The actual and potential aroma of winemaking grapes

This review intends to rationalize the knowledge related to the aroma of grapes and to the aroma of wine with specific origin in molecules formed in grapes. The actual flavor of grapes is formed by the few free aroma molecules already found in the pulp and in the skin, plus by those aroma molecules quickly formed by enzymatic/catalytic reactions. The review covers key aroma components of aromatic grapes, raisins and raisinized grapes, and the aroma components responsible from green and vegetal notes. This knowledge is used to explain the flavor properties of neutral grapes. The aroma potential of grape is the consequence of five different systems/pools of specific aroma precursors that during fermentation and/or aging, release wine varietal aroma. In total, 27 relevant wine aroma compounds can be considered that proceed from grape specific precursors. Some of them are immediately formed during fermentation, while some others require long aging time to accumulate. Precursors are glycosides, glutathionyl and cysteinyl conjugates, and other non-volatile molecules

A cartografia escolar e o desenvolvimento da habilidade espacial

The map is, for excellence, a visual representation of geography space. As a language, the use of maps requires more than learning the signs and how to arrange the objects on them, but depends on a skill in the context of spatial intelligence. The present paper has as purpose to reflect upon the spatial ability in geography teaching and aims to extend knowledge of teachers in their use of cartography, as well as their ability for visualization of extensions, fluxes and intensities of the different geographical phenomena and facts, and so contribute to improve studies of high school geography.A representação visual do espaço geográfico é, por excelência, o mapa. Como linguagem, sua utilização requer mais do que o aprendizado dos signos e do como dispor os objetos em uma carta, mas de um aprendizado desenvolvido no âmbito da habilidade espacial. O presente texto tem como propósito refletir sobre o desenvolvimento desta habilidade para o aprendizado da Geografia, e se orienta para os conhecimentos cartográficos dos professores em suas capacidades para visualizar as extensões, fluxos e intensidades dos distintos fenômenos e fatos geográficos. Pretende-se colaborar para um melhor encaminhamento dos estudos de Geografia no ensino médio

New Analytical Methods for teh Study of Wine Aroma. Applications to the Characterizaton of the Headspace Evoluction an Ultra-trace Analysis

