Sensory evaluation of black instant coffee beverage with some volatile compounds present in aromatic oil from roasted coffee

The oil obtained from Brazilian roasted coffee by supercritical CO2 extraction shows considerable aromatic properties, mainly composed by five aromatic compounds, 2-methylpyrazine; 2-furfurylalcohol, 2,5-dimethylpyrazine; γ-butyrolactone and 2-furfurylacetate. Sensory analyses were used to verify the influence of a mixture of these important classes of aromatic coffee compounds (pyrazines, furans and lactones) and of the roasted coffee aromatic oil on the coffee aroma and flavour of black instant freeze and spray-dried coffee beverages. In the acceptance evaluation of the aroma, the samples prepared with freeze-dried instant coffee without the mixture of volatile compounds (sample 4) were not significantly different from the freeze-dried instant coffee in which the aromatic coffee oil was added (sample 5) and from the sample prepared with freeze-dried coffee in which the mixture of the five volatile was added (sample 3), coincidentally from the same drying process. Therefore, sample (3) did not differ from samples prepared with spray dried instant coffee without (sample 1) and to which (sample 2) the mixture of volatile was added. Therefore, with respect to this attribute, the addition of this mixture did not interfere in this drink acceptance. Taking into consideration the flavor, samples prepared with freeze-dried instant coffee in which the aromatic coffee oil was added (5) and the samples with (3) and without (4) the mixture of the five volatile was added did not differ significantly, however sample (4) did not differ from samples (1) and (2). Regarding this attribute, the addition of the aromatic oil of roasted coffee or a mixture of volatile in samples of freeze-dried instant coffee had a better acceptance than those dried by spray dryer (1) and (2). Thus, the enrichment of drinks with the aromatic oil of roasted coffee, or even with the mixture of the five components did not influence the consumer acceptance with respect to the aroma, but exerts influence with respect to flavour.

Operant measurement of auditory threshold in prelingually deaf users of cochlear implants: II

Two experiments evaluated an operant procedure for establishing stimulus control using auditory and electrical stimuli as a baseline for measuring the electrical current threshold of electrodes implanted in the cochlea. Twenty-one prelingually deaf children, users of cochlear implants, learned a Go/No Go auditory discrimination task (i.e., pressing a button in the presence of the stimulus but not in its absence). When the simple discrimination baseline became stable, the electrical current was manipulated in descending and ascending series according to an adapted staircase method. Thresholds were determined for three electrodes, one in each location in the cochlea (basal, medial, and apical). Stimulus control was maintained within a certain range of decreasing electrical current but was eventually disrupted. Increasing the current recovered stimulus control, thus allowing the determination of a range of electrical currents that could be defined as the threshold. The present study demonstrated the feasibility of the operant procedure combined with a psychophysical method for threshold assessment, thus contributing to the routine fitting and maintenance of cochlear implants within the limitations of a hospital setting.

Dimensões dos arcos dentários na má oclusão Classe II, divisão 1, com deficiência mandibular

OBJETIVO: identificar alterações dimensionais nos arcos dentários superior e inferior na má oclusão Classe II, divisão 1, com deficiência mandibular (Padrão esquelético II). MÉTODOS: 48 pacientes com má oclusão Classe II, igualmente divididos quanto ao gênero, foram comparados com 51 indivíduos com oclusão normal, sendo 22 do gênero masculino e 29 do gênero feminino. Todos os 99 indivíduos estavam no estágio de dentadura permanente, com os segundos molares permanentes irrompidos ou em irrupção, com idade média de 12 anos e 5 meses (desvio-padrão de 1 ano e 3 meses), numa faixa etária oscilando entre 11 anos e 4 meses e 20 anos. CONCLUSÃO: os resultados permitem concluir que, na má oclusão Classe II, divisão 1 com deficiência mandibular, o arco dentário superior encontra-se alterado, mostrando-se atrésico e mais longo, enquanto o arco dentário inferior é pouco influenciado pela discrepância sagital de Classe II.

