Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 3.119
Filtrar
1.
J Agric Food Chem ; 68(6): 1654-1665, 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-31935099

RESUMO

Microalgae accumulate bioavailable selenium-containing amino acids (Se-AAs), and these are useful as a food supplement. While this accumulation has been studied in phototrophic algal cultures, little data exists for heterotrophic cultures. We have determined the Se-AAs content, selenium/sulfur (Se/S) substitution rates, and overall Se accumulation balance in photo- and heterotrophic Chlorella cultures. Laboratory trials revealed that heterotrophic cultures tolerate Se doses ∼8-fold higher compared to phototrophic cultures, resulting in a ∼2-3-fold higher Se-AAs content. In large-scale experiments, both cultivation regimes provided comparable Se-AAs content. Outdoor phototrophic cultures accumulated up to 400 µg g-1 of total Se-AAs and exhibited a high level of Se/S substitution (5-10%) with 30-60% organic/total Se embedded in the biomass. A slightly higher content of Se-AAs and ratio of Se/S substitution was obtained for a heterotrophic culture in pilot-scale fermentors. The data presented here shows that heterotrophic Chlorella cultures provide an alternative for Se-enriched biomass production and provides information on Se-AAs content and speciation in different cultivation regimes.


Assuntos
Aminoácidos/metabolismo , Chlorella/metabolismo , Chlorella/efeitos da radiação , Selênio/metabolismo , Aminoácidos/análise , Biomassa , Chlorella/classificação , Chlorella/crescimento & desenvolvimento , Processos Heterotróficos , Microalgas/química , Microalgas/crescimento & desenvolvimento , Microalgas/metabolismo , Microalgas/efeitos da radiação , Processos Fototróficos , Selênio/análise
2.
J Agric Food Chem ; 68(6): 1525-1535, 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-31942799

RESUMO

Enrichment of food crops with iodine is an option to alleviate dietary deficiencies. Therefore, foliar iodine fertilizer was applied on wheat and rice, in the presence and absence of the other micronutrients zinc and selenium. This treatment increased the concentration of iodine, as well as zinc and selenium, in the staple grains. Subsequently, potential iodine losses during preparation of foodstuffs with the enriched grains were studied. Oven-heating did not affect the iodine content in bread. Extraction of bran from flour lowered the iodine in white bread compared to wholegrain bread, but it was still markedly higher compared to the control. During subsequent in vitro gastrointestinal digestion, a higher percentage of iodine was released from foods based on extracted flour (82-92%) compared to wholegrain foods (50-76%). The foliar fertilization of wheat was found to be adequate to alleviate iodine deficiency in a population with a moderate to high intake of bread.


Assuntos
Iodo/metabolismo , Oryza/metabolismo , Selênio/metabolismo , Triticum/metabolismo , Zinco/metabolismo , Biofortificação , Pão/análise , Culinária , Fertilizantes/análise , Farinha/análise , Alimentos Fortificados/análise , Temperatura Alta , Humanos , Iodo/análise , Oryza/química , Sementes/química , Sementes/metabolismo , Selênio/análise , Triticum/química , Zinco/análise
3.
Chemosphere ; 242: 125289, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31896204

RESUMO

Selenium (Se) and zinc (Zn) are essential microelements for humans with crucial biological functions. In this study, we determined Se and Zn concentrations in soils and rice grains on Hainan Island and investigated how their spatial distributions are related to soil mineral elements, topography, and vegetation coverage. Overall, the concentrations of Se and Zn in soils were higher than the background values for Chinese soil; the Se concentrations in rice grains were higher than the threshold value for Se deficiency in grains, but Zn concentrations were lower than the proposed critical concentration. Both Spearman's correlation and stepwise regression analysis showed that the concentrations of soil Fe and Ca significantly affected soil Se and Zn: a difference of 1 g kg-1 in soil Fe changed soil Se by 2.820 µg kg-1 and soil Zn by 0.785 mg kg-1, respectively, while a difference of 1 g kg-1 in soil Ca changed soil Se by 3.249 µg kg-1 and soil Zn by 0.356 mg kg-1, respectively. For rice grains, Se and Zn concentrations decreased with increasing elevation; every 100 m increase in elevation could decrease Se by 0.022 mg kg-1 and Zn by 0.912 mg kg-1. Moreover, the impact of Fe and Ca on soil Zn was relatively strong in the northeast region, while the influence of elevation on rice grain Se was more significant in the central region. The findings contribute to a better understanding of factors driving the distribution of Se and Zn in soils and crops.


