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A cerveja e uma das bebidas alcoolicas mais antigas consumidas pela humanidade, tendo sido descoberta ha cerca de 7.000 anos. A bebida e composta por quatro ingredientes essenciais: agua, malte, lupulo e levedura. Quando consumida em quantidades moderadas, a cerveja pode trazer beneficios a saude semelhantes aos do vinho. Apesar da grande importância economica, cultural e cientifica que a cerveja possui, percebe-se a escassez de uma literatura em portugues voltada ao tema. Neste sentido, o presente trabalho tem como objetivo reunir informacoes presentes na literatura cientifica, apresentando os aspectos quimicos envolvidos na producao cervejeira, as tecnicas analiticas empregadas na caracterizacao da bebida, autenticacao e controle dos processos produtivos, assim como a atividade biologica que a cerveja possui. Dessa forma, na producao de cerveja sao observadas 5 etapas basicas, como a mostura, fervura, fermentacao, maturacao e envase, sendo avaliados na etapa final de producao o pH, acidez total, amargor, cor e teor alcoolico. Na identificacao dos compostos da cerveja, bem como na autenticacao e controle dos processos produtivos, as tecnicas analiticas utilizadas sao a espectroscopia na regiao do infravermelho (IV), ressonância magnetica nuclear de hidrogenio (RMN 1H), espectrometria de massas (MS) e cromatografia gasosa acoplada ao espectrometro de massas (CG-MS). Alem disso, estudos sobre as atividades biologicas de compostos presentes na cerveja revelam um potencial antioxidante, anti-inflamatorio, antimicrobiana, antitumoral, entre outros, ressaltando que o consumo moderado da bebida pode trazer beneficios na saude dos consumidores

COMPARING THE PERFORMANCE OF TWO MASS ANALYZERS (FT-ICR MS & LTQ MS): AN EXPERIMENTAL CLASS ON ANALYSIS OF ORGANIC COMPOUNDS. Mass spectrometry (MS) is a high-performance analytical technique that allows a measurement of the mass/charge (m/z) ratio of compounds present in a sample. MS is able to separate two m/z ions with determined values (mass resolution), being an important characteristic, especially in the analysis of biochemical components and complex mixtures. Mass analyzers define the resolving power and accuracy of different types of mass spectrometers. Herein, the performance of two mass analyzers (Fourier Transform Ion Cyclotronic Resonance (FT-ICR) and quadrupole ion trap (LTQ)) was tested on low (Mw = 165-679 Da) and high (Mw = 783-8.58 kDa) molecular weight molecules (Phenacetin, Procaine, Benzocaine, Caffeine anhydrous, Lidocaine, two metal porphyrin standards, the first cobalt and the second vanadium, and two protein standards, Ubiquitin and Beauvericin), and finally, for an oil sample. LTQ-MS and FT-ICR-MS had similar performance and high reproducibility. However, the mass accuracy and resolution power of the FT-ICR (error lower than 5 ppm and RP higher than 400,000) was higher, being therefore, it was more suitable for the analysis of proteins and oil, for instance. On the other hand, the CID analysis via LTQ demonstrated its applicability in fragmentation experiments, being able to determinate the chemical connectivity of organic compounds in non-complex mixtures.

Brazilian oil production of pre-salt layer consists of oils with high content of saturated compounds. The identification of paraffinic and naphthenic compounds in these crude oils is key to understanding their rheological behavior. In the present study, comprehensive two-dimensional gas chromatography was performed to assess the greater separation capacity of products when compared with one-dimensional gas chromatography. Accordingly, it was possible to estimate relative the various classes existing in the saturated fraction of the crude oil. The results indicate that naphthenic compounds (53-77%) are more abundant than n-paraffins and iso-paraffins (22-46%) in nonpolar petroleum fractions from medium to low gravity, according American Petroleum Institute (API). Light oils showed high amount of iso-paraffins (37%), and the second most abundant class was the monocyclic compounds (30%). Crude oils with high pour point showed higher amount of heavy n-paraffins than oils with low pour point, suggesting a correlation between pour point and high molecular weight n-paraffins.

This paper describes pour point behavior of three heavy oils with the addition of kerosene, turpentine, toluene and gas condensate. The study showed a decrease in the pour point of all oils that relates with the oil chemical composition. The oil with lower API gravity (higher amount of asphaltenes and resins) showed higher pour point decay for all solvents, highlighting gas condensate and turpentine. The use of gas condensate to reduce the pour point of heavy oils is particularly advantageous, when available in the oilfield. Prevent the stoppage in the oil production, due to clogging and flow problems in the pipelines, and facilitate the logistics, reducing process operational costs

According to the relevant literature, the Diels-Alder reaction of furan without a catalyst can last several weeks and shows a low yield due to the diene's low reactivity. The use of Lewis acid catalysts or high pressures is described as an effective method for improving the reaction yields. This paper describes our recent study on the use of niobium pentachloride as the catalyst in Diels-Alder reactions between furan and several reactive dienophiles, among which methyl acrylate showed good yields, especially at lower temperatures. Other dienophiles have shown lower yields because of problems such as byproduct formation and the high reversibility of the reaction.