The impact of automatic and manual shelling methods during manual/visual sorting of different batches of Brazil nuts from the 2010 and 2011 harvests was evaluated in order to investigate aflatoxin prevention.The samples were tested as follows: in-shell, shell, shelled, and pieces in order to evaluate the moisture content (mc), water activity (Aw), and total aflatoxin (LOD = 0.3 µg/kg and LOQ 0.85 µg/kg) at the Brazil nut processing plant. The results of aflatoxins obtained for the manually shelled nut samples ranged from 3.0 to 60.3 µg/g and from 2.0 to 31.0 µg/g for the automatically shelled samples. All samples showed levels of mc below the limit of 15%; on the other hand, shelled samples from both harvests showed levels of Aw above the limit. There were no significant differences concerning the manual or automatic shelling results during the sorting stages. On the other hand, the visual sorting was effective in decreasing the aflatoxin contamination in both methods.

Um estudo foi realizado para avaliar a associação dos níveis de radioatividade, selênio e aflatoxinas em castanha-do-Brasil descascada, que foram classificadas em diferentes tamanhos, para exportação. As determinações de selênio foram realizadas por espectrometria de emissão óptica com plasma indutivamente acoplado (LOQ=3,0 µg kg-1) e aflatoxinas foram detectadas por LC-MSMS (LOQ=0,85 µg kg-1), as taxas de recuperação ficaram entre 92 e 100%. A radioatividade foi medida por espectrometria gama de alta resolução. A concentração média de selênio foi de (22,7 ± 7,4) µg g-1. (n = 30). A atividade média determinada para os radioisótopos foram: 15,77 Bq kg-1 para o 224Ra, 104,8 Bq kg-1 para 226Ra e 99,48 Bq kg-1 para 228Ra. Para 226Ra, os níveis não variaram significativamente com o tamanho das nozes, embora tais diferenças foram observadas para 224Ra e 228Ra. Não houve associação estatisticamente significativa entre o nível de selênio e a atividade de radionuclídeos, no entanto, houve correlação entre os radionuclídeos. Não foi encontrado aflatoxinas acima do limite de quantifcação.

A study was carried out to evaluate the association of levels of radioactivity, selenium and aflatoxin in shelled Brazil nuts, which were classified in different sizes, for export. The selenium determinations were performed by inductively coupled plasma optical emission spectrometry (LOQ = 3.0 µg g-1), and aflatoxins were detected by Liquid chromatography-mass spectrometry (LOQ = 0.85 µg kg-1), recovery rates were between 92 and 100%. Radioactivity was measured by high-resolution gamma spectrometry. The selenium mean concentration was (22.7 ± 7.4) µg g-1. (n = 30). Mean activities determined for the following radium isotopes were: 15.77 Bq kg-1 for 224Ra, 104.8 Bq kg-1 for 226Ra and 99.48 Bq kg-1 for 228Ra. For 226Ra, the levels did not vary significantly with nut sizes, although such differences were observed for 224Ra and 228Ra. There was no statistically significant association between the level of selenium and the activity of radionuclides, however, there was correlation between the radionuclides. Aflatoxins above the quantification limit were not found.

A castanha-do-Brasil tem um alto teor nutricional e é um importante produto comercial para alguns países da América Latina. Com objetivo de avaliar a segurança, 120 amostras de diferentes etapas da cadeia produtiva, foram analisadas quanto a: teor de umidade, fungos aflatoxigênicos e aflatoxinas (LOQ = 1,95 μg.kg-1 aflatoxinas totais) por CCD. Das amostras, 4 (6,7%) da área de recepção, e 5 (16,7%) do varejo apresentaram aflatoxinas acima do LOQ. Nas amostras após secagem na usina não foram detectadas aflatoxinas(< LOQ). As amostras positivas estavam acima dos limites aceitos pela União Européia (4,0 μg.kg-1) e Brasil (30 μg.kg-1). A média do teor de umidade foi de 22,43% na etapa de recepção, maior do que as outras etapas estudadas. Todas as cepas de A. flavus eram aflatoxigênicas e houve associação estatística entre a presença de aflatoxinas e a presença da cepa de flavus. As cepas aflatoxigênicas associadas às aflatoxinas das amostras demonstram que é neccessario um controle efetivo da segurança alimentar na cadeia produtiva da castanha-do-Brasil

Brazil nut has a high nutritional content and is a very important trade commodity to some Latin American countries. In order to evaluate its safety, 120 samples from different stages of the productive chain were analyzed in terms of: moisture content (mc), aflatoxigenic fungi and aflatoxin (LOQ = 1.95 μg.kg-1 total aflatoxin) using TLC. Among all samples, 4 (6.7%) from the receiving area, and 5 (16.7%), from retail presented aflatoxins above the LOQ, but the amount of aflatoxins was below the LOQ after the samples were dried in the plant. The positive samples were above the limit of total aflatoxin permitted by the European Union (4.0 μg.kg-1) and Brazil (30 μg.kg-1). The mc mean was 22.43% in the receiving area, which is higher than that in the other stages samples. All the A. flavus strains were aflatoxigenic, and there was statistic association between the presence of aflatoxin and flavus strains. The aflatoxigenic fungi strains associated to the aflatoxins levels in the samples show that an effective control is necessary for the food safety in the Brazil nut production chain.