Incidência de aflatoxinas B1, B2, G1 e G2 em amendoins / Incidence of aflatoxins B1, B2, G1 and G2 in peanuts

Micotoxinas são substâncias tóxicas produzidas por fungos e encontradas nos alimentos. As micotoxinas mais tóxicas são as aflatoxinas, produzidas, principalmente por Aspergillus flavus. Estudos realizados no país demonstraram alta incidência dessas micotoxinas em produtos de amendoim, que representa risco à saúde da população. O objetivo do estudo foi avaliar a incidência de aflatoxinas B1, B2, G1 e G2 em amostras de amendoins comercializados na região Nordeste do Estado de São Paulo nos períodos de 1994-2001 e 2016-2017. O método utilizado para analisar as amostras no primeiro período foi extração líquido-líquido e cromatografia em camada delgada e no segundo foi utilizando colunas de imunoafinidade, cromatografia líquida com derivatização pós-coluna e detector por fluorescência. No levantamento de 1994-2001 das 82 amostras, 39% tiveram contaminação de aflatoxinas variando de 11 a 1556 μg/kg com 37% das amostras contendo níveis maiores que 20 μg/kg, enquanto na pesquisa de 2016-17, das 56 amostras, 38% apresentaram contaminação destas toxinas variando de 0,09 a 60,40 μg/kg com 13% das amostras contendo níveis maiores que 20 μg/kg. Os resultados dos dois períodos estudados indicam que houve uma diminuição na incidência e nível das aflatoxinas estudadas, embora esta contaminação em amendoim permaneça um problema de saúde pública.

Mycotoxins are toxic compounds produced by fungi found in food. The most toxic mycotoxins are the aflatoxins produced mainly by Aspergillus flavus. Studies carried out in Brazil showed a high incidence of these mycotoxins in peanut products, a fact that represents public health problems. The aim of the study was to evaluate aflatoxins B1, B2, G1, and G2 in samples of peanuts sold in cities of the Northeast of the State of São Paulo in the period from 1994 to 2001 and from 2016 to 2017. The samples of the first period were analyzed using liquid-liquid extraction and thin-layer chromatography and the second using immunoaffinity columns, post-column derivative liquid chromatography and fluorescence detector. In the 1994-2001 survey, among 82 samples, 39% presented aflatoxins contamination ranging from 11 to 1556 μg/kg with 37% with levels greater than 20 μg/kg whereas, in the 2016-17 survey, 38% of the 56 samples presented contamination of aflatoxins ranging from 0.09 to 60.40 μg/kg and 7 samples 13% containing aflatoxins levels higher than 20 μg/kg. The results indicated there was a decrease in the incidence and level of aflatoxins, but the contamination of aflatoxins in peanuts remains a public health problem.

Transcriptome and proteome analyses of resistant preharvest peanut seed coat in response to Aspergillus flavus infection

BACKGROUND: The infection of peanut (Arachis hypogaea L.) seed coat by the pathogenic fungus Aspergillus flavus has highly negative economic and health impacts. However, the molecular mechanism underlying such defense response remains poorly understood. This study aims to address this issue by profiling the transcriptomic and proteomic changes that occur during the infection of the resistant peanut cultivar J11 by A. flavus. RESULTS: Transcriptomic study led to the detection of 13,539 genes, among which 663 exhibited differential expression. Further functional analysis found the differentially expressed genes to encode a wide range of pathogenesis- and/or defense-related proteins such as transcription factors, pathogenesis-related proteins, and chitinases. Changes in the expression patterns of these genes might contribute to peanut resistance to A. flavus. On the other hand, the proteomic profiling showed that 314 of the 1382 detected protein candidates were aberrantly expressed as a result of A. flavus invasion. However, the correlation between the transcriptomic and proteomic data was poor. We further demonstrated by in vitro fungistasis tests that hevamine-A, which was enriched at both transcript and protein levels, could directly inhibit the growth of A. flavus. Conclusions: The results demonstrate the power of complementary transcriptomic and proteomic analyses in the study of pathogen defense and resistance in plants and the chitinase could play an important role in the defense response of peanut to A. flavus. The current study also constitutes the first step toward building an integrated omics data platform for the development of Aspergillus-resistant peanut cultivars