Assuntos
Grão Comestível/química , Monitoramento Ambiental/métodos , Oryza/química , Selênio/análise , Solo/química , Zinco/análise , Altitude , Cálcio/análise , China , Humanos , Ferro/análise , Ilhas , Análise de Regressão , Análise Espacial
4.
Ecotoxicol Environ Saf ; 187: 109820, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31670242

RESUMO

Huge amounts of fly ash (FA) can be annually produced in power plants. Fly ash always contains high levels of arsenic (As) and selenium (Se) due to the preconcentration of these two elements during coal combustion process. It would be much concerned to screen their fractions and potential environmental behaviors in fly ash for beneficial use and treatment. Fast and practical methods for this purpose are urgently needed. Two fast and effective microwave-assisted sequential extraction schemes (MASE) were developed for fast screening As and Se fractions in fly ash for the first time. The extraction parameters including microwave irradiation time, temperature and power energy were optimized by comparing the results from MASE and the conventional scheme (Wenzel method). The results indicate that the extraction efficiency of As and Se in various fractions can be significantly accelerated by microwave irradiation. The whole procedure operation time can be significantly reduced from 24.5 h to 44 min by microwave assistance compared with the conventional shaking schemes. The recoveries of As and Se in the various extracted fractions were all above 80% with relative standard deviations (RSDs) below 8%. The developed methods were further confirmed by the validation of the certified reference material GBW08401 and fly ash samples from six power plants. The developed MASE methods are practical and effective for fast screening arsenic and selenium fractions in fly ash samples.


Assuntos
Arsênico/análise , Cinza de Carvão/análise , Monitoramento Ambiental/métodos , Poluentes Ambientais/análise , Micro-Ondas , Selênio/análise , Disponibilidade Biológica , Centrais Elétricas
5.
Sci Total Environ ; 698: 134106, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31505350

RESUMO

Chronic exposure to cadmium (Cd) can cause renal dysfunction. Studies of animals, cell cultures, and plants have found that selenium (Se) can effectively alleviate the hazard generated by Cd, but there has been little study of this in general human populations. This study recruited 313 subjects from China's Hubei Province, including 160 living in areas with high soil Cd and Se (exposure group) and 153 living in clean areas (control group). The levels of the following were detected: Cd and Se in blood (B-Cd and B-Se), urine (U-Cd and U-Se), and hair (H-Cd and H-Se); N-acetyl-ß-D-glucosaminidase (U-NAG), ß2-microglobulin (U-ß2-MG), and albumin (U-ALB) in urine; and malondialdehyde (S-MDA), superoxide dismutase (S-SOD), and glutathione peroxidase (S-GSH-Px) in serum. In addition, the interactions between Cd and Se were assessed. The median levels of B-Cd, B-Se, U-Cd, U-Se, H-Cd, H-Se, S-MDA, and S-GSH-Px of exposure group (2.60 ng/mL, 238.90 ng/mL, 3.13 µg/g Cr, 45.43 µg/g Cr, 0.06 µg/g, 0.70 µg/g, 5.22 nmol/mL, and 308.89 U, respectively) were significantly higher than of controls (0.95 ng/mL, 130.50 ng/mL, 1.08 µg/g Cr, 30.51 µg/g Cr, 0.04 µg/g, 0.49 µg/g, 4.71 nmol/mL, and 267.54 U, respectively), but there were no significant differences in U-NAG, U-ß2-MG, U-ALB, or S-SOD between the two groups. U-NAG levels were significantly negatively associated with the interaction between Cd and Se (B: -0.511, 95% CI: -0.886, -0.136). Additionally, changes in the direction of the estimated regression coefficient in the low and high H-Se groups were observed for U-Cd and S-MDA (from 0.018 to -0.090), U-Cd and S-GSH-Px (from -0.039 to 0.101). This study found that populations living in areas with high levels of soil Cd and Se did not show greater Cd-induced renal tubular and glomerular injuries than the control population, which could attribute to the protective effects of Se. The protective effects may be related to the peculiar function of Se that Se can combine with free Cd to activate the antioxidant enzyme system.


Assuntos
Cádmio/análise , Exposição Ambiental/estatística & dados numéricos , Nefropatias/epidemiologia , Selênio/análise , Poluentes do Solo/análise , Acetilglucosaminidase/metabolismo , Antioxidantes , Cádmio/metabolismo , China/epidemiologia , Glutationa Peroxidase/metabolismo , Humanos , Nefropatias/metabolismo , Malondialdeído/metabolismo , Substâncias Protetoras/metabolismo , Selênio/metabolismo , Poluentes do Solo/metabolismo , Superóxido Dismutase/metabolismo , Microglobulina beta-2/metabolismo
6.
Sci Total Environ ; 699: 134330, 2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-31522043

