Carlos Alexandre Galinaro

Teores de carbamato de etila em aguardentes de cana e mandioca: parte II

Herein, we report the concentration of ethyl carbamate (EC) and copper in 380 samples of sugar-cane spirit and 45 samples of manioc spirit as determined by GC-MS and FAAS respectively. The cyanide content determined spectrophotometrically is reported for the manioc spirit. Sugar cane spirit produced by alembic distillation (70,0 µg L-1) shown a lower content of EC than samples produced by column distillation (270 µg L-1). No simple correlation between the content of EC and copper for sugar cane spirit as well among the concentration of EC, copper, and cyanide for manioc spirit could be observed.

Formação de carbamato de etila em aguardentes recém-destiladas: proposta para seu controle

The commercial sugar cane spits redistillation decreased up to 92,5% their ethyl carbamate (EC) original content. Quantitative analysis of EC in 15 samples of sugar cane spirit (alembic and column), fresh distilled and collected in situ demonstrated that the urethane is formed mostly after distillation. The average time to achieve the complete EC formation is independent of the diffuse light presence and of the distillation apparatus used. The kobs for urethane formation at 25 oC was calculate as (3,3 ± 0,5) x 10-5/s and the activation parameters are: ΔH‡ 34 kcal/mol; ΔS‡ - 69 cal/mol K; and ΔG‡ 54 kcal/mol.

Avaliação sensorial de cachaça

The hedonic level of commercial cachacas, was evaluated by consumers and by a tasters. The results of sensorial methods analyzed trough Principal Components Analysis, Hierarchical Cluster Analysis and the Pearson linear correlation indicated that the best classified cachacas were produced in copper stills and aged in oak casks. By contrast the worst classified exhibited as the main features be not aged and high alcohol percentage. The index of preference is positively correlated with the intensity of yellow color, wood flavor, sweetness and fruit aroma. There is a negative preference correlation with the acidity, the taste of alcohol and bitterness.

Determination of Parabens in Surface Water from Mogi Guaçu River (São Paulo, Brazil) Using Dispersive Liquid-Liquid Microextraction Based on Low Density Solvent and LC-DAD

A method using dispersive liquid-liquid microextraction (DLLME) based on low density solvent (LDS) combined with liquid chromatography with diode array detection (LC-DAD) has been developed for determination of parabens. Some DLLME parameters such as kind and volumes of extraction and disperser solvents, pH of the aqueous samples, ionic strength, extraction, centrifugation and speed time, were investigated. The method exhibits good linearity (0.9990 to 0.9993), limits of detection (0.5-0.8 µg L-1), and limits of quantification (1.3-2.4 µg L-1). In optimum conditions, enrichment factors and recoveries of studied parabens obtained were 38.9 to 88.4% and 30.3 to 68.0%, respectively. Surface water samples collected from Mogi Guacu River (Sao Paulo state, Brazil) were analyzed, showing average contents of methyl-, ethyl-, propyl-, and n-butylparaben of 8.0, 5.8, 13.1 and 15.1 µg L-1, respectively. This is the first study on parabens in a Brazilian River, in a long stretch of river (ca. 300 km of extension).

Comparação do perfil químico entre cachaças de um mesmo vinho destiladas em alambiques e em colunas

Six wines were distilled in two different distillation apparatus (alembic and column) producing 24 distillates (6 for each alembic fraction - head, heart and tail; 6 column distillates). The chemical composition of distillates from the same wine was determined using chromatographic techniques. Analytical data were subjected to Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) allowing discrimination of four clusters according to chemical profiles. Both distillation processes influenced the sugarcane spirits chemical quality since two types of distillates with different quantitative chemical profiles were produced after the elimination of fermentation step influence.

Hidrocarbonetos policíclicos aromáticos (HPAS) em cachaça, rum, uísque e álcool combustível

The concentration of 15 polycyclic aromatic hydrocarbons (PAHs) in 57 samples of distillates (cachaca, rum, whiskey, and alcohol fuel) has been determined by HPLC-Fluorescence detection. The quantitative analytical profile of PAHs treated by Partial Least Square - Discriminant Analysis (PLS-DA) provided a good classification of the studied spirits based on their PAHs content. Additionally, the classification of the sugar cane derivatives according to the harvest practice was obtained treating the analytical data by Linear Discriminant Analysis (LDA), using naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benz[a]anthracene, benz[b]fluoranthene, and benz[g,h,i]perylene, as a chemical descriptors.

Cyanate as an Active Precursor of Ethyl Carbamate Formation in Sugar Cane Spirit.

