RESUMO
Methylmercury (MeHg+) is a mercury species that is very toxic for humans, and its monitoring and sorption from environmental samples of water are a public health concern. In this work, a combination of theory and experiment was used to rationally synthesize an ion-imprinted polymer (IIP) with the aim of the extraction of MeHg+ from samples of water. Interactions among MeHg+ and possible reaction components in the pre-polymerization stage were studied by computational simulation using density functional theory. Accordingly, 2-mercaptobenzimidazole (MBI) and 2-mercaptobenzothiazole (MBT), acrylic acid (AA) and ethanol were predicted as excellent sulfhydryl ligands, a functional monomer and porogenic solvent, respectively. Characterization studies by scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) revealed the obtention of porous materials with specific surface areas of 11 m2 g-1 (IIP-MBI-AA) and 5.3 m2 g-1 (IIP-MBT-AA). Under optimized conditions, the maximum adsorption capacities were 157 µg g-1 (for IIP-MBI-AA) and 457 µg g-1 (for IIP-MBT-AA). The IIP-MBT-AA was selected for further experiments and application, and the selectivity coefficients were MeHg+/Hg2+ (0.86), MeHg+/Cd2+ (260), MeHg+/Pb2+ (288) and MeHg+/Zn2+ (1510), highlighting the material's high affinity for MeHg+. The IIP was successfully applied to the sorption of MeHg+ in river and tap water samples at environmentally relevant concentrations.
RESUMO
Bee pollen consumption has increased in the last years, mainly due to its nutritional value and therapeutic applications. The quantification of mineral constituents is of great importance in order to evaluate both, the toxicity and the beneficial effect of essential elements. The purpose of this work was to quantify the essential elements, Ca, Mg, Zn, P and K, by diffuse reflectance spectra in the near infrared region (NIR) combined with partial least squares regression (PLS), which is a clean and fast method. Reference method used was ICP OES. The determination coefficients for calibration models (R2) were above 0.87 and the mean percent calibration error varied from 5 to 10%. For external validation R2 values were higher than 0.76. The results indicated that NIR spectroscopy can be useful for an approximate quantification of these minerals in bee pollen samples and can be used as a faster alternative to the standard methodologies.
Assuntos
Minerais/análise , Pólen/química , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Animais , Abelhas , Brasil , Calibragem , Análise dos Mínimos Quadrados , Metais/análise , Espectroscopia de Luz Próxima ao Infravermelho/estatística & dados numéricosRESUMO
Polycyclic aromatic hydrocarbons (PAHs) are food-processing contaminants considered to be carcinogenic and genotoxic. Due to its drying process stage, teas may be contaminated with PAHs. The aim of the study was to validate an analytical method involving QuEChERS and HPLC-FLD for the determination of PAH4 in teas and evaluate the contamination levels in 10 different types of teas from Brazil. Recoveries varied from 54% to 99% and relative standard deviations from 1% to 21%. Limits of detection and quantification were from 0.03 to 0.3 µg/kg and 0.1 to 0.5 µg/kg, respectively. Mate tea presented the highest PAH levels, with PAH4 varying from 194 to 1795 µg/kg; followed by black (1.8-186 µg/kg), white (24-119 µg/kg), and green teas (3.1-92 µg/kg). Teas with lowest PAH4 were strawberry, lemongrass, peppermint, and boldo. Only trace levels of PAHs were detected in tea infusions, so apparently it would not affect PAH intake by Brazilian population.
