Aflatoxins are carcinogenic mycotoxins most frequently associated with the filamentous fungus, Aspergillus flavus. These potent toxins pose serious health threats and their concentrations in foods are widely regulated. Maize, a critical staple of billions, is frequently contaminated with aflatoxins. Development of commercial maize hybrids with superior resistance to aflatoxin contamination has been sought for over 30 years without success. Analyses of native maize land races (MLRs) from Mexico revealed several accessions with significant resistance to both aflatoxin contamination and fungal reproduction. Physical barriers are important components of MLRs resistance. Traditional use of MLRs may reduce human exposure to aflatoxins. MLRs may contribute resistant genes of significant value in breeding for aflatoxin resistance. In Mexico, maize is produced from<10 to over 2,000 masl. Elevation had only minor influence on community compositions of aflatoxin-producing fungi associated with maize over three years in Sonora, Mexico. Most variation in community structure occurred between years. Dominant vegetative compatibility groups (VCGs) differed among years but were detected in similar frequencies across four agroecological zones. Multiple locations and multiple years must be sampled to obtain realistic assessments of the most successful VCGs. Elevated frequencies of VCG YV150 throughout Sonora during 2006 led to investigate genetic diversity within this VCG using microsatellite loci. The 2006 increases were attributed to rapid increase of a single clone. Examination of YV150 isolates collected over 20 years in the US and Mexico revealed several haplotypes and two genetically distinct populations, which were composed of isolates containing only a population specific mating-type idiomorph. Microsatellite loci in each population were in gametic equilibrium. Gene flow between isolates with different idiomorphs was not detected. VCG YV36, to which the biocontrol agent AF36 belongs, was found to be endemic to Mexico. Microsatellite loci revealed diversity within YV36 from Mexico, but all isolates harbored the single nucleotide polymorphism in the aflatoxin polyketide synthase gene, pksA, that confers atoxigenicity to AF36. Three YV36 isolates also had deletions in pksA suggesting continued degradation. Presence of endemic YV36 isolates in Mexico may facilitate rapid regulatory approval of AF36 for use in prevention of aflatoxin contamination of maize in Mexico.

<p>Dosada&scaron;nji objavljeni literaturni podaci ukazuju da aflatoksini, usled njihovog dokazanog toksičnog, mutagenog, teratogenog i kancerogenog efekta na organizam ljudi i životinja, predstavljaju najpoznatiju i najrizičniju grupu mikotoksina. Nasuprot navedenom, dostupna naučna i stručna literatura iz Republike Srbije ukazuje na nedostatak sistematski sprovedenih monitoringa učestalosti pojave aflatoksina. Kao sirovine za ispitivanje pojave aflatoksina, u ovoj doktorskoj disertaciji, odabrani su kukuruz i mleko. Kukuruz je odabran jer predstavlja jednu od najzastupljenijih žitarica u Srbiji. Navedena činjenica dodatno povećava potrebu za istraživanjem, jer pojava aflatoksina u velikoj meri utiče i na kvalitet kukuruza, kao i smanjenje prinosa i ekonomskog profita zemlje. Cilj da se ispita mleko proistekao je iz činjenice da ono usled velike frekventnosti u ishrani, predstavlja namirnicu sa najvećim potencijalnim rizikom za unos aflatoksina u organizam ljudi.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Analiza pojave aflatoksina u kukuruzu obuhvatila je 1000 uzoraka, sakupljenih tokom perioda od četiri godine (2009-2012.). Dobijeni rezultati ukazali su da aflatoksini nisu detektovani u uzorcima kukuruza iz 2009., 2010. i 2011. godine. Međutim, od 700 analiziranih uzoraka kukuruza iz 2012., čak 553 (79%) bilo je kontaminirano aflatoksinima. Značajne razlike u pojavi aflatoksina u kukuruzu, iz različitih proizvodnih godina, mogu se objasniti izuzetno toplim i suvim vremenskim uslovima zabeleženim u 2012. godini. Su&scaron;ni vremenski uslovi bili su povoljni za razvoj plesni i sintezu aflatoksina u kukuruzu, a takođe su u velikoj meri doprineli i visokom nivou pojave aflatoksina M1 (AFM1) u mleku. Analiza 200 uzoraka različitih kategorija kravljeg mleka pokazala je da je AFM1 sa koncentracijama od 0,01 do 1,20 ug/kg detektovan u 198 (98,7%) uzoraka. Na osnovu određenih koncentracija AFM1 u uzorcima mleka, prikupljenih informacija o prosečnom unosu mleka, telesnoj težini različitih starosnih kategorija i polova 1500 ispitanika, procenjen je rizik od unosa AFM1. Dobijeni rezultati ukazali su da su sve ispitane starosne kategorije, a posebno deca, izložena visokom riziku od unosa AFM1 u organizam preko kontaminiranog mleka.