Brazil Nut Shell Research Articles

Microwave drying and disinfestation of Brazil nut seeds

Fungal contamination of Brazil nuts can cause health problems, which limits their worldwide consumption and leads to economic restrictions for the producing regions. In this study the contamination of Brazil nut seeds by aflatoxin-producing fungal strains was investigated. It was observed that of the 31 strains isolated from the inside of the seed coat, 39% showed aflatoxigenic potential, indicating a high level of contamination by microorganisms which produce aflatoxins, which have strong carcinogenic and hepatotoxic activity. The moisture content and water activity are determining factors for fungal growth. Measurements of the dielectric properties at microwave frequencies of the Brazil nut shell and the kernel reveals that the shell has a higher loss tangent (0.12) at 30 °C relative to the kernel (0.06) and high values for the penetration depth of both shell (20 cm) and kernel (35 cm) that are related to their chemical composition. Microwave heating was employed leading to reductions in the moisture content (46.4%) and water activity (20%). Furthermore, the effectiveness of microwave dielectric heating as a disinfestation process for contaminated nuts was investigated, showing that colonization inside the shell decreased by 61.67% and on the kernel by 81.75%, without damaging the organoleptic properties of the Brazil nut seeds.

Comparison of the thermal power availability of different agricultural residues using a residential boiler

This study presents a comparison of combustion performance, losses, and efficiency at steady-state and transient conditions for different biomass types in a residential boiler. The types of biomass used were O6 and O8 mm wood pellets, O6 mm sugarcane bagasse pellets, O6 mm sunflower husk pellets, and Brazil nut shells. The comparison in the development of the temperature in the combustion chamber during the start-up revealed that the O6 mm wood pellets ignite and propagate faster than the rest of the biomass fuels due to their smaller size compared with O8 mm wood pellets and lower ash content compared with the rest of the biomass sorts. Thermal power output and efficiencies under steady-state and transient conditions were calculated by the direct method, i.e., by measuring the heat recovery by the water boiler, and the indirect method, i.e., by measuring the heat losses. By using the indirect method, the availability of the flue gas thermal power during the start-up was seen more in detail than when the other method was applied. When comparing both methods as tools for boiler efficiency evaluation for different fuel types, the discrepancy of the resulting efficiencies between is larger when there are higher amounts of chemical losses in the boiler. Therefore, this method shows good agreement also for bagasse pellets but is, without modification, proposed not to be valid for fuels emitting higher amount of carbon monoxide (CO). Boiler efficiencies reached class 3 boilers according to EN 303-5 (>74.8 %) for all biomass sorts.

The production of porous brick material from diatomaceous earth and Brazil nut shell ash

Diatomaceous earth was mixed with Brazil nut shell ash (BNS ash) in different amounts between 0 and 30wt% and sintered at temperatures between 750 and 950°C. The BNS ash contains 33wt% K2O and 11wt% CaO mainly in carbonate form. The addition of BNS ash into the diatomaceous earth caused significant changes of the microstructure after sintering. The BNS ash addition produces lightweight porous bricks with acceptable strength at lower sintering temperature. The best combination of strength and porosity was achieved for a mixture of 10wt% of BNS ash in the diatomaceous earth sintered at 850°C. The achieved high porosity was 49%, density 1.06g/cm3, thermal conductivity 0.20W/(mK) and the compressive strength was 8.5MPa.

A kinetic study on microwave-assisted conversion of cellulose and lignocellulosic waste into hydroxymethylfurfural/furfural

Native cellulose, lignocellulosic materials from Brazil (carnauba palm leaves and macauba pulp and shell) and pine nut shell from Spain have been studied as substrates for the production of HMF and furfural in a conventional microwave oven. In order to promote the dissolution of native cellulose, several ionic liquids, catalysts, organic solvents and water doses have been assessed. The most suitable mixture (5mL of choline chloride/oxalic acid, 2mL of sulfolane, 2mL of water, 0.02g of TiO2 and 0.1g of substrate) has been chosen to conduct kinetic studies at different reaction times (5–60min) and various temperatures (120–200°C) and to evaluate the best conditions for HMF+furfural production according to Seaman’s model. The best production yields of HMF+furfural have been attained for native cellulose, with a yield of 53.24% when an ultrasonic pretreatment was used prior to a microwave treatment with stirring.