Promotion of iron nutrition and growth on peanut by Paenibacillus illinoisensis and Bacillus sp. strains in calcareous soil

ABSTRACT This study aimed to explore the effects of two siderophore-producing bacterial strains on iron absorption and plant growth of peanut in calcareous soil. Two siderophore-producing bacterial strains, namely, YZ29 and DZ13, isolated from the rhizosphere soil of peanut, were identified as Paenibacillus illinoisensis and Bacillus sp., respectively. In potted experiments, YZ29 and DZ13 enhanced root activity, chlorophyll and active iron content in leaves, total nitrogen, phosphorus and potassium accumulation of plants and increased the quality of peanut kernels and plant biomass over control. In the field trial, the inoculated treatments performed better than the controls, and the pod yields of the three treatments inoculated with YZ29, DZ13, and YZ29 + DZ13 (1:1) increased by 37.05%, 13.80% and 13.57%, respectively, compared with the control. Based on terminal restriction fragment length polymorphism analysis, YZ29 and DZ13 improved the bacterial community richness and species diversity of soil surrounding the peanut roots. Therefore, YZ29 and DZ13 can be used as candidate bacterial strains to relieve chlorosis of peanut and promote peanut growth. The present study is the first to explore the effect of siderophores produced by P. illinoisensis on iron absorption.

Compatibility of Azospirillum brasilense and Pseudomonas fluorescens in growth promotion of groundnut ( Arachis hypogea L)

ABSTRACT We attempted to study the compatibility among plant beneficial bacteria in the culture level by growing them near in the nutrient agar plates. Among all the bacteria tested, Rhizobium was found to inhibit the growth of other bacteria. From the compatible group of PGPR, we have selected one biofertilizer (Azospirillum brasilense strain TNAU) and one biocontrol agent (Pseudomonas fluorescens strain PF1) for further studies in the pot culture. We have also developed a bioformulation which is talc powder based, for individual bacteria and mixed culture. This formulation was used as seed treatment, soil application, seedling root dip and foliar spray in groundnut crop in vitro germination conditions. A. brasilense was found to enhance the tap root growth and P. fluorescens, the lateral root growth. The other growth parameters like shoot growth, number of leaves were enhanced by the combination of both of the bacteria than their individual formulations. Among the method of application tested in our study, soil application was found to be the best in yielding better results of plant growth promotion.

Fungos potencialmente toxigênicos em amostras de amendoim disponível para o consumo humano / Potentially toxigenic fungi in peanut samples available for human consumption

Avaliou-se a contaminação por fungos potencialmente toxigênicos em amendoim in natura disponível para consumo humano e comercializado em supermercados de Juiz de Fora, MG. Foram adquiridas 31 amostras de sete diferentes marcas de amendoim em grãos cru; amendoim torrado em grãos e amendoim torrado e triturado (moído), em embalagens originais e invioladas, em cinco estabelecimentos comerciais. A análise da presença de fungos potencialmente toxigênicos nos grãos de amendoim foi realizada por meio da técnica de plaqueamento direto em placas de Petri, contendo os meios de cultura Ágar Batata Dextrose (ABD) e Ágar Dicloran Rosa de Bengala Cloranfenicol (ADRBC). Das 31 amostras analisadas, 17 (54,84%) estavam contaminadas por fungos potencialmente toxigênicos (Aspergillus niger, Aspergillus flavus e/ou Aspergillus parasiticus, Aspergillus fumigatus e Penicillium spp) além de outros não toxigênicos (Rhizopus spp. e leveduras). O índice de contaminação nas diferentes amostras de amendoim avaliadas foi expressivo, sendo que as espécies encontradas foram de fungos potencialmente toxigênicos produtores de micotoxinas importantes como as aflatoxinas.

