Brazil Nut Research Articles

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

Drying is fundamental in the processing of Brazil nuts to prevent contamination by aflatoxins which are produced by fungi, as well as to extend the shelf life of the product. The binomial time/temperature is applied to guarantee the efficiency of drying stages. In this context, the objective of this study was to evaluate the parameters of moisture content (mc) and water activity (Aw) in processed and unprocessed nuts obtained from a processing plant in the Amazonas state, Brazil, during the harvests of 2019 and 2020. Differences were observed regarding Aw between the harvests, and in processed and unprocessed samples. However, for mc, no differences between years or interaction between factors were observed. Processed samples from 2019 and 2020 showed a significant reduction in moisture content when compared to unprocessed samples and this may be because some modernization occurred in the drying process and raw material was stored under better conditions. We therefore conclude that the time/temperature binomial has a direct impact on product safety and should be applied from the moment of collection of raw material until the industrial process begins to guarantee economic maintenance of the production chain.

Chemical and bioactive properties of the oils from Brazilian nuts

This paper aims to determine the content of bioactive substances of lipid fractions extracted from Bertholletia excelsa, Lecythis pisonis and Dipteryx lacunifera, in by the interest of better identifying the quality of these raw materials. Proximate composition of nuts was determined by official methods and total carbohydrate was calculated by difference. The oils were extracted from the nuts by cold pressing and analyzed for fatty acid composition, tocopherols, phytosterols and total carotenoids and phenolics compounds. The fatty acid composition of oil extracted from L. pisonis was more unsaturated compared with others oils. L. pisonis oil showed to be richer in total tocopherol and γ-tocopherol, moreover showed considerable total phytosterol and carotenoid amounts, thus representing an important source of vitamins A and E. The oils showed significant content of phenolic compounds, with the exception of the oil extracted from D. lacunifera. The study revealed that the oils from Brazilian nuts contain bioactive compounds in relevant quantities, L. pisonis oil standing out. This fact favors their use for food and, as raw material in chemical, pharmaceutical and cosmetic industries, adding value to products derived from these oils, increasing the viable sources of raw materials.

Intra-swarm migration of size-variable robotic modules utilizing the Brazil nut effect

In this work, we apply physical granular segregation phenomena to the problem of intra-swarm module migration in a robotic swarm. These segregation phenomena allow for complex relative motion between interacting particles on the basis of differing physical properties. In particular, the Brazil nut effect is one such phenomenon that causes segregation of particles based on relative size difference. We simulated size-variable modules in order to take advantage of this effect and induce intra-swarm module migration. Intra-swarm module migration refers to the movement of the modules within the confines of the swarm, relative to each other, as well as the swarm container. We introduced two methods to produce different kinds of module movement. The first of these, called the flashlight method, induced movement of an individual module relative to its neighbours. The second, called the zone method, induced an orientation-aligned global module motion within the swarm. In this work, we evaluate the effects of different parameters on the nature of the movements induced by these methods.

Development and sun protection factor of emusionated formulation containing Brazil nut oil

Brazil nut (Bertholletia excelsa H.B.K) is oil rich and contains compounds with bioactive properties wich grants potential for usage in new formulations with photo-protective potential, as well as other pharmaceutical and cosmetic applications. The aim of this study was the development and in vitro determination of the sun protection factor of emulsionated formulations containing Brazil nut oil, targeting its use as a photo-protective carrier. Brazil nut oil was extracted with hexane using the ultrasound assisted method. After the oil quality against oxidation was evaluated, it was incorporated into the formulations. The emulsions were evaluated for their preliminary stability, accelerated stability, rheological characterization, mean globule diameter, in vitro SPF determination and potential antioxidant activity by the DPPH radical scavenging method. The same emulsified systems containing a chemical sunscreen were also evaluated, looking for synergism possibilities. The emulsions containing 20 and 30% of Brazil nut oil, with and without the chemical sunscreen, were characterized as oil-in-water type, showing elastic/solid rheological characteristics, and presented better stability characteristics in the assessed parameters. However, the presented photo-protective activity was attributed to the chemical sunscreen itself, rather than the base formulation and the antioxidant activity was considered low. The base formulation developed with Brazil nut oil presented adequate characteristics for incorporating sunscreen, opening up possibilities for incorporating several active substances, like the sunscreen and many others.