<br />Usled svega navedenog, proizilazi potreba za kontinuiranim praćenjem pojave aflatoksina u kukuruzu i AFM1 u mleku, sa ciljem za&scaron;tite stanovni&scaron;tva od rizika povezanih sa njihovim dokazanim toksičnim i kancerogenim efektima. Tokom poslednjih godina, do&scaron;lo je do povećane tražnje za razvojem osetljive, tačne, jednostavne i brze metode, čijom primenom će se obezbediti pouzdano određivanje različitih aflatoksina pri niskim koncentracijama. Usled toga, ELISA metode, kao i metode tečne hromatografije sa različitim detektorima (HPLC-FLD, HPLC-UV light-FLD, LC-MS/MS) su razvijene, optimizovane i validovane. Validacija je izvr&scaron;ena prema smernicama odgovarajućih evropskih Regulativa, analizom sertifikovanih referentnih materijala i spajkovanih uzoraka. Dobijeni parametri validacije potvrdili su da se sve primenjene metode sa visokom pouzdano&scaron;ću mogu koristiti za određivanje aflatoksina u kukuruzu, odnosno AFM1 u mleku. Validovane metode su zatim primenjene za analizu aflatoksina i AFM1 u prirodno kontaminiranim uzorcima kukuruza i mleka. Analizom prirodno kontaminiranih uzoraka kukuruza uočeno je da određena koncentracija aflatoksina u velikoj meri zavisi od neravnomerne raspodele aflatoksina unutar čvrstih uzoraka. Pored toga, analiza uzoraka kukuruza iz skladi&scaron;ta, takođe je ukazala na neravnomernu raspodelu ukupnih plesni, vrste Aspergillus flavus, kao i aflatoksina. S druge strane, dobijeni koeficijenti korelacije (&gt; 0,9) između primenjenih metoda za određivanje AFM1 u mleku, ukazali su da među dobijenim rezultatima postoji snažna korelacija, koja može poticati i od relativno homogenije raspodele AFM1 unutar tečnih uzoraka.</p> / <p>Recent studies have demonstrated that аflatoxins (AFs) represent the best known and most intensively researched mycotoxins in the world, with proven toxic, mutagenic, teratogenic and carcinogenic effects on human and animal health. However, up to the author&#39;s knowledge, there are no investigations concerning the occurrence of AFs in food or feed from Republic of Serbia. For that purpose, maize and cow&acute;s milk samples were chosen as matrixes for investigation. Maize is selected because it represents one of the major crops grown in Serbia and presence of AFs leads to reduction of maize quality as well as significant economical losses. On the other hand, milk has the greatest demonstrated potential for AFs introducing into the human diet since it represents one of the main foodstuffs in human nutrition.<br />An investigation regarding occurrence of AFs in maize included 1000 samples collected during four years period (2009-2012). Obtained results indicate that AFs were not detected in maize samples collected during 2009-2011 period. However, among 700 analyzed maize samples from 2012 even 553 (79%) samples contained AFs. Significant differences in occurrence of AFs in maize could be contributed to extremely hot and dry weather conditions noted during maize growing season 2012. Described weather conditions were favorable for mould growth and AFs synthesis in maize and also could be the possible reason for high contamination frequency of aflatoxin M1 (AFM1) in milk. Analysis of 200 cow&acute;s milk samples showed that AFM1 were detected in 198 (98.7%) samples in concentrations ranged from 0.01 to 1.20 &mu;g/kg. On the basis of the obtained AFM1 concentrations in cow&rsquo;s milk samples, collected information about average milk intake and mean body weight (bw) for different age&rsquo;s categories, mean ingestion of AFM1 in ng/kg per bw per day were estimated. Obtained results showed that all age&rsquo;s categories, especially children, are exposed with high risk related to presence of AFM1 in milk.<br />Based on everything stated above, presence of AFs in maize and AFM1 in milk should be continuously controlled in order to protect the population from risks associated with its proven toxicity and carcinogenicity. During recent years, there has been an increase in demand for development of sensitive, accurate, simple and fast method which is reliable to detect AFs and AFM1 at low concentrations. For that purpose, enzyme linked immunosorbent asssay (ELISA), high performance liquid chromatography with fluorescence detector (HPLC-FLD; HPLC-UV light-FLD) and high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) were optimized and validated. The method validation was performed according European Union Regulative using certificated reference material as well as spiked blank maize and milk samples. The obtained validation parameters indicate that all applied methods