title: Monitoring and determination of fungi and mycotoxins in stored Brazil nuts.
abstract: Brazil nut (Bertholletia excelsa) is an important commodity from the Brazilian Amazon, and approximately 37,000 tons (3.36 × 10⁷ kg) of Brazil nuts are harvested each year. However, substantial nut contamination by Aspergillus section Flavi occurs, with subsequent production of mycotoxins. In this context, the objective of the present investigation was to evaluate the presence of fungi and mycotoxins (aflatoxins and cyclopiazonic acid) in 110 stored samples of cultivated Brazil nut (55 samples of nuts and 55 samples of shells) collected monthly for 11 months in Itacoatiara, State of Amazonas, Brazil. The samples were inoculated in duplicate onto Aspergillus flavus and Aspergillus parasiticus agar and potato dextrose agar for the detection of fungi, and the presence of mycotoxins was determined by high-performance liquid chromatography. The most prevalent fungi in nuts and shells were Aspergillus spp., Fusarium spp., and Penicillium spp. A polyphasic approach was used for identification of Aspergillus species. Aflatoxins and cyclopiazonic acid were not detected in any of the samples analyzed. The low water activity of the substrate was a determinant factor for the presence of fungi and the absence of aflatoxin in Brazil nut samples. The high frequency of isolation of aflatoxigenic Aspergillus section Flavi strains, mainly A. flavus, and their persistence during storage increase the chances of aflatoxin production on these substrates and indicates the need for good management practices to prevent mycotoxin contamination in Brazil nuts.
authors.affiliation: Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, 05508-000 São Paulo, Brazil. arianne.baquiao@hotmail.com
authors.forename: Arianne Costa
authors.initials: AC
authors.lastname: Baquião
authors.forename: Maitê M M
authors.initials: MM
authors.lastname: De Oliveira
authors.forename: Tatiana A
authors.initials: TA
authors.lastname: Reis
authors.forename: Patrícia
authors.initials: P
authors.lastname: Zorzete
authors.forename: Danielle D
authors.initials: DD
authors.lastname: Atayde
authors.forename: Benedito
authors.initials: B
authors.lastname: Corrêa
mesh_terms: D000348:Aflatoxins / Q000032:analysis / Q000096:biosynthesis; D001230:Aspergillus / Q000302:isolation & purification*; D001231:Aspergillus flavus / Q000302:isolation & purification; D031383:Bertholletia / Q000737:chemistry* / Q000382:microbiology*; D002851:Chromatography, High Pressure Liquid; D003257:Consumer Product Safety; D005506:Food Contamination / Q000032:analysis*; D005670:Fusarium / Q000302:isolation & purification; D009183:Mycotoxins / Q000032:analysis*; D010407:Penicillium / Q000302:isolation & purification
chemical_list: D000348:Aflatoxins; D009183:Mycotoxins