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O objetivo deste trabalho é comparar a eficiência de diferentes adsorventes na purificação de biodiesel produzido por transesterificação alcalina do óleo de soja (metanol/KOH). As metodologias propostas foram baseadas na utilização de Magnesol ® , sílica, Amberlite BD10 DRY ® e Purolite PD 206 ® como adsorventes e foram desenvolvidas por adsorção a 65 ºC. A eficiência de cada adsorvente foi medida através do teor residual de potássio, álcool, água e sabão, dissolvidos no biodiesel purificado. Como resultado, observamos que Magnesol ® e sílica apresentaram melhores propriedades de adsorção que Amberlite BD10 DRY® e Purolite PD 206 ® , especialmente para remover sabão, glicerina livre e ligada e potássio. Em comparação com a lavagem ácida convencional, estas matrizes foram consideradas adequadas para a remoção de espécies contaminantes inorgânicas e orgânicas do biodiesel. Os principais resultados encontrados para estes dois adsorventes (Magnesol ® 1% e sílica 2%) foram valores abaixo de 0,17 mg KOH g -1 de acidez, 1 mg kg -1 de potássio, 61 ppm de sabão, 500 mg kg -1 de água, 0,22% de metanol, 0,30% de glicerina livre e 0,03% de glicerina ligada.The purpose of this work is to compare the efficiency of different adsorbents in the purification of biodiesel produced by alkaline transesterification of soybean oil (Methanol/KOH). The proposed methodologies were based on the use of Magnesol ® , silica, Amberlite BD10 DRY ® and Purolite PD 206 ® as adsorbents and were developed by adsorption at 65 ºC. The response of each adsorbent was measured through the residual potassium, alcohol, water and soaps dissolved in the purified biodiesel. As a result, we observe that Magnesol ® and silica showed better adsorption properties than Amberlite BD10 DRY ® and Purolite PD 206 ® , especially for removing soap, free and bonded glycerol and potassium. In comparison to the conventional acid water washing, these matrices were found to be equally appropriate for the removal of inorganic and organic contaminant species from biodiesel. The main results found for these two adsorbents (Magnesol ® 1% and silica 2%) were values below 0.17 mg KOH g -1 for acid number, 1 mg kg -1 of K, 61 ppm of soap, 500 mg kg -1 of water, 0.22% of methanol and 0.03% of free glycerol. IntroductionBiodiesel is a diesel fuel substitute obtained mainly by basic catalytic transesterification of oils and fats, and it is composed by fatty acid mono-alkyl esters that are produced from the reaction of low-acid-number vegetable oils with an alcohol in the presence of a basic catalyst. [1][2][3] Biodiesel is currently produced by the base-catalyzed transmethylation of triglycerides, producing fatty acids methyl esters (FAME). 4,5 At the end of the reaction, the Faccini et al. 559 Vol. 22, No. 3, 2011 glycerol rich-phase is separated from the methyl ester layer by decantation.Methyl esters usually contain contaminant materials that are detrimental to the quality of the fuel, and must be eliminated from the product. Removal of glycerol and glycerides from biodies...

This work reports antimicrobial activity of oregano (Origanum vulgare) essential oil against several bacteria in sausage. The in vitro minimum inhibitory concentration (MIC) was determined for 9 selected aerobic heterotrofic bacteria. The antimicrobial activity of distinct concentrations of the essential oil on the basis of the highest MIC found was tested in a food system comprised of fresh sausage. Batch food samples were also inoculated with Escherichia coli with a fixed concentration and the time course of the product was evaluated with respect to the action of the different concentrations of essential oil. Sensory analysis were conducted, and results showed that the addition of oregano essential oil to sausage may be a promising route as bacteriostatic effect was verified for oil concentrations lower than the MIC.

In this work sub- and supercritical CO(2) were used to obtain extracts from two origanum samples, one commercial, and another cultivated under agronomic control. The experiments were performed in the temperature range of 293-313 K and from 100 to 200 bar in pressure, employing around 26 g of origanum samples. Results show that the commercial sample provides a higher yield of extract if compared to the other sample. It is also achieved that a raise in temperature at constant pressure leads to an increase in the extraction yield despite solvent density changes. Chemical analyses were carried out in a GC-MSD, allowing the identification of around 24 compounds by use of the library of spectra of the equipment and injection of some standard compounds for both commercial and cultivated origanum samples. It was also found that the distribution of chemical components as a function of extraction time differs appreciably between the origanum species. The chromatographic analysis permitted the identification of thymol and cis-sabinene hydrate as the most prominent compounds present in commercial oregano sample and carvacrol and cis-sabinene hydrate in the cultivated Origanum vulgare.