Assuntos
Carcinógenos Ambientais/análise , Contaminação de Alimentos , Hidrocarbonetos Policíclicos Aromáticos/análise , Chá/química , Chás de Ervas/análise , Métodos Analíticos de Preparação de Amostras , Benzo(a)Antracenos/análise , Benzo(a)Antracenos/isolamento & purificação , Benzo(a)pireno/análise , Benzo(a)pireno/isolamento & purificação , Brasil , Carcinógenos Ambientais/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Crisenos/análise , Crisenos/isolamento & purificação , Fluorenos/análise , Fluorenos/isolamento & purificação , Manipulação de Alimentos , Inspeção de Alimentos/métodos , Ilex paraguariensis/química , Limite de Detecção , Oxirredução , Folhas de Planta/química , Hidrocarbonetos Policíclicos Aromáticos/isolamento & purificação , Reprodutibilidade dos Testes , Espectrometria de Fluorescência , Chá/economia , Chás de Ervas/economiaRESUMO
Initially, meat emulsions were studied in a model system to optimize phosphate and potassium chloride concentrations. In the second step, frankfurters containing 1.00%, 1.30% and 1.75% sodium chloride (NaCl) were processed and their stability was monitored over 56 days. In the emulsion tests, the best levels in relation to shear force found in model system were 0.85% and 0.25% of potassium chloride and phosphate, respectively. In the second step, treatments with 1.30% and 1.75% NaCl performed better in most of the analysis, particularly the sensory analysis. Consumers could identify the levels of salt, but this was not the factor that determined the overall acceptability. In some technological parameters, frankfurters with 1.30% NaCl were better than those with 1.75%. This represents a reduction of approximately 25% sodium chloride, or 18% reduction in sodium (916 mg/100g to 750 mg/100g), and it appears to be feasible from a technological, microbiological and sensory point of view.
Assuntos
Produtos da Carne/análise , Produtos da Carne/microbiologia , Cloreto de Potássio/análise , Cloreto de Sódio/análise , Paladar , Adolescente , Adulto , Animais , Fenômenos Químicos , Comportamento do Consumidor , Emulsões , Feminino , Análise de Alimentos , Contaminação de Alimentos/análise , Manipulação de Alimentos , Microbiologia de Alimentos , Humanos , Concentração de Íons de Hidrogênio , Masculino , Pessoa de Meia-Idade , Nitritos/análise , Suínos , Adulto JovemRESUMO
The NaCl levels in dry fermented sausages were reduced by 50% or were substituted with KCl, CaCl2 , or a blend of KCl and CaCl2 (1:1). The quality, safety, and the potential consumer market of dry fermented sausages were assessed. Neither 50% reduction of the NaCl content nor the substitution of 50% of the NaCl with KCl influenced the fermentation and maturation process. However, when CaCl2 was used as the substitute salt (50%), there was a significant decrease in pH, an increase in the water activity, and a decrease in lactic acid and micrococcus bacterial counts. Overall, the sensory acceptance decreased in dry fermented sausages with reduced sodium content. However, cluster analysis and internal preference mapping revealed potential for commercialization of samples with 50% of the NaCl content substituted with KCl or with a mixture of KCl and CaCl2 (1:1).
Assuntos
Cloreto de Cálcio , Comportamento do Consumidor , Preferências Alimentares , Produtos da Carne/análise , Cloreto de Potássio , Cloreto de Sódio na Dieta/administração & dosagem , Paladar , Adolescente , Adulto , Cloreto de Cálcio/análise , Dieta Hipossódica , Feminino , Fermentação , Microbiologia de Alimentos , Humanos , Concentração de Íons de Hidrogênio , Ácido Láctico/análise , Masculino , Micrococcus , Pessoa de Meia-Idade , Cloreto de Potássio/análise , Sódio/administração & dosagem , Água/fisiologia , Adulto JovemRESUMO
INTRODUCTION: The levels of cadmium (Cd) and lead (Pb) in foods should be monitored as a function of health risks. OBJECTIVE: To evaluate Cd and Pb levels in oral hospital diets and in an oral food complement (OFC) according to their respective consumption by patients, and to estimate the patient's exposition risk. METHODS: The levels of Cd and Pb were determined by ICP-OES in samples of regular, blend, soft and renal diets and OFC, collected on 6 weekdays. About 14.3% of the diets and OFC served were analyzed. RESULTS AND DISCUSSION: 163 patients participated, with mean weights and ages of 62.7 kg and 56.5 years, respectively, the majority being men (59.5%). The mean Cd content consumed was greater for men fed the regular and blend diets and similar amongst the sexes for the soft diet. The consumption of Cd (max. 21.02 µg/day) was below the provisional tolerable monthly intake (PTMI). The mean Pb ingested (max. 199.49 µg/day) was similar amongst the sexes. The soft diet showed the highest Pb content in September/2010, whereas the other showed no variation according to season. In September/2010 and January/2011, the soft and regular diets associated with the OFC offered 207.50 and 210.50 µg/day of Pb, respectively. CONCLUSIONS: The combination of the diet with the OFC increased the risk of an excessive ingestion of Pb, and the vulnerability of the patients to an excessive exposition to Pb could be greater due to water and medications. It was concluded that whereas the calculated ingestion of Cd conformed to the PTMI, the Pb level and ingestion represented a risk to the health of the patients.
