57 resultados para acid oil


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It has been shown previously that malnourished rats are resistant to acute gastric lesions but not to subchronic gastric ulceration. It also has been demonstrated that the essential oil obtained from the bark of Croton cajucara (Sacaca) has antiulcer properties. In the present study, the ability of this essential oil to prevent the formation of gastric ulcers in rats fed a diet with 17 % protein (normoproteic rats) or 6 % protein (malnourished rats) was investigated. At a dose of 100 mg/kg body weight, orally, the essential oil significantly reduced the gastric injury caused by indomethacin (25 % after 2 h and 70 % after 4 h) only in normoproteic rats. In the pylorus ligature model, the essential oil increased the pH and gastric volume, but decreased the total acid concentration in both groups when compared to the respective control group. The essential oil significantly increased prostaglandin E2 production in glandular cells by 50 % compared to the controls in both groups of rats. In addition, the amount of gastric mucus was two-fold higher in malnourished rats than in normoproteic rats. The present results show that the enhanced protective effect of essential oil in malnourished rats involved an increase in prostaglandin E2 production and mucus secretion, which are both factors that protect the gastric mucosa against damage. In agreement with this, malnourished rats always had a lower number of acute gastric ulcers.

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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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Por razões econômicas e de proteção à saúde, pesquisas têm sido dirigidas para ampliar a estabilidade dos óleos vegetais. Existe uma tendência para a adição de antioxidantes naturais, em particular, um crescente interesse em ervas e especiarias. Desta forma, os objetivos deste trabalho foram avaliar o potencial antioxidante das oleorresinas de orégano, manjericão e tomilho e seu comportamento ao serem aplicadas ao óleo de soja em diferentes concentrações. Numa primeira etapa foi determinada a atividade antioxidante pelo sistema β-caroteno/ácido linoleico e a quantificação de compostos fenólicos totais. Posteriormente, foram adicionadas ao óleo de soja diferentes concentrações das oleorresinas (500 a 3000 mg.kg-1) e analisado seu potencial antioxidante por meio da estabilidade oxidativa utilizando o Rancimat. A concentração de 3000 mg.kg-1das oleorresinas de orégano e tomilho foi a que apresentou melhor estabilidade oxidativa ao óleo de soja, o que as tornam alternativa natural na conservação de óleos vegetais.

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

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Partial pseudoternary phase diagrams were constructed for soy bean oil (SBO)/surfactant/NaCl aqueous solution systems, at 25 degrees C, using the anionic sodium bis(2-ethylhexyl) sulfosuccinate (ACT) and zwiterionic phosphatidylcholine (PC) or mixtures of these surfactants. The isotropic single phase of water-in-oil (W/O) microemulsions (MEs) is shown in the phase diagram and their viscosity reported. ME samples containing small amount of surfactant exhibit slightly higher viscosity than pure SBO, and were used in the solubilization of small water soluble molecules. NaCl enhances the area of the ME phase and MEs with different surfactant composition exhibit different induction time as obtained from tests of oxidative stability, and so are the MEs enriched with ascorbic acid, folic acid and FeSO4, with the latter exhibiting lower stability. The so prepared enriched soy bean oil has potential application in food industry since the surfactants are food grade. (C) 2007 Elsevier B.V. All rights reserved.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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The jeriva is a well-known fruit, which belongs to the Arecaceae family, Syagrus romanzoffiana species frequently found in Brazil. Extraction of the jeriva oil was carried out, and the fatty acid profile of this oil indicates the linoleic and oleic acid presence, around 29.35 and 28.89%, respectively. Thermogravimetry (TG), derivative thermogravimetry (DTG), and differential scanning calorimetry (DSC) were used to characterize this oil. Additionally, this oil was evaluated by DSC from 25 to -80 A degrees C, and the crystallization behavior was verified. Details concerning the thermal behavior as well as data of kinetic parameters of these stages have been described here. The obtained data were evaluated, and the values were plotted in activation energy (E (a)/kJ mol(-1)) in function of the conversion degree (alpha).

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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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Microwave-assisted acid decomposition, direct dilution in kerosene, and oil-in-water emulsion were evaluated as lubricating oil pretreatment procedures for Cu, Cr, Fe, Ni, Pb, Sb, and Zn determination by High-Resolution Continuum Source Flame Atomic Absorption Spectrometry (HR-CS FAAS). For wet digestion, results were compared with those obtained by Flame Atomic Absorption Spectrometry (FAAS). The ultrasound probe used in emulsions sonication contaminated samples with Cr, although better results have been observed for the other six elements in this condition. In general, recovery percentages ranging from 81-106%(Cu), 80-107%(Cr), 85-114%(Fe), 82-116%(Ni), 86-117%(Pb), 85-115%(Sb), and 81-114%(Zn) were obtained. The HR-CS FAAS showed to be faster and more sensitive than FAAS.

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

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In this study, the influence of the addition of antioxidants in vivo on the fatty acid composition of the flesh of a freshwater fish known as pacu (Piaractus mesopotamicus) is verified. Four groups (one being the control group) of juvenile pacu were cultured on isocaloric and isoproteic diets. The lipid source was soybean oil and diets were added with either 100 ppm of alpha-tocopheryl acetate, or 100 ppm of BHT or 1.4 g of rosemary extract (Herbalox(R))/kg diet. The fatty acid composition of the lipids of the different groups was determined before and after irradiation at 2 and 3 kGy, respectively, for the evaluation of the protective effects of the different antioxidants. Similarly, thiobarbituric acid reactive substances (TBARS) were determined from irradiated and nonirradiated samples. The results showed that the use of antioxidants altered the fatty acid composition of the fillets. TEARS and irradiation confirmed their important role in protecting against lipid oxidation. Among all the antioxidants used, tocopherol was the most efficient, as shown by the highest percentage of polyunsaturated fatty acids (PUFA), by the lowest values of TEARS and by the analyses of the individual fatty acid levels at different irradiation doses. Significant statistical differences were observed only in 17% of the fatty acids in the fillets of the groups. (C) 1999 Elsevier B.V. Ltd. All rights reserved.