88 resultados para Pesticide residues in food


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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Bovine mastitis is considered the main disease causing great economic losses in dairy herds. It is usually treated by antimicrobial chemicals that promote drug resistance, residues in food and environmental contamination. However, consumers in different countries requires more natural foods and with higher quality. Thus, the objective was to check the activities of propolis in controlling bovine mastitis. Seventy-two Holstein cows were used. The mastitis was identified by the California Mastitis Test, somatic cell counts and microbiological examination of milk. Four treatments were held: in group EAP1 10ml of a 30% alcoholic propolis extract (EAP) were given orally for seven consecutive days; in group EAP2 the same procedure described for the first group was used, in addition EAP was used for immersion of the teats before and after milking; in group CA alcohol was used for immersion of the teats before and after milking; and in group CT animals were subjected to soaking and disinfection, procedures routinely used by the property. The results were analyzed by the non-parametric variance model for repeated measures complemented by independent groups in multiple comparisons. There was a decrease of the somatic cell count in all groups. The biological activities of propolis provide great prospects; however, under the conditions evaluated, it was not possible to observe differences between treatments. The great diversity in its chemical composition and the complexity of multiple synergistic mechanisms involved in its biological activity require additional clinical trials.

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Pós-graduação em Microbiologia Agropecuária - FCAV

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The use of pesticides in Brazil has intensified over the years. And since 2009 it was ranked as the largest market for pesticides worldwide. The consequential diffuse contamination of the environment is therefore due to the increasing number of chemicals of different classes, origins and modes of action. Little is known about the action of pesticides on human health in situations of co-exposure. Possible toxic effects are not restricted to agricultural and industrial workers, but also the general population that may be exposed continuously to its residues in food and water. Although these pesticides are mostly present in the environment at low doses, it must be considered that possible cumulative or synergistic effects may occur when there are concurrent or sustained exposure for two or more of these agents, which can lead to late manifestation of subclinical damages, sometimes irreversible. Thus, the specific objective of this study was to assess the effect of carcinogenesis promotion of a mixture of pesticides at low doses and analyze the phenomena of cell proliferation and apoptosis in rat liver. A total of 50 male Lewis rats was separated into 5 groups for 8 weeks in a medium term hepatocarcinogenesis model. The three different classes of pesticides (dieldrin, dicofol, endosulfan, dichlorvos and permethrin), whose residues were detected by ANVISA during the period from 2001 to 2005 in tomatoes cultures, were added to the feed of rats initiated to hepatocarcinogenesis with diethylnitrosamine (DEN- 200mg/kg ip). We used two different mixtures, one with no toxic effects at doses (MEX1) referring to the NOEL (no-observed-effect level) and another at doses LOEL / LEL / LOAEL (Lowest-observed-effect level / Lowest-effect level / Lowest -observed-adverse-effect level), to the installation of adverse effects (MEX2), derived from chronic studies. All animals ...(Complete abstract click electronic access below)

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Persistent organic pollutants (POPs), organochlorine pesticides and polychlorinated biphenyls (PCBs), listed as per the Stockholm Convention (α -HCH, β -HCH, γ -HCH, p,p′-DDT, o,p′-DDT, p,p′-DDD, p,p′-DDE, aldrin, endrin, dieldrin, PCBs 28, 52, 118, 138, 153, and 180), were analyzed in municipal solid waste (MSW) compost samples from three different Brazilian composting plants located in three São Paulo State cities: Araras, Araraquara and São Paulo (Vila Leopoldinha). Quantitative and qualitative analyses were carried out using gas chromatography electron capture detection (GC-ECD) and gas chromatography mass spectrometry (GC-MS) (Ion Trap, electron impact ionization), respectively. The samples were analyzed in triplicate and the target POPs were not detected by GC-ECD. Twelve pollutants were identified in two samples when qualitative analysis (GC-MS) was used (β -HCH, γ -HCH, p,p′-DDT, o,p′-DDT, p,p′-DDD, and p,p′-DDE, PCBs 28, 118, 138, 153 and 180). The composting process has advantages such as urban solid waste reduction and landfill life-span increase, however the MSW compost quality, which can be utilized for agricultural purposes, should be evaluated and be controlled. This kind of study is the first step in making available information to answer questions regarding MSW compost for sustainable agricultural use, such as the pollutants accumulation in soil and in groundwater, and plants uptake. Copyright © Taylor & Francis Group, LLC.