English

Aflatoxins are the main mycotoxin related to the contamination of Brazil nut and an important product extracted from the Amazon region that has a high number of consumers due to its health benefits. Considering the frequent occurrence of aflatoxins in Brazil nuts, it is necessary to study the levels of exposure to these toxins associated with its consumption using biomarkers. To do this, a study was carried out with 30 volunteers of both sexes, where each volunteer received a kit containing Brazil nuts for the ingestion of 2 (two) units / day for 30 days. Urine samples were collected from each volunteer at 0 and 30 days, and the level of Aflatoxin M1 (AFM1) was determined by ELISA using the Helica Kit®. A questionnaire was used to obtain information on weight, height, age, medication use, pathological conditions, frequency of weekly consumption of certain foods more susceptible to aflatoxin contamination, and 24-h food recall. Of the 30 samples analyzed at time 0 (zero) for exposure, AFM1 presented positive results in 3 (10%) samples with a range of 2.75-70.41 ng/mL. In the analysis of the 30 days after Brazil nut consumption, the presence of AFM1 in the urine was not detected, suggesting that Brazil nut consumption did not generate impact on the urinary levels and exposure to AFM1. In conclusion, no association was found between food consumption of food susceptible to aflatoxin contamination and concentration of AFM1 in urine. Key words: Aflatoxin, nuts, ELISA, selenium.

Processing and physicochemical characterization of a water-soluble extract based on Pará nut (Bertholletia excelsa) and baru nut (Dipteryx alata Vogel)

Despite the nutritional and functional qualities of Pará nut (Bertholletia excelsa) and of Baru nut (Dipteryx alata Vogel), the industrial exploitation of these two nuts is still scarce. With this, the elaboration of a water-soluble extract based on Pará and Baru nuts could be consider an alternative for the consumption of foods based on these vegetables, both little used industrially. Thus, by way of a simplex centroid experimental mixture design, this study aimed to elaborate water-soluble vegetable extracts based on Pará and Baru nuts. This study allowed evaluate the behavior of the physicochemical and physical characteristics of the processed vegetable extracts. The special cubic model obtained the best fit for the response variables, both for the physicochemical characterizations of moisture, lipid, protein, ash, carbohydrate, pH value and acidity, and for the physical characteristics of luminosity, chroma and hue angle. The results obtained showed that the model is highly predictive (all R2 > 97%). The water content directly influenced the nutritional aspects of the water-soluble extracts, where a decrease in the proportion of water in the mixture provided greater content of proximate composition. The behavior of the color parameter predicted by the model showed that variations in the proportions of the nuts concentrations changes the behavior of the luminosity indexes. The pH had higher values when there was an increase in the concentration of Pará nuts, while an increase in the proportion of baru nuts decreased the acidity of the water-soluble extract. The mathematical models used allow to evaluate the effects of the interactions between variables and responses, highlighting their applicability in the food industry.

Trace Elements and Radionuclides in Brazil Nuts from the Brazilian Amazon

The Brazil nut tree (Bertholletia excelsa) is an accumulating plant and, as such, absorbs metals from the soil according to the different geographic regions in which it is found. In this context, some Brazil nuts can exceed the safe level of certain trace elements and thus become toxic to consumers. To provide risk assessment information, the aim of this study was to evaluate trace elements and radionuclides found in Brazil nuts from the Brazilian Amazon. Trace elements were evaluated using ICP-MS, however As, Ca, Cr, Mg, Hg and Pb were not detected. The levels of Fe, Zn and Ti were within the maximum levels stipulated for Dietary Reference Intake. The results provide preliminary data concerning the surveillance of antimony (Sb) in the samples analyzed. Further studies are necessary to evaluate the bioavailability of Sb and other metals, and the Se mechanisms for detoxifying Sb. Concerning radionuclides, the committed effective dose was below the established limits by UNSCEAR (2000). In conclusion, the levels of trace elements and radionuclides in the samples did not levels that could be considered toxic to human health.

Domestication in Motion: Macrofossils of Pre-Colonial Brazilian Nuts, Palms and Other Amazonian Planted Tree Species Found in the Upper Purus

ABSTRACT Evidence from several earthwork-building societies has recently been discovered in Amazonia that challenges existing theories about precolonial, human-environment interactions. Combining data obtained by plant macrofossil analyses, archaeological excavations, historical sources, and indigenous oral histories, we focus on the pre-colonial sources of subsistence and domestication processes of some tree species. Our study shows that the societies that built geoglyph-type earthworks in southwestern Amazonia harvested and consumed both wild and domesticated palm fruits, Brazil nuts and other identified species in the first millennium of the Common Era. Drawing on theories of human ecology, we argue that in the pre-colonial Amazonian context, plant domestication occurred as complex and nonlinear activities of protecting, supporting, and cultivating. This multifaceted indigenous cultural phenomenon of domestication had an important long lasting impact on Amazonian forest composition, and it is obvious that human and botanical interaction has also led to clear and observable differences in Brazil nuts and some palm fruits compared to their ancestors.

