Determination of aflatoxin risk components for in-shell Brazil nuts

Abstract

A study was conducted on the risk from aflatoxins associated with the kernels and shells of Brazil nuts. Samples were collected from processing plants in Amazonia, Brazil. A total of 54 test samples (40 kg) were taken from 13 in-shell Brazil nut lots ready for market. Each in-shell sample was shelled and the kernels and shells were sorted in five fractions: good kernels, rotten kernels, good shells with kernel residue, good shells without kernel residue, and rotten shells, and analysed for aflatoxins. The kernel : shell ratio mass (w/w) was 50.2/49.8%. The Brazil nut shell was found to be contaminated with aflatoxin. Rotten nuts were found to be a high-risk fraction for aflatoxin in in-shell Brazil nut lots. Rotten nuts contributed only 4.2% of the sample mass (kg), but contributed 76.6% of the total aflatoxin mass (µg) in the in-shell test sample. The highest correlations were found between the aflatoxin concentration in in-shell Brazil nuts samples and the aflatoxin concentration in all defective fractions (R ²= 0.97). The aflatoxin mass of all defective fractions (R ²= 0.90) as well as that of the rotten nut (R ²= 0.88) were also strongly correlated with the aflatoxin concentration of the in-shell test samples. Process factors of 0.17, 0.16 and 0.24 were respectively calculated to estimate the aflatoxin concentration in the good kernels (edible) and good nuts by measuring the aflatoxin concentration in the in-shell test sample and in all kernels, respectively.

Keywords:

• survey
• exposure
• risk assessment
• mycotoxins
• aflatoxins

Acknowledgements

The CONFORCAST Project could not be implemented without the collaboration of José Carlos Barroso^a, Thais Alves de Sá^b, Julio Cesar Garcia^b, Giovana Aparecida Amaral Gonçalves^b, Kátia Letícia de Carvalho^b, Maria Isabel de Almeida^b, Kássia Priscila da Silva^c, Luciana de Castro^b, Nilton Giovani de Almeida^c and Cristina Neres da Silva^c (^aMinistério da Agricultura, Pecuária e Abastecimento, Superintendência Federal de Agricultura do Estado do Pará, Brasil; ^bMinistério da Agricultura, Pecuária e Abastecimento, Laboratório de Controle de Qualidade e Segurança Alimentar/LANAGRO-MG; and ^cFinep – Conforcast, Projeto No. 1.265/05) and the support of FINEP.