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The persistence of five pesticides (acephate, azinphos methyl, carbendazim, diazinon and dimethoate) in peach fruit was studied in real operating conditions. Pesticides showed different degradation rates. Diazinon was degraded with a half-life (t(1/2)) of 5.2 days, acephate, azinphos methyl and dimethoate with t(1/2) of ca 12 days and carbendazim with t(1/2) of 15.5 days. After the pre-harvest interval (PHI) all pesticide residues were within the limits established by Italian law.

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Freshly harvested lemons [(Citrus limon (L.) Burm)] were dipped 3 min in water with and without imazalil (IMZ) at 50, 100, and 200 ppm at 50 degrees C and at 1000 ppm IMZ at 20 degrees C. Following treatments fruit were kept at 9 degrees C and 90%-95% relative humidity (RH) for 13 weeks and an additional week at 21 degrees C and ca. 75% RH, to simulate a marketing period (SMP). No decay control was observed with fruit dipped in water at 50 degrees C. In contrast, IMZ treatments provided 90%-96% control of Penicillium rots during cold storage and SMP. Fungi other than Penicillium spp. were also found in all samples as differences among treatments were negligible. IMZ treatment caused some external damage to the fruit (peel browning), and the percentage of damaged fruit was related to the amount of active ingredient (AI) present in it. Dipping in 200 or 1000 ppm IMZ promoted off-flavor development after 10 weeks of storage, and fruit were judged to be unacceptable for consumption after 13 weeks of cold storage. After 1000 ppm IMZ dipping at 20 degrees C, residue concentration in fruit was 8.20 ppm; this value doubled that found in a previous investigation on lemons treated with comparable IMZ levels. Residue concentrations in fruit after treatment at 50 degrees C was strictly related to the amount of fungicide employed. After 13 weeks Al residues in fruit decreased to average ca. 35% of the initial values. During the 1 week SMP, residue levels decreased by a further ca. 25%. It was concluded that it is possible to achieve significant control of decay in lemons during longterm storage by dipping fruit in 50 ppm IMZ mixtures at 50 degrees C. Such treatment should be advised to remarkably reduce potential pollution in the environment due to packinghouse wastewater disposal.

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A rapid and simple gas chromatographic method for determinating cyprodinil, fludioxonil, pyrimethanil, and tebuconazole in grapes, must, and wine is described. An on-line microextraction method was used with a one-step extraction-partition procedure. Nitrogen-phosphorus and mass spectrometric detectors were used, because of their low sensitivity and high selectivity. Because of high selectivity of detector, no cleanup was necessary and the extract was concentrated 5 times. Recoveries from fortified grapes, must, and wine ranged from 93 to 110%. Limits of determination were 0.05 mg/kg for cyprodinil and pyrimethanil and 0.10 mg/kg for fludioxonil and tebuconazole.