Occurrence of fungi and aflatoxins B in nuts and products marketed the Brazilian northeastern regions / Ocorrência de fungos e aflatoxinas do tipo B em castanhas e produtos comercializados no Nordeste brasileiro

Aflatoxin contamination has been considered as a public health problem, especially in tropical countries, including Brazil. In order to investigate the presence of type B aflatoxins in products marketed in the city of Fortaleza, 23 samples were analyzed by thin layer chromatography. Visible fungal contamination in food was identified according to their macroscopic and microscopic features. The contamination by aflatoxins was detected in 8.7 % of 23 analyzed samples, and 12.5 % of Brazilian nuts samples were positive for AFB1 (<8 µg/kg) and for AFB2 in a contamination rate above the allowed value (16 µg/kg). Among the peanut samples, 33.3 % were positive to AFB1 and AFB2, also in a contamination rate (317.1 µg/kg) which was higher than that recommended by ANVISA. The isolation and morphological characteristics of fungi detected mainly in Brazilian nuts with peel showed the occurrence of the following species: Aspergillus flavus, Aspergillus niger, Mucor sp, Cladosporium sphaerospermum, Cladosporium cladosporoides, Fusarium sp, Aspergillus terreus and bacteria of Actinomycetes phylum. These findings indicate that it is needed to apply the mostly effective quality monitoring of food available to consumers.

A contaminação por aflatoxinas tem sido considerada um problema de saúde pública principalmente em países tropicais, incluindo o Brasil. Com o intuito de investigar a presença de aflatoxinas do tipo B em produtos comercializados na cidade de Fortaleza, 23 amostras foram analisadas por meio de cromatografia em camada delgada. Os fungos visivelmente presentes em alimentos foram identificados de acordo com suas características macroscópicas e microscópicas. A contaminação por aflatoxina foi detectada em 8,7 % das 23 amostras analisadas; e 12,5 % das amostras de castanha-do-Brasil apresentaram positividade para AFB1 (<8 µg/kg) e para AFB2 com taxa de contaminação acima do valor permitido (16 µg/kg). Quanto às amostras de amendoim, 33,3 % apresentaram positividade para AFB1 e AFB2, também com nível de contaminação (317,1 µg/kg) acima do preconizado pela ANVISA. O isolamento e a caracterização morfológica dos fungos encontrados principalmente nas castanhas-do-Brasil com casca revelaram a presença das espécies: Aspergillus flavus, Aspergillus niger, Mucor sp, Cladosporium sphaerospermum, Cladosporium cladosporoides, Fusarium sp, Aspergillus terreus e bactérias do filo Actinomicetos. Estes resultados demonstram que há necessidade de fiscalização mais efetiva da qualidade dos alimentos oferecidos aos consumidores.

Molecular characterisation of Aspergillus flavus isolates from peanut fields in India using AFLP

Aflatoxin contamination of peanut, due to infection by Aspergillus flavus, is a major problem of rain-fed agriculture in India. In the present study, molecular characterisation of 187 Aspergillus flavus isolates, which were sampled from the peanut fields of Gujarat state in India, was performed using AFLP markers. On a pooled cluster analysis, the markers could successfully discriminate among the ‘A’, ‘B’ and ‘G’ group A. flavus isolates. PCoA analysis also showed equivalent results to the cluster analysis. Most of the isolates from one district could be clustered together, which indicated genetic similarity among the isolates. Further, a lot of genetic variability was observed within a district and within a group. The results of AMOVA test revealed that the variance within a population (84%) was more than that between two populations (16%). The isolates, when tested by indirect competitive ELISA, showed about 68.5% of them to be atoxigenic. Composite analysis between the aflatoxin production and AFLP data was found to be ineffective in separating the isolate types by aflatoxigenicity. Certain unique fragments, with respect to individual isolates, were also identified that may be used for development of SCAR marker to aid in rapid and precise identification of isolates.

Fermentação em estado sólido de Aspergillus parasiticus e produção de aflatoxinas / Solid state fermentation of Aspergillus parasiticus and aflatoxin production

Aflatoxinas são metabólitos secundários de fungos com grande potencial carcinogênico, produzidos principalmente por Apergillus flavus e Aspergillus parasiticus. Em vista da ampla variedade de alimentos em que se encontram essas micotoxinas, o presente estudo teve como objetivo determinar condições de cultivo para o Aspergillus parasiticus e produção das quatro principais aflatoxinas (AFB1, AFB2, AFG1 e AFG2) considerando diferentes substratos conhecidos pela contaminação por estas micotoxinas, entre eles arroz branco, arroz cateto, amendoim, milho e farinha de trigo integral, e diferentes valores de umidade e pH. Ao analisar por cromatrografia em camada delgada os extratos dos diferentes substratos, verificou-se a produção de aflatoxinas em todos os alimentos, porém na cromatografia líquida de alta eficiência foi possível perceber a maior produção de aflatoxinas no arroz cateto e na farinha de trigo integral. Para a continuidade do trabalho, utilizou-se o arroz cateto e então preparou- se diferentes meios sólidos com valores de pH entre 3,5 e 7,5 e umidade entre 42 % e 62 %. Ao analisar por CLAE, todas as amostras apresentaram produção de AF, porém as amostras com o maior valor de água agregada (62%) apresentaram maior produção enquanto a variação de pH não apresentou influência nesta produção.