are suitable for determination of AFs in maize as well as AFM1 in milk samples. Afterwards, validated methods were applied for analysis of natural contaminated maize and milk samples. Analysis of natural contaminated maize samples indicate that determined AFs concentration mostly depends of uneven distribution of AFs in solid samples. Furthermore, analysis of maize samples from different warehouses indicates an uneven distribution of moulds, Aspergillus flavus and AFs. On the other hand, obtained correlation coefficients (&gt;0.9) indicate that strong correlation exists between applied methods for AFM1 determination. Relatively homogeneous distribution of AFM1 in liquid samples could be the possible reason for obtained strong correlation between applied methods.</p>

O objetivo deste estudo foi avaliar a presença de fungos e micotoxinas [aflatoxinas e ácido ciclopiazônico (ACP)] em amostras de castanha-do-Brasil coletadas em diferentes estados da região Amazônia brasileira: Acre, Amazonas, Amapá e Pará. Um total de 200 amostras de casca e 200 amostras de amêndoa foram semeadas em ágar Aspergillus flavus-parasiticus para pesquisa da micobiota. As micotoxinas foram analisadas por cromatografia líquida de alta eficiência. A morfológica clássica e a análise molecular revelou a presença dos seguintes fungos, em ordem decrescente de frequência: Phialemonium spp., Penicillium spp., Fusarium spp., Phaeoacremonium spp. e Aspergillus spp. A presença de aflatoxinas e ACP foi detectada em amostras de amêndoa, na frequência de 11% e 22%, respectivamente. Aspergillus nomius e Aspergillus flavus foram as espécies mais isoladas de Aspergillus. A presença de fungos não implica necessariamente na contaminação por micotoxinas, porém a amêndoa da castanha-do-Brasil parece ser um bom substrato para o crescimento de fungos. / The aim of this study was to evaluate the presence of fungi and mycotoxins [aflatoxin and cyclopiazonic acid (ACP)] in Brazil nut samples collected in different States of the Brazilian Amazon: Acre , Amazonas , Amapá and Pará. A total of 200 almond and 200 husk samples were plated on agar Aspergillus flavus - parasiticus for mycobiota isolation. Mycotoxins were analyzed by high performance liquid chromatography. The classical morphological and molecular analysis revealed the presence of the following fungi , in decreasing order of frequency: Phialemonium spp., Penicillium spp., Fusarium spp., Phaeoacremonium spp. and Aspergillus spp. The presence of aflatoxins and ACP was detected in almonds samples at a frequency of 11% and 22% , respectively. Aspergillus nomius and Aspergillus flavus species were the most isolated from Aspergillus. The presence of fungi does not necessarily imply the mycotoxin contamination, but the almond samples of Brazil nut seem to be a good substrate for the growth of fungi.

Apesar da perda econômica, representada pela contaminação por fungos toxigênicos em castanhas-do-Brasil, um importante produto extrativista da região Norte do Brasil, estudos realizados ainda são incipientes quanto ao controle da contaminação por fungos aflatoxigênicos utilizando métodos como radiação gama (R.G) e, sobretudo, feixe de elétrons (F.E). Esses fatos motivaram a presente pesquisa teve como objetivo avaliar os efeitos da radiação gama e da aplicação de feixe de elétrons em amostras de castanha-do-Brasil inoculadas artificialmente com Aspergillus flavus. Para atingir tal objetivo, foram estudadas 50 amostras de castanha-do-Brasil, previamente, inoculadas com suspensão de esporos de A. flavus e, posteriormente, incubadas a 30 ºC em ambiente com umidade relativa controlada a 93 %. Após 15 dias de incubação, as amostras foram divididas em 5 grupos que receberam as seguintes doses de radiação: controle (0 kGy), 5 e 10 kGy F.E, 5 e 10 kGy R.G. A micobiota foi realizada através de diluição seriada, com semeadura em superfície utilizando ágar batata. Os resultados demonstraram que o tratamento com F.E utilizando a dose de 5 kGy e 10 kGy resultou na redução de crescimento de A. flavus em 74% (37/50) e 94% (47/50) das amostras. Quanto às amostras tratadas com R.G na dose de 5 kGy e 10 kGy não ocorreu crescimento fúngico em 92% (46/50) e 100% (50/50) delas. A pesquisa de aflatoxinas mostrou que doses de F.E de 5 kGy e 10 k Gy reduziram os níveis de AFB1 em 53,32% e 65,66%, respectivamente. Por sua vez, a aplicação de raios gama nas doses de 5 e 10 kGy reduziu os níveis das toxinas em 70,61% e 84,15 % respectivamente. Tal resultado pode ser atribuído a maior penetrabilidade da radiação gama. Análise sensorial demonstrou maior aceitação das amostras irradiadas com F.E e R.G na dose de 10 kGy. Concluímos que, apesar