Abstract In the present work, a simple and high-throughput analytical procedure based on ultrasound-assisted extraction with diluted acid was proposed for the determination of Ca, Mg, K, P, S, Fe, Cu and Mn in guarana samples using inductively coupled plasma optical emission spectrometry. Two multivariate approaches were employed for optimization of the extraction procedure: mixture and Doehlert designs. The best experimental conditions were established by application of a multi-response function (overall desirability). An extractor medium composed of diluted nitric acid was selected for analytes extraction. Optimized conditions for ultrasound-assisted extraction followed the temperature of 60 °C, sonication time of 10 min and power of 100% applied to the ultrasonic bath. After the analytical validation step, the proposed procedure was successfully employed for determination of essential elements in thirty-three guarana samples from the state of Bahia, Brazil. Mass fractions higher than 0.42% (m m-1) were found for potassium in all analyzed samples. For the other macro-elements, the mass fraction ranged from 514 mg kg-1 (magnesium) to 0.19% m m-1 (calcium). The mass fraction of micro-elements ranged from 5.1 to 91.3 mg kg-1 for cooper and iron, respectively.

ABSTRACT. The objective of this study was to evaluate the effect of use of agroindustrial co-products in the diet of lambs on the performance and nutritional quality of meat fat. Twenty lambs were distributed into four experimental groups: control diet (C) or diets containing cottonseed (CS), sunflower meal (SFM), and castor cake (CC). During the experimental period, data on dry matter consumption (DMC) and total weight gain (TWG) were collected. After slaughter, samples of Logissimus dorsi (LD) muscle were taken for fatty acids and cholesterol analysis. Diets C and CS provided similar characteristics of fat quality and animal performance. However, SFM and CC diets tend to form isolated groups, with different fat and performance characteristics. The SFM diet results in meat with a higher saturated fatty acids and cholesterol content. The CC diet is related to improved performance characteristics and lower cholesterol content. In conclusion, the inclusion of CC in the experimental diets provided, in the proportions used in this experiment, better characteristics of animal performance and meat fat quality.

Abstract In the present study, the physicochemical properties and mineral composition of commercially-frozen soursop pulps from the southern region of the state of Bahia, Brazil, were evaluated. The physicochemical parameters such as soluble solids (°Brix), acidity and pH were determined according to reference methodologies. For mineral composition evaluation, samples were digested in a closed microwave system and the elements K, P, S, Ca, Mg, Fe, Cu, Zn, and Mn were quantified through inductively coupled plasma optical emission spectrometry (ICP OES). Soluble solids content ranged from 4.77 to 15.37 °Brix among the different brands of analyzed frozen pulps. Titratable acidity (equivalent to citric acid) and pH ranged from 0.49 to 1.00 and 3.61 to 4.57, respectively. Some samples presented irregularities in regard to quality pattern established in the Brazilian legislation. The following range of concentration, in μg g-1, were found for essential elements: K (544-1761), P (44.3-139), S (71.8-174), Ca (24.3-77.0), Mg (47.2-132), Fe (1.40-4.05), Mn (0.32-1.22), Cu (0.30-0.88) and Zn (0.36-0.84). The use of principal component analysis (PCA) enabled a more in-depth data analysis, performing correlations between different variables and frozen pulp brands.

RESUMO A hidroxiapatita tem se destacado entre os materiais cerâmicos devido a sua versatilidade estrutural, pois permite a substituição do Ca2+ ou do PO43-da sua estrutura possibilitando diversas aplicações. A utilização da hidroxiapatita como suporte e, ou catalisador tem recebido destaque como tema de pesquisa. Com isso, o objetivo deste trabalho foi a síntese, modificação e caracterização da hidroxiapatita para aplicação como catalisador em reação de esterificação. A hidroxiapatita foi obtida pelo método de precipitação e modificada por troca iônica no estado sólido, utilizando Zn(NO3)2 como precursor. As cerâmicas resultantes foram caracterizadas por análise térmica, espectrometria na região do Infravermelho por transformada de Fourier, difração de Raios-X e teste de acidez de Bronsted. Os catalisadores preparados, o HAP e o Zn-HAP foram avaliados frente à reação de esterificação do ácido oléico com metanol com as seguintes condições reacionais: razão metanol : ácido oléico (20:1), 10% m/m de catalisador e 3 h de reação a 150 °C apresentando conversões de 16,9% e 37,0%, respectivamente. Estes resultados são interessantes, principalmente do ponto de vista econômico, por se tratar de materiais de baixo custo utilizados como suporte para catalisadores heterogêneos.

