Coffee is one of the most popular and consumed products in the world, with high nutritional value and economic importance. However, some factors can change the organoleptic properties of a coffee species, without causing significant damage such as loss of important components. The present study evaluated the chemical profile, via nuclear magnetic resonance (NMR), of the main biological properties and substances of the drink, verifying similarities in the composition of different types of arabica coffee made in different conditions, such as the roasting time and temperature. The main components were identified, using information from the literature and a database, and compared with the experimental data of 1D and 2D 1H NMR. The spectral data were analyzed and grouped via principal component analysis (PCA) using the Bruker Amix 3.9.14 software. 1H NMR was able to monitor the roasting process and qualify the intact bean and chemical profile of the coffee according to the roasting conditions. Due to the importance of the monitored components, the coffee species analyzed can be identified, along with the appearance of unwanted or adulterating compounds that are normally added to the product to reduce the cost of commercialization.
Several published studies have evaluated the problems associated with the utilization of biodiesel obtained from safflower (Carthamus tinctorius L.) oil due to the low oxidative stability, caused by the high content of unsaturated fatty acids. Thus, this study aimed at the extraction of safflower seed oil and its use as an unsaturation source to obtain a synthetic antioxidant. The synthesis of this phenolic additive was done by modifying its structure through the addition of hydroquinone to the unsaturation of the oil, by electrophilic substitution. It was investigated and confirmed that this reaction is promising for obtaining phenolic products, with high yields (83.5%). The product obtained in this research was evaluated as an antioxidant in commercial biodiesel by the Rancimat method, using 5000 ppm of the synthesized additive the induction period increased from 8 to 17 h (2.12 times). Therefore, this paper brought a positive response to the improvement of biodiesel oxidation stability that creates a possibility to increase the use and expansion of this fuel in the market, as utilization of the safflower seed as raw material for additives, bringing a new market for these seeds.
Despite the efforts of the pharmaceutical industry to reduce the ethanol content in medicines, many of these products are still commercially available. These medicines must be monitored by quality control techniques using accurate method. Therefore, this study proposes to develop and validate an analytical method for ethanol quantification in adult and pediatric syrups, in order to guarantee the safety of medication certificates. For this, headspace multidimensional gas chromatography (heart-cut) coupled to mass spectrometry (HS-MDGC/MS) was used. The method was validated according to the norm established by National Agency of Sanitary Surveillance (ANVISA) presenting limit of detection (LOD) of 0.03% (v/v) and limit of quantification (LOQ) of 0.06% (v/v) ethanol, excellent selectivity and the recovery values (accuracy) were between 96.71 and 101.38%. Ethanol concentrations in commercial medicines syrups varied from 0.06 to 8.83%, which makes evident the need to control the syrup producing industries.
During biodiesel storage, chemical reactions may occur, producing sludges. The aim of this study was to characterize the chemical and microbial composition of the sludge found in a biodiesel storage tank. The material was collected in a biodiesel production plant. The sludge chemical characterization was performed by Fourier transform infrared (FTIR) spectroscopy, flame atomic absorption spectroscopy (FAAS), gas chromatography (GC), and the microbial investigation used culture-dependent techniques. The deteriogenic potential of the native microbial community was evaluated using the sludge as a microbial inoculum in a 60 day experiment. The microbial growth, biodiesel degradation, pH alterations, and the detection of esters in the aqueous phase were evaluated. The chemical analysis indicated the sludge composition as fatty acids esters and metallic ions; sterols glycosides were not detected. Seven bacteria and five fungi species were obtained from the sludge. The microbial growth analysis indicated that the native community does not have high biodiesel deteriogenic capacity.
Considering the high interest and commercial value of pigments from microalgae, this study aimed to stablish the best lutein and β-carotene extraction method for Desmodesmus sp., a microalgae with high biomass production. The evaluation was done considering the best solvent or solvent mixture, number of extractions, pre-treatment of dry biomass with acetone, saponification in methanol and ethanol and stability evaluation of the obtained extract. Among achieved results, the best solvent extractor was a hexane:ethanol mixture in a 1:1 (v/v) proportion. In order to obtain maximum yield, the pattern stablished includes six extractions performed for 40 minutes. Stability tests presented that xanthophylls and carotenes pigments were more stable in methanol and that xanthophylls and carotenes pigments were less negatively affected than chlorophylls in the methanolic extract. Chromatographic identification and quantification of pigments from Desmodesmus sp. microalgae revealed that its major constituents are trans-zeaxanthin, chlorophyll b, β-carotene and trans-lutein.