Aflatoxins are secondary metabolites of fungi with great carcinogenic potencial, mainly produced by Aspergillus flavus and Aspergillus parasiticus. In order of the wide variety of foods where mycotoxins are found in, this study aimed to determine growth conditions for Aspergillus parasiticus and production of four major aflatoxins (AFB1, AFB2, AFG1 and AFG2) considering different substrates known for contamination by these aflatoxins, including white rice, cathetus rice, peanuts, maize and whole wheat flour, and different pH and humidity values. When extracts of different substrates were analyzed by thin layer chromatography, it has been verified the production of aflatoxins in all foods; however, when high performance liquid chromatography (HPLC) analysis was performed, the greater production of aflatoxins was observed in cathetus rice and whole-wheat flour. Cathetus rice was then selected to continue the study and different solid medium with pH values between 3.5 and 7.5 and humidity percentages between 42 % and 62 % were prepared. When analyzed by HPLC, all samples showed production of aflatoxins, but the samples with higher humidity value (62%) showed greatest production while the pH changes had no effect on this production.

Impact of water potential on growth and germination of Fusarium solani soilborne pathogen of peanut

Studies were conducted to determine the effect of osmotic and matric stress on germination and growth of two Fusarium solani strains, the etiological agent responsible of peanut brown root rot. Both strains had similar osmotic and matric potential ranges that allowed growth, being the latter one narrower. F. solani showed the ability to grow down to -14 MPa at 25 °C in non-ionic modified osmotic medium, while under matric stress this was limited to -8.4 MPa at 25 °C. However, both strains were seen to respond differently to decreasing osmotic and matric potentials, during early stages of germination. One strain (RC 338) showed to be more sensitive to matric than osmotic (non ionic) and the other one (RC 386) showed to be more sensitive to osmotic than matric imposed water stress. After 24 h of incubation, both isolates behaved similarly. The minimum water potential for germination was -8.4 MPa on glycerol amended media and -5.6 MPa for NaCl and PEG amended media, respectively. The knowledge of the water potential range which allow mycelia growth and spore germination of F. solani provides an inside to the likely behaviour of this devastating soilborne plant pathogen in nature and has important practical implications.

Distribution of aflatoxins and micro organisms in peanut and sunflower seed products and their potential health Hazards

Aflatoxins are mould metabolites of Aspargillus flavus and parasiticus that contaminate foodstuffs stored in warm moist places. These toxins are hepatotoxic and produce hepatocellular carcinoma in animals and man. To determine the presence of aflatoxins and microorganisms in ready to consume products of peanuts and sunflower seeds of an edible oil processing factory. Five hundred grams each of peanut kernels, peanut pellets, sunflower seed pellets, peanut oil and sunflower seed oil produced by a local oil extracting factory were supplied for extraction and estimation of aflatoxins and microorganisms like Salmonella, Escherichia coli [E.coli], Bacillus and Moulds. Aflatoxins B[1], B[2], G[1] and G[2] were extracted in chloroform and concentration was measured using silica gel columns. The quantitative estimation of these aflatoxins B[1], B[2], G[1] and G[2] was done by fluorescence evaluation on Thin Layer Chromatograms. All test samples contained four types of aflatoxins. The highest aflatoxin values were seen in the pellets and lowest in refined oils. All samples contained higher content of aflatoxins B[1] and B[2] than G[1] and G[2]. Refined peanut oil contained much lower aflatoxin than the sunflower seed oil. This study has also identified the presence of several types of microorganisms such as Salmonella, E. coli, Bacillus and Moulds in ready to eat peanut and sunflower seed products. Detection of high levels of aflatoxins and microorganisms in ready to eat food stuff should be a concern for food regulatory agencies since these products are consumed daily by the common man and their cumulative effect on the body might be adding to liver cancer in the population. Food regulatory agencies should regularly carry out thorough surveillance on food stuff