Uno de los principales desafíos en la Química del vino es contestar a la pregunta de si la percepción sensorial del mismo puede se explicada o incluso predicha mediante la determinación de su composición química. Aunque conocer la composición en volátiles de la fase líquida del vino es imprescindible, no es suficiente para explicar las notas aromáticas más relacionadas con el espacio decabeza que se encuentra sobre el vino. Está claro que interpretar el papel jugado por los estímulos aromáticos en la percepción global debe implicar otros aspectos, tales como la integración de los procesos perceptuales, los cambios asociados a la liberación de los volátiles y sus modificaciones temporales. Otro aspecto importante es que algunos odorantes impacto pueden dominar el perfil aromático de una variedad de vino particular, incluso encontrándose en niveles de ultratraza requiriendo, por tanto, estrategias de análisis cuantitativo más sensibles. La presente tesis ha caracterizado la liberación de compuestos volátiles y su evolución en el espacio de cabeza de diferentes vinos y también ha investigado el análisis de alquilmetoxipirazinas en vino a niveles ultratraza mediante la aplicación de nuevas metodologías analíticas.Con la consideración de estudiar la composición del espacio de cabeza del vino en condiciones de no-equilibrio, más cercanas a una cata real del vino, en el Capítulo 1 se ha desarrollado un método de análisis basado en la automatización del espacio de cabeza dinámico (DHS) combinado con desorción térmica (TD) y cromatografía gas con detección espectrométrica (GC-MS). Gracias a esta estrategia rápida y dinámica de muestreo, el método proporciona una “instantánea” de la composición de los vapores emanados del vino, ya que permite conocer la concentración de hasta 40 compuestos aromáticos, incluyendo el metanotiol, el dióxido de azufre, los alcoholes de fusel o los fenoles volátiles.En el Capítulo 2, el método DHS validado anteriormente se ha aplicado para evaluar los cambios en los espacios de cabeza del vino y sus cambios temporales, monitorizando los niveles de 34 odorantes emitidos al espacio de cabeza desde 4 vinos diferentes durante 5 puntos en el tiempo. Se han encontrado tres tipos de patrones en cuanto al comportamiento de la evolución de dichos aromas. Estos patrones corresponden a las características físico-químicas de los compuestos volátiles y a las interacciones con los componentes matriciales, lo que sugiere que la predicción del impacto aromático de estos componentes debería incluir una estimación de sus interacciones odorante-matriz en ese vino particular.El Capítulo 3 recoge la aplicación del método DHS, validado previamente, al estudio de las potenciales influencias de los parámetros físicos en la liberación de los compuestos volátiles desde el vino. Estos fenómenos que ocurren durante el periodo de cata incluyen la agitación, evaporación, oxidación y desgasificación. Además, las tendencias de evolución del espacio de cabeza en un vino tinto y otro blanco fueron estudiadas durante 30 min. Durante los experimentos, las características físico-químicas de los compuestos estudiados fueron la clave para explicar su comportamiento en la liberación al espacio de cabezaLos Capítulos 4 y 5 se dedican fundamentalmente al estudio del impacto de las potenciales interacciones compuesto volátil-matriz en el comportamiento de liberación de dichos compuestos, usando el método DHS para detectar los contenidos en un volátil determinado a diferentes tiempos de evaporación. El Capítulo 4 presenta los resultados de la reconstitución de 7 vinos modelo mediante la adición de una mezcla estándar de aromas a vinos desaromatizados con matrices muy diferenciadas. En el Capítulo 5 se aplica la misma estrategia pero al estudio de los cambios en el espacio de cabeza relacionados con la presencia de macromoléculas usadas frecuentemente como aditivos enológicos (diversos polisacáridos y polifenoles).El Capítulo 6 está dedicado al estudio exhaustivo de dos vinos de categoría Premium. En este caso, se combinaron tanto los datos analíticos de los componentes volátiles en fase líquida y fase gas, como los datos obtenidos de un estudio sensorial llevado a cabo por un panel de catadores, en ambos casos en diferentes puntos del proceso de cata. Los datos sensoriales en los diferentes momentos del consumo del vino se correlacionan con la correspondiente concentración en el espacio de cabeza de los compuestos volátiles que son relevantes para cada descriptor de aroma.Las alquilmetoxipirazinas son odorantes muy potentes de muchos alimentos y también en algunos vinos. Normalmente se encuentran presentes en dichos vinos en concentraciones extremadamente bajas. En el Capítulo 7, se desarrolla y valida un nuevo método para la identificación y cuantificación de 3-isopropil- 2-metoxipirazina, 3-sec-butil-2-metoxipirazina y 3-isobutil-2- metoxipirazina. De acuerdo con el método validad, los analitos se extraen de 5 mL de vino usando una barra de extracción SBSE seguido por una desorción térmica y una cromatografía gas multidimensional. El método es automatizable, respetuoso con el medioambiente y proporciona los mejores límites de detección para estos compuestos publicados hasta la fecha (en el rango de las ppq). El método se ha aplicado a la determinación de estos analitos en 111 vinos españoles y franceses elaborados con variedades de uva minoritarias.One of the main challenges in wine chemistry is to answer the question that whether flavor perception can be explained or even predicted by the determination of the chemical composition or not. Although knowing the general volatile composition in the liquid phase of wine is essential, it is not enough for explaining the aroma nuances that are more related to the headspace above the wine. It is clear that interpreting the role played by aroma stimuli in the overall perception needs to involve other aspects, such as the integration of the perceptual processes, the changes associated to the release of volatiles and their temporal modifications. Another important aspect is that some impact odorants can dominate the aroma profile of a particular variety of wine even at ultra-trace levels, requiring more sensitive quantitative strategies. The present thesis has investigated the characterization of the release of volatile compounds and their evolution in the headspace above wines and also has researched the quantitative analysis of ultra-trace alkylmethoxypyrazines in wines by developing new analytical methodologies. With the consideration to study the headspace composition of wine under non-equilibrium conditions that are more closely to the headspace of real wine tasting, an automated dynamic headspace (DHS) method combined with thermal desorption (TD) and gas chromatography-mass spectrometry (GC-MS) has been developed in Chapter 1. Thanks to this fast dynamic sampling strategy, the method could provide a snapshot of the contents in the wine vapors of up to 40 aroma compounds, including methanethiol, sulfur dioxide, aldehydes, fusel alcohols or volatile phenols. In Chapter 2, the validated DHS method has been applied to assess the changes in the wine headspaces with time, monitoring the levels of 34 odorants emitted to the headspace by 4 different wines during five consecutive time points. Three patterns of behavior within the evolution of the aromas were found. These patterns corresponded to the physicochemical characteristics of volatile compounds and the potential interactions with wine matrix components, which suggests that prediction of the aroma impact in these cases should include an estimation of the odorant-matrix interactions in wine. Chapter 3 presents the application of the validated DHS method to study the potential influences of physical parameters on the release of volatile compounds from wine, which occur during tasting period, including agitation, evaporation, oxidation and degasification that could occur during wine drinking. Furthermore, the trends of the headspace evolution of a red and a white wine were studied during a 30 min period. The physicochemical characteristics of the volatile compounds were crucial to explain their release behavior. Chapter 4 and Chapter 5 mainly studied the impact of the potential volatile-matrix interactions on the release behavior of volatile compounds, using the DHS method to detect the contents of given volatile compounds in the headspace within different evaporation times. Chapter 4 reconstituted 7 model wines by adding a standard aroma solution to deodorized wines with distinct matrices. Chapter 5 applied the same strategy but to the study of the headspace changes relating to macromolecules that were oenological additives, such as polysaccharides and polyphenols. Chapter 6 was devoted to the comprehensive study of two premium category wines. In this case, both the analytical data of the volatile components in the liquid phase and those of the headspace at different time points were combined with a complete simultaneous sensory study carried out by a panel of tasters. The sensory data at different moments of wine tasting were correlated with the corresponding concentration data in the headspace of volatile compounds that were relevant to each aroma descriptor. Alkylmethoxypyrazines are potent odorants in many food products, as well as in wines. Usually, they are presented at extremely low concentration levels. In Chapter 7, a new method for the identification and quantitation of 3-isobutyl-2-methoxypyrazine, 3-isopropyl-2-methoxypyrazine and 3-sec-butyl-2-methoxypyrazine has been developed and applied to wine. According to the validated method, the analytes were extracted from 5 mL of wine using stir-bar sorptive extraction followed by thermal desorption and multidimensional gas chromatography-mass spectrometry analysis in a single oven. The method is not only automatable and environmentally friendly but also provides the best limits of detection for these compounds published to date. The method has been applied to the analysis of 111 Spanish and French wine samples produced with minor and rare grape varieties.<br /

