Greener production of a starch-based nanohybrid material (core-shell) for the simultaneous extraction of persistent organic pollutants in shrimp samples.

Here, a novel nanohybrid material (Ag@CD@ANS) based on oat starch was produced, characterized, and applied to extract persistent organic pollutants in a shrimp sample. By the characterization experiments, Ag@CD@ANS was successfully synthesized. The functionalization of the material by 1,2-naphthoquinone-4-sulphonic acid (ANS) was confirmed using the infrared technique and CHN elemental analysis. The isotherm study showed that the material has a high adsorption capacity for the pesticides of interest (flutriafol, atrazine, heptachlor, DDT and bifenthrin) allowing their extraction from shrimp samples. The optimal condition for extraction was obtained using multivariate analysis. The nature of the elution solvent (hexane, methanol, acetonitrile) and the mass ratio between sample:adsorbent (1:1; 1:5 and 1:10) were the evaluated factors for extraction using Ag@CD@ANS and commercial adsorbents (neutral alumina, octadecyl, silica gel). From the multivariate analysis, it was observed that the optimal condition for pesticide extraction using Ag@CD@ANS was reached, using a 1:5 ratio (sample:adsorbent) and acetonitrile (10 mL) as elution solvent. For the commercial adsorbents, the optimal condition for pesticide extraction was reached, using a 1:3 ratio (sample:adsorbent), acetonitrile (10 mL) and neutral alumina as commercial adsorbent. Ag@CD@ANS efficiency was compared with an optimal commercial adsorbent (neutral alumina). No significant difference (p < 0.05) between neutral alumina and Ag@CD@ANS was observed. Recoveries ranging from 75 to 105 % with coefficients of variation ≤ 15 % (n = 3) were obtained using neutral alumina while using Ag@CD@ANS, recoveries ranging from 73 to 102 %, with coefficient of variation ≤ 13 % (n = 3) were obtained for the target pesticides. Limits of detection ranging from 0.5 to 1.0 µg Kg-1 and limits of quantification ranging from 1.6 to 3.3 µg Kg-1 were reached. The results demonstrated that Ag@CD@ANS can alternatively be used as a support for the extraction of persistent organic pollutants, having the advantage of being reusable for up to three cycles.

The efficacy of washing strategies in the elimination of fungicide residues and the alterations on the quality of bell peppers.

Food safety problems caused by pesticide residues in vegetables have become a top issue to raise public concern. In this study, bell peppers were grown in an experimental field and sprayed with two systemic (azoxystrobin and difenoconazole) and one contact (chlorothalonil) fungicides. Ozone (ozonated water and water continuously bubble with ozone) or conventional domestic (washing with distilled water, detergent, acetic acid, sodium bicarbonate, and sodium hypochlorite solutions) procedures were investigated to identify the most effective way to remove fungicide residues in bell peppers. The residues in the fruits and the washing solutions were determined by solid-liquid extraction with a low-temperature partition (SLE/LTP) and liquid-liquid extraction with a low-temperature partition (LLE/LTP), respectively, and analyzed by gas chromatography. Water continuously bubbled with ozone a concentration of 3 mg L-1 was the most efficient treatment with removal of fungicides residues ranging from 67% to 87%. However, similar treatment at a lower concentration (1 mg L-1) did not only efficiently removed fungicide residues (between 53% and 75%) but also preserving the quality of the fruit along a storage time of 13 days. Among the conventional solutions, sodium bicarbonate at 5% showed good efficiency removing between 60% and 81% of the fungicide residues from bell peppers, affecting the color quality of the fruit. Overall, the most affected physicochemical parameters in bell peppers after the treatments were weight loss, color, and vitamin C content.

Building robust models for identification of adulteration in olive oil using FT-NIR, PLS-DA and variable selection.

Being a product with a high market value, olive oil undergoes adulterations. Therefore, studies that make the verification of the authenticity of olive oil more efficient are necessary. The aim of this study was to develop a robust model using FT-NIR and PLS-DA to discriminate extra virgin olive oil samples and build individual models to differentiate adulterated extra virgin olive oil samples. The best PLS-DA-OPS classification model for olive oils showed specificity (Spe) and accuracy (Acc) values higher than 99.7% and 99.9%. For the classification of adulterants, PLS-DA-OPS models presented values of Spe at 96.0% and Acc above 95.5% for varieties. For the blend, the best PLS-DA-GA model presented Acc and Spe values greater than 98.2% and 98.8%. Reliable and robust models have been built, allowing differentiation from seven adulterants to genuine extra virgin olive oils.