Assuntos
Cádmio/análise , Chumbo/análise , Brasil , Dieta , Análise de Alimentos , Serviço Hospitalar de Nutrição , Humanos , Medição de RiscoRESUMO
INTRODUCTION: The contribution of diet and treatment planning in the treatment of Chronic Kidney Disease (CKD) has been recognized as having a significant clinical impact if introduced early. OBJECTIVE: determine the levels of carbohydrates, proteins, lipids, energy and energy density (ED) in an oral hospital diet prescribed to CKD patients, and to evaluate the adequacy of this diet with respect to dietary recommendations. METHODS: Diets were collected in a Brazilian public hospital on two non-consecutive days of six different weeks. The carbohydrate, protein, and lipid (total, saturated, monounsaturated, polyunsaturated, linoleic, linolenic and trans fatty acids) contents were determined in a laboratory. The amount of energy and the ED of the diets were calculated using the correction factor Atware and by dividing the total energy of the diet by weight, respectively. RESULTS AND DISCUSSION: About 14.3% of the diets produced for patients with CKD were analyzed. The average density of the diets was low (0.7 kcal/g). In terms of nutritional adequacy, the average lipid content (15%) and linolenic fatty acid content (0.4%) were below the recommendation, as was energy (23.4 kcal / kg / day). The average carbohydrate content (63.5%) and protein content (1.0 g/kg/day) exceeded the recommendations levels. CONCLUSION: The oral hospital diet prepared for patients with CKD were considered unbalanced, and an unfavorable clinical treatment for these patients.
Introducción: La contribución de la dieta y planificación del tratamiento en el tratamiento de la enfermedad renal crónica (ERC) ha sido reconocida por tener un impacto clínico significativo si introducida tempranamente. Objetivo: determinar los niveles de hidratos de carbono, proteínas, lípidos, energía y densidad de energía (DE) en una dieta hospitalaria oral recetada para los pacientes con ERC, y evaluar la adecuación de esta dieta con respecto a las recomendaciones dietéticas. Métodos: Las dietas fueron recogidas en un hospital público brasileño en dos días no consecutivos de seis semanas diferentes. Los contenidos de los hidratos de carbono, proteínas, y lípidos (totales, saturadas, monoinsaturadas, poliinsaturadas, ácidos grasos linoleico, linolénico y trans) fueran determinados en un laboratorio. La cantidad de energía y la DE de las dietas se calcularon utilizando el factor de corrección de Atware, dividiendo la energía total de la dieta en peso, respectivamente. Resultados y Discusión: Fueran analizadas cerca de 14.3% de las dietas producidas y servidas a los pacientes con ERC. La densidad media de las di etas fue baja (0,7 kcal/g). Fue encontrada inadecuación nutricional para el contenido medio en lípidos (15%) y contenido de ácido graso linolénico (0,4%) y de energía (23,4 kcal/kg/día). El contenido de carbohidratos (63,5%) y el contenido de proteínas (1,0 g/kg/día) superaron los niveles de recomendaciones. Conclusiones: La dieta hospitalaria oral preparada para los pacientes con enfermedad renal crónica se muestra desequilibrada y desfavorable para el tratamiento clínico de los pacientes.
