Quality of in-shell Brazil nuts after drying using a pilot natural convection oven in the state of Acre, Brazil

Abstract

The natural drying of in-shell Brazil nuts carried out by the extractivists is not effective in reducing contamination by aflatoxin-producing fungi. Thus the use of an artificial heater could prove to be a favourable method to bring about a rapid reduction in the moisture content of the nuts and thereby prevent fungal growth. Hence the objective of this study was to evaluate the efficiency of a natural convection-type drier with respect to the physical, physicochemical and microbiological quality of nuts after drying for 6 hours at 45 °C. A random block experimental design with two treatments (nuts before and after drying) was used, using 10 replications of 3 kg. The nuts were analysed for their moisture, ash, protein, dietary fibre, total carbohydrates and lipid contents, water activity, total count of filamentous, potentially aflatoxin-producing fungi, and also the quantification of aflatoxins B1, B2, G1, G2 and the total aflatoxins. There was no effect of drying on the Aspergillus flavus and Aspergillus parasiticus counts or on the physicochemical composition of the nuts, except for the ash content. However the moisture content of the nuts was reduced by 39.7% and there was a decrease in the contamination by pre-existing total filamentous fungi. The dryer was effective in reducing the average time taken for drying as compared to the traditional method used by extractivists.

Aflatoxins in raw Brazil nut (Bertholletia excelsa H.B.K.)

“…The data suggest that efforts are needed to better control the mc before processing, since this variable can interfere with AFL production. For aw, we found an average content of 0.96, like that of Da Costa et al (2017). Silva & Marsaioli-Junior (2003) reported the aw content of 0.79, and in another work, analyzed Brazil nuts directly from extractive communities in different harvests, 2019 and 2020, with a range of 0.88-0.99, and 0.98-0.99, respectively.…”

Drying in Brazil Nut Processing as Tool for Prevention of Contamination by Aflatoxins

“…At the factory storage stage, silos and drying kilns have temperature and humidity measurement ISSN 2166-0379 2020 systems. Aeration was a system adopted in the silos for nut storage in the study by Costa et al (2017) and samples were compared to the traditional method. Costa et al (2017) found that this system reduced the moisture content of the nuts by 78.2% after 150 days, however this reduction was not fast enough to avoid contamination completely, and potentially produced filamentous AFL fungi .The Aw of nuts ranged from 0.99-0.52, showing a trend of reduction over storage time.…”

“…Aeration was a system adopted in the silos for nut storage in the study by Costa et al (2017) and samples were compared to the traditional method. Costa et al (2017) found that this system reduced the moisture content of the nuts by 78.2% after 150 days, however this reduction was not fast enough to avoid contamination completely, and potentially produced filamentous AFL fungi .The Aw of nuts ranged from 0.99-0.52, showing a trend of reduction over storage time. According to Botelho et al (2019), to reduce the risk of fungal development, the Brazil nut must be stored at temperatures <55 °C and the mc content must be <8.2%.…”

Composição Química E Atividade Antifúngica Do Óleo Essencial De Campomanesia Xanthocarpa

“…São capazes de contaminar os alimentos ainda na fase de cultivo ou durante o processo de estocagem (LINS, 2014). Além disso, estes fungos produzem micotoxinas como metabólitos secundários, designadas de aflatoxinas, que são prejudiciais à saúde humana e animal, apresentando potencial carcinogênico (COSTA et al, 2017).…”