Application of multi-criteria decision-making methods: certification mechanisms for organic produce in Brazil

A rural producer who wishes to market organic products must obtain the Brazilian Organic Conformity Assessment System seal and consider a series of criteria for certification. The objective of this article is to identify which criteria should take priority and which organic conformity assessment mechanism (certification by Audit or by the Participatory Guarantee System—SPG) is the most appropriate option for a rural producer who wishes to obtain the seal of organic certification. After a bibliometric analysis, the researchers used the Analytic Hierarchy Process multicriteria method. A sensitivity analysis was also carried out to investigate variations in the priorities of the criteria and certification alternatives. The results indicated the following order of priority of the criteria: cost, market access, and producer availability. SPG was the most relevant assessment mechanism.     

Determination of phosphorus in biodiesel using FIA with spectrophotometric detection

In this work, a method for the determination of phosphorus in biodiesel (B100) using flow injection analysis with spectrophotometric detection (FIA-SD) is described. Samples were digested using an acid mixture in a heating block. The phosphorus concentrations obtained by the (FIA-SD) method were similar to those obtained by the official method. Recovery tests show results between 98.6% and 101.0% for biodiesel produced from sunflower and between 102.1% and 113.5% for biodiesel produced from castor and soybeans. The limits of detection (LOD) and quantification (LOQ) obtained using the FIA system were 0.14 mg L⁻¹ and 0.46 mg L⁻¹, respectively.     

Can artisanal “Coalho” cheese from Northeastern Brazil be used as a functional food?

Brazilian artisanal “Coalho” cheeses from six Northeast towns were investigated as a functional food based on their peptide profiles and antioxidant, zinc-binding and antimicrobial activities. The peptides (WSP) from “Coalho” cheese showed high antioxidant activity, the best value of TEAC being 2223 ± 10.10 μM, which means 91.1 ± 0.43% oxidative inhibition and peptide concentration for IC₅₀ of 7 mg/mL (21 μg of peptides) for sample from the town of Correntes. The smallest TEAC value (1896 ± 17 μM), which means 75.9 ± 0.7% oxidative inhibition and IC₅₀ of 10.5 mg/mL (31.5 μg of peptide), was obtained for samples from the town of São Bento do Una. The zinc-binding activities were: Arcoverde (72.21 ± 0.24%) Cachoeirinha (75.02 ± 0.02%), Capoeiras (61.78 ± 0.65%), Correntes (75.47 ± 0.5%), São Bento do Una (75.41 ± 0.15%), and Venturosa (74.36 ± 0.04%). The WSP extracts showed antimicrobial activity against Enterococcus faecalis, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa. All the results obtained suggest that “Coalho” cheese has potential as a functional food.     

Poly(lactic acid) biocomposites with mango waste and organo-montmorillonite for packaging

Poly(lactic acid) (PLA) is a biodegradable polymer used in packaging, but its properties can be improved by manufacturing composite matrixes. The combination of PLA, starch, and nano-montmorillonite leads to materials with superior mechanical properties. Mango lump is rich in cellulose and starch. The goal of this study is to develop and characterize biocomposites based on PLA, mango waste, and nano-organo-montmorillonite for packaging. The samples were microstructurally, morphologically, and mechanically characterized. Physical interaction between the phases was observed. The mango components displaced the PLA X-ray diffraction peaks and the clays altered their intensity, by interfering with chain packing. The addition of single components to PLA increased the samples’ transition temperatures, but the addition of multiple components diminished them. PLA showed adhesiveness to cellulose fibers and nonadhesiveness to starch granules. Thicker samples presented better mechanical properties. PLA–mango–“chocolate clay” samples are relatively stable materials, while PLA–mango–“bofe clay” samples could represent promising highly biodegradable materials. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47512.     

Alternative energy sources in the Amazon

This paper discusses the evaluation of energy potential of palm oil for the generation of electricity in isolated communities. In Brazil, the energy sector culture has historically been directed almost exclusively toward major projects geared to meet the demands of those sectors of society that have the greatest economic and political influence. Prioritizing industrialization and an accelerated urbanization, they have oriented the national energy system toward centralized production of enormous blocks of energy adapted to meet major urban concentration consumption but incapable of satisfying the needs of a large part of the population that inhabits the rural areas. These small- and medium-sized communities are sometimes isolated from the developed urban centers and not connected to the conventional electricity networks. In this scenario, the Amazon region stands out due to its huge territorial extension and low demographic density, which is scattered among islands and other locations not easily accessible. As a rule, these areas lack electricity, and, when they do have it, supply is precarious and provided through fossil fuels for electricity production     

Induction of crystallization influences the retention of volatile compounds in freeze-dried marolo pulp

The effects of sucrose, maltodextrin, and ethanol as prefreezing treatments on the retention of volatile compounds in freeze-dried marolo pulp were evaluated. The volatile compounds were extracted using a solid-phase microextraction technique and investigated by gas chromatography combined with mass spectrometry. The transition temperatures, X-ray diffraction-derived microstructures, particle sizes, and scanning electron microscopy images were examined. The optimum inducer concentrations which produced typically amorphous structures were maltodextrin up to 60.0?g/L and lower ethanol and sucrose concentrations, which were optimized to achieve maximum retention of volatile substances compared with the original fruit pulp.     