RESUMO

Rice is one of the principal staple foods, essential for safeguarding the global food and nutritional security, but due to different natural and anthropogenic sources, it also acts as one of the biggest reservoirs of potentially toxic metal(loids) like As, Hg, Se, Pb and Cd. This review summarizes mobilization, translocation and speciation mechanism of these metal(loids) in soil-plant continuum as well as available cost-effective remediation measures and future research needs to eliminate the long-term risk to human health. High concentrations of these elements not only cause toxicity problems in plants, but also in animals that consume them and gradual deposition of these elements leads to the risk of bioaccumulation. The extensive occurrence of contaminated rice grains globally poses substantial public health risk and merits immediate action. People living in hotspots of contamination are exposed to higher health risks, however, rice import/export among different countries make the problem of global concern. Accumulation of As, Hg, Se, Pb and Cd in rice grains can be reduced by reducing their bioavailability, and controlling their uptake by rice plants. The contaminated soils can be reclaimed by phytoremediation, bioremediation, chemical amendments and mechanical measures; however these methods are either too expensive and/or too slow. Integration of innovative agronomic practices like crop establishment methods and improved irrigation and nutrient management practices are important steps to help mitigate the accumulation in soil as well as plant parts. Adoption of transgenic techniques for development of rice cultivars with low accumulation in edible plant parts could be a realistic option that would permit rice cultivation in soils with high bioavailability of these metal(loid)s.


Assuntos
Exposição Dietética/estatística & dados numéricos , Monitoramento Ambiental , Metaloides/análise , Poluentes do Solo/análise , Agricultura , Arsênico/análise , Cádmio/análise , Humanos , Chumbo/análise , Mercúrio/análise , Oryza , Selênio/análise , Solo
7.
J Sci Food Agric ; 100(1): 225-234, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31512247

RESUMO

BACKGROUND: Metabolic syndrome, a group of factors that increase the risk of health problems, is becoming increasingly common. Strategies to prevent metabolic syndrome have received substantial attention. Black tea consumption and selenium (Se) intake have been reported to be associated negatively with the prevalence of metabolic syndrome. We therefore sought to investigate whether Se-rich black tea might have a stronger effect than Se-deficient black tea in the prevention of metabolic syndrome. RESULTS: Sprague-Dawley rats were divided into four groups and fed a normal rodent diet, high-fat diet, high-fat diet containing 3% Se-rich black tea, or a high-fat diet containing 3% Se-deficient black tea for 4 weeks. Blood and tissue samples were tested at the end of the experiment. The results suggested that both types of black tea ameliorated high-fat diet-induced body-weight gain, lowered serum triglycerides and attenuated intestinal barrier dysfunction. Selenium-rich black tea showed stronger activity in decreasing fasting serum glucose and increasing insulin sensitivity, as well as stronger hepatoprotection, owing to higher total antioxidant capacity and activated hepatic antioxidant enzymes. However, it did not exhibit better effects in preventing fat accumulation. The different effects of Se-rich and Se-deficient black tea on the gut microbiota might have been partially responsible for the results. CONCLUSION: Compared with Se-deficient black tea, Se-rich black tea displayed stronger activity in preventing high-fat diet-induced hyperglycemia and liver damage but was not better at preventing fat accumulation and attenuating dysbiosis. More experiments are needed to understand the underlying mechanisms further. © 2019 Society of Chemical Industry.


Assuntos
Camellia sinensis/química , Síndrome Metabólica/prevenção & controle , Selênio/análise , Chá/metabolismo , Animais , Glicemia/metabolismo , Camellia sinensis/metabolismo , Dieta Hiperlipídica/efeitos adversos , Jejum , Humanos , Resistência à Insulina , Masculino , Síndrome Metabólica/etiologia , Síndrome Metabólica/metabolismo , Ratos , Ratos Sprague-Dawley , Selênio/metabolismo , Chá/química
8.
Food Chem ; 302: 125371, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31437711

RESUMO

Dietary selenium deficiency is recognized as a global problem. Pork is the most widely consumed meat throughout the world and an important source of selenium for humans. In this study, a reliable approach was developed for analyzing selenium and its speciation in the muscles of pigs after different selenium treatments. The selenium source deposition efficiency was ranked as: selenomethionine > methylselenocysteine > selenite, and the muscle selenium content had a dose effect with selenomethionine supplementation. In total, four species of selenium were detected in the muscles of pigs and the distributions of these selenium species were greatly affected by the dietary selenium supplementation forms and levels. Selenomethionine (>70% of total selenium) and selenocystine (>11%) were the major selenium species, followed by methylselenocysteine and selenourea. Therefore, selenium-enriched pork produced from selenomethionine is a good source for improving human dietary selenium intake.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas/métodos , Músculo Esquelético/química , Compostos de Selênio/farmacologia , Selênio/análise , Animais , Cistina/análogos & derivados , Cistina/análise , Suplementos Nutricionais , Análise de Alimentos/métodos , Masculino , Músculo Esquelético/efeitos dos fármacos , Compostos Organosselênicos/análise , Reprodutibilidade dos Testes , Ácido Selenioso/farmacologia , Compostos de Selênio/análise , Selenocisteína/análogos & derivados , Selenocisteína/farmacologia , Selenometionina/análise , Selenometionina/farmacologia , Suínos , Ureia/análogos & derivados , Ureia/análise
9.
Sci Total Environ ; 694: 133716, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31756789

