Processing of Brazil-nut flour: characterization, thermal and morphological analysis

A castanha-do-Brasil (Bertholletia excelsea H. B. K.) destaca-se por seus elevados teores em lipídios e proteínas de alta qualidade biológica, parâmetros que justificam a necessidade de maiores pesquisas e incentivos para a elaboração de novos produtos comerciais. No presente estudo, busca-se identificar novas formas de aproveitamento tecnológico dessas amêndoas pela indústria alimentícia, através de seu processamento sobre a forma de farinha sem alteração do teor energético. Os resultados após sua elaboração mostraram um produto com alto valor energético 431,48 kcal.100 g–1, teor de proteína de 45,92 g.100 g–1 e fibra alimentar de 17,14%. As análises térmicas indicam que a introdução de outro componente proteico, como o isolado proteico de soja, não altera as reações e comportamentos térmicos. Já as morfológicas evidenciaram estruturas granulares semelhantes à estrutura das matrizes de proteínas globulares. Constata-se que, após o processamento e obtenção de farinha, o produto mantém seu alto teor energético-proteico e, ao ser submetido a altas temperaturas, mantém suas características.

Chemical evaluation and thermal behavior of Brazil nut oil obtained by different extraction processes

Brazil nut richness has been widely studied aiming at finding transformation models that increase its yield, keep its quality, reduce costs, and increase its productivity. The objective of this study is to evaluate the spectroscopic profile and the chemical and thermal behavior of Brazil nut oil obtained by different extraction processes. Lipid soxhlet extractions with petroleum ether and hexane, and using hydraulic pressing and supercritical carbon dioxide (CO2) were performed. The physicochemical analyses showed an acidity index with significant differences between the samples obtained by hydraulic pressing and supercritical CO2. The peroxide index presented significant difference for the oil obtained by hydraulic pressing compared to that obtained by the other extraction processes. The fatty acid profiles showed a relevant presence of the omega series (w-3, w-6, and w-9) with significant differences for the extraction processes evaluated. The results of the thermogravimetric and differential analyses did not indicate changes in mass loss and presented predominantly exothermic behavior. The spectroscopic profiles indicate that the extraction processes do not change the spectral profile of the oils. (c) 2011 Elsevier Ltd. All rights reserved.

Effect of Brazil Nut Supplementation on Plasma Levels of Selenium in Hemodialysis Patients: 12 Months of Follow-up

Background: Large amounts of reactive oxygen species are produced in hemodialysis (HD) patients, and, at higher concentrations, reactive oxygen species are thought to be involved in the pathogenesis of cardiovascular disease. It has been proposed that selenium (Se) may exert an antiatherogenic influence by reducing oxidative stress. The richest known food source of Se is the Brazil nut (Bertholletia excelsa, family Lecythidaceae), found in the Amazon region. Objective: The objective of this work was to determine if Se plasma levels in HD patients submitted to a program of supplementation during 3 months with 1 Brazil nut by day could be sustained after 12 months. Methods: A total of 21 HD patients (54.2 +/- 15.2 years old; average time on dialysis, 82.3 +/- 51.6 months; body mass index, 24.4 +/- 3.8 kg/m(2)) from the RenalCor Clinic in Rio de Janeiro, Brazil, were followed up 12 months after the supplementation study ended. The Se plasma levels were determined by atomic absorption spectrophotometry with hydride generation. Results: The Se Plasma levels (17.3 +/- 19.9 mg/L) were below the normal range (60 to 120 mu g/L) before nut supplementation, and after 3 months of supplementation, the levels increased to 106.8 +/- 50.3 mu g/L (P < .0001). Twelve months after supplementation, the plasma Se levels decreased to 31.9 +/- 14.8 mu g/L (P < .0001). Conclusions: The data showed that these patients were Se deficient and that the consumption of Brazil nut was effective to increase the Se parameters of nutritional status. Se levels 12 months after the supplementation period were not as low as presupplementation levels but yet significantly lower, and we needed to motivate patients to adopt different dietary intake patterns. (C) 2012 by the National Kidney Foundation, Inc. All rights reserved.

