Glória Maria Direito

Influence of water activity, temperature and time on mycotoxins production on barley rootlets

Aims:  The objective of this study was to determine the ochratoxin (OT) and aflatoxin (AF) production by three strains of Aspergillus spp. under different water activities, temperature and incubation time on barley rootlets (BR).

Characterization of Aspergillus species based on fatty acid profiles

Cellular fatty acid (FA) composition was utilized as a taxonomic tool to discriminate between different Aspergillus species. Several of the tested species had the same FA composition and different relative FA concentrations. The most important FAs were palmitic acid (C16:0), estearic acid (C18:0), oleic acid (C18:1) and linoleic acid (C18:2), which represented 95% of Aspergillus FAs. Multivariate data analysis demonstrated that FA analysis is a useful tool for differentiating species belonging to genus Aspergillus. All the species analyzed showed significantly FA acid profiles (p < 0.001). Furthermore, it will be possible to distinguish among Aspergillus spp. in the Flavi Section. FA composition can serve as a useful tool for the identification of filamentous fungi.

Oral administration of piperine for the control of aflatoxin intoxication in rats.

Aflatoxins are mycotoxins that have important toxic effects on human and animal health, even if consumed at low doses. The oral administration of piperine (1.12 mg/kg) during 23 days in rats seemingly interfered with the toxicity of aflatoxins, decreasing hepatic injuries and the leukocyte depletion in experimentally intoxicated animals.

In-house validation of a method for determining aflatoxins B1, B2, G1 and G2 in wheat and wheat by-products

Aflatoxins are naturally occurring carcinogenic substances, extremely toxic to humans, which have been identified in wheat and wheat by-products. The use of reliable analytical methods to evaluate and monitor such contaminants is extremely important. This study aimed to in-house validate a methodology to determine aflatoxins B 1 , B 2 , G 1 and G 2 in wheat grains using pre-column derivatization and quantification by High Performance Liquid Chromatography with fluorescence detection (HPLC-FLD). Three methods were evaluated and the most suitable one was the method based on the extraction with chloroform, removal of interfering chemicals by filtration, liquid-liquid partition with hexane-methanol-water and methanol-water-chloroform and pre-column derivatization with trifluoroacetic acid. The method showed a Relative Standard Deviation lower than 15% and recovery values in the 70-110% range, with limits of detection and quantification (0.6 µg kg -1 and 1.2 µg kg -1 , respectively) below the maximum level of aflatoxins allowed in wheat and wheat by-products by the European Commission (4.0 µg kg -1 ) and by the Brazilian legislation (5.0 µg kg -1 ). Using the validated method, aflatoxins were quantified in 20 commercial samples of wheat grains, wheat bran, whole wheat flour and refined wheat flour intended for direct human consumption. Six samples (30%) were positive for aflatoxins and all samples presented levels below the maximum limit stipulated by the Brazilian legislation.

Ochratoxin A in serum of swine from different Brazilian states.

The aims of the current study were to monitor the presence of ochratoxin A (OTA) in the serum of slaughtered swine and to investigate its distribution in 4 major geographical regions of Brazil. A total of 400 samples of serum were collected from 4 major states of Brazil (100 samples each). Ochratoxin A concentrations were determined by high-performance liquid chromatography. In Santa Catarina State, 60% of the samples had OTA concentrations ranging from 4.01 to 75.4 mg/l. In Mato Grosso State, 75% of the samples had OTA concentrations ranging from 0.17 to 46.79 mg/l. Bahia State samples had OTA concentrations ranging from 2.72 to 4.13 mg/l in 36% of the samples, whereas 68% of the samples from Rio de Janeiro State had OTA concentrations ranging from 0.16 to 115 mg/l. Only Santa Catarina State and Rio de Janeiro State had serum samples that exceeded 75 mg/l OTA in 20% and 2% of the samples, respectively. A direct relationship between the higher concentrations of OTA in serum from the States of Santa Catarina and Rio de Janeiro and the highest concentrations of OTA in food intended for animal consumption in the same 2 Brazilian states was found in the present study. Ochratoxin A distribution in foodstuffs is very heterogeneous, and an alternative method by which to monitor the presence of OTA in feed includes analyzing swine serum samples, which reflect the toxin content of the ingested feed. This strategy could prevent the occurrence of ochratoxicosis in animal production, reduce economic losses, and minimize hazards to human health.