RESUMO

This study aims to quantify the selenium contribution from tuna to the Spanish diet and evidence the Se protective role against mercury and inorganic arsenic toxicity. Selenium concentrations in tuna were determined by ICP-MS spectrometry (expressed as mg kg-1), and the risk assessment was evaluated joined to Hg and iAs contrasting criteria of regulatory agencies with those that consider the Se protective role. Differences between Se average concentrations in fresh (1.24) and preserved (1.17) tuna were not statistically significant. In canned tuna species, Se presented higher mean levels in Thunnus albacares (1.28) than Thunnus alalunga (1.01) with statistically significant differences (p = 0.002), and among canned preparations a decreasing sequence was observed in different preparation-packaging media: oil (1.42) > natural (1.01) > pickled (0.92). Statistical study showed Hg-iAs as the only pair significantly correlated in all samples. The HI (sum of individual target hazard quotients -THQs-) on the consumption of tuna in Spain, due to exposure to Se, Hg and iAs, revealed the possibility of risk of adverse chronic effects in the six-year-old children group (1.09). According to the maximum allowable tuna consumption rate in meals/week (CRmw) and the THQs obtained, tuna intake, especially in children, should be moderated. The health benefit values (HBVSe) were positive in all samples, 14.53 and 15.65 in fresh and preserved tuna, respectively, which allows tuna to be considered safe. The benefit-risk value (BRV) evidenced the Se molar excess with respect to Hg that reached a surplus of 14.32% on Se AI in adults. Since iAs reduces the Se bioavailability, applying a new BRV criterion, the aforementioned percentage decreased to 13.49% of Se AI. In conclusion, tuna offers high levels of selenium to counteract adverse effects by the presence of Hg and iAs, and to provide consumers an important source of this essential element safely.


Assuntos
Arsênico/análise , Exposição Dietética/estatística & dados numéricos , Mercúrio/análise , Substâncias Protetoras/análise , Selênio/análise , Atum , Adulto , Animais , Criança , Contaminação de Alimentos , Humanos , Medição de Risco
10.
J Agric Food Chem ; 67(45): 12408-12418, 2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31644287

RESUMO

Vegetables are an ideal source of human Se intake; it is important to understand selenium (Se) speciation in plants due to the distinct biological functions of selenocompounds. In this hydroponic study, the accumulation and assimilation of selenite and selenate in pak choi (Brassica rapa), a vastly consumed vegetable, were investigated at 1-168 h with HPLC speciation and RNA-sequencing. The results showed that the Se content in shoots and Se translocation factors with selenate addition were at least 10.81 and 11.62 times, respectively, higher than those with selenite addition. Selenite and selenate up-regulated the expression of SULT1;1 and PHT1;2 in roots by over 240% and 400%, respectively. Selenite addition always led to higher proportions of seleno-amino acids, while SeO42- was dominant under selenate addition (>49% of all Se species in shoots). However, in roots, SeO42- proportions declined substantially by 51% with a significant increase of selenomethionine proportions (63%) from 1 to 168 h. Moreover, with enhanced transcript of methionine gamma-lyase (60% of up-regulation compared to the control) plus high levels of methylselenium in shoots (approximately 70% of all Se species), almost 40% of Se was lost during the exposure under the selenite treatment. This work provides evidence that pak choi can rapidly transform selenite to methylselenium, and it is promising to use the plant for Se biofortification.


Assuntos
Brassica rapa/genética , Brassica rapa/metabolismo , Ácido Selênico/metabolismo , Ácido Selenioso/metabolismo , Selênio/metabolismo , Biotransformação , Brassica rapa/química , Brassica rapa/crescimento & desenvolvimento , Cromatografia Líquida de Alta Pressão , Hidroponia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/química , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Ácido Selênico/análise , Ácido Selenioso/análise , Selênio/análise , Análise de Sequência de RNA
11.
Aquat Toxicol ; 216: 105299, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31593906