Incidência de aflatoxinas em amendoim industrializado em Caxias do Sul, RS / Incidence of aflatoxins in peanuts industrialized in Caxias do Sul, RS

O problema da contaminação de alimentos com aflatoxinas é de interesse atual e recebeu muita atenção durante as últimas décadas. Neste contexto, o objetivo do presente trabalho foi verificar a ocorrência de aflatoxinas (AFB e AFG ) em amendoim, destinados à alimentação humana, industrializado em Caxias do Sul/RS, no período de janeiro/2000 a dezembro/2007. Foram coletadas 288 amostras de amendoim e as aflatoxinas presentes quantificadas pelo método de cromatografia líquida de alta eficiência, verificando-se que 186 (64,5%) estavam contaminadas com as aflatoxinas AFB e AFG em concentrações de 1,05 a 35,5 µg/kg. A partir desses resultados, ressalta-se a necessidade de um controle eficaz dos níveis de aflatoxinas em todas as etapas de cultivo e industrialização.

Comunidades de fungos micorrízicos arbusculares associados ao amendoim forrageiro em pastagens consorciadas no Estado do Acre, Brasil / Communities of arbuscular mycorrhizal fungi associated with peanut forage in mixed pastures in the state of Acre, Brazil

O objetivo deste trabalho foi identificar e estimar a diversidade de comunidades de fungos micorrízicos arbusculares (FMAs) autóctones associados ao amendoim forrageiro (Arachis pintoi), em monocultivo e consorciado com outras forrageiras. A amostragem foi realizada em sete áreas, em Rio Branco, AC, sendo coletadas quatro amostras de solo em cada área, na profundidade de 0-10 cm, nas estações seca (junho de 2004) e chuvosa (janeiro de 2005). As áreas cultivadas com A. pintoi foram: monocultivo, consórcio com pastagens de gramíneas e outras leguminosas e como cobertura do solo em cafeeiro, além de capoeira e mata adjacentes como testemunhas. Foi verificada a ocorrência de 21 espécies de FMAs nas duas estações, sendo 18 espécies no período seco e 16 no chuvoso. As espécies foram distribuídas em cinco gêneros: Acaulospora, Entrophospora, Gigaspora, Glomus e Scutellospora. A densidade de esporos foi maior no consórcio A. pintoi x Brachiaria brizantha x Pueraria phaseoloides e a menor nas áreas de A. pintoi x cafeeiro, capoeira e mata. As colonizações radiculares foram maiores na estação chuvosa (15 a 63%) do que na estação seca (5 a 37%). Os índices de diversidade no monocultivo foram semelhantes aos das demais áreas avaliadas, indicando que o amendoim serve como hospedeiro de diferentes espécies de FMAs e que o seu cultivo pode aumentar a presença desses organismos nos sistemas produtivos, melhorando a qualidade biológica do solo.

The purpose of this study was to identify the autochthonous communities of arbuscular mycorrhizal fungi (AMF) associated with Arachis pintoi and estimate its diversity. Samples of soil were collected in a Field at Rio Branco, AC. The sampling was carried out in seven areas, being collected four samples from soil in each area, in a depth of 0-10cm, in dry season (June 2004) and rainy season (January 2005). The areas cultivated with A. pintoi were: monoculture, grass pasture and others legumes intercropped, coffee plant under cover of A. pintoi, besides brush and forest adjacent like a control. It was verified the occurrence of 21 species of AMF in the two seasons, 18 species in the dry period and 16 in the rainy. The species were distributed in five genres: Acaulospora, Entrophospora, Gigaspora, Glomus and Scutellospora. The densities of spores were higher in A. pintoi x Brachiaria brizantha x Pueraria phaseoloides intercropped and lowest in the areas of A. pintoi x coffee plants, brush and forest. Mycorrhizal colonization was higher in the rainy season (15 to 63%) than in the dry season (5 to 37%). The diversity indices in monoculture were similar to those of other areas evaluated, indicating that the A. pintoi serves as host of AMF of different species and that its cultivation may increase the presence of these organisms in production systems, improving the biological soil quality.

