Noni seeds have been used for years as an important medicinal source, with wide use in the pharmaceutical and food industry. Drying is a fundamental process in the post-harvest stages, where it enables the safe storage of the product. Therefore, the present study aimed to fit different mathematical models to experimental data of drying kinetics of noni seeds, determine the effective diffusion coefficient and obtain the activation energy for the process during drying under different conditions of air temperature. The experiment used noni seeds with initial moisture content of 0.46 (decimal, d.b.) and dehydrated up to equilibrium moisture content. Drying was conducted under different controlled conditions of temperature, 40; 50; 60; 70 and 80 ºC and relative humidity, 24.4; 16.0; 9.9; 5.7 and 3.3%, respectively. Eleven mathematical models were fitted to the experimental data. The parameters to evaluate the fitting of the mathematical models were mean relative error (P), mean estimated error (SE), coefficient of determination (R2), Chi-square test (c2), Akaike Information Criterion (AIC) and Schwarz’s Bayesian Information Criterion (BIC). Considering the fitting criteria, the model Two Terms was selected to describe the drying kinetics of noni seeds. Effective diffusion coefficient ranged from 8.70 to 23.71 × 10-10 m2 s-1 and its relationship with drying temperature can be described by the Arrhenius equation. The activation energy for noni seeds drying was 24.20 kJ mol-1 for the studied temperature range.

The purpose of this study is to characterize native bee plants regarding their capacity to extract and accumulate trace elements from the soil and its consequences to the sanity of the produced pollen. The trace elements Cu, Mn, Pb and Zn were analyzed in soil, plants and bee pollen from Teresina region (PI), Brazil, by flame atomic absorption spectrophotometer. Considering the studied plant species, Cu and Pb metals presented in the highest levels in the roots of B. platypetala with 47.35 and 32.71 μg. (from soil to pollen) of Mn and Zn was more effective than in case of Cu and Pb, therefore, the bee pollen can be used as food supplement without causing risks to human health.

The drying is one of the stages of processing Brazil nuts, being an important stage due to the high moisture content and water activity of the product. This study aimed to adjust mathematical models to the drying kinetics data of Brazil nuts, calculating the effective diffusion coefficient and obtaining activation energy for the drying process. Brazil nuts were collected in amazon region, and then the product was homogenized for processing. The nuts were subjected to drying in a forced ventilation oven at temperatures of 40, 50, 60, 70 and 80 °C in 4 replicates, each one consisting of approximately 200 g of samples in aluminum containers. Mathematical models were adjusted to the experimental data of the moisture content ratio. Thompson, Midilli, Logarithmic and Two Terms models are suitable for estimating the drying of Brazil nuts. The Two Terms model was selected to represent the drying phenomenon for presenting better results in the analyzed parameters. The effective diffusion coefficient increased with increasing temperature and the activation energy for the liquid diffusion in the drying was 35.69 kJ mol -1 .

The use of silage has been an efficient alternative to feed supply during the shortage of roughage in dry periods, providing quality feed that is widely used in ruminant feeding. Thus, the objective of this study was to evaluate the fermentative characteristics and nutritive value of corn silage with Tamani guinea grass (Panicum maximum BRS cv. Tamani) through chemical composition, in vitro dry matter digestibility and protein fractionation. The experiment was conducted in a completely randomized design with four replications. The treatments consisted of five silages: corn; corn with 10% Tamani guinea grass; corn with 20% Tamani guinea grass; corn with 30% Tamani guinea grass; and corn with 40% Tamani guinea grass, totalling 20 experimental silos. The addition of tamani grass to silages was determined based on fresh matter. For ensiling, corn was harvested with 320 g kg-1 DM (dry matter) and Tamani guinea grass in a 30-day development cycle with 286 g kg-1 DM. After 50 days of silage, the silos were opened to analyse the fermentative characteristics, chemical composition and protein fractionation of the silage. The results showed that the addition of Tamani guinea grass in corn silage increased the pH and buffering capacity and reduced the dry matter and lactic acid concentration but did not compromise the fermentative characteristics of silages. The addition of 40% Tamani guinea grass in corn silage provided increased levels of crude protein, in vitro dry matter digestibility, protein A, B1 and C, and decreased the fractions B3 and C, which makes Tamani guinea grass an alternative to improve the quality of exclusive corn silage, resulting in better quality silage.

The diversity of grasses in the intercropping promotes greater soil cover regardless of the grazing intensity used. The aim was evaluated how cultivation systems (monoculture and intercropped) influence the proportion of soil discovered under different grazing intensities. The experiment was conducted at the premises of the Brazilian Agricultural Research Company. The pastures were combined two cultivation systems: monoculture of Panicum maximum cv. BRS Zuri; intercropping of Panicum maximum cv. BRS Zuri, Brachiaria brizantha cv. Xaraes and Brachiaria decumbens cv. Basilisk. Four evaluation cycles were performed, which totaled in 2136 observations. In the contrast between evaluation cycles, it is possible to infer that cycles II, III and IV have a negative effect in relation to cycle I, because after the first evaluation there is an increase in the proportion of soil discovered in the pastures studied. In relation to cultivation systems, the intercropped managed at high grazing intensities impacts negative effects, and it is possible to observe the highest values of uncovered soil, as well as the lowest tussock distribution values. The intercropping of tropical climate pastures has greater soil cover when managed in lenient grazing intensity.