Mycobiota and mycotoxins in Brazil nut samples from different states of the Brazilian Amazon region

The objective of this study was to evaluate the presence of fungi and mycotoxins (aflatoxins and cyclopiazonic acid) in Brazil nut samples collected in different states of the Brazilian Amazon region: Acre, Amazonas, Amapa, and Para. A total of 200 husk samples and 200 almond samples were inoculated onto Aspergillus flavus-parasiticus agar for the detection of fungi. Mycotoxins were analyzed by high-performance liquid chromatography. The mycobiota comprised the following fungi, in decreasing order of frequency: almonds - Phialemonium spp. (54%), Penicillium spp. (16%), Fusarium spp. (13%), Phaeoacremonium spp. (11%), and Aspergillus spp. (4%), husks - Phialemonium spp. (62%), Phaeoacremonium spp. (11%), Penicillium spp. (10%), Fusarium spp. (9%), and Aspergillus spp. A polyphasic approach was used for identification of Aspergillus species. Aflatoxins were detected in 22 (11%) of the 200 almond samples, with 21 samples presenting aflatoxin B-1 levels above 8 mu g/kg, the limit established by the European Commission for Brazil nuts for further processing. Nineteen (9.5%) of the 200 husk samples contained aflatoxins, but at levels lower than those seen in almonds. Cyclopiazonic acid (CPA) was detected in 44 (22%) almond samples, with levels ranging from 98.65 to 1612 mu g/kg. Aspergillus nomius and A. flavus were the most frequent Aspergillus species. The presence of fungi does not necessarily imply mycotoxin contamination, but almonds of the Brazil nut seem to be a good substrate for fungal growth. (C) 2012 Elsevier B.V. All rights reserved.

Influence of different genotypes in the pattern of selenoprotein expression in response to Brazil nut supplementation

The micronutrient selenium is essential to human physiology. As the amino acid selenocysteine, it is inserted into selenoproteins with a wide range of functions including antioxidant capacity, thyroid hormone metabolism, improvement of immune system, brain function, fertility and reproduction. Low selenium status has been associated with increased risk for chronic diseases, such as cancer, type-2 diabetes and cardiovascular disease. In this context, several studies have been conducted in order to investigate if selenium supplementation could reduce the risk of such diseases. However, genetic variations may interfere in the response of individuals to a dietary intervention and must be considered as a important source of inter-individual variation. Therefore, this study was conducted was conducted to investigate the influence of genetic variations in selenoproteins genes on the response to an intervention with Brazil nuts, the richest source of selenium known in nature. The study included 130 healthy volunteers with both genders, aged 20 to 60 years old selected in University of São Paulo. They received nuts for 8 weeks, eating one nut a day, and did a washout period for more 8 weeks. All volunteers had a blood sampling collection every 4 weeks during 4 months, in a total of 5. The following analysis were done: anthropometric measurements, lipid profile, plasma malondialdehyde, plasma and erythrocyte Se, selenoprotein P, plasma and erythrocyte GPx activity, gene expression of GPX1, SEPP1, SELS and SEP15. The volunteers were also genotyped for SNPs rs1050450, rs3811699, rs1800699, rs713041, rs3877899, rs7579, rs34713741 and rs5845. Each unit of Brazil nut provided an average of 300 µg of selenium. All 130 volunteers completed the protocol. The concentrations of total cholesterol and glucose decreased after 8 weeks of supplementation. Moreover, HDL concentrations were higher for carriers of the variant T allele for GPX4_rs713041. The frequencies of the variant genotypes were 5,4% for rs1050450, rs3811699 e rs1088668, 10% for rs3877899, 19,2% for rs713041 e rs7579, 11,5% for rs5845 and 8,5% for rs34713741. The levels of the five biomarkers increased significantly after supplementation. In addition, erythrocyte GPx activity was influenced by rs1050450, rs713041 and rs5845; erythrocyte selenium was influenced by rs5845 and plasma selenium by rs3877899. Gene expression of GPX1, SEPP1 and SEP15 were higher after supplementation. The SNP rs1050450 influenced GPX1 mRNA expression and rs7579 influenced SEPP1 mRNA expression. Therefore, it can be concluded that the supplementation with one of Brazil nut for 8 weeks was efficient to reduce total cholesterol and glucose levels and to increase the concentrations of the main biomarkers of selenium status in healthy adults. Furthermore, our results suggest that GPX4_rs713041 might interfere on HDL concentrations and GPx1 activity, GPX1_rs1050450 might interfere on GPx1 activity, SEP15_rs5845 might interfere on GPx1 activity and erythrocyte selenium and SEPP1_3877899 might interfere on plasma Se levels. Therefore, the effect of genetic variations should be considered in future nutritional interventions evaluating the response to Brazil nut supplementation.