Inhibition of Aspergillus flavus colonization and aflatoxin (AfB1) in peanut by methyleugenol.

Methyleugenol is naturally occurring substance in oils and fruits and in various foods as flavoring agent. Effect of this methyleugenol in inhibiting A. flavus colonization and aflatoxin production on peanut pods and kernels has been studied. Spray of methyleugenol (0.5%) on peanut pods and kernels checked the colonization of A. flavus and aflatoxin synthesis. This chemical can be used as both prophylactic or post infection spray on peanut pods before storage. It is the first report on the inhibition of A. flavus by methyleugenol on peanut.

Survey of peanut fungal contamination and its relationship with ambient conditions in the Bazar of Zanjan

Different food products such as corn, wheat and peanut have shown high potential to be contaminated in suitable environmental conditions, such as temperature and humidity. Some fungi can produce toxins, like Aflatoxin, and some of them are carcinogen. The purpose of this research was to study fungal contamination in peanuts being sold in the BAZAR of the city of Zanjan. 20 samples of 50g roasted and salted peanuts and 16 samples of 50g unsalted peanuts [pure] were collected from Zanjan Bazar. Ambient conditions such as light intensity, temperature and air flow of the BAZAR and also the relative humidity of peanuts were measured. Samples were analyzed for fungal colony and were identified using slide culture technique. Results showed that Mold fungi were dominant among the colonies as. Aspergillus flavus [39.1%], Penicillium [9.2%], Rhizopus [7.2%], Mucor [2.5%], Alternaria [1.03%] and Nigrospora [0.5%]. Temperature and the samples relative humidity were higher than the standard range. The results indicated a significant relation between relative humidity, light intensity, temperature and peanuts' type [pure or salted] with level of fungal contamination. Also, roasting and processing reduced the relative humidity of peanuts and the level of contamination. Hence roasting, salting and provision of appropriate ambient conditions can be useful to peanut storage

Eliminação ou inativação de fungos do gênero Aspergillus em amendoim (Arachis hypogea, L), e o aumento de sua vida de prateleira, quando tratado com radiação gama / Elimination or inactivation of the fungi genus Aspergillus in peanut (Arachis hypogea, L), and increased its shelf-life when treated with gamma radiation

A presente pesquisa, investigou a eficácia da aplicação da radiação gama para evitar o aparecimento de fungos patogênicos em amendoim (Arachis hypogea, L), conseqüentemente, conferindo ao produto uma melhor qualidade fitossanitária e maior vida de prateleira. Foram pesquisadas amostras processadas salgadas e in-natura. Depois de submetidas à radiação proveniente de uma fonte de césio-137, para absorverem doses de 0; 1,5; 2,0 e/ou 2,5 kGy, as amostras foram monitoradas sensorial e micologicamente e comparadas às testemunhas (não irradiadas). Análises sensoriais periódicas mostraram que o tratamento por irradiação com dose de 2,0 kGy não alterou perceptivelmente o sabor do amendoim in-natura, mas causou uma evidente alteração no sabor das amostras de amendoim processado.(...).

A survey of the occurrence of aflatoxins in groundnuts (peanuts) and groundnut products in Säo Paulo State/Brazil in 1994

Foram analisadas 321 amostras de amendoim e produtos de amendoim, comercializados no Estado de Säo Paulo, em 1994 e colhidos pela Vigilância Sanitária da Secretaria de Saúde do Estado de Säo Paulo quanto ao teor de aflatoxinas. Um total de 116 amostras (36 por cento) mostraram níveis de aflatoxinas B1+G1 acima do limite permitido pela legislaçäo brasileira (30 ug.Kg1). As amostras foram analisadas por cromatografia em camada delgada e o resultado, quantificado visualmente. As concentrações variam de 5 a 2.440 ug.Kg1 e o 90th percentil foi de 489 ug.Kg1. O limite de quantificaçäo do método é de 5 ug.Kg1. Os dados confirmam a extensäo e o nível de ocorrência de aflatoxinas em amendoim e produtos de amendoim em Säo Paulo e também mostra que este problema ainda existe, principalmente em condições de temperatura e umidade alta, clima predominante no Estado de Säo Paulo favorável ao crescimento de fungos toxigênico

