A small growth study of Aspergillus section Flavi, and potentially aflatoxigenic fungi and aflatoxin occurrence in Brazil nuts from local markets in Manaus, Brazil

This study aimed to gain more knowledge about morphological features of eight different species of Aspergillus section Flavi, which may aid in identification of these species. The presence of potentially toxigenic Aspergillus section Flavi, and occurrence of aflatoxins, in ready-to-eat Brazil nuts (...

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Autor principal: Andersson, Ellinor
Formato: First cycle, G2E
Lenguaje:sueco
Inglés
Publicado: 2012
Materias:
Acceso en línea:https://stud.epsilon.slu.se/4967/
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author Andersson, Ellinor
author_browse Andersson, Ellinor
author_facet Andersson, Ellinor
author_sort Andersson, Ellinor
collection Epsilon Archive for Student Projects
description This study aimed to gain more knowledge about morphological features of eight different species of Aspergillus section Flavi, which may aid in identification of these species. The presence of potentially toxigenic Aspergillus section Flavi, and occurrence of aflatoxins, in ready-to-eat Brazil nuts (Bertholletia excelsa) were also investigated. Seventeen different strains, representing eight species from section Flavi, were grown at different water activities and different temperatures. After 7 days, as well as at 14 and 28 days for the lower water activities, colonies were visually inspected, and diameter and macroscopic characteristics were noted. Ten samples of Brazil nuts were collected from different market stalls in the city of Manaus, Brazil. Aspergillus section Flavi were isolated and identified by morphology and toxin profile. Toxin production was evaluated by the agar plug technique and quantification of aflatoxins in the Brazil nuts was performed by high-performance liquid chromatography. It was found that macromorphology can be used to differentiate between some of the species if the different methods were combined, but for more certain identification, other available methods are better. One hundred and thirty five strains of suspected Aspergillus section Flavi were isolated and aflatoxin production was observed in 100 of them (74%). The most common species was Aspergillus nomius, followed by A. flavus and A. tamarii. Total aflatoxin content detected in the nuts did not exceed the European legislative limit of 10 µg/kg for ready-to-eat Brazil nuts, which would be considered safe to be consumed.
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spelling RepoSLU49672012-10-18T14:25:27Z https://stud.epsilon.slu.se/4967/ A small growth study of Aspergillus section Flavi, and potentially aflatoxigenic fungi and aflatoxin occurrence in Brazil nuts from local markets in Manaus, Brazil Andersson, Ellinor Food contamination and toxicology This study aimed to gain more knowledge about morphological features of eight different species of Aspergillus section Flavi, which may aid in identification of these species. The presence of potentially toxigenic Aspergillus section Flavi, and occurrence of aflatoxins, in ready-to-eat Brazil nuts (Bertholletia excelsa) were also investigated. Seventeen different strains, representing eight species from section Flavi, were grown at different water activities and different temperatures. After 7 days, as well as at 14 and 28 days for the lower water activities, colonies were visually inspected, and diameter and macroscopic characteristics were noted. Ten samples of Brazil nuts were collected from different market stalls in the city of Manaus, Brazil. Aspergillus section Flavi were isolated and identified by morphology and toxin profile. Toxin production was evaluated by the agar plug technique and quantification of aflatoxins in the Brazil nuts was performed by high-performance liquid chromatography. It was found that macromorphology can be used to differentiate between some of the species if the different methods were combined, but for more certain identification, other available methods are better. One hundred and thirty five strains of suspected Aspergillus section Flavi were isolated and aflatoxin production was observed in 100 of them (74%). The most common species was Aspergillus nomius, followed by A. flavus and A. tamarii. Total aflatoxin content detected in the nuts did not exceed the European legislative limit of 10 µg/kg for ready-to-eat Brazil nuts, which would be considered safe to be consumed. 2012-10-15 First cycle, G2E NonPeerReviewed application/pdf sv https://stud.epsilon.slu.se/4967/1/andersson_e_121015.pdf Andersson, Ellinor, 2012. A small growth study of Aspergillus section Flavi, and potentially aflatoxigenic fungi and aflatoxin occurrence in Brazil nuts from local markets in Manaus, Brazil. First cycle, G2E. Uppsala: (NL, NJ) > Dept. of Microbiology <https://stud.epsilon.slu.se/view/divisions/4024.html> urn:nbn:se:slu:epsilon-s-1782 eng
spellingShingle Food contamination and toxicology
Andersson, Ellinor
A small growth study of Aspergillus section Flavi, and potentially aflatoxigenic fungi and aflatoxin occurrence in Brazil nuts from local markets in Manaus, Brazil
title A small growth study of Aspergillus section Flavi, and potentially aflatoxigenic fungi and aflatoxin occurrence in Brazil nuts from local markets in Manaus, Brazil
title_full A small growth study of Aspergillus section Flavi, and potentially aflatoxigenic fungi and aflatoxin occurrence in Brazil nuts from local markets in Manaus, Brazil
title_fullStr A small growth study of Aspergillus section Flavi, and potentially aflatoxigenic fungi and aflatoxin occurrence in Brazil nuts from local markets in Manaus, Brazil
title_full_unstemmed A small growth study of Aspergillus section Flavi, and potentially aflatoxigenic fungi and aflatoxin occurrence in Brazil nuts from local markets in Manaus, Brazil
title_short A small growth study of Aspergillus section Flavi, and potentially aflatoxigenic fungi and aflatoxin occurrence in Brazil nuts from local markets in Manaus, Brazil
title_sort small growth study of aspergillus section flavi, and potentially aflatoxigenic fungi and aflatoxin occurrence in brazil nuts from local markets in manaus, brazil
topic Food contamination and toxicology
url https://stud.epsilon.slu.se/4967/
https://stud.epsilon.slu.se/4967/