Stereoscopy and scanning electron microscopy of Brazil nut (Bertholletia excelsa H.B.K.) shell, brown skin, and edible part: part one--healthy nut.

In this article, tissue layers and cells characteristics of the Brazil nut (Bertholletia excelsa H.B.K.) shell (tegument), brown skin (testae), and edible part (cotyledons) were identified by stereoscopy (SM) and scanning electron microscopies (SEM). (a) The shell (a lignin rich, protective wall) varies in thickness throughout the nut structure and comprises different tissue types (total 3)/texture (hard/mid-hard/soft), layers (2 to 5), colors (light to dark brown and white to cream), cell shape (amorphous/flattened on both surfaces; polygonal and cylindrical with thick, porous primary and secondary wall in cross-section), and vascular distribution (helically and polyedrical thickened vessels at soft tissue and locule/channel structures). These variations are observed either in the shell faces, face corners, nut tips, or locule in testae. (b) The brown skin (shell nut part linked to both the shell and edible part) is made of flattened irregular-shaped parenchymal cells distributed in several layers with more flexible fibrous, thinner wall tissue than shell. It has both rough and smooth shiny texture on the upper and lower surfaces, respectively. However, the nut (c) edible part, that is the nut storage tissue, shows several different tissue/cell layers starting from epidermis (double/triple cells sequence of round and palisade shapes) layer-the endosperm tissue. The parenchymal tissues show cells of irregular shape with small and larger sizes distributed in regular and randomly layers, respectively, separated by a short meristem tissue layer. The cortex cells increase in size as they approach the cotyledons junction. The Brazil nut part's tissue layers and cells were identified by the SM and SEM microscopy methods applied, which provides knowledge for further understanding of nut alterations that may occur either in the forest or during the factory processing. Knowledge about the characteristics and nature of the waste woody tissues from the Brazil nut factories is of interest for potential applications in the industry. Understanding the nut tissues and cells structures helps in judging how much whole nut edible part gets spoiled/deteriorated (either raw or processed), for further development of procedures to prevent and/or control such spoiling/deterioration for achieving nut quality and safety (to be discussed in Part Two).

Characterization of Aspergillus species on Brazil nut from the Brazilian Amazonian region and development of a PCR assay for identification at the genus level

BackgroundBrazil nut is a protein-rich extractivist tree crop in the Amazon region. Fungal contamination of shells and kernel material frequently includes the presence of aflatoxigenic Aspergillus species from the section Flavi. Aflatoxins are polyketide secondary metabolites, which are hepatotoxic carcinogens in mammals. The objectives of this study were to identify Aspergillus species occurring on Brazil nut grown in different states in the Brazilian Amazon region and develop a specific PCR method for collective identification of member species of the genus Aspergillus.ResultsPolyphasic identification of 137 Aspergillus strains isolated from Brazil nut shell material from cooperatives across the Brazilian Amazon states of Acre, Amapá and Amazonas revealed five species, with Aspergillus section Flavi species A. nomius and A. flavus the most abundant. PCR primers ASP_GEN_MTSSU_F1 and ASP_GEN_MTSSU_R1 were designed for the genus Aspergillus, targeting a portion of the mitochondrial small subunit ribosomal RNA gene. Primer specificity was validated through both electronic PCR against target gene sequences at Genbank and in PCR reactions against DNA from Aspergillus species and other fungal genera common on Brazil nut. Collective differentiation of the observed section Flavi species A. flavus, A. nomius and A. tamarii from other Aspergillus species was possible on the basis of RFLP polymorphism.ConclusionsGiven the abundance of Aspergillus section Flavi species A. nomius and A. flavus observed on Brazil nut, and associated risk of mycotoxin accumulation, simple identification methods for such mycotoxigenic species are of importance for Hazard Analysis Critical Control Point system implementation. The assay for the genus Aspergillus represents progress towards specific PCR identification and detection of mycotoxigenic species.