The thermodynamic and kinetic aspects of ethyl carbamate (EC) formation through the reaction between cyanate and ethanol were investigated. The rate constant values for cyanate ion decay and EC formation are (8.0 ± 0.4) × 10(-5) and (8.9 ± 0.4) × 10(-5) s(-1), respectively, at 25 °C in 48% aqueous ethanolic solution at pH 4.5. Under the investigated experimental conditions, the rate constants are independent of the ethanol and cyanate concentrations but increase as the temperature increases (ΔH1(⧧) = 19.4 ± 1 kcal/mol, ΔS1(⧧) = −12.1 ± 1 cal/K, and ΔG1(⧧) = 23.0 ± 1 kcal/mol) and decrease as the solution pH increases. According to molecular modeling (DFT) that was performed to analyze the reaction mechanism, the isocyanic acid (HNCO) is the active EC precursor. The calculated ΔG1(⧧), ΔH1(⧧), and ΔS1(⧧) values are in very good agreement with the experimental ones.

Correlation between chemical composition and sensory properties of Brazilian sugarcane spirits (cachaças)

The correlation between the chemical composition and the sensory data for 28 cachaca samples was investigated using principal component analysis (PCA). A chemical model was then developed using linear discriminant analysis (LDA) to classify the distillate samples according to their sensory qualities. This model presented predictive abilities of calibration and validation of 87.4 and 100%, respectively, and was able to recognize correctly 7 out of 9 additional samples according to their sensory evaluations, showing itself as a potential alternative tool of recognizing cachaca sensory qualities.

Ecotoxicological effects of bisphenol A and nonylphenol on the freshwater cladocerans Ceriodaphnia silvestrii and Daphnia similis

Abstract Toxicities of bisphenol A (BPA) and nonylphenol (NP) to the neotropical freshwater cladocerans Ceriodaphnia silvestrii and Daphnia similis were studied under laboratory conditions. Acute exposures to BPA generated mean 48-h EC50 values of 14.44 (6.02–22.85) mg L−1 for C. silvestrii and 12.05 (1.73–22.37) mg L−1 for D. similis. When the organisms were exposed to acute doses of NP, mean 48-h EC50 values were 0.055 (0.047–0.064) mg L−1 (C. silvestrii) and 0.133 (0.067–0.200) mg L−1 (D. similis). Ceriodaphnia silvestrii was also tested in chronic bioassays, which resulted in mean 8-d IC25 values of 2.43 (2.16–2.69) mg L−1 BPA [no observed effect concentration (NOEC): 1.38 mg L−1] and 0.020 (0.015–0.026) mg L−1 NP (NOEC: 0.015 mg L−1). These laboratory tests are valuable to broaden the understanding of the environmental threat posed by BPA and NP in aquatic ecosystems, and to increase the knowledge about the sensitivity of neotropical indigenous species to these contaminants. In addition to the laboratory bioassays, species sensitivity distributions were used to suggest protective concentrations of BPA and NP to prevent adverse effects on freshwater organisms. According to the obtained results, concentrations lower than 36.47 µg L−1 BPA and 1.39 µg L−1 NP are not expected to adversely impact aquatic organisms in natural ecosystems.

Photolysis of parabens using medium-pressure mercury lamps: Toxicity effects in MCF7, Balb/c 3T3 cells and Ceriodaphnia dubia

Degradation studies of the propylparaben (PrP), butylparaben (BuP) and of the propylparaben-butylparaben mixture (PrP-BuP) in deionized water and surface river water was investigated as a function of pH and initial concentration of the reactants using a medium-pressure mercury lamp. The photolysis of parabens (concentration ranging from 5 to 30 mg L-1) followed apparent pseudo-first-order kinetics, with rate constants (k) in deionized water and surface river water changed from 1.80 × 10-1 to 3.68 × 10-2 min-1 and 1.43 × 10-1 to 1.45 × 10-2 min-1, respectively. Degradation reaction was faster at pH 5 in comparison with pH 7 or 11. The photolysis of parabens was greater than 91%, with low mineralization (26.15%) observed in acidic medium after 95 min. Analysis by chromatography coupled to mass spectrometry (LC-MS/MS) showed that only one product was generated during the degradation reaction and has UV bands similar to 3,4-dihydroxybenzoic acid. Estrogenic activity tests showed that non-degraded parabens stimulated the growth of breast adenocarcinoma (MCF-7) cells and this effect was evaluated after the photolysis. Cytotoxicity assays using fibroblasts cells (Balb/C 3T3 clone A31) indicated that the parental compounds and degradation products were not cytotoxic. On the contrary, non-degraded parabens were toxic to Ceriodaphnia dubia, but the product of photolysis was not. Overall, the photolytic method presented was able to degrade these parabens providing safe and non-estrogenic reaction product.