Assuntos
Tratamento Conservador/métodos , Dieta , Ingestão de Energia , Insuficiência Renal Crônica/dietoterapia , Insuficiência Renal Crônica/terapia , Brasil , Estudos Transversais , Carboidratos da Dieta , Gorduras na Dieta , Proteínas Alimentares , Análise de Alimentos , Hospitais , Humanos , Desnutrição/prevenção & controle , PrescriçõesRESUMO
BACKGROUND & AIMS: Many trace elements are nutrients essential to humans, acting in the metabolism as constituents or as enzymatic co-factors. The iron, zinc, copper, manganese and selenium contents of hospital diets (regular, blend and soft) and of oral food complement (OFC) were determined, evaluating the adequacy of each element in relation to the nutritional recommendations (DRIs) and the percent contribution alone and with OFC. METHODS: Duplicate samples were taken of six daily meals and of the OFC on two non-consecutive days from a hospital in Belo Horizonte (MG, Brazil) in May and September of 2010 and January of 2011. The elements were determined by ICP OES. RESULTS: Of the diets, the soft diet showed the highest elements content. Offering the OFC was insufficient to provide adequate levels of the trace elements. CONCLUSION: The oral hospital diets were inadequate in relation to the RDAs for the trace elements studied and the use of the OFCs was insufficient to compensate the values.
Assuntos
Cobre/análise , Dieta , Ferro da Dieta/análise , Manganês/análise , Selênio/análise , Zinco/análise , Administração Oral , Adulto , Brasil , Cobre/administração & dosagem , Feminino , Serviço Hospitalar de Nutrição , Humanos , Ferro da Dieta/administração & dosagem , Masculino , Manganês/administração & dosagem , Refeições , Pessoa de Meia-Idade , Necessidades Nutricionais , Recomendações Nutricionais , Selênio/administração & dosagem , Adulto Jovem , Zinco/administração & dosagemRESUMO
BACKGROUND & AIMS: Deficiencies in the consumption of foods and nutrients favor malnutrition in patients. Considering the recommendations for the ingestion of minerals, the content, consumption and percent adequacy of the minerals (Ca, Cu, Fe, Mg, Mn, K, P, Na, Zn and Se) were evaluated amongst oncology patients who received oral diets isolated or associated with an oral food complement (OFC), evaluating the need and composition of an oral supplement. METHODS: The mineral composition as determined by ICP-OES, and the food consumption of the patients served regular, bland and soft diets, were evaluated on six non-consecutive weekdays. Patients with increased nutritional needs received OFC. The consumptions were calculated by deducting the weight of the leftovers from the value served. RESULTS: A total of 163 patients took part of which 59.5% were men, the mean age was 57 ± 15 years old, and 126 (77.3%), 27 (16.6%) and 10 (6.1%) were served the regular, bland and soft diets, respectively, with (23.0%), 8 (30.7%) and 4 (40.0%) receiving the OFC. Patient consumption was lower when the regular (74.2 vs 79.7%) and soft (68.9 vs 74.2%) diets were combined with OFC. For all diets, less was consumed at the lunch (61.2%-65.7%) and dinner (39.9%-62.8%) meals. Patients that received the OFC showed reduced meal consumption and higher Ca ingestion. The mineral contents of the diets were inadequate, with 66.8% of the patients ingesting Na above the UL and K below the nutritional recommendation (100%). CONCLUSION: The diet consumption, isolated or associated with OFC was insufficient, and hence the exclusion of OFC and the inclusion of a mineral supplement (without P and Na) was indicated to adequate ingestion to the nutritional recommendations.