de a análise sensorial ter demonstrado perda de algumas características organolépticas, ambos os processos de radiação foram eficazes na redução da contagem de A. flavus e dos níveis de aflatoxinas. / Despite the economic loss represented by contamination by toxigenic fungi in Brazil nuts, a major product of extractive Northern of Brazil, studies are still preliminary as the control of contamination aflatoxigenic fungal using methods such as gamma radiation (G.R) and mainly, electron beam (E.B). These facts motivated this research, which aimed to evaluate the effects of gamma radiation and application of electron beam in samples of Brazil nut artificially inoculated with Aspergillus flavus. This goal, we were studied 50 samples of the Brazil nut previously inoculated with spores of A. flavus and subsequently incubated at 30 °C in relative humidity controlled at 93%. After incubation, period of 15 days, the average water activity of the samples was 0.80, the samples were divided into 5 groups that received the following doses of radiation: control (0 kGy), 5 and 10 kGy 5 E.B and G.R. The mycobiota was performed by serial dilution, plated on surface using potato dextrose agar. The results demonstrated that treatment with E.B using a dose of 5 kGy and 10 kGy resulted in reduced growth of A. flavus in 74% (37/50) and 94% (47/50) of samples. The samples treated with G.R at the dose of 5 kGy and 10 kGy no fungal growth occurred in 92% (46/50) 100% (50/50) of. The study of aflatoxins showed that doses of E.B of 5 kGy and 10 kGy reduced levels of AFB1 at 53.32% and 65.66% respectively. The application of gamma rays at doses of 5 and 10 kGy reduced levels of toxins in 70.61% and 84.15% respectively. This result may be attributed to higher penetrability of gamma radiation. Sensory analysis showed greater acceptance of the judges for the samples irradiated with E.B and G.R at the dose of 10 kGy. We concluded that although sensory analysis have demonstrated some loss of organoleptic characteristics, both processes of radiation were effective in reducing the count of A. flavus and aflatoxin contamination.

O presente trabalho teve como objetivos avaliar a micobiota e a ocorrência de micotoxinas em grãos de milho provenientes de quatro regiões do Brasil; identificar os isolados de A. flavus pela técnica de AFLP (Amplified Fragment Length Plymorphism) e de Fusarium verticillioides, utilizando as técnicas de AFLP e sequenciamento parcial do gene do fator de elongação 1-&#945; comparar o potencial toxigênico das cepas com a expressão dos genes aflR e aflP (A. flavus) e FUM1 e FUM19 (F. verticillioides), através da técnica de real time RT-PCR. Demonstrou-se prevalência de Fusarium verticillioides e de fumonisinas nos grãos. Do total de isolados, 96 % foram identificados como F. verticillioides. A similaridade dos isolados de A. flavus com a cepa padrão variou de 79 % a 100 %, e não foi observado agrupamento origem geográfica específico entre os isolados de A. flavus e F. verticillioides. Observou-se elevada correlação positiva entre a expressão de FUM1 e FUM19 e a produção de toxinas por F. verticillioides, e baixa correlação positiva entre os transcritos de aflR e aflP em relação ao perfil de produção de aflatoxinas por A. flavus, demonstrando necessidade de estudos referentes a expressão de genes relacionados à produção de micotoxinas. / The present study aimed to verify the mycoflora and occurrence of mycotoxins in freshly harvested corn samples in four regions of Brazil; to identify Aspergillus flavus strains by AFLP (Amplified Fragment Length Polymorphism) technique and Fusarium verticillioides by AFLP and by the translation elongation factor 1-&#945 partial gene sequencing (TEF-1-&#945); to compare the toxigenic potential of the strains in relation to aflR and aflP gene expression (A. flavus) and FUM1 and FUM19 (F. verticillioides), using Real Time RT-PCR technique. Our data showed predominance of F. verticillioides and fumonisins in the corn samples. Of the total strains, 96 % were identified as F. verticillioides. The similarity of A. flavus isolates with the standard strain ranged from 79 % to 100 %, and the results of AFLP, demonstrated a lack of relationship between the groups of the phylogenetic tree and the different geographic origins, for both A. flavus and F. verticillioides. A high positive correlation was observed between the expression of FUM1 and FUM19 genes and fumonisin production, and a low positive correlation was observed between the expression of aflR and aflP genes and aflatoxin production. These data demonstrate the need for studies concerning gene expression related to mycotoxins production.