Determination of ppq-levels of alkylmethoxypyrazines in wine by stirbar sorptive extraction combined with multidimensional gas chromatography- mass spectrometry

Alkylmethoxypyrazines are powerful odorants in many food products. A new method for analysing 3-isopropyl- 2-methoxypyrazine, 3-s-butyl-2-methoxypyrazine and 3-isobutyl-2-methoxypyrazine has been developed and applied to wine. The analytes were extracted from 5 mL of wine using stirbar sorptive extraction followed by thermal desorption and multidimensional gas chromatography-mass spectrometry analysis in a single oven. The extraction conditions were optimized in order to obtain a high recovery of the 3-alkyl-2-methoxypyrazines (MP). The detection limits of the method in all cases were under 0.08 ng/L, well below the olfactory thresholds of these compounds in wine. The reproducibility of the method was adequate (below 10%), the linearity satisfactory and the recoveries in all cases close to 100%. The method has been applied to the analysis of 111 Spanish and French wine samples. The levels found suggest that MP have a low direct impact on the aroma properties of wines from the regions around the Pyrenean massif

A two-run heart-cut multidimensional gas chromatography method using flame ionization and mass spectrometry for automated and robust determination of nearly complete wine aroma-volatile profiles

A quantitative analytical method capable of determining the concentrations of 81 aroma-relevant wine volatiles covering nine orders of magnitude was developed and validated in this study. The method is based on stir bar sorptive extraction (SBSE) of 200 μL of wine diluted with 1.8 mL NaCl brine with pH 3.5. Volatiles thermally desorbed from the stir bars were separated in two runs in a heart-cut multidimensional gas chromatographic system and quantified using either a flame ionization detector (FID) in the first dimension (27 aroma compounds) or a mass spectrometer in the second dimension (54 aroma compounds, transferred to 22 cuts). Typical limits of compound detection lay around 0.02 mg/L by FID or ranged from 0.001 to 0.30 μg/L by mass spectrometry detector, liying below the corresponding odor thresholds in all cases. Linearity, reproducibility, and recovery were considered satisfactory for most compounds, with typical R2 values of 0.989–0.999, relative standard deviation below 10 % for 37 compounds and between 10 and 20 % for 44 compounds, and recovery rates of approximately 100 % (85–109 %) for all but acetaldehyde. An analysis of 20 wine samples completed our validation of the method, showing that a single-sample preparation procedure combined with heart-cut multidimensional two-detector gas chromatography can determine wine volatile concentrations ranging from 350 mg/L of isoamyl alcohol to 3.8 ng/L of 3-isobutyl-2-methoxypyrazine

Comparative evaluation of the effects of a new biological adhesive (Colagel) on the tensile strength and healing of intestinal anastomoses