Antigenotoxic Effect of Piperine in Broiler Chickens Intoxicated with Aflatoxin B1.

Piperine is an abundant amide extracted from black pepper seeds which has been shown to have protective effects against cytotoxic and genotoxic carcinogenesis induced by certain chemical carcinogens and aflatoxin B1 (AFB1) in vitro. The aim of this work was to study, in vivo, the antigenotoxic potential of feed-added piperine on broiler chickens experimentally intoxicated with AFB1, using micronucleus and comet assays. The antigenotoxicity assessment of 9-day-old chicks was performed on a total of 60 chickens divided into four groups of 15 broilers each: (C) control, (P) 60 mg·piperine kg−1 feed, (A) 0.5 mg·AFB1·kg−1 body weight, (daily by oral route), and (P + A) co-treatment with piperine and AFB1. The experiment was conducted for 26 days. Chicks intoxicated with AFB1 showed significant genotoxic effects in the first 24 h post intoxication, and the effects remained in the other periods analyzed (48, 72, and 96 h and 26 days of treatment). The DNA damage in peripheral blood cells, the number of erythrocytes with micronuclei, and polychromatic-to-normochromatic erythrocyte ratio were significantly reduced or absent in the piperine/AFB1 group. No significant differences were observed between the group piperine/AFB1 and the control and piperine-alone groups. The addition 60 mg·kg−1 of piperine to the diet of the broiler chicks was safe, promoting beneficial effects in poultry health with respect to the toxic effects 0.5 mg·AFB1·kg−1 body weight.

Aflatoxinas y tricotecenos en trigo y derivados: incidencia de la contaminación y métodos de determinación

Trichothecenes and aflatoxins are natural contaminants produced by filamentous fungi and they are widely present in wheat. The presence of these mycotoxins a...

Detecção de ácido ocadaico em mexilhões Perna perna (LINNÈ, 1758) cultivados em fazenda de maricultura na baía de Ilha Grande, Angra dos Reis, RJ

Este trabalho foi realizado na fazenda de maricultura localizada na enseada de Macieis, baia de Ilha Grande (Angra dos Reis,RJ). No outono de 2004, mexilhoes (Perna perna) foram coletados para detectar a presenca da ficotoxina acido ocadaico (AO).Esta toxina pode ser produzida por algumas especies de dinoflagelados pertencentes aos generos Prorocentrum e Dinophysis.Os mexilhoes, ao se alimentarem destas microalgas, acumulam a toxina, principalmente em sua glândula digestiva(hepatopâncreas), desencadeando no ser humano a sindrome do Envenenamento Diarreico por Moluscos (EDM). A ficotoxinaAO e o principal responsavel pela sindrome EDM, que e caracterizada por nauseas, dores abdominais, vomitos e diarreia, seforem consumidos moluscos contaminados com concentracoes a partir de 48 mg AO.g-1 de hepatopâncreas de molusco.Glândulas digestivas dos mexilhoes coletados foram homogeneizadas para extracao e deteccao de AO. As amostras foramanalisadas por Cromatografia Liquida de Alta Eficiencia com Deteccao Fluorescencia (CLAE-DF). Os resultados cromatograficosindicaram a presenca da toxina AO, em baixa concentracao (~ 2ng AO.g-1 hepatopâncreas de molusco), em apenas uma dasamostras da primeira coleta (marco/2004) e sua ausencia nas coletas posteriores (abril e maio/2004).