title: Effects of Gamma and Electron Beam Radiation on Brazil Nuts Artificially Inoculated with Aspergillus flavus.
abstract: The aim of this study was to evaluate the effects of gamma radiation (GR) and electron beam (EB) on Brazil nut samples contaminated with Aspergillus flavus. Fifty samples were spread with an A. flavus suspension and incubated at 30°C and a relative humidity of 93%. After 15 days of incubation, mycobiota and aflatoxin analysis were performed. The samples were divided into three groups (control, group 1, and group 2) that received radiation doses of 0 kGy (control) and 5 and 10 kGy each of GR and EB (groups 1 and 2). Noninoculated samples were irradiated with the same doses for sensory evaluation. The results showed that after 15 days of incubation, the average water activity of the samples was 0.80. The irradiation with GR and EB at doses of 5 and 10 kGy was able to eliminate A. flavus in Brazil nut samples. Aflatoxin analysis showed that EB doses of 5 and 10 kGy reduced aflatoxin B1 levels by 53.32 and 65.66%, respectively, whereas the same doses of GR reduced the levels of this toxin by 70.61 and 84.15% compared with the level in the control groups. Sensory evaluation demonstrated that the texture and odor of irradiated Brazil nut samples were acceptable. The taste evaluation indicated that 5 kGy of GR was judged acceptable. The results highlight that both irradiation processes (5- and 10-kGy doses) showed efficiency in A. flavus and aflatoxin elimination. GR and EB treatments resulted in some alterations in the sensory attributes of samples with the doses used in this study; however, Brazil nut samples irradiated with 5-kGy GR doses were considered acceptable.
authors.affiliation: Laboratório de Micotoxinas, Instituto de Ciências Biomédicas-ICB II, Universidade de São Paulo, Avenue Prof. Lineu Prestes, 1374, CEP 05508000, São Paulo, São Paulo, Brazil. ednei@usp.br.
authors.forename: Ednei
authors.initials: E
authors.lastname: Assunção
authors.affiliation: Laboratório de Micotoxinas, Instituto de Ciências Biomédicas-ICB II, Universidade de São Paulo, Avenue Prof. Lineu Prestes, 1374, CEP 05508000, São Paulo, São Paulo, Brazil.
authors.forename: Tatiana Alves
authors.initials: TA
authors.lastname: Reis
authors.affiliation: Laboratório de Micotoxinas, Instituto de Ciências Biomédicas-ICB II, Universidade de São Paulo, Avenue Prof. Lineu Prestes, 1374, CEP 05508000, São Paulo, São Paulo, Brazil.
authors.forename: Arianne Costa
authors.initials: AC
authors.lastname: Baquião
authors.affiliation: Laboratório de Micotoxinas, Instituto de Ciências Biomédicas-ICB II, Universidade de São Paulo, Avenue Prof. Lineu Prestes, 1374, CEP 05508000, São Paulo, São Paulo, Brazil.
authors.forename: Benedito
authors.initials: B
authors.lastname: Corrêa
mesh_terms: D000348:Aflatoxins / Q000378:metabolism; D001231:Aspergillus flavus / Q000254:growth & development* / Q000378:metabolism / Q000528:radiation effects; D005506:Food Contamination / Q000517:prevention & control; D005514:Food Irradiation / Q000379:methods*; D005720:Gamma Rays; D009754:Nuts / Q000382:microbiology*
chemical_list: D000348:Aflatoxins