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OBJETIVO: Determinar as concentrações de nitrito e nitrato, potencial hidrogeniônico (pH) e atividade de água (Aa) em salsichas comercializadas em uma região do sul do Brasil, e comparar essas concentrações entre as diferentes marcas. MÉTODOS: Estudo experimental, transversal, quantitativo, realizado com 72 amostras de salsicha coletadas em dois municípios da Região do Vale do Taquari/RS, entre junho e agosto de 2015. Avaliaram-se três amostras de lotes diferentes, por meio das variáveis de nitrito, nitrato, pH e atividade de água, em triplicata, de cada uma das oito marcas de salsichas fiscalizadas pelo Serviço de Inspeção Federal. Dados submetidos aos testes ANOVA e Qui-quadrado, com p<0,05. RESULTADOS: A totalidade das amostras apresentou-se dentro dos padrões para pH e Aa (6,33 ± 0,32 e 0,91 ± 0,01, respectivamente), enquanto 40,3% (29) e 50,0% (36) apresentaram níveis de nitrito e nitrato, respectivamente, significativamente acima do estabelecido pela legislação (p<0,05). A média de nitrito das amostras restantes apresentou-se significativamente inferior (p=0,001), e a média de nitrato, significativamente superior (p=0,009) ao valor estabelecido pela legislação. CONCLUSÃO: A totalidade das amostras estava adequada em relação aos níveis de pH e Aa. Do total das oito marcas avaliadas, três se encontravam em condições satisfatórias referente à adição do nitrato e nitrito. A média de nitrito e Aa foi significativamente inferior, e as médias do nitrato e pH, significativamente superior, enquanto os níveis de nitrato e nitrito apresentaram médias superiores aos valores estabelecidos legislação, em cinco marcas analisadas

OBJECTIVE: To determine nitrite and nitrate levels, hydrogen potential (pH), and water activity (aw) in sausages marketed in Southern Brazil, and compare the levels among different brands. METHODS: Quantitative experimental cross-sectional study conducted with 72 sausage samples collected in two municipalities in the Região do Vale do Taquari, Rio Grande do Sul,,between June and August 2015. Three samples from different batches of each eight distinct sausage brands which were supervised by the Federal Inspection Service were analyzed in triplicate according to their nitrite and nitrate levels, pH and water activity. Data underwent ANOVA and Chi-squared tests with p<0.05. RESULTS: Samples met the recommended standards for pH and water activity (6.33 ± 0.32 and 0.91 ± 0.01, respectively), while 40.3% (29) and 50.0% (36) of the samples presented nitrite and nitrate levels, respectively, significantly above what is recommended by the legislation (p<0.05). The mean nitrite levels of the remaining samples were significantly lower (p=0.001), and mean nitrate levels were significantly higher (p=0.009) than the value established by legislation. CONCLUSION: The samples met the recommended levels of pH and water activity. Of eight brands assessed, three presented satisfactory levels of nitrate and nitrite. The mean levels of nitrite and water activity were significantly lower and the mean levels of nitrate and pH were significantly higher than the recommendations. Additionally, mean nitrate and nitrite levels of five brands were significantly higher than what is recommended by the legislation

OBJETIVO: Determinar las concentraciones de nitrito y nitrato, del potencial de hidrógeno (pH) y de la actividad del agua (Aa) de salchichas del comercio de una región del sur de Brasil y compararlas entre las distintas marcas comerciales. MÉTODOS: Estudio experimental, transversal y cuantitativo realizado con 72 muestras de salchichas recogidas en dos municipios de la Región del Vale del Taquari/RS entre junio y agosto de 2015. Se evaluaron tres veces tres muestras de lotes distintos a través de las variables de nitrito, nitrato, pH y actividad del agua de cada una de las ocho marcas de salchichas fiscalizadas por el Servicio de Inspección Federal. Los datos fueron sometidos a las pruebas ANOVA y Chicuadrado para p<0,05. RESULTADOS: La totalidad de las muestras se presentó dentro de los patrones para el pH y la Aa (6,33 ± 0,32 e 0,91 ± 0,01, respectivamente) mientras el 40,3% (29) y el 50,0% (36) presentaron niveles de nitrito y nitrato, respectivamente, significativamente por encima de la legislación (p<0,05). La media de nitrito de las muestras restantes se presentó significativamente inferior (p=0,001) y la media de nitrato, significativamente superior (p=0,009) de la legislación. CONCLUSIÓN: La totalidad de las muestras estaba adecuada respecto a los niveles de pH y Aa. Del total de las ocho marcas evaluadas, tres se encontraban en condiciones satisfactorias de adicción del nitrato y nitrito. La media de nitrito y Aa fue significativamente inferior y las medias de nitrato y pH significativamente superior mientras los niveles de nitrato y nitrito presentaron medias superiores de la legislación em cinco marcas analizadas