Novel carbon-supported Fe-N electrocatalysts synthesized through heat treatment of iron tripyridyl triazine complexes for the PEM fuel cell oxygen reduction reaction

2,4,6-Tris(2-pyridyl)-1,3,5-triazine (TPTZ) was used as a ligand to prepare iron-TPTZ (Fe-TPTZ) complexes for the development of a new oxygen reduction reaction (ORR) catalyst. The prepared Fe-TPTZ complexes were then heat-treated at temperatures ranging from 400 °C to 1100 °C to obtain carbon-supported Fe-N catalysts (Fe-N/C). These catalysts were characterized in terms of catalyst composition, structure, and morphology by several instrumental methods such as energy dispersive X-ray, X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy. With respect to the ORR activity, the Fe-N/C catalysts were also evaluated by cyclic voltammetry, as well as rotating disk and ring-disk electrodes. The results showed that among the heat-treated catalysts, that obtained at a heat-treatment temperature of 800 °C is the most active ORR catalyst. The overall electron transfer number for the catalyzed ORR was determined to be between 3.5 and 3.8, with 10-30% H₂O₂ production. The ORR catalytic activity of this catalyst was also tested in a hydrogen-air proton exchange membrane (PEM) fuel cell. At a cell voltage of 0.30 V, this fuel cell can give a current density of 0.23 A cm⁻² with a maximum MEA power density of 0.070 W cm⁻² indicating that this catalyst has potential to be used as a non-noble catalyst in PEM fuel cells.     

A Low-Protein,High-Carbohydrate Diet Stimulates Thermogenesis in the Brown Adipose Tissue of Rats via ATF-2

The aim of this study was to evaluate thermogenesis in the interscapular brown adipose tissue (IBAT) of rats submitted to low‐protein, high‐carbohydrate (LPHC) diet and the involvement of adrenergic stimulation in this process. Male rats (~100 g) were submitted to LPHC (6 %‐protein; 74 %‐carbohydrate) or control (C; 17 %‐protein; 63 %‐carbohydrate) isocaloric diets for 15 days. The IBAT temperature was evaluated in the rats before and after the administration of noradrenaline (NA) (20 µg 100 g b w^?1 min^?1). The expression levels of uncoupling protein 1 (UCP1) and other proteins involved in the regulation of UCP1 expression were determined by Western blot (Student's t test, P ≤ 0.05). The LPHC diet promoted a 1.1 °C increase in the basal temperature of IBAT when compared with the basal temperature in the IBAT of the C group. NA administration promoted a 0.3 °C increase in basal temperature in the IBAT of the C rats and a 0.5 °C increase in the IBAT of the LPHC group. The level of UCP1 increased 60 % in the IBAT of LPHC‐fed rats, and among the proteins involved in its expression, such as β3‐AR and α1‐AR, there was a 40 % increase in the levels of p38‐MAPK and a 30 % decrease in CREB when compared to the C rats. The higher sympathetic flux to IBAT, which is a consequence of the administration of the LPHC diet to rats, activates thermogenesis and increases the expression of UCP1 in the tissue. Our results suggest that the increase in UCP1 content may occur via p38 MAPK and ATF2.     

Using Proteomics to Understand How Leishmania Parasites Survive inside the Host and Establish Infection

Leishmania is a protozoan parasite that causes a wide range of different clinical manifestations in mammalian hosts. It is a major public health risk on different continents and represents one of the most important neglected diseases. Due to the high toxicity of the drugs currently used, and in the light of increasing drug resistance, there is a critical need to develop new drugs and vaccines to control Leishmania infection. Over the past few years, proteomics has become an important tool to understand the underlying biology of Leishmania parasites and host interaction. The large-scale study of proteins, both in parasites and within the host in response to infection, can accelerate the discovery of new therapeutic targets. By studying the proteomes of host cells and tissues infected with Leishmania, as well as changes in protein profiles among promastigotes and amastigotes, scientists hope to better understand the biology involved in the parasite survival and the host-parasite interaction. This review demonstrates the feasibility of proteomics as an approach to identify new proteins involved in Leishmania differentiation and intracellular survival.     

Development of a cloud-point extraction method for copper and nickel determination in food samples

A new, simple and versatile cloud-point extraction (CPE) methodology has been developed for the separation and preconcentration of copper and nickel. The metals in the initial aqueous solution were complexed with 2-(2'-benzothiazolylazo)-5-(N,N-diethyl)aminophenol (BDAP) and Triton X-114 was added as surfactant. Dilution of the surfactant-rich phase with acidified methanol was performed after phase separation, and the copper and nickel contents were measured by flame atomic absorption spectrometry. The variables affecting the cloud-point extraction were optimized using a Box-Behnken design. Under the optimum experimental conditions, enrichment factors of 29 and 25 were achieved for copper and nickel, respectively. The accuracy of the method was evaluated and confirmed by analysis of the followings certified reference materials: Apple Leaves, Spinach Leaves and Tomato Leaves. The limits of detection expressed to solid sample analysis were 0.1 microg g(-1) (Cu) and 0.4 microg g(-1) (Ni). The precision for 10 replicate measurements of 75 microg L(-1) Cu or Ni was 6.4 and 1.0, respectively. The method has been successfully applied to the analysis of food samples.