No leite tipo \"B\" comercializado em São Paulo foram pesquisados a presença de aflatoxina M1 e de inibidores bacterianos (penicilina, água oxigenada, formol e cloro}. As amostras de leite utilizadas foram provenientes das quatro marcas de maior consumo pela população de São Paulo. O trabalho constituiu-se em um estudo longitudinal, com amostragem probabilística, dividido em dois períodos iguais de 140 dias com 224 amostras analisadas. No primeiro período, de 14 de junho a 31 de outubro de 1982, foram pesquisados todos os contaminantes propostos. No segundo período, de 01 de novembro de 1982 a 30 de março de 1983, a aflatoxina não foi pesquisada, pois, como sofre influência sazonal, há maior possibilidade de ser encontrada nos meses de temperaturas mais baixas. A aflatoxina, embora em baixos níveis e em pequena proporção (1 ,8 por cento ), fez-se presente nas quatro marcas. Foi constatada alta prevalência de inibidores bacterianos. No primeiro e no segundo período a proporção foi de 4,95 por cento e 4,50 por cento respectivamente. No primeiro período a incidência de resíduos de penicilina e de inibidores não identificados foi de 0,9 por cento , e de 3,6 por cento respectivamente. No segundo foi de 0,45 por cento e de 3,15 por cento . Houve uma baixa proporção de amostras com água oxigenada e formal, e ausência de cloro. De acordo com os resultados, concluiu-se que há necessidade do estabelecimento de limites de tolerância para a aflatoxina no leite, ausentes na nossa legislação; e pela necessidade da atuação da Saúde Pública através de inspeção, e através de amplos programas educativos junto aos produtores e indústrias. / B-type milk sold in the city of São Paulo, Brazil, was examined for Aflatoxin M1 and bacterial inhibitors, such as penicilin, hydrogen peroxide, formaldehyde and chlorine. Samples were taken from the faur most consumed brands. The study was longitudinal, with probabilistic sampling, divided in two equals periods of 140 days each; the total number studied was 224 in each period. During the first period, June 14 th through October, 31st, 1982, all mentioned contaminants were studied where as aflatoxin was not studied in the second period, November 1st, 1982 through March, 30th, 1983, as its occurrence is seasonal and the probability of it being encountered is practically null. Aflatoxin, although is small proportion (1.8%) and at low levels, was present in the four brands studied. The prevalence of bacterial inhibitors was high is both periods (4.95% in the first period and 4.50% in the second). During the first period the incidence of penicillin residues and non-identified inhibitors was 0.9% and 3.6% respectively, in the first period, and 0.45% and 3.15% respectively in the second. The proportion of samples containing hidrogen peroxide, formaldehyde was low and chlorine was absent in all. Our results show the need for establishing legal tolerance limits for aflatoxin in milk (which has not been done as yet) and the need for Public Health measures regarding inspection and education of productors and industrial plants.

O amendoim é freqüentemente invadido por fungos toxigênicos antes da colheita. Este trabalho teve como objetivos: determinar a micoflora do solo, ar, sementes plantadas, flores, ginóforo e grãos e cascas de amendoim em diferentes fases de maturação e após a secagem; analisar aflatoxinas B1, B2, G1 e G2, ácido ciclopiazônico e fumonisinas B1 e B2 nas sementes plantadas, grãos e cascas de amendoim em diferentes fases de maturação e após a secagem. Os fungos mais freqüentes nos grãos e cascas de amendoim foram Fusarium spp. e Aspergillus flavus. A espécie A. flavus também foi encontrada em amostras do solo e do ar. Aflatoxinas e ácido ciclopiazônico foram detectados em 32 % das amostras de grãos de amendoim analisadas em concentrações que variaram de 4,20<font face=\"symbol\">mg/kg a 198,84 <font face=\"symbol\">mg/kg e de 260 <font face=\"symbol\">mg/kg a 600 <font face=\"symbol\">mg/kg, respectivamente. Nas cascas somente aflatoxinas foram detectadas em concentrações que variaram de 5,76 <font face=\"symbol\">mg/kg a 218,52 <font face=\"symbol\">mg/kg. Fumonisinas não foram detectadas. Boas práticas agrícolas são indicadas para região. / Peanuts are contaminated frequently by toxigenic fungi before harvest. the present study aimed to: identify the mycoflora of the soil, air, flower, pegs, peanut kernels and hulls in the different maturation stages and after drying; determinate the occurrence of aflatoxins B1, B2, G1 and G2, cyclopiazonic acid (CPA) and fumonisins B1 and B2 in peanut kernels and hulls in different maturation stages and after drying. Fusarium spp. Aspergullus flavus were the most frequent fungi isolated in peanuts hulls and kernels. A. flavus was isolated, also, in air and soil samples. Aflatoxins and cyclopiazonic acid were detected in 32% of the kernels samples in concentration from 4.20 <font face=\"symbol\">mg/kg to 198.84 <font face=\"symbol\">mg/kg and from 260 <font face=\"symbol\">mg/kg to 600 <font face=\"symbol\">mg/kg, respectively. In the peanut hulls only aflatoxins were detected in 24 % of the samples in concentration from 5.76 <font face=\"symbol\">mg/kg to 218.52 <font face=\"symbol\">mg/kg. Fumonisins were not detected. Good agriculture practices are indicated to region.