Ambiental volatile organic compounds in the megacity of São Paulo

In order to characterize the composition of the main urban air organic compounds in the megacity of Sao Paulo, analysis of samples collected during the winter of 2003 downtown was carried out. The samplings were performed on the roof of a building in the commercial center of São Paulo. Hydrocarbons and carbonyls compounds were collected on August 4, 5 and 6. Comparing to previous data, the concentration of hydrocarbons presented no decrease in the concentration, except for the aldehydes, which decreased when compared to previous data. Among the HCs species analyzed, the highest concentrations observed were those of toluene (7.5 ± 3.4 ppbv), n-decane (3.2 ± 2.0 ppbv), benzene (2.7 ± 1.4 ppbv) and 1,3,5-trimethylbenzene (2.2 ± 1.5 ppbv).

Influência do treinamento físico aeróbio no transporte mitocondrial de ácidos graxos de cadeia longa no músculo esquelético: papel do complexo carnitina palmitoil transferase

O ácido graxo (AG) é uma importante fonte de energia para o músculo esquelético. Durante o exercício sua mobilização é aumentada para suprir as necessidades da musculatura ativa. Acredita-se que diversos pontos de regulação atuem no controle da oxidação dos AG, sendo o principal a atividade do complexo carnitina palmitoil transferase (CPT), entre os quais três componentes estão envolvidos: a CPT I, a CPT II e carnitina acilcarnitina translocase. A função da CPT I durante o exercício físico é controlar a entrada de AG para o interior da mitocôndria, para posterior oxidação do AG e produção de energia. Em resposta ao treinamento físico há um aumento na atividade e expressão da CPT I no músculo esquelético. Devido sua grande importância no metabolismo de lipídios, os mecanismos que controlam sua atividade e sua expressão gênica são revisados no presente estudo. Reguladores da expressão gênica de proteínas envolvidas no metabolismo de lipídios no músculo esquelético, os receptores ativados por proliferadores de peroxissomas (PPAR) alfa e beta, são discutidos com um enfoque na resposta ao treinamento físico.

Pulsar binary systems in a nonsymmetric theory of gravitation II. Dipole radiation

This paper deals with the emission of gravitational radiation in the context of a previously studied metric nonsymmetric theory of gravitation. The part coming from the symmetric part of the metric coincides with the mass quadrupole moment result of general relativity. The one associated to the antisymmetric part of the metric involves the dipole moment of the fermionic charge of the system. The results are applied to binary star systems and the decrease of the period of the elliptical motion is calculated.

Estudo do comportamento eletroquímico de substâncias complexantes utilizando eletrodo de cobre

Copper electrode can be used for determination of complexing compounds through complexation reactions between Cu(II) and the analites. In this work some studies with three compounds were performed: glycine (precursor of glyphosate synthesis), herbicide glyphosate and aminomethylphosphonic acid (main metabolite of glyphosate). These compounds are complexing agents for Cu electrodes. Through simple experiments (cyclic voltammetry and corrosion studies) the applicability of the copper electrode as electrochemical sensor for complexing compounds in flow systems was presented.

The UV/H2O2 - photodegradation of poly(ethyleneglycol) and model compounds

The general mechanism for the photodegradation of polyethyleneglycol (PEG) by H2O2/UV was determined studying the photooxidation of small model molecules, like low molecular weight ethyleneglycols (tetra-, tri-, di-, and ethyleneglycol). After 30 min of irradiation the average molar mass (Mw) of the degradated PEG, analysed by GPC, fall to half of its initial value, with a concomitant increase in polydispersitivity and number of average chain scission (S), characterizing a random chain scission process yielding oligomers and smaller size ethyleneglycols. HPLC analysis of the photodegradation of the model ethyleneglycols proved that the oxidation mechanism involved consecutive reactions, where the larger ethyleneglycols gave rise, successively, to smaller ones. The photodegradation of ethyleneglycol lead to the formation of low molecular weight carboxylic acids, like glycolic, oxalic and formic acids.

