Quality of Brazil nuts stored in forced aeration silos

David Aquino Da Costa,Vlayrton Tomé Maciel,Virgínia De Souza Álvares,Daniela Popim Miqueloni,Jorge Ferreira Kusdra,Roberta Martins Nogueira

doi:10.1590/0034-737x201663030005

David Aquino Da Costa, Vlayrton Tomé Maciel + Show 4 more

Open Access

https://doi.org/10.1590/0034-737x201663030005

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Abstract

ABSTRACT The traditional system of collection and storage of Brazil nut compromises seriously the quality of these almonds as it contributes to the high incidence of contaminants, like fungi of the genus Aspergillus, which can produce aflatoxins. In this study, the objective was to evaluate the influence of the storage period in studied conditions, on the physicochemical characteristics and on the microbiological contamination of Brazil nuts. The experimental was designed as completely randomized, considering as treatments the storage period (0 - control, 30, 60, 90, 120 and 150 days) with four replicates of 3 kg of Brazil nuts each. The samples were submitted to physicochemical and microbiological analysis. It was observed that almonds submitted to the storage had their moisture content reduced by 78.2% at 150 days of storage, however, this reduction was not fast enough to avoid surface contamination by filamentous and potentially aflatoxins producing fungi. The critical period of contamination occurred on the first 30 days of storage when there was an increase of the studied fungi, as well as B1 and total aflatoxin. The studied storage conditions were four times more effective in reducing the product moisture content than the traditional methods, however, pre-drying is necessary to avoid contamination of the product.

Highlights

Some reports state that the presence of aflatoxins, a group of secondary metabolites produced by Aspergillus section Flavi, which are extremely toxic and carcinogenic, are common in the Brazil nut
The presence of these compounds is due to the traditional system of collection, pre-drying and storage of Brazil nut, which seriously compromises the quality of the almonds, favoring the high incidence of Aspergillus fungi
The storage conditions of nuts seem to have an important influence on the population of fungi Aspergillus section Flavi (Reis et al, 2014)

Summary

Introduction

The Brazil nut (Bertholletia excelsa Humb. & Bonpl. Lecythidaceae) is considered one of the most important species with economic exploitation of the Amazon rainforest. Some reports state that the presence of aflatoxins, a group of secondary metabolites produced by Aspergillus section Flavi, which are extremely toxic and carcinogenic, are common in the Brazil nut The presence of these compounds is due to the traditional system of collection, pre-drying and storage of Brazil nut, which seriously compromises the quality of the almonds, favoring the high incidence of Aspergillus fungi. After about 15 days, according to the extractives’ experience, the nuts are stored in raffia bags in that warehouse until shipment to the processing plants, with no control over the moisture content of the product, as well as contamination by micro-organisms These authors state that the Brazil nut, after the traditional pre-drying at this site, reaches 15% b.u., reducing by 50% its initial content, this moisture is still not low enough to avoid growth of micro-organisms. The storage conditions of nuts seem to have an important influence on the population of fungi Aspergillus section Flavi (Reis et al, 2014)

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