The effects of a new biological adhesive based on a mixture of gelatin-resorcin and formaldehyde (Colagel) for use as an adjuvant in the reinforcement, impermeabilization and healing of intestinal anastomoses were evaluated and compared to those obtained with omentun fixation, the standard procedure used for this purpose. Two ileal anastomoses were performed in each of 12 experimental dogs using an extramucosal technique and single plane sutures. One of the anastomoses in each animal was covered with adhesive and the other with omentun, in random order. The anastomosed intestinal segments were tested for tensile strength and analysed histopathologically 1, 3, 7, 14, 21 and 28 days after surgery. The tensile strength of the anastomoses treated by the two different procedures was statistically identical. Histopathology revealed normal healing evolution for both procedures on days 1, 3 and 7, and greater exudation in the adhesive group on days 14, 21 and 28 after surgery.Os efeitos de un novo adesivo biológico a base de gelatina - resorcina e formaldefdo (Colagel), como adjuvante no reforço, impermeabilização e cicatrização de anastomoses intestinais,    foram avaliados e comparados com a omentopexia, procedimento padrão em cirurgias dessa natureza. Duas anastomoses ileais foram realizadas em 12 cães de experimentação empregando-se, como sutura, técnica em pontos simples separados extramucosos em plano único. Para a avaliação comparativa, estas receberam, respectivamente, o adesivo e a omentopexia. Os segmentos intestinais que receberam as anastomoses foram avaliados segundo a força tênsil e histopatologia aos 1, 3, 7, 14, 21 e 28 dias de pós-operatório. 0 estudo da força tênsil das anastomoses tratadas pelos procedimentos não mostrou diferenças estatisticamente significativas. A histopatologia revelou evolução normal da cicatrização em ambas as técnicas, nos dias 1, 3 e 7 e maior exudação no grupo cota aos 14, 21 e 28 dias de pós-operatório

Rural population travel time to health services, mapped on Geographic Information System (GIS)

Distance and travel time are important parameters in the evaluation of access to health services, especially for the population living in the countryside. In the present work, a GIS-based methodology is developed for the mapping of rural road networks and the determination of travel impedances in order to optimize the travel time of the rural population to health care facilities. Data on rural roads classes, slope, sinuosity, visibility and land use are considered in the composition of the impedances synthesis and its application on car travel time. The methodology was applied to the region of Registro (SP), and the results indicate an unequal distribution of health services.Para a população que vive no campo a distância e o tempo de viagem são parâmetros importantes para a avaliação do acesso aos serviços de saúde. O objetivo deste trabalho é apresentar uma metodologia baseada em SIG para o mapeamento das redes de estradas rurais, tendo em vista a determinação de impedâncias de viagem para a medida do tempo de viagem da população rural aos locais de atendimento à saúde. Dados sobre as classes de rodovias rurais, declividade, sinuosidade, visibilidade e uso da terra são considerados na composição de uma síntese de impedâncias e sua aplicação ao tempo de viagem por veículo automotor. A metodologia foi aplicada na Região de Registro (SP) e os resultados indicam uma distribuição espacial desigual dos serviços de saúde

Perception of occupational stress by military firefighters from a city in the countryside of Minas Gerais

Objective: to identify the factors those predispose the military fireman to develop occupational stress. Method: this was a descriptive study, with quantitative and qualitative approach. 32 interviews were conducted using a semistructured questionnaire and an interview recorded with guiding questions. The data were analyzed using the SPSS 16.0 version and for the interviews was used content analysis. Results: Seven categories namely: understanding stress, stress in daily work; factors stressors and emotional damage due to stress. Conclusion: It was noticed in this study the difficulty of theoretical science on this subject. Moreover, we can infer that concern firefighters, feel and express stress in different ways and thus to realize when they are under job stress

Ants (Hymenoptera: Formicidae) from an Amazonian fragmented landscape, Juara, Mato Grosso, Brazil, with new records of ant species

The state of Mato Grosso is the 3rd largest Brazilian state, is covered with three major Brazilian biomes, including the Pantanal, Cerrado, and Amazonia. To date, 449 ant species are recorded in literature for the state. In the present work, we documented the ants sampled along a fragmented landscape, in the municipality of Juara, in the Cerrado-Amazon transition zone in the state of Mato Grosso, Brazil. The ant species were captured with Pitfall traps installed in 20 trails with 10 traps in each (totaling 200). Our results show 151 species, belonging to 43 genera and eight subfamilies, of which 28 species were recorded for the first time in the state and five species recorded for the first time in Brazil. Most genera collected were Pheidole Westwood, 1839 (45 species) followed by Crematogaster Lund, 1831 (11 species). By highlighting species recorded for the first time in state of Mato Grosso and Brazil, we hope to encourage new discoveries and increase the general knowledge of the ant fauna of different biomes in the region