No abstract

Os agrotóxicos são usados em muitas culturas para prevenir e preservar os grãos de possíveis ataques de pragas. O objetivo deste trabalho foi avaliar a distribuição dos agrotóxicos bispiribaque de sódio, carbofurano, clomazona e tebuconazol nas diferentes frações do arroz beneficiado (arroz branco, farelo de arroz, arroz com casca, arroz parboilizado beneficiado, farelo de arroz parboilizado e arroz parboilizado com casca), o qual foi cultivado em campos experimentais sob condições controladas de aplicação. Para tanto, o método QuEChERS foi otimizado para a extração dos agrotóxicos e validou-se um método utilizando CLAE-DAD para quantificação e CL-EM para confirmação. O método QuEChERS modificado foi adequado na extração dos agrotóxicos, bem como as condições cromatográficas para identificação e quantificação, conforme os indicativos de eficiência determinados: LOD de 0,07 mg kg -1 e LOQ de 0,2 mg kg -1 para a mistura dos agrotóxicos, e recuperação para arroz e farelo de arroz de 119 e 116%, 84 e 119%, 113 e 96%, 103 e 97% para carbofurano, bispiribaque de sódio, clomazona e tebuconazol, respectivamente. O método desenvolvido foi aplicado nas frações do beneficiamento e o farelo apresentou maior concentração de resíduo dos agrotóxicos, quando comparado ao arroz beneficiado, sendo 8,0, 2,3, 2,2 e 1,6 vezes mais contaminado, em média, para tebuconazol, clomazona, carbofurano e bispiribaque de sódio, respectivamente. Apenas o clomazona e o tebuconazol apresentaram concentrações dentro do limite aceitável estabelecidos pelo Codex Alimentarius (0,1 mg kg -1 ) para o arroz beneficiado nas safras analisadas.Pesticides are used to prevent pests from attacking grains in order to preserve the crops. This paper aims at evaluating the distribution of the pesticides bispyribac-sodium, carbofuran, clomazone and tebuconazole in different fractions of milled rice (white rice, rice bran, husked rice, parboiled rice, parboiled rice bran, and husked parboiled rice) which is planted on experimental fields under controlled conditions. The QuEChERS method was adapted to the extraction of pesticides and validated by using HPLC-DAD for quantification and LC-MS for confirmation. The analytical method of extracting pesticides, as well as the chromatographic conditions for identification and quantification, were suitable, according to certain efficiency indicators: 0.07 mg kg -1 LOD and 0.2 mg kg -1 LOQ for the mixture of pesticides and rice and rice bran recoveries of 119 and 116%, 84 and 119%, 113 and 96%, 103 and 97% for carbofuran, bispyribac-sodium, clomazone and tebuconazole, respectively. The method under development was applied to rice fractions: bran had the highest residue concentration of the studied pesticides, when compared to milled rice, showing 8.0, 2.3, 2.2 and 1.6 times more contamination, in average, with tebuconazole, clomazone, carbofuran and bispyribac-sodium, respectively. Only clomazone and tebuconazole were in the acceptable limits established by Codex Alimentarius (0.1 mg kg -1 ) for milled rice.

No abstract

Mycotoxins are secondary metabolites produced by several fungal species, toxic to humans, animals and plants. Their ingestion, inhalation or dermal absorption may cause different diseases and even death. These compounds have been described for many decades, however in the beginning of the s, they have been chemically characterized due to the discovery of aflatoxins [ ]. The word aflatoxin is the combination of other words a for Aspergillus genus, fla for the species flavus and toxin, meaning poison [ ]."flatoxin is the mycotoxin generating the greatest losses and the highest management costs due to its extremely high toxicity on a unit basis, and its long history of stringent regulation. The costs are inversely related to the regulatory level that must be met, and lower concentration allowances will increase the costs of crop management. Several effective ways for the management of mycotoxin contamination in agriculture have been stressed. One strategy to manage mycotoxin contamination and decrease health risks and economic costs is to instruct food producers and handlers on how to minimize mycotoxin contamination, and to encourage the adoption of process-based guidelines such as Good "gricultural Practices G"Ps before harvest and good manufacturing practices GMPs after harvest. These actions would minimize risk throughout the production, handling, and processing chain, and can complement product standards [ ]. To control the presence of aflatoxins in foods, many countries established maximum tolerated concentrations through legislation Van Egmond, a cited [ ] .This chapter focuses on properties of aflatoxins and their occurrence in feeds and animal products as meat, eggs, liver, kidneys and milk. Topics regarding mycotoxins absorbents and legislation in feed ingredients and feeds are also covered.