Heat treatment of polymeric PBAT/PCL membranes containing activated carbon from Brazil nutshell biomass obtained by electrospinning and applied in drug removal

Abstract This work aimed to perform a heat treatment on biodegradable polymeric membranes produced by the electrospinning technique to be used in the retention of residual drugs from water. For this, a blend with a concentration of 20 % (w/v) was produced, composed of 75 % Poly(butylene adipate-co-terephthalate) (PBAT) and 25 % poly (e-caprolactone) (PCL) (w/w), solvated in chloroform (CL) and N,N-dimethylformamide (DMF) in the proportion of 85/15 % (v/v), respectively. A portion of 10 % (w/w) activated carbon from Brazil nut shell biomass (CA-BCB) was incorporated in the polymeric solution, which was subjected to electrospinning to obtain the polymeric membranes. Thermal treatments were then carried out on the surface of the electrospun membranes. The membranes were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and membranes surface wettability by contact angle. The results of the micrograph images (SEM) showed that the incorporation of CA-BCB produced fibers with smaller diameters without changing the chemical structure of the polymers, which was confirmed by the FTIR analysis. With the addition of activated carbon, there was an increase in the thermal stability of the material, which was confirmed by TGA analysis. In the permeability tests carried out with distilled water (1290 kg h−1 m-2) and tetracycline hydrochloride solution (TCH), 1220 kg h−1 m-2 with 200 min of operation. A PBAT/PCL membrane retention capacity, with heat treatment and addition of CA-BCB, of approximately 67 % was verified. This result suggests that the membranes produced by electrospinning, together with a heat treatment, can be used to retain emerging pollutants.

Characterization of fermented beverages made with soybean and Brazil nut hydrosoluble extracts

The objective of this study was to elaborate mixed formulations of fermented beverages made with different combinations of soybean hydrosoluble extract (SHE) and Brazil nut hydrosoluble extract (BNHE) and to evaluate their chemical composition and technological properties. The following formulations were produced: (i) 100% SHE, (ii) 75% SHE + 25% BNHE, (iii) 50% SHE + 50% BNHE, (iv) 25% SHE + 75% BNHE and (v) 100% BHNE. All formulations were inoculated with lactic acid bacteria. The analyzed variables included fermentation, syneresis, chemical composition, and color of the beverages. The greatest pH variation was observed in the beverage formulated with 75.0% SHE and 25.0% BNHE. The formulation elaborated with a higher percentage of SHE presented lower lipid content but showed higher sodium content. The formulation containing 75.0% SHE and 25.0% BNHE proved to be the most viable since it presented the best technological properties.

Rheological behavior of plant-based beverages

Abstract The aim of this research was to study the rheological behavior of a plant-based beverage made of Brazil nut (Bertholletia excelsa) and Baru (Dipteryx alata Vogel) and a nut-based beverage made of Brazil nut (Bertholletia excelsa) and Macadamia (Macadamia integrifolia) at the temperatures of 25, 45 and 80 °C. Experimental data were adjusted to the models of Newton, Ostwald-de Waele, Herschel Bulkley and Bingham. The formulations of the beverages were obtained from a simplex-centroid design, based on the panelists acceptance in the sensorial evaluation. Rheological behavior showed no differences between the beverages and rheological data were best fit to Ostwald-de Waele model, at the three temperatures for both beverages, presenting a non-Newtonian behavior, with a pseudoplastic characteristic (n <1). In general, the nut-based beverage made of Brazil nut and Macadamia presented lower values than a plant-based beverage made of Brazil nut and Baru for an apparent viscosity, at the three temperatures, requiring less tension to flow.