Ingestive behavior of sheep fed Brazil nut cake in the diet.

Avaliou-se o comportamento ingestivo de ovinos alimentados com níveis de inclusão (0, 15, 30 e 60%) de torta de castanha-do-pará (TC) (Bertholletia excelsa Bonpl.), na dieta à base de silagem de milho. Foram utilizados 16 cordeiros, sem raça definida e peso médio de 33 ± 6.04 kg, distribuídos aleatoriamente nos quatro tratamentos. Os dados foram analisados quanto à normalidade, submetidos à análise de variância, ajustados em equações de regressão e ao teste de Williams, estimando-se o ponto W. Os consumos voluntários de matéria seca (MS) e fibra insolúvel em detergente neutro (FDN), reduziram linearmente (P=0,013 e P=0,002) em 5,0 g e 2,41 g dia-1, respectivamente, para cada 1% de TC inclusa na dieta. O tempo despendido em alimentação (288,75 min dia-1) não foi afetado significativamente, o tempo em ócio cresceu linearmente (P=0,002) em 3,10 minutos, e o tempo gasto em ruminação decresceu (P=0,001) em 2,62 minutos, para cada 1% de inclusão do coproduto. O número de bolos ruminados (NBR) sofreu efeito decrescente (P=0,004) em 4,61 nº dia-1. Quanto às mastigações merícicas, o tempo gasto por bolo (37,5 seg) e o número por bolo (56,14) não diferiram (P>0,05) entre os tratamentos, mas o tempo total de mastigação (TTM) reduziu linearmente (P=0,002) em 0,05 h dia-1 e o número de mastigações por dia apresentou efeito quadrático (P=0,008), com máximo estimado em 17,5% de TC. A eficiência de ruminação não diferiu entre os tratamentos (101,95 g MS h-1 e 36,76 g FDN h-1) e a eficiência de alimentação (EAL) sofreu redução linear (P=0,045) em 0,42 g FDN h-1, mas foi semelhante para g MS h-1 (172,5). Os consumos diários de MS e FDN apresentaram pontos W estimados em 51,96 e 30,67% de TC, respectivamente. As variáveis NBR, TTM e EAL (g FDN h-1) tiveram os pontos W estimados em 56,64, 56,19 e 56,33% de TC. A torta de castanha-do-pará, em níveis superiores a 56% da MS da dieta, afeta o comportamento ingestivo dos animais, principalmente em variáveis relacionadas à ruminação, sendo que a partir de 30,67% já passa a afetar o consumo de FDN, tendo como principais fatores o teor de extrato etéreo e a fonte de fibra das dietas.

IgE cross-reactivity between the major peanut allergen Ara h 2 and tree nut allergens