RESUMO

Selenium (Se) is an essential trace element of concern that is known to contaminate aquatic ecosystems as a consequence of releases from anthropogenic activities. Selenium is of particular toxicological concern for egg-laying vertebrates as they bioaccumulate Se through the diet and deposit excess Se to embryo-offspring via maternal transfer, a process which has been shown to result in significant teratogenic effects. The purpose of the present study was to determine and compare the in ovo effects of Se exposure on early development of a laboratory model fish species native to North American freshwater systems, the fathead minnow (Pimephales promelas), through two different exposure routes, maternal transfer and microinjection. For maternal transfer studies, fathead minnow breeding groups (3 females: 2 males) were exposed to diets containing Se-background levels (1.21 µg Se/g food, dry mass [dm]) or environmentally relevant concentrations of selenomethionine (SeMet; 3.88, 8.75 and 26.5 µg Se/g food dm) and bred for 28 days. Embryos were collected at different time points throughout the study to measure Se concentrations and to assess teratogenicity in embryos. While exposure to dietary Se did not negatively affect fecundity among treatment groups, the lowest treatment group (3.88 µg Se/g food dm) produced on average the most embryos per day, per female. The maternal transfer of excess Se occurred rapidly upon onset of exposure, reaching steady-state after approximately 14 days, and embryo Se concentrations increased in a dose-dependent manner. The greatest concentrations of maternally transferred Se significantly increased the total proportion of deformed embryo-larval fathead minnows but did not impact hatchability or survival. In a second study, fathead minnow embryos were injected with SeMet at concentrations of 0.00 (vehicle control), 9.73, 13.5 and 18.9 µg Se/g embryo dm. Microinjection of SeMet did not affect hatchability but significantly increased the proportion of deformed embryo-larval fish in a dose-dependent manner. There was a greater proportion of deformed fathead minnows at embryo Se concentrations of 18.9 µg Se/g embryo dm when exposed via microinjection versus maternal transfer at concentrations of 28.4 µg Se/g embryo dm. However, the findings suggest that both exposure routes induced analogous developmental toxicities in early life stage fish at Se concentrations between 9.73 and 13.5 µg Se/g embryo dm. Overall, this study demonstrated that microinjection has utility for studying the effects of Se in embryo-larval fish and is a promising method for the study of early life stage Se exposure in egg-laying vertebrates.


Assuntos
Cyprinidae/embriologia , Embrião não Mamífero/efeitos dos fármacos , Exposição Materna , Microinjeções , Selenometionina/administração & dosagem , Selenometionina/toxicidade , Animais , Antioxidantes/farmacologia , Dieta , Ecossistema , Feminino , Água Doce , Larva/efeitos dos fármacos , Estágios do Ciclo de Vida/efeitos dos fármacos , Modelos Lineares , Masculino , Reprodução/efeitos dos fármacos , Selênio/análise , Poluentes Químicos da Água/toxicidade
12.
Environ Pollut ; 255(Pt 1): 113134, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31520910

RESUMO

Sediment porewater can be an important source of contaminants in the overlying water, but the mechanisms of metal(loid) and phosphorus (P) remobilization remain to be investigated. In this study, high-resolution dialysis (HR-Peeper) and diffusive gradients in thin films (DGT) samplers were used to determine the porewater dissolved iron (Fe), manganese (Mn), cobalt (Co), chromium (Cr), vanadium (V), selenium (Se), arsenic (As), P and DGT-Labile S in coastal sediments in the Jiulong River Estuary (JRE), China. The results showed that high concentrations of dissolved Mn, Se and P were present in the overlying water, indicating potential water pollution with excessive amounts of Mn, Se and P. The dissolved Mn concentrations in the porewater were higher than the dissolved Fe concentrations, especially at submerged sites, demonstrating that Mn(III/IV) reduction is the dominant diagenetic pathway for organic carbon (OC) degradation, which directly affects Fe cycling by the competitive inhibition of Fe(III) reduction and Fe(II) reoxidation. Dissolved Co, Cr, V, Se, As and P show significant positive correlations with Mn but nearly no correlations with Fe, suggesting that the mobility of these metal(loid)s and P is associated with Mn but not Fe cycling in this region. In addition, the coelevated concentrations of the metal(loid)s, P and Mn at the submerged sites are attributed to the strengthened Mn reduction coupled with OC degradation fueled by hypoxia. The higher positive diffusion fluxes of Mn, Se and P were consistent with the excess Mn, Se and P concentrations in the overlying water, together with the approximately positive fluxes of the other metal(loid)s, indicating that sediment Mn(III/IV) reduction and concomitant metal(loid) and P remobilization might be vital pathways for metal(loid) and P migration to the overlying water.