Influencia de la distancia de plantación y selección de genotipos de mani (arachis hypogaea l.) resistentes a cercosporidium personatum (berk & curt.)deigh. y puccinia arachidis speg / Influence of spacing arrangement and genotype selection of peanut (arachis hypogaea l.) resistent to cercosporidium personatum (berck & curt) deigh and puccinia arachidis speg

La mancha negra y la roya, causadas respectivamente por los hongos cercosporidium personatum y puccinia arachidis, constituyen las principales enfermedades, 15 genotipos de maní fueron analizados con respecto a los niveles de resistencia bajo condiciones naturales de infección. El diseño se efectuó en bloques completos al azar, con 5 repeticiones. La evaluación fue efectuada a los 85 días después de la siembra, midiéndose la incidencia y la severidad de las enfermedades en 45 folíolos por parcela. Los genotipos BR-1, L2IAC2, CNPA Senegal y CNPA 125 AM, se destacaron de los demás al evidenciar los menores niveles de severidad de la mancha negra, mientras en la incidencia de la roya se destacó CNPA Senegal y CNPA Havana. El efecto de los tipos de espaciamientos de siembra fueron de 0,3, 0,5 y 0.7m entre líneas con 5,10 y 15 plantas/m lineal. Los niveles de severidad de las enfermedades fueron analizadas utilizándose el cultivar IAC Tupa. la evaluación fue efectuada 90 días después de la siembra, en 45 folíolos de la linea central de cada parcela. Los resultados no evidenciaron un efecto significativo de los tipos de espaciamientos en la severidad de la mancha negra y de la roya

Standartization of a method for the inoculation of peanuts (Arachis hypogael L) - Tatu vermelho variety with Aspergillus flavus NRRL 6513, an Aflatoxin B1 producer

Foram determinadas as condiçöes analíticas ideais para a inoculaçäo de uma cepa de Aspergillus flavus NRRL 6513, fortemente produtora de aflatoxina B1 em amendoim, variedade Tatu Vermelho. A maior produçäo de aflatoxina foi verificada após a adiçäo, em 1,0g de amendoim moído e autoclavado (121oC/20 min.), de 0,5 ml de suspensäo salina de esporos (4x10.6) esporos/ml) de Aspergillus flavus NRRL 6513, de 10 dias de idade, seguido de incubaçäo por 7 dias

Effect of propionic acid on fungal growth and aflatoxin production in moist inshell groudnuts

O efeito do ácido propiônico nas concentraçöes de 3,0 g/kg (AP1) e 5,0 g./kg (AP2) foi avaliado em laboratório para verificar sua eficiência sobre o crescimento fúngico e produçäo de aflatoxinas quando aplicado sobre amendoim em casca úmido. As avaliaçöes, crescimento fúngico sobre as vagens e seus gräos e as análises de aflatoxinas, foram realizadas antes da incubaçäo e aos 7, 14, 21 e 28 dias de incubaçäo. O tratamentoAP1 foi ineficiente no controle do crescimento fúngico a partir de 14§ dia

Aflatoxinas em alimentos comercializados no Distrito Federal de 1985 a 1995 / Aflatoxins in comercialized food at Federal District area from 1985 to 1995

Amostras de alimentos comercializados no Distrito Federal no priodo de 1985 a 1995 foram analisadas quanto ao teor de aflatoxinas B1 e G1. Das 681 amostras, 450 foram amendoim e produtos de amendoim, 117 castanhas diversas, 28 feijäo, 19 arroz e produtos de arroz, 16 trigo e produtos de trigo, 9 milho e produtos de milho, entre outros. Apenas amendoim e produtos de amendoim e uma única amostra da castanha do pará, apresentaram contaminaçäo por aflatoxinas. Das amostras positivas de amendoim e seus produtos 19,8(por cento), 39,3(por cento) apresentaram teores de aflatoxinas B1 + G1 acima do limite permitido pela legislaçäo brasileira (30ug/kg), sendo que o maior teor foi encontrado em amostras de amendoim cru (600ug/kg). Estes valores estäo abaixo dos níveis de contaminaçäo reportados nas regiöes sul e sudeste do país, principais regiöes produtoras de gräos e fornecedoras de alimentos indutrializados ao Distrito Federal.