Solenir Ruffato

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°.

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