The objective of this work was to determine aflatoxin M 1 in fresh milk from fifty-two small farms in the city of Concórdia -SC, Brazil. Samples from the cooling tanks of each property were collected from November 2014 to January 2015. The QuEChERS method was used for the extraction of aflatoxin M 1 , and quantification was performed in UHPLC-FL. 40.4% of the analyzed samples (eg, 21 samples) showed contamination levels by aflatoxin M 1 above the maximum limit allowed by the Brazilian regulation, which is 0.5 μg L -1. These results suggest the importance of implementing Good Practices in obtaining feed for dairy cows, since the contamination of milk by aflatoxin M 1 occurs through the biotransformation of aflatoxin B 1 , after the ingestion of feed or silage contaminated by the animals, posing risk to the animals themselves, as well as to consumers of milk and dairy products. Keywords: aflatoxins; QuEChERS; UHPLC-FL.Practical Application: Contamination by aflatoxin M 1 of the evaluated fresh milk was high.

O arroz (Oryza sativa, L.), dentre os cereais cultivados, se destaca por ser alimento básico da maioria da população em várias regiões do planeta. No Brasil, o consumo médio varia de 74 a 76 kg/habitante/ano, tomando-se por base o grão em casca (EMBRAPA, 2005). Segundo dados da Associação Brasileira da Indústria do Arroz Parboilizado (Abiap), 23% do consumo de arroz do Brasil é do cereal que passa por parboilização, sendo este índice significativo, visto que há 25 anos atrás o produto representava apenas 4% do mercado (TREICHEL, 2007). O grão inteiro é constituído por diversos tecidos, que apresentam estrutura, composição química e funções diferenciadas. A casca constitui de 15 a 30% do peso do grão, dependendo da variedade, práticas culturais, localização geográfica, estação do ano e temperatura. Minerais (sílica) e celulose são os maiores componentes da casca (GUTOSKI; ELIAS, 1994; FELIPE et al., 1997; SALUNKHE; CHAVAN; KADAM, 1999). Alencar e Alenvarenga (1991) e Salunkhe, Chavan e Kadam (1999) relataram que o pericarpo (farelo) é composto pelas camadas que envolvem o endosperma amiláceo do grão de arroz, sendo rico em proteínas, lipídios, vitaminas e sais minerais, constituindo 5 a 7% do peso do grão. A camada de aleurona é formada pela parte externa do endosperma, sendo que o número de camadas presentes varia dependendo da origem do grão, variedade e fatores ambientais. As células do endosperma são uma excelente fonte de carboidratos complexos, representados principalmente pelo amido, que se encontra presente na forma de amilose e amilopectina. O conteúdo de amilose varia de 12 a 35% no arroz normal, enquanto que variedades cerosas contêm um baixo teor de amilose. O processo de parboilização tem sido largamente utilizado como uma das formas de minimizar a quebra dos grãos durante o beneficiamento, evitar a remoção excessiva de compostos importantes do ponto de vista nutricional e resultar em um produto com melhores condições de conservação (GUTKOSKI; ELIAS, 1994; AMATO; ELIAS, 2005). Embora estes efeitos sejam benéficos, algumas transformações físico-químicas

Wheat (Triticum aestivum) is an annual crop, cultivated in the winter and spring and susceptible to several pathogens, especially fungi, which are managed with fungicides. It is also one of the most consumed cereals, and can be contaminated by mycotoxins and fungicides. The objective of this study was to validate an analytical method by LC-MS for simultaneous determination of mycotoxins and fungicide residues in wheat grains susceptible to fusarium head blight treated with fungicides, and to evaluate the relationship between fungicide application and mycotoxin production. All parameters of the validated analytical method were within AOAC and ANVISA limits. Deoxynivalenol was the prevalent mycotoxin in wheat grain and epoxiconazole was the fungicide residue found in the highest concentration. All fungicidal treatments induced an increase in AFB2 production when compared to the control (without application). AFB1 and deoxynivalenol, on the contrary, were reduced in all fungicide treatments compared to the control.

This study aimed to evaluate the effect of fungicides on rice cultivation, regarding the occurrence and the distribution of mycotoxins in fractions of the processed grain, by a validated chromatographic method. A method based on extraction with acetonitrile:water, determination by HPLC-DAD, and confirmation by LC-MS was validated before the mycotoxin evaluation. Control samples and samples to which triazole fungicides had been applied were collected from experimental fields for four years. Results showed that 87% of the samples were contaminated with deoxynivalenol or zearalenone, and that all samples treated with fungicide were contaminated with some of these mycotoxins. Aflatoxin B(1) and ochratoxin A were found in 37% of the samples; half of them had been treated with fungicide. Therefore, fungicides tend to be stressors for toxigenic fungi found in the fields.