Allergy to peanut and tree nuts is characterised by a high frequency of life-threatening anaphylactic reactions and typically lifelong persistence. Although peanut is the most common cause of nut allergy, peanut allergic patients are frequently also sensitive to tree nuts. It is not known if this is due to cross-reactivity between peanut and tree nut allergens. In this study, the major peanut allergen Ara h 2 was cloned from peanut cDNA, expressed in E. coli cells as a His-tag fusion protein and purified using a Ni-NTA column. Immunoblotting, ELISA and basophil activation indicated by CD63 expression all confirmed the IgE reactivity and biological activity of rAra h 2. To determine whether or not this allergen plays a role in IgE cross-reactivity between peanut and tree nuts, inhibition ELISA was performed. Pre-incubation of serum from peanut allergic patients with increasing concentrations of almond or Brazil nut extract inhibited IgE binding to rAra h 2. Purified rAra h 2-specific serum IgE antibodies also bound to proteins present in almond and Brazil nut extracts by immunoblotting. This indicates that the major peanut allergen, Ara h 2, shares common IgE-binding epitopes with almond and Brazil nut allergens, which may contribute to the high incidence of tree nut sensitisation in peanut allergic individuals.

Mycoflora and mycotoxins in field samples of Brazil nuts

Fungal and mycotoxin contamination was investigated in field samples of nuts, shells and pods of the Brazil nut collected during different periods in Itacoatiara, State of Amazonas, Brazil: day 0, samples still on the tree: days 5, 10 and 15, samples in contact with soil for 5, 10 and 15 days, respectively. The most prevalent fungi were Aspergillus flavus in fruit pods and nuts and Fusarium spp. in shells. Penicillium spp. and A. flavus were isolated from soil, and Fusarium spp. and Penicillium spp. from air. Aflatoxins and cyclopiazonic acid were not detected in any of the samples analyzed. The high frequency of isolation of aflatoxigenic A. flavus strains from soil and Brazil nuts increases the chance of aflatoxin production in these substrates. These findings suggest a possible contamination before drying and indicate soil as the main source of fungal contamination of Brazil nuts. (c) 2012 Elsevier Ltd. All rights reserved.

Monitoring and determination of fungi and mycotoxins in stored Brazil nuts

Brazil nut (Bertholletia excelsa) is an important commodity from the Brazilian Amazon, and approximately 37,000 tons (3.36 × 10⁷ kg) of Brazil nuts are harvested each year. However, substantial nut contamination by Aspergillus section Flavi occurs, with subsequent production of mycotoxins. In this context, the objective of the present investigation was to evaluate the presence of fungi and mycotoxins (aflatoxins and cyclopiazonic acid) in 110 stored samples of cultivated Brazil nut (55 samples of nuts and 55 samples of shells) collected monthly for 11 months in Itacoatiara, State of Amazonas, Brazil. The samples were inoculated in duplicate onto Aspergillus flavus and Aspergillus parasiticus agar and potato dextrose agar for the detection of fungi, and the presence of mycotoxins was determined by high-performance liquid chromatography. The most prevalent fungi in nuts and shells were Aspergillus spp., Fusarium spp., and Penicillium spp. A polyphasic approach was used for identification of Aspergillus species. Aflatoxins and cyclopiazonic acid were not detected in any of the samples analyzed. The low water activity of the substrate was a determinant factor for the presence of fungi and the absence of aflatoxin in Brazil nut samples. The high frequency of isolation of aflatoxigenic Aspergillus section Flavi strains, mainly A. flavus, and their persistence during storage increase the chances of aflatoxin production on these substrates and indicates the need for good management practices to prevent mycotoxin contamination in Brazil nuts.

Quality of Brazil nuts stored in forced aeration silos.

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.

Morte de enxertos de castanheira do Pará.

1972

Densities and Viscosities of vegetable oils of nutritional value

Densities and viscosities of five vegetable oils (Babassu oil, Buriti oil, Brazil nut oil, macadamia oil, and grape seed oil) and of three blends of Buriti oil and soybean oil were measured as a function of temperature and correlated by empirical equations. The estimation capability of two types of predictive methodologies was tested using the measured data. The first group of methods was based on the fatty acid composition of the oils, while the other was based on their triacylglycerol composition, as a multicomponent system. In general, the six models tested presented a good representation of the physical properties considered in this work. A simple method of calculation is also proposed to predict the dynamic viscosity of methyl and ethyl ester biodiesels, based on the fatty acid composition of the original oil. Data presented in this work and the developed model can be valuable for designing processes and equipment for the edible oil industry and for biodiesel production.