Preparação de membranas de acetato de celulose organomodificadas para adsorção dos íons Cu(II), Cd(II), Mn(II) e Ni(II)

Cellulose acetate polymeric membranes had been prepared by a procedure of two steps, combining the method of phase inversion and the technique of hydrolysis-deposition. The first step was the preparation of the membrane, and together was organomodified with tetraethylortosilicate and 3-aminopropyltrietoxysilane. Parameters that exert influence in the complexation of the metallic ion, as pH, time of complexation, metal concentration, had been studied in laboratory using tests of metal removal. The membranes had presented resistance mechanics and reactivity to cations, being able to be an alternative for the removal, daily pay-concentration or in the study of the lability of metals complexed.

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.

Efficient synthesis of benzothiazine and acrylamide compounds

This article describes the synthesis of the new (2Z)-2-(4-methoxybenzylidene)-6-nitro-4H -benzo[1,4]thiazin-3-one, (2Z)-2-(4-methoxybenzylidene)-4-methyl-6-nitro-4H-benzo[1,4]thiazin-3-one, (2Z)-6-amino-2-(4-methoxybenzylidene)-4H -benzo[1,4]thiazin-3-one, (2Z)-6-butylamino-2-(4-methoxybenzylidene)-4-methyl-4H-benzo[1,4]-thiazin-3-one and (2E)-N-alkyl-N-(2-hydroxy-5-nitrophenyl)-3-phenylacrylamides and the spectroscopic data. The arylidenebenzothiazine compounds were prepared using the Knoevenagel condensation with substituted benzaldehydes in the presence of sodium methoxide in DMF. The presence of a nitro substituent in the 4-position, water and a slightly acid reaction medium in this condensation caused the rupture of the benzothiazine ring and subsequent formation of the phenylacrylamide compounds. A crystallographic data was presented for (2E)-3-(4-bromophenyl)-N-dodecyl-N -(2-hydroxy-5-nitrophenyl) acrylamide.

Development of a flow through photo-reactor to study degradation of organic compounds by Sequential Injection Analysis (SIA)

This work describes a photo-reactor to perform in line degradation of organic compounds by photo-Fenton reaction using Sequential Injection Analysis (SIA) system. A copper phthalocyanine-3,4',4²,4²¢-tetrasulfonic acid tetrasodium salt dye solution was used as a model compound for the phthalocyanine family, whose pigments have a large use in automotive coatings industry. Based on preliminary tests, 97% of color removal was obtained from a solution containing 20 µmol L-1 of this dye.

Oxidative DNA damage induced by S(IV) in the presence of Cu(II) and Cu(I) complexes

The DNA damage induced by S(IV) in the presence of some Cu(II) complexes in air saturated solution was investigated. The addition of S(IV) to an air saturated solution containing CuII GGA (GGA = glycylglycyl-L-alanine), CuII G3 (G3 = triglycine) or CuII G4 (G4 = tetraglycine) and Ni(II) traces, causes rapid formation of the respective Cu(III) complex, with simultaneous O2 uptake and S(IV) oxidation. SO3•- and HO• were detected by EPR-spin trapping experiments. The DNA strand breaks were attributed to the oxysulfur radicals formed. In the reduction of Cu(II)/BCA (BCA = 4,4' dicarboxy-2-2'-biquinoline) by S(IV), with CuI BCA complex formation, there is the possible formation of carbon centered radical of BCA or peroxyl radical (ROO•) capable of oxidizing DNA bases. The intensity of DNA damage in the presence of these Cu(II) complexes and S(IV) (10-300 µmol L-1) followed the order: CuII BCA ∼ CuII G4 ∼ Cu(II) (added as Cu(NO3)2) > CuII G3 ∼ CuII GGA. Specifically for CuII BCA the damage occurred even at lower S(IV) concentration (0.1 µmol L-1). For the Cu(II) complexes with glycylglycylhistidine, glycylhistidylglycine, glycylhistidyllysine and glycylglycyltyrosylarginine the Cu(III) formation and the DNA damage was not observed.