Headspace Solid-Phase Microextraction: Validation of the Method and Determination of Allyl Isothiocyanate Persistence in Cowpea Beans.

Essential oils are widely recognized as an efficient and safe alternative for controlling pests in foods. However, a few studies have determined the persistence of these compounds in stored grains. The present study optimized and validated a fast and effective method for extraction and quantification of allyl isothiocyanate (AITC-the main component of mustard essential oil) residue in cowpea beans. It also investigated the persistence of this substance in the grains. The proposed method employs headspace solid-phase microextraction (HS-SPME) and gas chromatography with a flame ionization detector (GC/FID). For optimizing it, a central composite design (CCD) was used, where the best conditions for the extraction of the AITC were achieved using 15 min fiber exposure at 30 °C. The performance of the method was assessed by studying selectivity, linearity, limits of detection (LOD) and quantification (LOQ), precision, and accuracy. The LOD and LOQ for AITC were 0.11 and 0.33 µg kg-1, respectively. The determination coefficient (R 2) was above 0.99. The relative recovery rate ranged from 108.2 to 114.8%, with an interday coefficient of variation below 9%. After 36 h, no residue was detected in the samples, demonstrating that the AITC has low persistence and can be safely used as a bioinsecticide for grains.

Use of ozone and detergent for removal of pesticides and improving storage quality of tomato.

The efficiencies of two conventional domestic procedures (immersion in pure water and detergent solution at 0.25 and 1%) and two treatments using ozone (immersion in water with bubbling O3 and immersion in ozonated water, both at 1 and 3 mg L-1) were evaluated for the removal of residues of the fungicides azoxystrobin, chlorothalonil and difenoconazole in tomatoes. The fungicides were sprayed on the fruits at the recommended concentration for the crop. The residues in the tomatoes and in the washing solutions were determined by extraction with low-temperature partition techniques and analysis by gas chromatography. More concentrated solutions were more effective in removing pesticide residues. The water bubbled with ozone at 3 mg L-1 was the most efficient treatment for the removal of fungicides, reaching a reduction of 70-90% of the residues. However, the treatments with the lowest concentration of ozone had lower loss of fruit mass during storage.

Eugenol diffusion coefficient and its potential to control Sitophilus zeamais in rice.

Given the insecticidal potential of eugenol as a fumigant, this work aimed to determine the diffusion coefficient of eugenol emanating from a pure standard solution (99%), as well as from clove essential oil (Eugenia caryophillata Thunb. (Myrtaceae)) through rice grain; to chemically analyse the volatile composition of commercially available eugenol and clove essential oil; and to evaluate the mortality of Sitophilus zeamais Motschulsky (Coleoptera: curculionidae) after exposure to eugenol inside a test chamber filled with rice. The solid phase microextraction method of extracting and quantifying eugenol by gas chromatography presented a good analytical response for the quantification of the analyte. There was no significant difference between the diffusion coefficient of eugenol diffusing from pure eugenol or from clove essential oil. The diffusion coefficient of eugenol through rice with the conditions herein adopted is 1.09 × 10-3 cm2 s-1. The characterization of clove essential oil confirmed the presence of eugenol as its major component (74.25%). A difference was observed in the composition of the distinct phases evaluated. The exposure of adult S. zeamais to diffused eugenol from pure eugenol over seven days resulted in significantly higher mortality rates (~37%) than eugenol diffused from clove essential oil (~11%). No differences in mortality rates were observed in individuals placed at different positions inside the test chamber during eugenol fumigation.

Difenoconazole and linuron dissipation kinetics in carrots under open-field conditions.

The dissipation of difenoconazole and linuron using an open-field experimental approach with carrots exposed to one-, two- and fivefold the recommended dose of the pesticides was evaluated to provide safe recommendation to ensure food safety of carrots. The pesticide residue analysis was performed with solid-liquid extraction with low temperature partitioning technique (SLE/LTP) followed by gas chromatography analysis. The recovery percentages of extracts obtained from samples of carrot passed through SLE/LTP extraction and fortified with difenoconazole and linuron pesticides varied from 93.4% to 106.3% and from 95.1% to 116.6%, respectively. The limit of detection for difenoconazole was 0.02 and 0.12 mg kg-1 for linuron. The limit of quantification for difenoconazole was 0.05 and 0.36 mg kg-1 for linuron. The degradation time for fifty percent of the applied pesticide at the different doses ranged from 2.4 to 3.6 days for difenoconazole and from 7.5 to 10.5 days for linuron. At the end of the pre-harvest interval, carrots treated with fivefold the recommended dose of both pesticides were considered unfit for consumption. Despite monitoring the degradation products of the applied pesticides by gas chromatography coupled to mass spectrometer, none degradation product was identified on the carrots.

