Bioacessibilidade in vitro de carotenoides e compostos fenólicos e capacidade antioxidante de farinhas do fruto pequi (Caryocar brasiliense Camb.)

Resumo Este trabalho objetivou avaliar a bioacessibilidade in vitro de α-caroteno, β-caroteno, licopeno e de compostos fenólicos, e a capacidade antioxidante em farinhas de amêndoa, polpa e casca do fruto pequi. Além disso, inter-relacionar estes resultados com a atividade de água, acidez e parâmetros de cor, por meio da análise de componentes principais. Os frutos foram coletados no estado de Mato Grosso, sendo higienizados, descascados, despolpados e retiradas as amêndoas. A quantificação das concentrações totais e bioacessíveis dos carotenoides e compostos fenólicos e a capacidade antioxidante foram feitas por espectrofotometria UV-Visível. Os ensaios de bioacessibilidade in vitro foram feitos por meio de três etapas: digestão salivar, gástrica e intestinal. As maiores concentrações de α-caroteno (63,81 µg/g), β-caroteno (59,83 µg/g) e licopeno (40,66 µg/g) foram obtidas para farinha da polpa do pequi. Porém, as maiores porcentagens de bioacessibilidade de α-caroteno (59,69%), β-caroteno (96,14%) e licopeno (44,13%) foram encontradas na farinha da amêndoa. Os teores de compostos fenólicos totais foram: 210,50, 402,21 e 9475,69 mg GAE/100g, para as farinhas de amêndoa, polpa e casca, respectivamente, sendo a maior porcentagem de bioacessibilidade (86,68%) encontrada na farinha da polpa. A farinha da casca do pequi apresentou maior capacidade antioxidante (EC50) 45,71 g/g de DPPH. Os maiores resultados de L* (42,19), a* (4,17), b* (8,39) e acidez titulável (17,83 mL NaOH/100 g) foram verificados na farinha da polpa e o menor pH (3,34), na farinha da casca. A análise de componentes principais indicou que o pH e a acidez titulável podem influenciar na bioacessibilidade de compostos fenólicos e carotenoides, e na capacidade antioxidante. Os resultados sugerem que as farinhas do pequi apresentam compostos bioativos bioacessíveis e boa capacidade antioxidante, e podem ser uma alternativa tecnológica no enriquecimento de produtos alimentícios.

Physicochemical and microbiological evaluation of natural mineral water produced in Mato Grosso State, Brazil

The aim of this work was to evaluate the physicochemical and microbiological properties of natural mineral waters bottled in 20 liter containers produced in Mato Grosso - Brazil. For this study, three lots of eight brands produced in the state and commercialized in Cuiabá were analyzed. The physicochemical parameters determined were pH, electrical conductivity, total dissolved solids, total alkalinity, metals, ammonium, anions and glyphosate, and the measurements were made according to the Adolfo Lutz Institute and Standard Methods for the Examination of Water and Wastewater. Chromogenic enzymatic substrates were used to determine Coliform bacteria and filtration with a filtering membrane was used for the Pseudomonas aeruginosa count. The results were compared with national and international legislation on bottled water and the labeled values. All physicochemical parameters, except for pH, showed concordant results with maximum values allowed by Brazilian and international law for the quality of bottled natural mineral waters. Six samples were investigated for the presence of coliforms and P. aeruginosa at 35 ºC. The results suggested possible contamination and failure during the industrialization process and the requirement for inspection during collection, manufacturing, labeling and commercialization of the natural mineral water bottled in 20 liter containers.

Determination of the Lead, Cadmium, and Chromium Concentration in Mineral Feeds and Supplements for Cattle Produced in the Mato Grosso State, Brazil

This work aimed to determine the concentration of lead (Pb), cadmium (Cd), and chromium (Cr) in mineral feeds and supplements for cattle produced in the Mato Grosso State, Brazil. Three different lots of nine mineral supplements and eleven mineral feeds were collected, and the samples were prepared by wet decomposition and quantified by flame atomic absorption spectrometry. The limits of detection and quantification ranged from 0.18 to 0.64 mg kg^-1 and 0.54 to 1.94 mg kg^-1, respectively. Cr concentrations varied from lower than the LQI to 11.9 mg kg^-1, and all samples presented values below the maximum recommended by the National Research Council (NRC) and European Union (EU). Cd concentrations varied from lower than the LQI to 6.1 mg kg^-1, and 100 % of the mineral supplements and 60 % of the mineral feed showed Cd concentrations above the recommended by the EU (1.0 mg kg^-1). Pb concentrations ranged from lower than the LQI to 33.1 mg kg^-1, and 100 % of the mineral supplements and 90 % of the mineral feed showed Pb concentrations above the recommended by the EU (5.0 mg kg^-1). All samples presented values below the maximum recommended by the NRC for Cd and Pb (10 and 100 mg kg^-1, respectively). A large scatter of results was observed in the different samples for the three elements analyzed. This can be attributed to inhomogeneous impurity levels between batches of phosphate rocks used in the mineral feeds and supplements. A strict control of such mineral feeds and supplements should be implemented.