Combustion of agricultural residues: An experimental study for small-scale applications

Energy services could be greatly improved by using of residues from local food industries in small-scale combustion units. Wood pellets are a reliant and proven fuel to be used in small-scale combustion units. However, these units should preferably be able to use different types of biomass depending what it is locally available. Therefore, studies have been focused on exploring the suitability of using agricultural residues for small-scale heat and power generation using direct combustion. This study targets to compare the combustion of different agricultural residues in a single unit designed for wood pellets. The different biomass fuels used are Ø6mm and Ø8mm wood pellets, Ø6mm bagasse pellets, Ø6mm sunflower husk (SFH) pellets and Brazil nut (BN) shells. The results reveal a decrease in the fuel power input, higher oxygen levels in the flue gases and shorter cycles for ash removal when using the agricultural residues. The excess air ratio was calculated based on a mass balance and compared with a standard equation showing a good agreement. CO and NO emission levels as well as the relative conversion of fuel-C to CO were higher for the BN shells and SFH pellets in comparison to the other biomass types. SO2 emission was estimated based on the analysis of unburned sulfur in ash and mass balances; the higher estimated levels corresponded to the BN shells and SFH pellets. All the biomass sorts presented over 95% relative conversion of fuel-C to CO2. Wood pellets and BN shells presented the highest amount of unburned carbon in ash relative to the fuel-C. The relative conversion of fuel-N to NO and fuel-S to SO2 were higher for wood pellets. Bagasse pellets showed similar emission levels and relative conversion efficiency to wood pellets.

Determination of aflatoxin risk components for in-shell Brazil nuts

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.

Brazil nut shells as a new biosorbent to remove methylene blue and indigo carmine from aqueous solutions

The adsorption of methylene blue and indigo carmine, respectively a basic and an acid dye, was studied on raw Brazil nut shells. The dye removal from solution by BNS was governed by: (i) polarization effects between the colored ions and the surface sites, leading to physisorbed species due to weak electrostatic forces and (ii) diffusion limitations affecting the kinetic parameters. Thermodynamic studies showed that the adsorption of methylene blue and of indigo carmine was spontaneous and exothermic occurring with entropy decrease. H 0 values confirmed the physical nature of the adsorption processes. The adsorption followed the Langmuir model and pseudo-second order kinetics over the entire range of tested concentrations but the process was controlled by intraparticle diffusion. The maximal uptakes were 7.81 mg g −1, for methylene blue, and 1.09 mg g −1 for indigo carmine, at room temperature. These results indicate that Brazil nut shells may be useful as adsorbent either for basic or acid dyes.

Lignocellulosic Materials as Potential Biosorbents of Trace Toxic Metals from Wastewater

The potential capability of Arundo donax stems, Brazil nutshells, sugarcane bagasse, and sawdust from a native wood species (Prosopis ruscifolia) to sequester trace metals from wastewater was comparatively examined using dilute aqueous solutions of Cd(II) or Ni(II) ions as models. Brazil nutshells showed the best effectiveness (>90%) for the uptake of both metals from solutions of 20 mg/L initial concentration for dosages larger than 0.2−0.4 mg/L, even superior to those obtained for a commercial activated carbon and/or red marine algae (Corallinales) used for comparison under identical conditions. Equilibrium isotherms of cadmium on the lignocellulosic and algae samples and of nickel on the nutshells were determined and properly described by the Langmuir model. The highest maximum sorption capacity of Cd(II) ions was obtained for the nutshells (Xm = 19.4 mg/g) among the lignocellulosic samples. The trend in the estimated Xm values was found to be consistent with their contents of lignin and total surface ...