Assuntos
Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Metais Pesados/análise , Fósforo/análise , Rios/química , Poluentes Químicos da Água/análise , Arsênico/análise , China , Cromo/análise , Cobalto/análise , Estuários , Compostos Férricos/análise , Ferro/análise , Manganês/análise , Selênio/análise , Vanádio/análise , Água/química
13.
Nature ; 574(7776): 95-98, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31554969

RESUMO

Micronutrient deficiencies account for an estimated one million premature deaths annually, and for some nations can reduce gross domestic product1,2 by up to 11%, highlighting the need for food policies that focus on improving nutrition rather than simply increasing the volume of food produced3. People gain nutrients from a varied diet, although fish-which are a rich source of bioavailable micronutrients that are essential to human health4-are often overlooked. A lack of understanding of the nutrient composition of most fish5 and how nutrient yields vary among fisheries has hindered the policy shifts that are needed to effectively harness the potential of fisheries for food and nutrition security6. Here, using the concentration of 7 nutrients in more than 350 species of marine fish, we estimate how environmental and ecological traits predict nutrient content of marine finfish species. We use this predictive model to quantify the global spatial patterns of the concentrations of nutrients in marine fisheries and compare nutrient yields to the prevalence of micronutrient deficiencies in human populations. We find that species from tropical thermal regimes contain higher concentrations of calcium, iron and zinc; smaller species contain higher concentrations of calcium, iron and omega-3 fatty acids; and species from cold thermal regimes or those with a pelagic feeding pathway contain higher concentrations of omega-3 fatty acids. There is no relationship between nutrient concentrations and total fishery yield, highlighting that the nutrient quality of a fishery is determined by the species composition. For a number of countries in which nutrient intakes are inadequate, nutrients available in marine finfish catches exceed the dietary requirements for populations that live within 100 km of the coast, and a fraction of current landings could be particularly impactful for children under 5 years of age. Our analyses suggest that fish-based food strategies have the potential to substantially contribute to global food and nutrition security.


Assuntos
Pesqueiros , Peixes/metabolismo , Abastecimento de Alimentos , Internacionalidade , Micronutrientes/deficiência , Micronutrientes/metabolismo , Estado Nutricional , Animais , Teorema de Bayes , Cálcio/análise , Pré-Escolar , Proteínas na Dieta/análise , Ácidos Graxos Ômega-3/análise , Produtos Pesqueiros/análise , Produtos Pesqueiros/economia , Pesqueiros/economia , Peixes/classificação , Humanos , Lactente , Ferro/análise , Micronutrientes/análise , Selênio/análise , Vitamina A/análise , Zinco/análise
14.
Environ Pollut ; 255(Pt 1): 113157, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31541838

RESUMO

As one of the highest energy consuming and polluting industries, the power generation industry is an important source of particulate matter emissions. Recently, implementation of ultra-low emission technology has changed the emission characteristic of fine particulate matter (PM2.5). In this study, PM2.5 emitted from four typical power plants in China was sampled using a dilution channel sampling system, and analyzed for elements, water-soluble ions and carbonaceous fractions. The results showed that PM2.5 concentrations emitted from the four power plants were 0.78 ±â€¯0.16, 0.63 ±â€¯0.09, 0.29 ±â€¯0.07 and 0.28 ±â€¯0.01 mg m-3, respectively. Emission factors were 0.004-0.005 g/kg coal, nearly 1-2 orders of magnitude lower than those reported in previous studies. The highest proportions of PM2.5 consisted of organic carbon (OC), SO42-, elemental carbon (EC), NH4+, Al and Cl-. Coefficients of divergence (CDs) were in the ranges 0.22-0.41 (for an individual plant), 0.43-0.69 (among different plants), and 0.60-0.99 (in previous studies). The results indicated that the source profiles of each tested power plant were relatively similar, but differed from those in previous studies. Enrichment factors showed elevated Se and Hg, in accordance with the source markers Se and As. Comparing source profiles with previous studies, the proportion of OC, EC and NH4+ were higher, while the proportion of Al in PM2.5 were relatively lower. The OC/EC ratio became concentrated at ∼5. Results from this study can be used for source apportionment and emission inventory calculations after implementation of ultra-low emission technologies.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Material Particulado/análise , Centrais Elétricas , Alumínio/análise , Arsênico/análise , Carbono/análise , China , Carvão Mineral/análise , Mercúrio/análise , Selênio/análise , Água/química
15.
Mar Pollut Bull ; 149: 110562, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31542601

RESUMO

Marine debris is widespread in all the world's oceans. Currently little is understood about how marine debris affects the chemistry of the surface oceans, particularly trace elements that can adsorb to the surface of marine debris, especially plastic debris, or be taken up by biofilms and algae growing on the surface of marine debris. Selenium (Se) is a micronutrient that is essential to all living organisms. Average seawater Se concentrations in the modern ocean are <1 nM. Here we measure the concentration of Se in surface water and one deep water sample and the concentration of Se found in algae/biofilms growing on the surface of macro-debris collected in October of 2012. Concentrations of Se in biofilm varied more according to the type of biofilm rather than the type of plastic. However, further Se measurements are needed for more conclusive results.


