey suffered an alcoholic fermentation,and finally an acetic fermentation by the Orleans process. The ash quantity, total acidity in acetic acid, dry extract, and alcohol content of the final product were analyzed based on the current vinegars legislation.The results showed that it is possible to obtain vinegars with good quality from ginger and cassava starch.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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In the postharvest management, the fruits can be exposed to injuries that depreciated the quality and the shelf life. Thus, it was evaluated the modified atmosphere effects on guavas var. Paluma subjected to different mechanical damages. Once harvested, the fruits were selected, sanitized and submitted to the treatments T1 (control) - without injuries or packaging in bags of low density polyethylene (LDPE); T2 - without injuries + LDPE bags; T3 - damage by fall of 1 m + LDPE bags; T4 - damage by compression of 9 N + LDPE bags; T5 - damage by fall of 1 m + damage by compression of 9 N + LDPE bags and T6 - damage by fall of 1 m + damage by compression of 9 N without LDPE bags. The treatments were kept in cold storage at 10 ± 1 o C and 94 ± 2% de R.H. The analysis of CO2/ethylene production, enzymatic activity, total and soluble pectins, pulp firmness, titratable acidity (TA), soluble solids (SS), reducing sugars and ascorbic acid were performed every 10 days of refrigeration, and an additional day outside cold storage (22 ± 1o C and 75 ± 3% R.H.) for 30 days. Guavas packed in LDPE bags, not subject to mechanical damage, presented the best quality standards. The fruits suffered only one kind of damage, when packaged, presented satisfactory pattern compared to the fruits without package and not exposed to any mechanical damages. Applying the two kinds of damages, the LDPE packaging was not adequate to decrease the metabolic rate of these fruits, making them unfit for marketing.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)