ABSTRACT Hydroxyapatite has stood out among the ceramic materials due to their structural versatility as it allows the replacement of Ca2 + or PO43-its structure enabling various applications. One area that is gaining prominence is the application of hydroxyapatite as support and or catalyst. Thus, the objective of this work was the synthesis, modification and characterization of hydroxyapatite for use as a catalyst in esterification reaction. The hydroxyapatite was obtained by the precipitation method and was modified by solid state ion-exchange method using Zn(NO3)2 as precursor. The resulting ceramics were characterized by thermal analysis, Fourier Transform Infrared Spectroscopy, X-ray diffraction and Bronsted acidity test. The catalysts HAP and Zn-HAP prepared were evaluated against the esterification reaction of oleic acid with methanol under the following reaction conditions: ratio methanol: oleic acid (20:1), 10% m/m of catalyst and 3h reaction at 150 °C showing conversions of 16.9% and 37.0%, respectively. These results are interesting, mainly from the economical point of view, since they are low cost materials used as support for heterogeneous catalysts.

ABSTRACT The objective of this study was to evaluate the effects of supplementing diet of lambs with agroindustrial co-products on the nutritional quality of meat fat and study the variation of fat quality parameters based on the type of muscle. Twenty lambs were distributed into four experimental groups and fed a control diet or diets containing cottonseed, sunflower meal, and castor cake. After 106 experimental days, the animals were slaughtered. Samples of Biceps femoris, Longissimus dorsi, Semimembranosus, and Triceps brachii muscles were taken for fatty acid and cholesterol analyses. Castor cake and sunflower meal diets produced meats with lower levels of n-6 polyunsaturated fatty acids (PUFA) compared with the control diet. Castor cake diet contributed to tissue reduction of n-3 PUFA. Lower conjugated linoleic acid concentration and polyunsaturated:saturated fatty acid (P:S) ratio and higher saturated fatty acids content and Thrombogenicity Index were observed in Longissimus dorsi meat. Of the co-products studied, although castor cake diet reduced cholesterol levels in Biceps femoris muscle, sunflower meal was identified as the preferred choice for lamb feeding, since it reduced n-6 PUFA without, however, decreasing n-3 PUFA. Longissimus dorsi meat had the lowest fat quality indexes. The more oxidative muscles, such as Biceps femoris, tend to generate meats with higher cholesterol concentrations.

In this study the mixed oxides ZrO2-SiO2, were synthesized by the sol-gel method with a molar ratio of 95:5 (Si/metal) and characterized by X-ray diffraction, absorption-desorption of N2, Fourier transform infrared spectroscopy, thermal gravimetric analysis, temperature-programmed desorption of ammonia, and acidity test by titration. The synthesized materials, which are amorphous to X-rays, are composed of a mixture of micro- and mesopores. They show a higher acid strength than the separate oxides, indicating that the ZrO2 is highly dispersed in the silica matrix.

Microalgae biomass has been described by several authors as the raw material with the greatest potential to meet the goals of replacing petroleum diesel by biodiesel while not competing with arable land suitable for food production. Research groups in different countries are seeking the most appropriate production model for productivity, economic viability and environmental sustainability. This review focused on recent advances and challenges of technology for the production of biodiesel from microalgae, including the procedures used to obtain biomass.

The establishment of quality standards for biodiesel was a key step to win the confidence of the market and the automotive industry, thus ensuring the success of the new fuel. In this review are presented standard methods and other analytical methods suggested for analysis of biodiesel. The methods of analysis were divided into groups according to information that may be provided on the contaminants from the raw material of the production process, the molecular structures of biodiesel and its degradation during storage.