Assuntos
Dieta , Suplementos Nutricionais , Necessidades Nutricionais , Serviço Hospitalar de Oncologia , Oligoelementos/administração & dosagem , Oligoelementos/análise , Administração Oral , Adulto , Idoso , Feminino , Serviço Hospitalar de Nutrição , Humanos , Pacientes Internados , Masculino , Pessoa de Meia-IdadeRESUMO
Chlorella vulgaris (CV) was examined for its modulating effects on the reduction induced by lead (Pb) on the numbers of marrow hematopoietic stem cells (HSCs) (c-Kit(+)Lin(-)), granulocyte-macrophage progenitors (Gr1(+)Mac1(+)) and total bone marrow cellularity. In mice gavage-treated daily with 50mg/kg dose of CV for 10 days, concomitant to a continuous offering of 1300 ppm lead acetate in drinking water, the treatment with the algae recovered the significantly reduced numbers of these cell populations to control values. As CV may have a myelostimulating effect through the induction of cytokines, we evaluated its modulating effects on the production of IL-1α, TNF-α, IFN-γ, IL-10 and IL-6. Our results demonstrated that lead significantly impairs the production of IFN-γ, IL-1α and TNF-α and increases the production of IL-10 and IL-6 and that these effects are successfully modulated by the CV treatment. The activity of NK cells, reduced in Pb-exposed animals, was raised to levels higher than those of controls in the exposed group treated with CV. Treatment with the algae also stimulated the production of IFN-γ, IL-1α, TNF-α and NK cells activity in normal mice. In addition, zinc bone concentrations, reduced in lead-exposed mice, were partially, but significantly, reversed by the treatment with CV.
Assuntos
Células da Medula Óssea/fisiologia , Chlorella vulgaris , Citocinas/metabolismo , Chumbo/toxicidade , Animais , Células da Medula Óssea/efeitos dos fármacos , Proliferação de Células , Citocinas/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Células Matadoras Naturais/efeitos dos fármacos , Células Matadoras Naturais/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Fitoterapia , ZincoRESUMO
A set of experiments was carried out to validate a method for inorganic contaminants in honeybee-collected pollen, consisting of digestion of the samples in a closed microwave-assisted system and quantification of 10 inorganic contaminants by ICP OES. Forty-three samples of Brazilian bee pollen, collected in southeastern Brazil during one year, were analyzed. Determination of these analytes is important both as bioindicators of pollution and to verify the safety of consuming the pollen itself. The method had satisfactory performance, with good accuracy and precision. The ranges of the mean levels were 10.4-268.0 mg/kg for Al, <0.01-1.38 mg/kg for As, 2.78-17.63 mg/kg for Ba, 0.003-0.233 mg/kg for Cd, <0.01-1.11 mg/kg for Co, <0.01-2.32 mg/kg for Cr, <0.10-1.13 mg/kg for Ni, <0.01-0.44 mg/kg for Pb, <0.035-1.33 mg/kg for Sb, and <0.0004-0.0068 mg/kg for Hg. Contamination seemed to occur in the following decreasing order: Sao Paulo > Minas Gerais > Espirito Santo. Generally higher levels of all studied contaminants were observed in samples produced in an urban site, compared to those of a rural site. Al, Cd, Co, and Pb tended to have higher levels during the dry months (July-October). Ingestion estimates showed that Al and As would have the highest contributions to the adult diet, reaching 27 and 8%, respectively, of the provisional tolerable weekly intake (PTWI) values, considering a daily portion of 25 g.
Assuntos
Abelhas/fisiologia , Monitoramento Ambiental , Contaminação de Alimentos/análise , Metais/análise , Pólen/química , Animais , Brasil , PolinizaçãoRESUMO
The aim of this study was to evaluate the relationship between iron concentration in mature breast milk and characteristics of 136 donors of a Brazilian milk bank. Iron, vitamin A, zinc, and copper concentrations were assessed in human milk and maternal blood. Data were collected on maternal anthropometrics, obstetric, socioeconomic, demographic, and lifestyle factors. Iron, zinc, and copper in milk and zinc and copper in blood were detected by spectrophotometry. Vitamin A in milk and blood was determined by high-performance liquid chromatography. Hemoglobin was measured by electronic counting and serum iron and ferritin by colorimetry and chemoluminescence, respectively. Transferrin and ceruloplasmin were determined by nephelometry. According to multivariate linear regression analysis, iron in milk was positively associated with vitamin A in milk and with smoking but negatively associated with timing of breast milk donation (P < .001). These results indicate that iron concentration in milk of Brazilian donors may be influenced by nutritional factors and smoking.