Assuntos
Biofilmes , Monitoramento Ambiental , Água do Mar/química , Selênio/análise , Resíduos/análise , Poluentes Químicos da Água/análise , Biofilmes/classificação , Biofilmes/crescimento & desenvolvimento , Oceanos e Mares , Plásticos/química , Oligoelementos/análise
16.
J Food Sci ; 84(10): 2840-2846, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31517998

RESUMO

Cu, Fe, Mn, Mo, Selenium (Se), and Zn bioavailability from selenate- and selenite-enriched lettuce plants was studied by in vitro gastrointestinal digestion followed by an assay with Caco-2 cells. The plants were cultivated in the absence and presence of two concentrations (25 and 40 µmol/L of Se). After 28 days of cultivation, the plants were harvested, dried, and evaluated regarding the total concentration, bioaccessibility, and bioavailability of the analytes. The results showed that biofortification with selenate leads to higher Se absorption by the plant than biofortification with selenite. For the other nutrients, Mo showed high accumulation in the plants of selenate assays, and the presence of any Se species led to a reduction of the plant uptake of Cu and Fe. The accumulation of Zn and Mn was not strongly influenced by the presence of any Se species. The bioaccessibility values were approximately 71%, 10%, 52%, 84%, 71%, and 86% for Cu, Fe, Mn, Mo, Se, and Zn, respectively, and the contribution of the biofortified lettuce to the ingestion of these minerals is very small (except for Se and Mo). Due to the low concentrations of elements from digested plants, it was not possible to estimate the bioavailability for some elements, and for Mo and Zn, the values are below 6.9% and 3.4% of the total concentration, respectively. For Se, the bioavailability was greater for selenite-enriched than selenate-enriched plants (22% and 6.0%, respectively), because selenite is biotransformed by the plant to organic forms that are better assimilated by the cells.


Assuntos
Cobre/análise , Ferro/análise , Alface/química , Manganês/análise , Molibdênio/análise , Selênio/análise , Zinco/análise , Biofortificação , Disponibilidade Biológica , Células CACO-2 , Cobre/metabolismo , Humanos , Ferro/metabolismo , Alface/metabolismo , Manganês/metabolismo , Molibdênio/metabolismo , Ácido Selênico/análise , Ácido Selênico/metabolismo , Ácido Selenioso/análise , Ácido Selenioso/metabolismo , Selênio/metabolismo , Zinco/metabolismo
17.
J Food Sci ; 84(10): 3027-3036, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31529805

RESUMO

This study aimed to investigate the effect of Se (Selenium) treatment on nutritional quality in radish sprouts. The results showed that 15 µM sodium selenite significantly increased phenolics compounds, flavonoids compounds, anthocyanins, and some essential amino acid content, while improving the total antioxidant capacity of radish sprouts. Besides, the Se-enriched radish sprouts significantly alleviated the liver damage caused by carbon tetrachloride (CCl4 ) in mice and improved the antioxidant capacity of the liver in mice, whereas the Se-enriched radish sprouts alleviated the inflammatory reaction and apoptosis caused by CCl4 . These results imply that Se-enriched radish sprouts have a positive impact on mice with CCl4 -induced liver injury, and that in future Se-enriched radish sprouts could be developed into an effective food and health care product for the liver injury prevention. PRACTICAL APPLICATION: Because selenium is an essential trace element in the human body, selenium-enriched sprouts can help eliminate free radicals in the body, relieve aging, and selenium-deficient diseases. They are easy to grow and have low costs. Hence, selenium-enriched sprouts have a great potential of being widely consumed.


Assuntos
Tetracloreto de Carbono/efeitos adversos , Doença Hepática Crônica Induzida por Substâncias e Drogas/dietoterapia , Substâncias Protetoras/metabolismo , Raphanus/metabolismo , Selênio/metabolismo , Animais , Antocianinas/análise , Antocianinas/metabolismo , Antioxidantes/análise , Antioxidantes/metabolismo , Doença Hepática Crônica Induzida por Substâncias e Drogas/etiologia , Doença Hepática Crônica Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Crônica Induzida por Substâncias e Drogas/prevenção & controle , Flavonoides/análise , Flavonoides/metabolismo , Humanos , Fígado/metabolismo , Masculino , Fenóis/análise , Fenóis/metabolismo , Substâncias Protetoras/análise , Raphanus/química , Raphanus/crescimento & desenvolvimento , Ratos , Ratos Wistar , Plântula/química , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Sementes/química , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Selênio/análise
18.
Ecotoxicol Environ Saf ; 184: 109623, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31518823