In this study, we developed a method for the visual detection of biodiesel in petrodiesel-biodiesel (BX) blends through the aminolysis of the methyl or ethyl esters of fatty acids that are found in biodiesel and that are absent from diesel and vegetable oils. This method is based on three reactional stages, which produce a dark red and easily visualized complex in the presence of biodiesel. In the absence of biodiesel, there is no dark red coloring, whereas in the presence of diesel or vegetable oil, there is a light red to yellow coloring. This simple, practical, inexpensive, and effective procedure may be applied by petrol stations to guarantee to consumers and resellers the presence of biodiesel in diesel blends, regardless of the BX blend's initial coloring or of the sulfur found in the diesel. In short, it ensures a safe fuel tank fill-up with BX blend.
In this study, the percentage content of free steroid in oils, fats and biodiesel was analyzed. For this, the saponification reaction on a microscale was used, and this procedure for extraction of unsaponifiable fraction was studied in several experimental steps. After the process of saponification, the unsaponifiable fraction was analyzed by gas chromatography with flame ionization detector, where all steroids present in each oil, fat and biodiesel were identified and their contents determined and compared to their respective biodiesel. A reduction in unsaponifiable fraction of each oil and fat and its biodiesel was noted, as well as a reduction in the content of free steroids. The results showed that, compared to the sedimentation problem of steroids in biodiesel, some raw materials, such as chicken fat and babassu oil may be promising because they have low content and high reduction percentages of steroids when converted to biodiesel.
The study of free steroids and their use in oil characterization is interesting because the distribution of these steroids varies from one oil to another. Although several papers analyze the most abundant steroids in oils, studies including less common steroids are scarce. Free steroids were extracted from unsaponifiable fraction using the saponification reaction adapted micro-scale. After extraction, steroids were characterized by gas chromatography (GC) using flame ionization (FID) and mass spectrometry (MS) detectors. All chromatographic peaks in the oils that could belong to free steroids were characterized and quantified. Results evidenced great diversity in types and levels of free steroids. Corn and moringa oils had higher levels of steroids than the other oils analyzed. Babassu, palm kernel and canola oils had the lowest steroid levels.
O estudo sobre os esteróides livres e sua utilização na caracterização de óleos é interessante já que sua distribuição é diferente para cada óleo. Embora vários trabalhos mostrem a análise desses esteróides em óleos, um trabalho mais abrangente mostrando a presença de esteróides menos abundantes ainda é limitado. Os esteróides foram extraídos a partir da matéria insaponificável usando reação de saponificação em microescala. Após a extração os esteróides foram caracterizados por cromatografia gasosa (GC) utilizando os detectores por ionização de chama (FID) e espectrometria de massas (MS). Todos os picos cromatográficos presentes nos óleos que poderiam ser de esteróides livres foram caracterizados e quantificados. Os resultados evidenciaram grande diversidade de tipos e teores de esteróides livres. Os óleos de milho e moringa apresentaram maiores teores de esteróides em relação aos outros óleos analisados. Os óleos de babaçu, palmiste e canola foram os que apresentaram os menores teores.
Parameters that influence the efficiency of the degradation of glyphosate (addition of Fe2+, simultaneous addition of Fe2+ and Fe3+ at a 1:1 (Fe2+/Fe3+) molar ratio, addition of oxalate and of H2O2) were evaluated at lab-scale. Synergic effects on its degradation and release of phosphate were observed using Fe2+/Fe3+, as well as adding oxalate. On the other hand, the concentration increase of Fe2+/Fe3+, oxalate and H2O2 did not promote a linear increase of glyphosate mineralization and release of phosphate. Using high concentrations of these species, the efficiency of glyphosate mineralization and release of phosphate was constant or even decreased. Under optimized conditions (0.27 mmol L-1 of Fe2+/Fe3+; 1.13 mmol L-1 of oxalate and 10.3 mmol L-1 of H2O2), close results for mineralization and release of phosphate were obtained in lab-scale and using a solar pilot plant. A direct ratio between reducing the toxicity and glyphosate concentration was also observed.
Parâmetros que influenciam a eficiência da degradação do glifosato (adição única de Fe2+, adição simultânea de Fe2+ e Fe3+ numa razão molar de 1:1 (Fe2+/Fe3+), adição de íons oxalato e de H2O2) foram avaliados em escala de laboratório. Efeitos sinérgicos sobre a degradação e formação de fosfato foram observados utilizando a adição simultânea de Fe2+/Fe3+, bem como adicionando oxalato. Por outro lado, aumentos nas concentrações de Fe2+/Fe3+, oxalato e H2O2 não proporcionaram incremento linear da mineralização de glifosato e liberação de fosfato. Utilizando concentrações elevadas dessas espécies, a eficiência de mineralização de glifosato e de liberação de fosfato foi constante ou até mesmo reduzida. Sob condições otimizadas (0,27 mmol L-1 de Fe2+/Fe3+; 1,13 mmol L-1 de oxalato e 10,3 mmol L-1 de H2O2), os resultados obtidos em escala laboratorial e de planta piloto solar foram próximos. Uma relação direta entre a redução da toxicidade e concentração de glifosato também foi observada.