Enrichment of population density of a bacterial consortium during bioremediation of a soil under successive contaminations with diesel oil / Enriquecimento da densidade populacional de um consórcio bacteriano durante a biorremediação de um solo sob sucessivas contaminações com óleo diesel

The effect of successive soil contamination with diesel oil was evaluated on population dynamics of a bacterial consortium (Acinetobacter baumannii LBBMA 04, Pseudomonas aeruginosa LBBMA 58, Ochrobactrum anthropi LBBMA 88b, Acinetobacter baumannii LBBMAES11, and Bacillus subtilis LBBMA 155) and on biodegradation of petroleum hydrocarbons (n-C12-C22). After each contamination with diesel oil, soil samples were collected for assessment of bacterial population and sequence of petroleum hydrocarbons degradation. At 20 and 40 days, the highest percentage of degradation was observed for the higher carbon chain hydrocarbons (n-C21 and C22). After the third contamination, there was a considerable reduction of n-C21degradation and a high degradation of hydrocarbons n-C13-15, C17 and C19, which contrasts with the low values of degradation of these hydrocarbons in the two previous phases. The highest growth rate of all members of the consortium occurred from 0 to 20 days, but population increase continued up to the end of the experiment (except for B. subitillis strain, whose population stabilized after 20 days). Our results show that the recurrent contamination by hydrocarbons affected the population structure of bacterial consortium and increased the total population density of the bacterial consortium.

O efeito da contaminação do solo com óleo diesel foi avaliado sobre a dinâmica populacional bacteriana de um consórcio (Acinetobacter baumannii LBBMA 04, Pseudomonas aeruginosa LBBMA 58, Ochrobactrum anthropi LBBMA 88b, Acinetobacter baumannii LBBMAES11 e Bacillus subtilis LBBMA 155) e sobre a biodegradação de hidrocarbonetos de petróleo (n-C12-C22). Após cada evento de contaminação com óleo diesel, foram coletadas amostras de solo para avaliação das populações bacterianas e da sequência de degradação de hidrocarbonetos de petróleo. Aos 20 e 40 dias, a maior porcentagem de degradação foi observada para os hidrocarbonetos de cadeia de carbono mais elevada (n-C21 e C22). Após a terceira contaminação, houve redução considerável da degradação de n-C21 e alta degradação dos hidrocarbonetos n-C13-15, C17 e C19, o que contrasta com os baixos valores de degradação desses hidrocarbonetos nas duas fases anteriores. A maior taxa de crescimento de todos os membros do consórcio ocorreu entre 0 e 20 dias, mas o aumento populacional continuou até o final do experimento (com exceção da linhagem B. subitilis, cuja população se estabilizou após 20 dias). Os resultados mostram que a contaminação sucessiva do solo com óleo diesel afetou a estrutura populacional do consórcio bacteriano e proporcionou aumento da densidade populacional total das bactérias.

Ozone treatment for pesticide removal from carrots: Optimization by response surface methodology.

The present study aimed to optimize ozone (O3) treatments, as gas and dissolved in water, to remove difenoconazole and linuron in carrots. We employed a central composite design to study three variables governing the efficacy of treatments: O3 concentration, temperature and treatment time. The temperature did not influence the efficacy of treatments. The removal percentage of pesticides increases with increases in ozone concentration and the time of treatment. O3 application promoted the removal of more than 80% of pesticides when the roots were exposed for approximately 120min at 5 and 10mgL-1, respectively, in treatments with O3 as gas and dissolved in water. After storage, pesticide removal was higher than 98% for difenoconazole and 95% for linuron. The degradation products from the pesticides resulting from treatment were monitored, but none were found. This is the first report demonstrating the removal of difenoconazole and linuron from carrots by ozone.

GIS applied to agriclimatological zoning and agrotoxin residue monitoring in tomatoes: A case study in Espírito Santo state, Brazil.