Effects of Nut Consumption on Colon Cell Proliferation, Apoptosis, and Inflammation Gene Expression

Abstract Objectives A disruption to the colon cell kinetic balance can increase one's risk for colorectal cancer (CRC). Studies using single nut consumption has been found to decrease CRC risk. This study aimed to determine if mixed nut consumption would be as effective as or even better than single nut consumption at preventing CRC through modulation of colon cell proliferation and apoptosis cell numbers in a healthy rat model. It was hypothesized that rats consuming a mixed nut diet would exhibit fewer proliferative cells and greater apoptotic cells compared to a single nut diet and a control. Methods Thirty 21-day-old Sprague Dawley male rats were assigned to one of three isocaloric diets: control diet (no nuts), pistachio diet, or mixed nut diet for eight weeks. The mixed nut diet contained almonds, Brazil nuts, cashews, macadamia nuts, peanuts, pecans, pistachios, and walnuts. Proliferative cells were marked using Ki-67 quantitative immunostaining and apoptotic cells with terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Colonic gene expression of prostaglandin endoperoxide synthase 2 (Ptgs2), nuclear factor kappa-B p65 subunit (Rela), Cyclin D1 (Ccnd1), peroxisome proliferator-activated receptor gamma (Pparγ), superoxide dismutase (SOD), and catalase (Cat) were determined by real-time quantitative polymerase chain reaction analysis. Results No significant differences were found in proliferation and apoptosis cell numbers between all three groups. Significantly lower levels of the inflammatory marker, Ptgs2, were only observed between the pistachio group and the control (p = 0.045). While both the pistachio and mixed nut groups had significantly lower levels of Rela compared to the control (p = 0.041). No significant differences were found among diets for Cyclind1, Pparγ, Sod, and Cat. Conclusions The results of this study show that nut groups were able to downregulate inflammation gene expression without alteration to colon cell proliferation and apoptosis. A longer study duration is needed to investigate if the lower gene expression involved in inflammation from nut consumption may change cell kinetics and further reduce colon cancer. Funding Sources American Heart Association (16GRNT31360007).

The Effects of Mixed Nut Consumption on the Microbiome in Healthy Adults

Abstract Objectives Nut consumption has been shown to have a wide range of health benefits from lowering cholesterol to extending longevity. Due to their prebiotic content, one potential mechanism is that nuts favorably impact the symbiotic relationship of the gut microbiome. So far studies have investigated the role of individual types of nuts, but more research is needed to determine if favorable microbiota changes extend to a nut mixture, which is often how people consume nuts. The purpose of this study was to examine the effects of daily mixed nut consumption on microbiome diversity as it relates to human health. Methods Subjects (N = 20) were randomized into two groups either consuming 42g (250 Kcal) of mixed nuts (n = 10, 9 females, 1 male, age 24.5 ± 1.2 y, BMI 24.8 ± 1.5 kg/m2) containing cashews, almonds, pecans, peanuts, walnuts, pistachios, Brazil and macadamia nuts or 46g of iso-caloric lightly salted potato chips (n = 10, 8 females, 2 males, age 24.2 ± 1.0 y, BMI 23.3 ± 1.0 kg/m2) every day for three weeks. Stool samples were collected at baseline and week three in DNA/RNA shield solution and isolated DNA was sequenced using 16S rRNA gene sequencing. Microbiome data were analyzed for alpha and beta diversity and taxa abundance using R. Results The intervention did not lead to significant changes in microbiota composition at the phyla or genera level; however, a trend towards a decreased Bacteroidetes to Firmicutes ratio was observed after consumption of potato chips for three weeks while an opposite trend was observed following mixed nut consumption. For within-subject (alpha) and between-subject (beta) diversity there were no significant changes at the species level. A significant (P = 0.018) 11.9 log fold increase in Dialister invisus was observed in the potato chips group. Although not statistically significant, the mixed nuts group had a 7.1 log fold decrease in Prevotella bivia (P = 0.058), a 4.5 log fold decrease in Eubacterium dolichum and a 3.6 log fold increase in Bifidobacterium longum. Conclusions Results indicate that the consumption of mixed nuts did not lead to a significant shift in microbiota composition; however, trends at the phyla and species levels suggest a longer intervention may be needed to observe microbiota changes that may contribute to human health. Funding Sources American Heart Association (16GRNT31360007).

Special issue in honour of Prof. Reto J. Strasser - Chlorophyll a fluorescence of Bertholletia excelsa Bonpl. plantations under thinning, liming, and phosphorus fertilization

Phosphorus (P) fertilization and liming can reduce negative effects caused by a sudden increase in light availability after thinning of forest plantations. In this study, immediately after thinning, photochemical performance (quantum yield of PSII and performance index) decreased, however, liming and P fertilization reduced the negative effects caused by thinning and accelerated the recovery of Bertholletia excelsa trees. After thinning, the remaining trees increased J-I phase with the formation of a positive K-band which occurred exclusively in unfertilized (no liming or no P) individuals. Additionally, enhanced effective dissipation (DI0/RC) values (140%) were found in individuals without liming or P after thinning, while plants under liming and P increased DI0/RC values by 47 and 79%, respectively. Photochemical performance of B. excelsa was positively correlated to iron, zinc, and manganese. Thus, P fertilization and liming are recommended for alleviating the stress caused by high irradiance after thinning in B. excelsa plantations.