Made available in DSpace on 2015-04-22T22:17:34Z (GMT). No. of bitstreams: 1 MARISTELA_MARTINS.pdf: 1215740 bytes, checksum: 334a5adaba7474a43d627037cb3dba35 (MD5) Previous issue date: 2010-06-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Food safety is an important aspect to be achieved by the food industry and the contamination of some products, such as the Brazil-nut (Bertholletia excelsa HBK), caused by aflatoxin and radioactivity has been shown in several studies. Natural compound of Brazil-nut, selenium is an element considered by the antioxidant present in large amounts in some foods, for example, in tree nuts. However, it is an element widely studied because of the ambiguity of his actions, beneficial or toxic effects on organisms. Considering these aspects, samples of nuts from Brazil classified in different sizes, shelled, export were evaluated with the aim of studying the interaction of levels of radioactivity, selenium and aflatoxin contamination. The analysis of selenium was performed by optical emission spectrometry with inductively coupled plasma (ICP / OES), using the method of atomic emission. The limit of detection (LOD) was 1.50 g/g, and the limit of quantification (LOQ) was 3.00 g/g. The analysis of aflatoxins were performed by mass spectrometry / mass (MS / MS) coupled to a liquid chromatograph (LC) with atmospheric pressure chemical ionization (APCI). The limits of detection (LOD) and quantification (LQ) for ΣAFLs were 0.3 and 0.85 mg/kg, respectively. Traces of radioactive radionuclide 228Ra, 226Ra and 224Ra were measured by gamma spectrometry, using a HPGe detector GEM-M 7080-PS, ORTEC, 66% relative efficiency. If levels ranged between 9.4 and 39.0 mg/g ± 7.36, mean of 22.71 mg/g. The average activity for the radionuclides studied were 15.77 Bq/kg for 224Ra, 104.81 Bq/kg for 226Ra and 99.48 Bq/kg for 228Ra. If the levels did not differ significantly between the different sizes, as well as 226Ra. Already the 224Ra and 228Ra showed differences between the sizes. There was no statistically significant association between the level of selenium and the activity of radionuclides, however, correlated with each other radionuclides. No sample was contaminated by aflatoxin. All committed effective doses calculated for the radionuclides are below the ceiling. / A segurança alimentar é um importante aspecto a ser alcançado pela indústria de alimentos e a contaminação de alguns produtos, como a castanha-do-Brasil (Bertholletia excelsa H. B. K.), causada por aflatoxinas e radioatividade tem sido evidenciada em diversos estudos. Composto natural da castanha-do-Brasil, o selênio constitui um elemento apreciado pela ação antioxidante, presente em grandes quantidades em alguns alimentos, como, por exemplo, em nozes de árvores. Entretanto, é um elemento bastante estudado devido à ambigüidade de sua ação, benéfica ou tóxica em organismos. Considerando estes aspectos, amostras de castanha-do-Brasil classificadas em diferentes tamanhos, sem casca, tipo exportação foram avaliadas com o objetivo de estudar a interação dos níveis de radioatividade, selênio e a contaminação por aflatoxinas. A análise de selênio foi realizada por espectrometria de emissão óptica com plasma indutivamente acoplado (ICP/OES), utilizando o método de emissão atômica. O limite de detecção (LOD) foi de 1,50 μg/g, e o limite de quantificação (LOQ) foi de 3,00 μg/g. As análises de aflatoxinas foram realizadas por espectrometria de massa/massa (MS/MS) acoplado a um cromatógrafo líquido (LC) com Ionização Química à Pressão Atmosférica (APCI). Os limites de detecção (LD) e de Quantificação (LQ) para ΣAFLs foram: 0,3 e 0,85 μg/kg, respectivamente. Os traços radioativos dos radionuclídeos 228Ra, 226Ra e 224Ra foram medidos por espectrometria gama, empregando-se um detector HPGe modelo GEM-M 7080-P-S,ORTEC, de 66% de eficiência relativa. Os níveis de Se variaram entre 9,4 e 39,0 μg/g±7,36, com média de 22,71 μg/g. As atividades médias para os radionuclídeos estudados foram: 15,77 Bq/kg para o 224Ra, 104,81 Bq/kg para o 226Ra e 99,48 Bq/kg para o 228Ra. Os níveis de Se não apresentaram diferença significativa entre os diferentes tamanhos, assim como o 226Ra. Já o 224Ra e o 228Ra apresentaram diferenças entre os tamanhos. Não houve associação estatística significativa entre o nível de selênio e a atividade dos radionuclídeos, no entanto, houve correlação com os radionuclídeos entre si. Nenhuma amostra apresentou contaminação por aflatoxinas. Todas as doses efetivas comprometidas calculadas para os radionuclídeos estão abaixo do limite máximo estabelecido.