Searches related to global warming have provided important insights into the response of terrestrial ecosystems, but few have examined the impacts on agricultural crops, particularly those associated with the monitoring of agrotoxin residues. In this context, the agriclimatological zoning is an important tool in the planning and consolidation of crops and should be considered in any initiative that involves such planning. This tool is particularly important in the analysis of agrotoxin residues and may be applied by the Program Analysis of Agrotoxin Residues in Food (PARA) created by the National Health Vigilance Agency of Brazil (ANVISA), which enables greater food security and contributes to the improvement of human health. The aim of this study was to elaborate the current and future agriclimatological zoning for the tomato crop, relating it with the monitoring of samples collected by PARA in Espírito Santo State, Brazil. The results indicate that a temperature increase of 5 °C creates a decrease in apt areas from 37.3% to 4.3%, for a total reduction of 33 percentage points (-88.5%). It is noted that of the 41 producing municipalities, only 26 have apt areas greater than 50%, highlighting the municipalities with apt areas greater than 90%, represented by Mantenópolis (100%), Guaçuí (98.5%), São José do Calçado (97.8%), Irupi (94.4%), Santa Teresa (92.3%), and Marechal Floriano (91.4%). The veracity of agriclimatological zoning is proved by a Kendall rank correlation coefficient of 0.876, indicating that the distribution of the variables of apt areas and productivity are similar at the significance level of 0.05 with a confidence interval 95%. After validation of the agriclimatological zoning for the tomato crop, it is recommended that the PARA should monitor 36 municipalities rather than the current 18, representing an increase of 100%. The methodology can be adjusted to agricultural crops of other countries.

Meia-vida do diuron em solos com diferentes atributos físicos e químicos / Half - life of diuron in soils with different physical and chemical attributes

A distribuição e a dissipação dos herbicidas nos solos são processos dinâmicos e únicos para cada relação solo-herbicida. Neste trabalho, a meia-vida do diuron foi determinada em cinco solos (Latossolo Vermelho Amarelo, Latossolo Vermelho e Latossolo Amarelo), com diferentes valores de pH. As concentrações do diuron foram determinadas em amostras dos referidos solos coletadas em oito épocas (1, 8, 15, 22, 36, 66, 96 e 156 dias após a aplicação do herbicida na dose 3,0kg ha-1). Em uma parte dessas amostras, foi feita a quantificação do diuron por cromatografia líquida de alta eficiência e, na outra parte, os testes biológicos, visando à confirmação dos resultados das análises cromatográficas. Constatou-se que a persistência do diuron é dependente dos atributos físicos e químicos dos solos. Todavia, a correção do pH do solo favoreceu apenas a degradação do herbicida em solos arenosos com baixo teor de matéria orgânica. A meia-vida do diuron nos solos estudados variou de 40 a 91 após a sua aplicação, sendo maior no solo com maior teor de matéria orgânica. Esses resultados foram confirmados pelos testes biológicos que se mostraram eficientes e complementares às análises cromatográficas.

The distribution and dissipation of herbicides on soils are dynamic and unique processes for each soil-herbicide relation. In this research, the half-life of diuron was determined in five soils (Red-Yellow Latosol, Red Latosol, and Yellow Latosol), with different pH values. Diuron concentrations were determined in samples of each soil collected at eight different times (1, 8, 15, 22, 36, 66, 96 and 156 days after herbicide application at 3.0kg ha-1). Part of each soil sample was used to quantify diuron by high performance liquid chromatography. The other part of soil sample was used to do biological tests in order to confirm the results of chromatographic analysis. It was found that the persistence of diuron is dependent on the physical and chemical soil attributes. However, the correction of soil pH favored only herbicide degradation in sandy soils with low organic matter content. The half-life of diuron in soils ranged from 40 to 91 after its application and it was higher in soil with higher organic matter content. The biological tests confirmed these results and they were efficient and complementary to the chromatographic analysis.

Perfil lipídico tecidual de ratos alimentados com diferentes fontes lipídicas / Tissue lipid profile of rats fed with different lipid sources