RISK ASSESSMENT OF AFLATOXIN IN BRAZIL NUT BY PRODUCT CONSUMPTION IN THE AMAZON REGION

Objective: Evaluate exposure to aflatoxins in processed Brazil nut (chopped and sliced) products marketed in Amazonas State.&#x0D; Methods: The samples were purchased during the 2017 harvest at the local retail in the city of Manaus/AM/Brazil in the form of sliced and chopped. Moisture content (MC) and water activity (aw) were verified, aflatoxins (AFB1, AFB2, AFG1, AFG2) were quantified by liquid chromatography. To characterize the risk of exposure to genotoxic use the population margin of exposure (MOE).&#x0D; Results: Chopped and sliced Brazil nut samples analyzed here presented an MC average of 1.62% and water activity of 0.26. These values indicate that samples are safe, according to physical-chemical baselines. Regarding aflatoxins presence, 8% of the samples presented aflatoxins total levels &gt;10 μg/kg. A risk evaluation was performed in which exposure of the population to these substances is observed and, once found; the MOE was 1036 ± 793 (&lt;10 000).&#x0D; Conclusion: Regarding the risk assessment, it was possible to observe that there is a possibility exposure of the population to these substances since the average of MOE found was 1036±793, or &lt;10 000, characterizing this possible risk.

Overcoming seed dormancy and rooting in air-layering polyembryonic seedlings of sapucaia (Lecythis pisonis Cambess.)

Lecythis pisonis produces edible seeds rich in nutritional and functional elements such as selenium and are a great alternative to Brazilian nuts. The seeds have low germination, which may be related to physical dormancy imposed by tegument, meaning that polyembryonic seedlings can be a strategy to increase final stand. The objective of this work was to study methods to overcome seed dormancy and auxin induction in polyembryonic seedlings of pisonis. The experiment to break dormancy consisted of seven treatments: T1: intact seeds; T2: seeds scarified on hilum’s opposite side; T3: seeds scarified hilum’s adjacent region; T4: seeds scarified in lateral region; T5: seeds scarified in both opposite and adjacent region to the hilum; T6: T2 + immersion in water at 40 °C/20 minutes; T7: T2 + immersion in water at 60 °C/5 minutes. The experiment to induce rooting was arranged in a 2 x 6 factorial randomized complete block design (environments: A. greenhouse and B. greenhouse covered with black polyolefin (80% shading) x concentrations of indole-3-butyric acid (IBA): 0; 1000; 2000; 3000; 4000 and 5000 mg L-1), with four replicates of eight polyembryonic seedlings. Seed coat scarification in hilum’s adjacent (T3) and lateral regions (T4) was the most efficient methods for breaking physical dormancy. IBA at 5000 mg L-1 promoted the greatest rhizogenesis of L. pisonis layers.

Evaluation of the antioxidant activity and mutagenicity of Brazil nut (Bertholletia excelsa Bonpl.).

This study evaluated the antioxidant capacity and the genotoxic and antigenotoxic effects of the fixed oil of B. excelsa Bonpl. in peripheral blood of Swiss mice. For the antioxidant capacity, were used the β-carotene/linoleic acid and DPPH methods. In the genotoxicity assay, were used healthy, 6-7 week old male Swiss mice, and there were six animals per group. For the genotoxic test, animals were treated with different concentrations of B. excelsa (500, 1.000 and 2.000 mg/kg body weight bw) in 0.5 mL orally. For the antigenotoxic test, animals were treated with predetermined concentrations, followed by intraperitoneal injection of doxorubicin (DXR 15 mg/kg bw) in 0.3 ml, in addition to the negative group (water) and dimethylsulfoxide (200 μL). Peripheral blood samples were collected 24 and 48 hours after the treatments. The frequency of micronucleated polychromatic erythrocytes (MNPCEs) was obtained from the analysis of 2.000 MNPCEs/animal. After data analysis, the conclusion was that the fixed oil of B. excelsa showed excellent protective activity by the β-carotene/linoleic acid method, demonstrated absence of genotoxic effect, and significant antigenotoxic effect according to the protocols and treatments performed in this study.

DO FOREST CONCESSIONS BENEFIT EXTRACTIVIST COMMUNITIES? THE CASE OF THE JAMARI NATIONAL FOREST

The study aims to analyze the exploration potential of the main non-timber forest products in the Forest Management Unit number III by the communities around Jamari National Forest. Were used the açaí fruit and Brazilian nuts production data based on the sustainable management plan, as well the Brazilian nut crop production for 2015, 2016 and 2017 reported by traditional communities, "Américo Ventura" and "Linhas 113-119". The data were analyzed and interpreted using economic indicators. As the main results, the productive potential amount of açaí fruit and Brazilian nuts available for harvest in each annual crop is 426,86 tons and 124,13 tons, respectively, providing an estimate of annual income of R$ 79.794,64 and R$ 195.134,63, respectively. For Brazilian nuts, the annually demand raised by the community was approximately 8 tons, from 2015 to 2017. The amount harvested represents 44.77% of the productive capacity of the three units. In addition, the cost-benefit ratio indicates that for each Brazilian Real invested in production the producer receives, on average, R$ 5,72. The Brazilian nut extraction shows to be an interesting activity in terms of production and economic value in both communities, presenting a net annual gain of R$ 1.812,108 per collector, for a total group of 50 extractivists residing in the communities “Américo Ventura” and “Linhas 113-119”, between 2015 to 2017. Thus, it is concluded that there is a great potential for exploration of these products in partnership with the concession forest, contributing to the sustainable development of extractivist communities.

DIAMETER STRUCTURE AND ITS RELATIONSHIP WITH FRUIT AND SEED PRODUCTION IN A NATIVE BRAZIL NUT GROVE IN MATO GROSSO

The study aimed to evaluate the annual variation in fruits and seed productivity of Brazil nut trees and to determine the association between diameter structure and fruit/seed productivity in a semi-deciduous seasonal forest undergoing logging in Mato Grosso, Brazil. Data were collected in two permanent plots (300 m x 300 m) spaced 3.5 km apart. All trees ( n = 279) with diameter at breast height (DBH) ≥ 10 cm were tagged and productivity was monitored from October to February during each of the five harvest seasons between 2012 and 2017. Associations between seed dry weight (SDW) per tree and DBH, crown position, crown shape and fruit number were established using stepwise regression analysis. The model based on DBH was a good predictor of seed production and revealed that SDW tree -1 increased by 1.3 kg on average for every 10 cm increase in DBH. Trees reached the reproductive phase with DBH < 50 cm. Characteristics and mean SDW values of the diameter classes were: 10 cm ≤ DBH < 30 cm - dominated/suppressed trees/malformed crowns (0.12 kg tree -1 year -1 ); 30 cm ≤ DBH < 70 cm - dominant/co-dominant/good crown shape (1.23 kg tree -1 year -1 ); DBH ≥ 70 cm - dominant/co-dominant/well-formed crowns (4.8 kg tree -1 year -1 ). DBH explained 34% of the variation in the mean SDW. Our results are important for the sustainable management of the study stands, allowing the assessment of current and future yields of Brazil nuts for the purpose of improving the economy of forest-dependent communities and associated enterprises.

Hierarchical levels of organization of the Brazil nut mesocarp

Aiming to understand Nature´s strategies that inspire new composite materials, the hierarchical levels of organization of the Brazil nut (Bertholletia excelsa) mesocarp were investigated. Optical microscopy, scanning electron microscopy (SEM), microtomography (MicroCT) and small-angle X-ray scattering (SAXS) were used to deeply describe the cellular and fibrillary levels of organization. The mesocarp is the middle layer of the fruit which has developed several strategies to avoid its opening and protect its seed. Fibers have a different orientation in the three layers of the mesocarp, what reduces the anisotropy of the structure. Sclereids cells with thick cell walls fill the spaces between the fibers resembling a foam-filled structural composite. The mesocarp has several tubular channels and fractured surfaces which may work as sites for crack trapping and increase toughness. The thick and lignified cell wall of sclereids and fibers and the weak interface between cells can promote a longer and tortuous intercellular crack path. Additionally, fibers with high strength and stiffness due to microfibrils oriented along the main cell axis (µ = 0° to 17°) were identified in the innermost layer of the mesocarp. Such an understanding of each hierarchical level can inspire the development of new cellular composites with improved mechanical behavior