Made available in DSpace on 2016-04-28T20:17:25Z (GMT). No. of bitstreams: 1 2007-Veronica da Silva Cardoso.pdf: 1668808 bytes, checksum: 8c509f980dcd2dcbfda2f388e9cd9a42 (MD5) Previous issue date: 2007-03-05 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The aim of the present study was to analyze the interference of the administration of piperine in broiler chickens with prolonged aflatoxins intoxication. The experiment was accomplished in two phases: (i) the chickens were separate in four groups test (n=15 broilers / I group), that received different piperine concentrations (1.12, 2.25 and 4.5mg/kg orally/14 days), and a control group, that was only inoculated with the vehicle; (ii) chickens were separate in 3 groups (n=15 broilers/group), a group that received only piperine (2.25 mg/kg), a group that received aflatoxins only (2.0 mg/kg) and another group that received an association of piperine (2.25 mg/kg) and aflatoxins (2.0 mg/kg), all orally / 14 days. At the end of the experiment, the chickens were slaughted and productivity indexes, hematological parameters and histopathological parameters of every digesting tract were evaluated. The results obtained in the first phase showed that the piperine, in the employed doses, didn't interfere in the productivity indexes nor in the result of the values of hematocrit, hemoglobin concentration, fibrinogen and erythrocyte counts, except for the highest doses of piperine, which were capable to promote an increase in the total counting of the white blood cells. The dose of 2.25 piperine mg/kg was not toxic or had and the histopathological lesions observed were dose-dependent. In the second phase of the experiment, it was observed that the productivity indexes in the group that received the association piperine and aflatoxins obtained better performing comparatively with those that just received aflatoxins. The piperine in the concentration of 2.25 mg/kg reduced in a significant way the immunosuppresor activity and the histopathological lesions caused by the aflatoxins. It can be suggested that piperine interferes in a positive way, reducing the toxic effects of the aflatoxins intoxication in broiler chickens. / Este trabalho teve como objetivo analisar a interfer?ncia da administra??o da piperina em frangos de corte com intoxica??o prolongada por aflatoxinas. O experimento foi realizado em duas fases: (i) os frangos foram separados em quatro grupos teste (n=15 aves/ grupo), que receberam diferentes concentra??es de piperina (1,12; 2,25 e 4,5mg/kg por via oral/14 dias), e um grupo controle, que foi inoculado apenas com o ve?culo; (ii) os frangos foram separados em 3 grupos (n=15 aves/grupo), um grupo que recebeu apenas piperina (2,25 mg/kg), um grupo que recebeu apenas aflatoxinas (2,0 mg/kg) e outro grupo recebeu piperina (2,25 mg/kg) em associa??o com aflatoxinas (2,0 mg/kg), todos por via oral/ 14 dias. Ao final do experimento, os frangos foram abatidos e avaliados quanto aos ?ndices de produtividade, par?metros hematol?gicos e par?metros histopatol?gicos de todo trato digest?rio. Os resultados obtidos na primeira fase mostraram que a piperina, nas doses empregadas, n?o interferiu nos ?ndices de produtividade ou nos valores de hemat?crito, hemoglobina, fibrinog?nio e n?mero de hem?cias, com exce??o das doses mais elevadas de piperina, as quais foram capazes de promover um aumento na contagem total de leuc?citos. A dose de 2,25 mg/kg de piperina n?o foi t?xica ou imunossupressora e as les?es histopatol?gicas observadas foram dose dependente. Na segunda fase do experimento, observou-se que de acordo com os ?ndices de produtividade, o grupo que recebeu piperina em associa??o com aflatoxinas obteve melhor desempenho comparativamente com aqueles que receberam apenas aflatoxinas. A piperina na concentra??o de 2,25 mg/kg reduziu de forma significativa ? imunossupress?o e as les?es histopatol?gicas causada pelas aflatoxinas. Desta forma, pode-se sugerir que a piperina interfere de forma positiva na intoxica??o de frangos de corte por aflatoxinas, diminuindo seus efeitos t?xicos.