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Naphthenic acids, C(n)H(2n+Z)O(2), are a complex mixture of alkyl-substituted acyclic and cycle-aliphatic carboxylic acids. The content of naphthenic acids and their derivatives in crude oils is very small, which hinders their extraction from matrixes of wide and varied composition. In this work, liquid-liquid extraction, followed by solid phase extraction with an ion exchange resin (Amberlyst A-27) and ultrasound desorption were used to isolate the acid fraction from heavy gas oil of Marlim petroleum (Campos, Rio de Janeiro, Brazil). The analysis was accomplished through gas chromatography coupled to mass spectrometry with electron impact ionization, after derivatization with N-methyl-N-(tert-butyldimethylsilyl)trifluoracetamide (MTBDMSTFA). The results indicate the presence of carboxylic acids belonging to families of alicyclic and naphthenic compounds which contain up to four rings in the molecule.

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This paper describes a comparative study of extraction methods of terpenes (terpenic alcohols and phytosterols), fatty acids and Vitamin E from leaves of Piper gaudichaudianum Kunth. The analysis of extracts was done by gas chromatography with mass spectrometric detection. The identification and quantification was made by co-injections of the extract with certified standards. The use of pressurized liquid extraction (PLE; Dionex trade name: ASE, for accelerated solvent extraction) decrease significantly the total time of extraction, the amount of solvent and the manipulation of sample and solvents in comparison with soxhlet (SE) and ultrasound-assisted (USE). In addition, PLE was more effective for the extractions of terpenes (terpenic alcohols and phytosterols), fatty acids and Vitamin E.

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Piperaceae family is original from tropical regions and it shows more than 700 species around the world. Piper gaudichaudianum Kunth is the specie more abundant in Brazil, occurring from Northeast to South Brazil. In this paper, it was investigated the influence of some experimental parameters on the pressurized liquid extraction (PLE) of P. gaudichaudianum Kunth leaves, using petroleum ether as extractor solvent. The optimization of the main variables involved in the PLE process (extraction temperature and time) has been done by response surface methodology (RSM) using, as responses, the extraction yield and the chromatographic profile (GC/MS) of the extracts. The optimized procedure employed 3 g of ground leaves, 10 min of extraction and one cycle of extraction at 85 degrees C. The major compounds present in the petroleum ether extracts were: palmitic acid, stearic acid and nerolidol. The results presented in this work show the possibility of using a fast and easy process to recover compounds from P. gaudichaudianum Kunth.

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Carbozoles are important compounds in crude oils, as they may be used as geochemical tracers, being the major type of nitrogen compounds in petroleum. At the same time, they are regarded as undesirable due to the problems they may cause in the refining process, such as catalyst poisoning, corrosion, gum or color formation in final products. As separation and identification of carbazoles are challenging goals, this work presents a chromatographic method, made of a pre-fractionation on neutral alumina followed by the separation and identification of two classes of carbazoles using FeCl(3)/Chromossorb W and gas chromatograph with mass spectrometer (GC/MS) (SIM-single ion monitoring mode) analysis. For the first time, a series of alkyl carbazoles and alkyl benzocarbazoles were identified in heavy gas oil (HGO) and atmospheric residue of distillation (ARD) obtained from Brazilian petroleum.

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