Assuntos
Ferro/metabolismo , Bancos de Leite Humano , Leite Humano/química , Adolescente , Adulto , Brasil , Cobre/sangue , Cobre/metabolismo , Feminino , Humanos , Ferro/análise , Leite Humano/metabolismo , Mães , Estado Nutricional , Fumar/efeitos adversos , Vitamina A/sangue , Vitamina A/metabolismo , Adulto Jovem , Zinco/sangue , Zinco/metabolismoRESUMO
BACKGROUND & AIMS: This study evaluated the relationship between vitamin A concentration in maternal milk and the characteristics of the donors of a Brazilian human milk bank. MATERIAL AND METHODS: A total of 136 donors were selected in 2003-2004 for micronutrient determinations in breast milk and blood, anthropometric measurements and investigation of obstetric, socioeconomic-demographic factors, and life style. Maternal serum/milk samples were obtained for vitamin A, iron, copper, and zinc determinations. Vitamin A concentrations in breast milk and blood were assessed by high-performance liquid chromatography. Copper, zinc and iron concentrations in breast milk, and copper and zinc concentrations in blood were detected by atomic emission spectrophotometry. Serum ceruloplasmin and serum iron were determined, respectively, by nephelometry and colorimetry. A linear regression model assessed the associations between milk concentrations of vitamin A and maternal factors. RESULTS: Vitamin A in milk presented positive associations with iron in milk (p<0.001), serum retinol (p=0.03), maternal work (p=0.02), maternal age (p=0.02), and oral contraceptive use (p=0.01), and a negative association with % body fat (p=0.01) (R(2)=0.47). CONCLUSION: These results suggest that some nutritional, obstetric, and socioeconomic-demographic factors may have an effect on mature breast milk concentrations of vitamin A in apparently healthy Brazilian mothers.
Assuntos
Leite Humano/química , Leite Humano/metabolismo , Mães , Oligoelementos/metabolismo , Vitamina A/metabolismo , Vitaminas/metabolismo , Adulto , Fatores Etários , Antropometria , Brasil , Anticoncepcionais Orais , Cobre/sangue , Cobre/metabolismo , Emprego/estatística & dados numéricos , Feminino , Humanos , Ferro/sangue , Ferro/metabolismo , Estilo de Vida , Fatores Socioeconômicos , Oligoelementos/sangue , Vitamina A/sangue , Vitaminas/sangue , Adulto Jovem , Zinco/sangue , Zinco/metabolismoRESUMO
In this study, Chlorella vulgaris (CV) was examined for its chelating effects on the ability of bone marrow stromal cell layer to display myeloid progenitor cells in vitro in lead-exposed mice, using the long-term bone marrow culture (LTBMC). In addition, the levels of interleukin (IL)-6, an important hematopoietic stimulator, as well as the numbers of adherent and non-adherent cells were also investigated. Mice were gavage treated daily with a single 50mg/kg dose of CV for 10 days, concomitant to continuous offering of 1300ppm lead acetate in drinking water. We found that CV up-modulates the reduced ability of stromal cell layer to display myeloid progenitor cells in vitro in lead-exposed mice and restores both the reduced number of non-adherent cells and the ability of stromal cells from these mice to produce IL-6. Monitoring of lead poisoning demonstrated that CV treatment significantly reduced lead levels in blood and tissues, completely restored the normal hepatic ALA levels, decreased the abnormally high plasma ALA and partly recovered the liver capacity to produce porphyrins. These findings provide evidence for a beneficial use of CV for combination or alternative chelating therapy to protect the host from the damage induced by lead poisoning.