Ocratoxina A em cafe brasileiro

AUTOR(ES)
DATA DE PUBLICAÇÃO

1998

RESUMO

Ochratoxin A is a toxic metabolite produced by several Aspergillus and Penicillium spp. Among those A. ochraceus is pointed out as a main producer. Ochratoxin A has been found in many types of foods such as maize, beans, and coffee. In 1996 Italy has set a limit of 4,0 ng/g for Ochratoxin A in green coffee and the European Union is considering a lower limit of 2,0 ng/g. In Brazil no limit has been set so faro Brazil is one of the largest coffee producers in the world and coffee represents a major source of revenue for the country. Nevertheless the situation of Brazilian coffee in regard to this toxin is unknown. The present work evaluated analytical techniques available for Ochratoxin A determination in foods for possible use in green and roasted coffee analysis. The recovery of Ochratoxin A standard was tested in solid phase extraction (SPE) columns of silica, octadecylsilyl, cyanopropyl, and immunoaffinity. Classical cleanup techniques such as clarification and partition were also tested. The results for SPE silica, cyanopropyl, and octadecylsilyl columns were not satisfactory. Immunoaffinity columns, however, were effective for cleanup and in terms of recovery (average 97%) for Ochratoxin A spiked samples. In recovery tests using pure standards the immunoaffinity columns were also superior to ali other techniques tested. A preliminary survey of the Brazilian coffee for the incidence of Ochratoxin A was conducted. Eighty-four samples of green coffee from six coffee producing states (Paraná, São Paulo, Bahia, Minas Gerais, Espírito Santo and Roraima) were analyzed. Ochratoxin A was found in 18 of the samples in levels from 1,7 a 147,5 ng/g. The analysis were conducted using immunoaffinity columns in the cleanup steps and HPLC with fluorescence detection in the quantification step. The analytical column was Spherisorb 00S-2 and mobile phase was methanol I acetic acid 9% (65+35).

ASSUNTO(S)

cafe micotoxinas

ACESSO AO ARTIGO

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