Environmental Behavior of Chlorpyrifos and Endosulfan in a Tropical Soil in Central Brazil

The environmental behavior of chlorpyrifos and endosulfan in soil was studied in the central-western region of Brazil by means of a field experiment. Sorption was evaluated in laboratory batch experiments. Chlorpyrifos and endosulfan were applied to experimental plots on uncultivated soil and the following processes were studied: leaching, runoff, and dissipation in top soil. Field dissipation of chlorpyrifos and endosulfan was more rapid than reported in temperate climates. Despite the high Koc of the studied pesticides, the two endosulfan isomers and endosulfan sulfate as well as chlorpyrifos were detected in percolated water. In runoff water and sediment, both endosulfan isomers and endosulfan sulfate were detected throughout the period of study. Observed losses of endosulfan by leaching (below a depth of 50 cm) and runoff were 0.0013 and 1.04% of the applied amount, whereas chlorpyrifos losses were 0.003 and 0.032%, respectively. Leaching of these highly adsorbed pesticides was attributed to preferential flow.

Comparative analysis of physicochemical properties of root perforation sealer materials

Objectives

This study evaluated the solubility, dimensional alteration, pH, electrical conductivity, and radiopacity of root perforation sealer materials.

Materials and Methods

For the pH test, the samples were immersed in distilled water for different periods of time. Then, the samples were retained in plastic recipients, and the electrical conductivity of the solution was measured. The solubility, dimensional alteration, and radiopacity properties were evaluated according to Specification No. 57 of the American National Standards Institute/American Dental Association (ANSI/ADA). Statistical analyses were carried out using analysis of variance (ANOVA) and Tukey's test at a significance level of 5%. When the sample distribution was not normal, a nonparametric ANOVA was performed with a Kruskal-Wallis test (α = 0.05).

Results

The results showed that white structural Portland cement (PC) had the highest solubility, while mineral trioxide aggregate (MTA)-based cements, ProRoot MTA (Dentsply-Tulsa Dental) and MTA BIO (Ângelus Ind. Prod.), had the lowest values. MTA BIO showed the lowest dimensional alteration values and white PC presented the highest values. No differences among the tested materials were observed in the the pH and electrical conductivity analyses. Only the MTA-based cements met the ANSI/ADA recommendations regarding radiopacity, overcoming the three steps of the aluminum step wedge.

Conclusions

On the basis of these results, we concluded that the values of solubility and dimensional alteration of the materials were in accordance with the ANSI/ADA specifications. PCs did not fulfill the ANSI/ADA requirements regarding radiopacity. No differences were observed among the materials with respect to the pH and electrical conductivity analyses.

Oxidation of p,p'-DDT and p,p'-DDE in highly and long-term contaminated soil using Fenton reaction in a slurry system

The degradation of DDT [1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane] and DDE [2,2-bis(4-chlorophenyl)-1,1-dichloroethylene] in highly and long-term contaminated soil using Fenton reaction in a slurry system is studied in this work. The influence of the amount of soluble iron added to the slurry versus the mineral iron originally present in the soil, and the influence of H(2)O(2) concentration on the degradation process are evaluated. The main iron mineral species encountered in the soil, hematite (Fe(2)O(3)), did not show catalytic activity in the decomposition of H(2)O(2), resulting in low degradation of DDT (24%) and DDE (4%) after 6 h. The addition of soluble iron (3.0 mmol L(-1)) improves the reaction reaching 53% degradation of DDT and 46% of DDE. The increase in iron concentration from 3.0 to 24 mmol L(-1) improves slightly the degradation rate of the contaminants. However, similar degradation percentages were obtained after 24 h of reaction. It was observed that low concentrations of H(2)O(2) were sufficient to degrade around 50% of the DDT and DDE present in the soil, while higher degradation percentages were achieved only with high amounts of this reagent (1.1 mol L(-1)).

Dissipation of DDT in a heavily contaminated soil in Mato Grosso, Brazil

After the prohibition of organochlorine-pesticide use in Brazil for controlling insect vector diseases, Mato Grosso State gathered the exceeding DDT and stored it irregularly in an open air area that belongs to the National Health Foundation, causing soil contamination. This study aimed to evaluate the contamination level and dissipation of p,p'-DDT and p,p'-DDE in this area. For that, surface soil samples were collected on 19 September 2000, 15 December 2000, 4 April 2001 and soil samples 30-40 cm; 60-70 cm and 90-100 cm deep were taken from five points in the studied area on 17 July 2001. The contaminants were determined by a small scale method which consists on extraction and clean-up steps combined into one step by transferring soil samples mixed with neutral alumina to a chromatographic column prepacked with neutral alumina and elution with hexane:dichloromethane (7:3 v:v). The eluate was concentrated and the analytes were quantified by gas chromatography with an electron-capture detector. p,p'-DDT at surface soil ranged from 3,800 to 7,300 mg kg(-1). 30-40 cm deep soil sample concentrations varied from 0.036 to 440 mg kg(-1) while 90-100 cm deep samples varied from 0.069 to 180 mg kg(-1). Volatilization is probably the main dissipation process. The p,p'-DDT is moving slowly downward in the soil profile, however, the levels of this contaminant are high enough to present risk to underground waters.