EQA - Escola de Química e Alimentos
URI permanente desta comunidadehttps://rihomolog.furg.br/handle/1/1610
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4 resultados
Resultados da Pesquisa
- ItemMigration of mycotoxins into rice starchy endosperm during the parboiling process(Elsevier, 2009) Dors, Giniani Carla; Pinto, Luiz Antonio de Almeida; Furlong, Eliana BadialeConsidering the occurrence of rice contamination by mycotoxins and the increase in rice consumption, the present work had the objective of assessing the migration of mycotoxins into the starchy endosperm during the parboiling process, as to propose conditions that provide lower contamination levels. The newly harvested rice grain sample was examined for the natural occurrence of mycotoxins (aflatoxin B1, aflatoxin B2, deoxynivalenol, ochratoxin A, and zearalenone); only the presence of aflatoxin B1 was found (17 ng/g). The samples were then artificially contaminated with deoxynivalenol and zearalenone, and the parboiling process was conducted according to a 23 factorial planning with central point, having as variables the contamination level deoxynivalenol 720, 1440, and 2160 ng/g, and zearalenone 476, 952, and 1428 ng/g the soaking time (4, 5, and 6 h) and autoclave time (15, 22.5, and 30 min). Mycotoxins aflatoxin B1 (AFA B1), deoxynivalenol (DON), and zearalenone (ZEA) were confirmed and determined through gas chromatography. Findings showed a lower migration trend for AFA B1 under 6 h of soaking and 30 min of autoclaving, for DON under 6 h of soaking regardless of the autoclaving time, and for ZEA under 4 h of soaking and 15 min of autoclaving. This information can contribute to the choice of process parameters that limit the migration of these mycotoxins if they happen in the raw material.
- ItemProfile of the Alcohols Produced in Fermentations with Malt Contaminated with Trichothecenes(2003) Reinehr, Christian Oliveira; Furlong, Eliana BadialeIn order to study the influence of mycotoxins on the production of alcohols, a fermentative process on a laboratorial scale was simulated. Malt was contaminated with deoxynivalenol and T-2 in different ratios (up to 500 ppb), according to a 32 factorial design, and the alcohols obtained after the fermentation were determined through gas chromatography. The results showed that trichothecenes influenced the profile of the alcohols produced by Saccharomyces cerevisiae during the fermentative process of malt, especially the profile of methyl and isoamyl alcohols.
- ItemOtimização de metodologia para derivação de desoxinivalenol através de planejamento experimental.(2008) Buffon, Jaqueline Garda; Furlong, Eliana BadialeThe objective of this work was to optimize the derivatization reaction for determining deoxynivalenol (DON) by gas chromatography employing an experimental planning procedure. The factors were: temperature, reaction time, catalyst and trifluoroacetic anhydride concentration. The relative peak areas were used to evaluated the effects. The best conditions for DON derivatization were 200 μL TFAA and 18 mg sodium bicarbonate for 6 min at 74 °C for 7 to 21 μg of DON. Under these conditions, the detection limit was 1.4 μg of DON.
- ItemDeterminação de tricotecenos em cerveja e avaliação de incidência no produto comercializado no Rio Grande do Sul(2004) Buffon, Jaqueline Garda; Macedo, Rejane Martins; Furlong, Eliana BadialeEste trabalho adaptou um método e avaliou os seus indicadores de mérito para determinação de tricotecenos, desoxinivalenol (DON)e toxina T-2, em cervejas comercializadas na região Sul do Rio Grande do Sul, empregando cromatografia gasosa. As adaptações foram realizadas na etapa de extração,purificação, derivação e condições cromatográficas usando amostras de cerveja artificialmente contaminadas,avaliando a adequação do procedimento pela recuperação obtida. Foram estudados os solventes acetonitrila, metanol e cloreto de metileno puro ou em misturas para a etapa de extração. A purificação do extrato foi realizada empregando ou não minicoluna de carvão:alumina:celite (7:5:3). Para a derivação testou-se basicidade do meio (bicarbonato de sódio, piridina), agente acilante (TFAA e HFBI), tempo (30 e 60 minutos) e temperatura (60 e 80ºC). Foram otimizadas as condições cromatográficas em cromatógrafo gasoso equipado com injetor split/splitless e detector de ionização de chama. A melhor recuperação foi obtida quando se empregou partição líquido-líquido com cloreto de metileno, seguida da limpeza em minicoluna e derivação com TFAA e piridina a 60°C durante 60 minutos.A recuperação média foi de 83 e 103% para DON e toxina T-2 respectivamente, para níveis de adição entre 50 e 200ng/mL. O coeficiente de variação assumiu valores de 2% e 4% e limite de detecção de 21 e 60 ng/mL. A aplicabilidade do método foi testada em um levantamento realizado em 72 amostras de cervejas. Destas 9,7% estavam contaminadas, sendo 5,3% com DON (50 a 336ng/mL)e 4,5% com toxina T-2 (114 a 249ng/mL).