Made available in DSpace on 2016-04-28T20:17:25Z (GMT). No. of bitstreams: 1 2007- Thalita Gagini Braga.pdf: 8852629 bytes, checksum: e6a948ca864bea46a3f48309716903c7 (MD5) Previous issue date: 2007-03-05 / Made available in DSpace on 2016-04-28T20:17:25Z (GMT). No. of bitstreams: 1 2007- Thalita Gagini Braga.pdf: 8852629 bytes, checksum: e6a948ca864bea46a3f48309716903c7 (MD5) Previous issue date: 2007-03-05 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Piperine (1- piperoyl piperidine) main black pepper (Pipper nigrum Linn.) and long pepper (Piper longum Linn.) alkaloid presents several pharmacological and biochemical effects as enzymes inhibition from hepatic metabolism interfering on xenobiotics and pro-carcinogenic substances biotransformation activated by P-450 cytochromo cycle. According to the scientific bibliography reports, piperine has been able in vitro for decreasing cytotoxicity as well as aflatoxin B1 genotoxicity on mice cells through the competition by P-450 cytochromo. Due to the importance of grains contamination by aflatoxinas, this survey had as proposal to verify piperine ability for decreasing in vivo some damages caused by these toxins. On first, at different piperine doses (1,12; 2,25 and 4,50 mg/Kg) Lou-M strain rats groups were inoculated by oral administrated to evaluated this amide toxicity on animal pattern. Parameters as: weight grain, anatomopathological and histopathological analyses beyond changes on hematological values have been researched. Piperine doses (1,12 mg/Kg) has showed to be appropriate as well as safe on biological assays and it has been used on rats experimental intoxication assays by aflatoxins. Three rats groups were inoculated with piperine (1,12 mg/Kg), aflatoxins (72 &#956;g/ 100 g) as well as piperine + aflatoxins according to the same parameters above described. Piperine has been able for interfering in vivo on aflatoxins toxicity, conspicuously decreasing histopathological injuries on intoxicated animals and significantly returning immunosupression mediated by aflatoxins. / A piperina (1-piperoil piperidina), principal amida constituinte da pimenta preta (Piper nigrum Linn.) e da pimenta longa (P. longum Linn.), apresenta diversos efeitos farmacol?gicos e bioqu?micos, como a inibi??o de enzimas do metabolismo hep?tico, interferindo na biotransforma??o de xenobi?ticos e subst?ncias pr?-carcin?genas ativadas pela via do citocromo P450. A literatura descreve a piperina como sendo capaz, in vitro, de diminuir a citotoxidez e a genotoxidez da aflatoxina B1 em c?lulas de ratos, atrav?s da competi??o pelo citocromo P450. Devido ? import?ncia da contamina??o de gr?os por aflatoxinas, este trabalho teve como objetivo verificar a capacidade da piperina em diminuir, in vivo, os danos causados por essas toxinas. Inicialmente, grupos de ratos da linhagem LOUM foram inoculados, via oral, com diferentes doses de piperina (1,12; 2,25 e 4,50 mg/kg de peso corporal), visando avaliar a toxidez dessa amida no modelo animal empregado. Par?metros como: ganho de peso, an?lises anatomopatol?gica e histopatol?gica, al?m das altera??es nos valores hematol?gicos foram investigados. A dose de 1,12 mg/kg de peso corporal de piperina demonstrou ser segura nos ensaios biol?gicos e foi empregada nos ensaios de intoxica??o experimental de ratos com aflatoxinas. Tr?s grupos de ratos foram inoculados com piperina (1,12 mg/kg de peso corporal), aflatoxinas (72 &#956;g/100g de peso corporal) e, piperina + aflatoxinas, sendo avaliados os mesmos par?metros acima descritos. A piperina foi capaz de interferir na toxidez das aflatoxinas, in vivo, diminuindo de forma acentuada as les?es histopatol?gicas evidenciadas nos animais intoxicados e, revertendo de forma significativa a imunossupress?o mediada pelas aflatoxinas.