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Studies of sub-lethal effects of pesticide residues on stingless bees are scarce and morphological analysis of organs would add information to toxicological analysis in order to clarify the continuous exposure of Scaptotrigona postica to insecticides. The aim of this study was to evaluate the morphology and histochemistry of the Malpighian tubules (excretory organ) of S. postica exposed to fipronil or boric acid to detect cellular responses that indicate toxicity or adaptative mechanisms to stress induced by exposure of worker bees to low doses of these chemical compounds. Newly emerged bees were submitted to toxicological bioassays and morphological analyses by optical microscopy and Transmission Electron Microscopy, as well as histochemical methods, were performed to detect proteins and glycoconjugates. Additionally, immunohistochemical detection of DNA fragmentation and HSP70 (70-kDa Heat shock protein) were performed to detect cell death and stress response, respectively. Statistical analysis, for the bioassays conducted with ingestion of contaminated diet with boric acid at 0.75% (w/w) or with fipronil at 0.1μg/kg of food, showed that the survival of bees that ingested the contaminated diets were significantly different to the survival rate presented by the control group (P<0.0001). Although some characteristics indicative of initiation of cell death were observed, the cells remained metabolically active in the processes of excretion and inactivation of chemical compounds. The data from this study reinforce the importance of research on sublethal effects of low doses of pesticides on bees in an attempt to assess a possible realistic dose and evaluate the risk assessment of stingless bee S. postica foraging in the vicinity of cultivated fields and/or in green urban areas. © 2013 Elsevier Ltd.

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Mangrove swamps are found in estuaries along the coastal plains of tropical regions and have be subjected to heavy occupation and use pressure due to their privileged locations and abundance of biological resources. The present work evaluated the ecological characteristics and solid wastes accumulated in eight areas along the Santos - Sao Vicente Estuary Complex. The superficially deposited residues at each sampling site were collected and subsequently washed, drained, counted, weighed and separated into classes according to their composition and predominant use. The predominant litter type in terms of density was plastic (62.81%) and, by weight, wood (55.53%). The greatest deposition of residues was associated with areas that were less inclined and that had low plant density levels, indicating that the presence of obstacles was not critical for retaining floating residues in mangrove areas. The presence of the most frequently encountered types of solid waste residues could be explained by local activities. (C) 2010 Elsevier Ltd. All rights reserved.

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We have shown that myocardial dysfunction induced by food restriction is related to calcium handling. Although cardiac function is depressed in food-restricted animals, there is limited information about the molecular mechanisms that lead to this abnormality. The present study evaluated the effects of food restriction on calcium cycling, focusing on sarcoplasmic Ca2+-ATPase (SERCA2), phospholamban (PLB), and ryanodine channel (RYR2) mRNA expressions in rat myocardium. Male Wistar-Kyoto rats, 60 days old, were submitted to ad libitum feeding (control rats) or 50% diet restriction for 90 days. The levels of left ventricle SERCA2, PLB, and RYR2 were measured using semi-quantitative RT-PCR. Body and ventricular weights were reduced in 50% food-restricted animals. RYR2 mRNA was significantly decreased in the left ventricle of the food-restricted group (control = 5.92 +/- 0.48 vs food-restricted group = 4.84 +/- 0.33, P < 0.01). The levels of SERCA2 and PLB mRNA were similar between groups (control = 8.38 +/- 0.44 vs food-restricted group = 7.96 +/- 0.45, and control = 1.52 +/- 0.06 vs food-restricted group = 1.53 +/- 0.10, respectively). Down-regulation of RYR2 mRNA expressions suggests that chronic food restriction promotes abnormalities in sarcoplasmic reticulum Ca2+ release.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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P>The present review reports on the main characteristics and properties of plants cultivated following organic and conventional procedures, in the attempt to clarify give a deeper insight into some possible differences and to compare the two cultivation procedures. Here, we summarise research results regarding nutritional and safety properties of vegetable foods, evidencing qualitative differences observed between the two cultivation methods. It appears that the intake of organic foods leads to some advantages, such as the ingestion of a higher content of phenolic compounds and some vitamins, such as vitamin C, and a lower content of nitrates and pesticides. From literature, it appears that a special care should be taken about the ingestion of foods in relation to the content of some substances, e.g. polyamines, substances stimulating cellular division, because some foods coming from organic origin present a higher content of these compounds, which could explain some of the effect of the diet on patients affected by certain syndromes.