Effect of pyrolysis temperature on composition, surface properties and thermal degradation rates of Brazil Nut shells

Changes in chemical and surface characteristics of Brazil Nut shells ( Bertholletia excelsa) due to pyrolysis at different temperatures (350°C, 600°C, 850°C) were examined. For this purpose, proximate and ultimate analyses, physical adsorption measurements of N 2 (−196°C) and CO 2 (25°C) as well as samples visualisation by scanning electronic microscopy (SEM) were performed. Appreciable differences in the residue characteristics, depending markedly on the pyrolysis temperature, were observed. Release of volatile matter led to the development of pores of different sizes. Progressive increases in micropore development with increasing pyrolysis temperature took place, whereas a maximum development of larger pores occurred at 600°C. Furthermore, kinetics measurements of Brazil Nut shells pyrolysis from ambient temperature up to 900°C were performed by non-isothermal thermogravimetric analysis. A model taking into account the significant changes in the residue during pyrolysis, through an increase in the activation energy with temperature and solid conversion, were found to properly fit the kinetics data over the wide range of degradation investigated.

Decay of Brazil Nuts

Next article FreeDecay of Brazil NutsEdwin Rollin SpencerEdwin Rollin Spencer Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by Volume 72, Number 5Nov., 1921 Article DOIhttps://doi.org/10.1086/332930 Views: 147Total views on this site Citations: 8Citations are reported from Crossref Journal History This article was published in the Botanical Gazette (1876-1991), which is continued by International Journal of Plant Sciences (1992-present). PDF download Crossref reports the following articles citing this article:EDNEI ASSUNÇÃO, TATIANA ALVES REIS, ARIANNE COSTA BAQUIÃO, BENEDITO CORRÊA Effects of Gamma and Electron Beam Radiation on Brazil Nuts Artificially Inoculated with Aspergillus flavus, Journal of Food Protection 78, no.77 (Jul 2015): 1397–1401.https://doi.org/10.4315/0362-028X.JFP-14-595Vildes M. Scussel, Daniel Manfio, Geovana D. Savi, Elisa H.S. Moecke Stereoscopy and Scanning Electron Microscopy of Brazil Nut ( Bertholletia excelsa H.B.K.) Shell, Brown Skin, and Edible Part: Part One- Healthy Nut, Journal of Food Science 79, no.77 (Jun 2014): H1443–H1453.https://doi.org/10.1111/1750-3841.12502T.A. Reis, T.D. Oliveira, A.C. Baquião, S.S. Gonçalves, P. Zorzete, B. Corrêa Mycobiota and mycotoxins in Brazil nut samples from different states of the Brazilian Amazon region, International Journal of Food Microbiology 159, no.22 (Oct 2012): 61–68.https://doi.org/10.1016/j.ijfoodmicro.2012.08.005Otniel Freitas-Silva, Armando Venâncio Brazil nuts: Benefits and risks associated with contamination by fungi and mycotoxins, Food Research International 44, no.55 (Jun 2011): 1434–1440.https://doi.org/10.1016/j.foodres.2011.02.047K. Arrus, G. Blank, D. Abramson, R. Clear, R.A. Holley Aflatoxin production by Aspergillus flavus in Brazil nuts, Journal of Stored Products Research 41, no.55 (Jan 2005): 513–527.https://doi.org/10.1016/j.jspr.2004.07.005C.M. Christensen MOISTURE AND SEED DECAY, (Jan 1978): 199–219.https://doi.org/10.1016/B978-0-12-424155-8.50013-4G. Ayerst, D. Budd Effect of moisture content on the storage of brazil nuts, Journal of the Science of Food and Agriculture 11, no.77 (Jul 1960): 390–396.https://doi.org/10.1002/jsfa.2740110710G. M. Hoffmann Untersuchungen zur Ätiologie pflanzlicher Actinomykosen, Journal of Phytopathology 34, no.11 (Jan 1959): 1–56.https://doi.org/10.1111/j.1439-0434.1959.tb03998.x