OBJETIVO:Determinar se fontes lipídicas com diferentes razões de ácidos graxos insaturados e saturados (PUFA+MUFA)/SFA na dieta altera o perfil lipídico tecidual, a concentração de lipídios (mg/g) dos tecidos hepáticos e mesentérico e a digestibilidade lipídica. MÉTODOS: Foi realizada cromatografia gasosa para determinar o perfil de ácidos graxos nos tecidos hepático e adiposo de ratos alimentados com diferentes fontes lipídicas. O coeficiente de digestibilidade foi determinado a partir da relação entre a quantidade de lipídios consumidos e a quantidade fecal excretada. RESULTADOS:Diferentes fontes lipídicas (óleo de soja, manteiga, margarina e gorduras de porco e de peixe) não alteraram o coeficiente de digestibilidade e o peso hepático, mas alteraram a deposição de lipídios em todos os tecidos adiposos estudados. Não foi possível fazer a correlação direta entre o perfil dietário dos ácidos graxos não essenciais e sua deposição nos tecidos estudados, visto que a lipogênese de novo impede a identificação dos ácidos graxos dietários. CONCLUSÃO:Não foi constatada uma relação direta entre o perfil dietário dos ácidos graxos e sua deposição nos tecidos estudados, exceto para os ácidos graxos trans e linoléico (C18:2) que não são sintetizados no rato. Esses ácidos graxos apresentaram uma concentração tecidual diretamente proporcional àquela das fontes dietárias. Quanto à razão (PUFA+MUFA)/SFA, encontrada no tecido hepático dos diferentes grupos, observa-se que esta foi diretamente proporcional aos valores apresentados pelas fontes lipídicas dietárias. Entretanto, essa associação não foi observada nos tecidos adiposos analisados.

OBJECTIVE:To determine if lipid sources with different unsaturated to saturated fatty acid ratios, (PUFA+MUFA)/SFA in the diet alter the lipid profile of tissues, the lipid concentration (mg/g) of the hepatic and mesenteric tissues and the lipid digestibility. METHODS:Gas chromatography was used to determine the profile of fatty acids in the hepatic and adipose tissues of rats fed with different lipid sources. The digestibility coefficient was determined based on the ratio between lipid intake and excreted in the feces. RESULTS:Different lipid sources (soy oil, butter, margarine and pig and fish fat) did not alter the digestibility coefficient and the hepatic weight, but they altered the lipid deposition in all adipose tissue evaluated. No direct correlation was observed between dietary non-essential fatty acid profile and its deposition in the studied adipose tissues, because of de novo which impedes the identification of the dietary fatty acid. CONCLUSION:A direct relationship was not verified between the dietary fatty acid profile and its deposition in the studied adipose tissues, except for the trans and linoleic (C18:2) fatty acids which are not synthesized in the rat. The tissue concentration of these fatty acids was directly proportional to their dietary sources. The (PUFA+MUFA)/SFA ratio found in the hepatic tissue of the different groups, was directly proportional to the values presented in the dietary lipid sources. However, this association was not observed in the adipose tissue.

A formação e os efeitos das espécies reativas de oxigênio no meio biológico / The formation and the effects of the reactive oxygen species in biological media

O oxigênio é utilizado como aceptor final de elétrons pelos organismos aeróbicos, porque permite elevada produção de energia na respiração, em conseqüência de seu alto potencial eletroquímico. Entretanto, devido a sua configuração eletrônica, o oxigênio pode sofrer reduções parciais e levar à formação de radicais livres, de forma que as Espécies Reativas de Oxigênio (EROs) estão constantemente presentes nas células eucarióticas. Esta revisão aborda os aspectos químicos da formação de EROs, os principais sítios de produção no metabolismo humano, os seus efeitos fisiológicos como mensageiros secundários na transdução de sinais e as defesas antioxidantes do organismo humano. O rompimento do equilíbrio entre a geração de EROs e as defesas antioxidantes resulta no estresse oxidativo, o qual está associado a algumas condições patológicas.

Efeito de constituintes químicos extraídos do fruto de Rheedia gardneriana (bacuparí) sobre bactérias patogênicas / Effect of chemical constituents from the fruit of Rheedia gardneriana (bacupari) on pathogenic bacteria

Rheedia gardneriana (bacupari) é planta da família Clusiaceae, encontrada na região Amazônica. A espécie estudada foi coletada no Horto Botânico da Universidade Federal de Viçosa. O estudo químico do fruto (pericarpo) conduziu à identificação dos seguintes constituintes: mistura de sesquiterpenos, ácido oleanóico e epiclusianona. Estes foram avaliados quanto ao potencial bactericida ou bacteriostático em testes in vitro. A epi-clusianona e o ácido oleanóico mostraram atividade inibitória no crescimento de Staphylococcus aureus e Listeria monocytogenes. A epi-clusianona inibiu o crescimento das fitobactérias Pseudomonas sp e Clavibacter michiganense subsp. michiganense