RESUMO

This study provides information on mercury (Hg) localization, speciation and ligand environment in edible mushrooms: Boletus edulis, B. aereus and Scutiger pes-caprae collected at non-polluted and Hg polluted sites, by LA-ICP-MS, SR-µ-XRF and Hg L3-edge XANES and EXAFS. Mushrooms (especially young ones) collected at Hg polluted sites can contain more than 100 µg Hg g-1 of dry mass. Imaging of the element distribution shows that Hg accumulates mainly in the spore-forming part (hymenium) of the cap. Removal of hymenium before consumption can eliminate more than 50% of accumulated Hg. Mercury is mainly coordinated to di-thiols (43-82%), followed by di-selenols (13-35%) and tetra-thiols (12-20%). Mercury bioavailability, as determined by feeding the mushrooms to Spanish slugs (known metal bioindicators owing to accumulation of metals in their digestive gland), ranged from 4% (S. pes-caprae) to 30% (B. aereus), and decreased with increasing selenium (Se) levels in the mushrooms. Elevated Hg levels in mushrooms fed to the slugs induced toxic effects, but these effects were counteracted with increasing Se concentrations in the mushrooms, pointing to a protective role of Se against Hg toxicity through HgSe complexation. Nevertheless, consumption of the studied mushroom species from Hg polluted sites should be avoided.


Assuntos
Agaricales/química , Contaminação de Alimentos/análise , Compostos de Mercúrio/análise , Poluentes do Solo/análise , Agaricales/metabolismo , Animais , Disponibilidade Biológica , Monitoramento Ambiental , Carpóforos/química , Carpóforos/metabolismo , Gastrópodes/metabolismo , Compostos de Mercúrio/metabolismo , Compostos de Mercúrio/toxicidade , Selênio/análise , Poluentes do Solo/metabolismo , Poluentes do Solo/toxicidade
19.
Sci Total Environ ; 692: 1116-1124, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31539943

RESUMO

Bacterial biofilms are structured cell communities embedded in a matrix of extracellular polymeric substances (EPS) and a ubiquitous growth form of bacteria in the environment. A wide range of interactions between biofilms and nanoparticles have been reported. In the present study, the influence of a mixed bacterial biofilm on retention of biogenic selenium nanoparticles (BioSeNPs) and consequences for immobilization of elemental mercury (Hg0) in a porous quartz sand system were examined. BioSeNPs were significantly retained in the presence of a biofilm through electrical double layer effects, hydrogen bonding, and hydrophobic, steric and bridging interactions. Moreover, enhanced surface roughness, pore clogging, sieving and entrapment effects mediated by the biofilm also contributed to deposition of BioSeNPs. Whereas, thiol groups associated with the biofilm is a little helpful for the capture of Hg0. It is proposed that oxidative complexation between Hg0 and thiol compounds or S containing organic matter in the biofilm may result in the formation of Hg2+-thiolate complexes and HgS during the binding of Hg0 with BioSeNPs. The formation of mercury selenide was also involved in Hg0 immobilization in the porous quartz sand system.


Assuntos
Mercúrio/análise , Modelos Químicos , Nanopartículas/análise , Selênio/análise , Biofilmes , Interações Hidrofóbicas e Hidrofílicas , Nanopartículas/química , Quartzo , Selênio/química
20.
Bull Environ Contam Toxicol ; 103(4): 521-527, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31473774

RESUMO

We determinated Hg and Se concentrations in liver, kidney, brain, lung and muscle of five bottlenose dolphin (Tursiops truncatus), four common dolphins (Delphinus delphis) and four Risso's dolphin (Grampus griseus) stranded along the Murcia coast, Southeast Spain, in order to evaluate the risk of Hg toxicity. Hg concentrations showed similar concentrations to other individuals in the Mediterranean Sea with the same length in the same period. We observed a positive correlation of Hg and Se in liver (r = 0.948, p < 0.001) and kidney (r = 0.939; p = 0.001) and ratio the Se/Hg molar was higher than 1 in most cases. Our results suggest that the protective effects of Se against Hg toxicity occur in cetaceans. However, we detected levels of Hg described as responsible liver damage and neurotoxicological effects so other tools, as biochemical markers, should be included. Besides, more studies are needed to evaluate the risk of Hg exposure in dolphins from Murcia coastline.


Assuntos
Golfinhos/metabolismo , Monitoramento Ambiental/métodos , Rim/química , Fígado/química , Mercúrio/análise , Selênio/análise , Animais , Golfinho Nariz-de-Garrafa/metabolismo , Golfinhos Comuns/metabolismo , Mar Mediterrâneo , Especificidade de Órgãos , Espanha
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA