Roberta Martins Nogueira

Physical properties of Brazil nuts

The Brazil-nut, also known as Para-nut, is widely used as food and in cosmetic industries. The seeds are rich in lipids and protein, and also present a considerable amount of selenium. Limited research has been conducted on postharvest of the Brazil nut, being an important information to design equipment related to aeration, drying, storage and transportation steps. Thus, the objective of this study was to determine the physical properties of the Brazil-nut with and without tegument. The dimensions found for the almonds with tegument were 39.35 mm in the X axis, 24.19 mm in the Y axis, and 17.88 mm in the Z axis. However for the almond without tegument the values were 31.05 mm in X, 14.38 in Y and 15.91 mm in Z axis. The sphericity was 66.40% and 51.59% for the kernels with and without seed tegument respectively. The kernels with and without tegument presented sphericity of 63.00% and 47.72% respectively. The mass of 1000 almonds was 6.13 kg for almond with teguments and 3.18 kg for almonds without teguments. Specific mass of 0.947 g.cm -3 and 1.003 g.cm -3 for the kernels with and without tegument, coupled with a porosity of 46.88% and 37.60% and, resulting on a bulk density of 0.504 g.cm -3 and 0.626 g.cm -3 for almonds with and without teguments respectively. Finally, the angle of repose for the kernels with teguments was 36.37°.

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.

Microemulsion of Brazil nut oil as a natural product to improve superoxide release in human phagocytes

Karol Patel Fioria, Maycon de Paula Ribeiro Torresa, Jessica Iara Schonsa, Elton Brito Ribeiroa, Roberta Martins Nogueirab, Leonardo G. Vasconcelosc, Carla R. Andrighettia, Marcos José Jacintoc e Denia M. de S. Valladãoa,* Instituto de Ciências da Saúde, Universidade Federal de Mato Grosso, 78557-267 Sinop – MT, Brasil Instituto de Ciências Agrárias e Ambientais, Universidade Federal de Mato Grosso, 78557-267 Sinop – MT, Brasil Departamento de Química, Universidade Federal de Mato Grosso, 78060-900, Cuiabá – MT, Brasil

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

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.

Walking stability of Rhyzopertha dominica (Fabricius, 1792) (Coleoptera: Bostrichidae)

Results obtained in studies can contribute to the advancement of science and innovative methods and techniques for developing practical activities. Reporting conditions that may restrict the implementation of research is critical to ensure the optimal development of further technical studies. The objective of this study was to assess the walking stability of R. dominica on a flat and smooth surface. The study was based on the determination of mortality, morphology and walking stability of the insect outside the grain mass, on a flat and smooth surface. Mortality of adults of this Coleoptera in conditions with and without food was similar, which explains the difficulty that this insect had for accessing the food source on the flat and smooth surface. The measurements of body length (BOL), width (BOW) and height (BOH) of R. dominica were compared with those of Tribolium castaneum (Coleoptera: Tenebrionidae), which showed good ability to walk in these conditions. This study indicated that the former presents lower BOL and BOW, and greater BOH than the second, and all these variables showed differences when analyzed simultaneously by means of the construction of multivariate morphometric indices (Width × Height, Length × Height and Height × Length × Width). These morphometric variables, together with the definition of the geometry most similar to the body shape, resulted in determination of the center of gravity (CG) and static rollover threshold (SRTgeom) for both species. Rhyzopertha dominica and T. castaneum presented CGs considered high and low, respectively, and together with the values obtained for SRTgeom, may justify that R. dominica can be considered a less stable species during movement, and presents greater risk of rollover on flat and smooth surfaces.

A valid method for determining the water content of the Brazil nut (Bertholletia excelsa) = Validação de um método para determinação do teor de água da castanha-do-Brasil (Bertholletia excelsa)

For proper handling of a product knowledge regarding its water content is essential. To provide fast, inexpensive and reliable results, the direct evaporation method of water in oil bath (EDABO) has been proven to be a viable alternative, at all stages of production of the Brazil nut. Therefore, adaptation and validation of the EDABO method for the almonds was developed using ten lots, five for each stage, maintaining the water content range between 3.73 and 29.13% w.b, which is the typical water content range for the product from the collection phase until its final marketing. The oil bath temperatures tested were 150° C to 200° C, from 10 to 10° C for the adaptation step. The results thus obtained were compared with the water content recorded for the same batch employing the vacuum oven method as the standard. In the adaptation step the most suitable temperature range was set. Next, the method was validated to test for the precision, accuracy and linearity of the pre-set temperature range. During this step, temperature of 150° C were observed to ensured water content results consistent with those determined by the standard method. In the validation step the temperature of 150° C revealed precision, accuracy and linearity and were comparable to the standard method. Therefore, considering the technical aspects for implementation of this method, it was concluded that 150° C temperature was validated.

Simulação e validação de um modelo matemático para o perfil de temperatura do milho armazenado em silo-bolsa

The increase in grain production associated with the deficit in static storage capacity has forced some producers to stockpile winter corn in the open, especially in the state of Mato Grosso. The use of silo bags has become a short time alternative for traditional farm-level storage. As there are many questions regarding the storage of grain in a silo bag and the temperature behavior of the grains during storage, the objective in this work was to simulate numerically, using the technique of computational fluid dynamics (CFD), the temperature distribution of corn stored for four months in a silo bag, and to validate these data with temperature measurement in real conditions. The simulations were performed based on data of the average air temperature in the region (24 oC) and an average of initial temperature for corn during storage (31 oC). The results obtained from simulations showed that from two weeks to one months storage, the temperature of the grain mass tends to come into equilibrium with the outside air temperature and that at the end of the storage period the entire product has reached the thermal equilibrium. The founded temperatures, both from the simulation as the measurement showed that the grain mass is maintained at a temperature averaging less than 35 °C , which ensures minimal losses of dry matter of the product. Thus, it can be concluded that the silo bag is a viable standpoint to maintaining the safe temperature for corn stored to four months. Additional keywords: CFD; storage; heat transfer. Cientifica, Jaboticabal, v.42, n.4, p.330–337, 2014 ISSN: 1984-5529

Triplaris americana L. (Polygonaceae), a New Host Plant For Aethalion reticulatum (Linnaeus, 1767) (Hemiptera: Aethalionidae)

Triplaris americana is a plant that has been applied as ornamental specie and also as natural medicine. Adults and immature stages of Aethalion reticulatum were observed colonizing specimens of this plant in Sinop, MT, Brazil, which represent the first record of this leafhopper colonizing this specie.