The Butia odorata has received special attention from the scientific community because of their nutritional and functional properties that have been revealed, in addition to its rightdown sensory characteristics. The aim of this study was to characterize different genotypes from Butia odorata fruit collected in Santa Maria - RS (SM) and Santa Rosa - RS (SR) regions during three consecutive harvests in relation to various physical and chemical properties. Many analyses were performed like: biometric, color and quality parameters, fatty acid composition in the Butia pulp. An HS-SPME method was developed for the isolation and subsequent quantification (GC-FID) and identification (GC/MS) of volatile compounds (VCs). The biometric parameters results showed pulp yields between 40.38 and 73.91%. The color of the pulp ranged between yellow and orange shades. TSS ranged between 12.39 and 15.50 °Brix, acidity between 0.69 and 2.26 g% citric acid and pH between 3.17 and 3.95. The fruit had humidity between 78.04 and 85.85 g%; ashes between 0.47 and 0.77 g%; protein between 0.57 and 0.93 g%, crude fiber between 0.84 and 4.02 g%; lipid between 0.12 and 2.27 g%. The fatty acids such as palmitic acid, linoleic and linolenic acids were found in abundance. It was possible to observe the partial discrimination between the two regions in the PCA using the physico-chemical variables. The samples from SR characterized by high scores for lipids and palmitic acid, while SM samples showed a higher humidity and TSS. The method employed use DVB/CAR/PDMS fiber for the VCs extraction of the centrifuged Butia pulp , added with 30% NaCl, and maintaining the system at a temperature of 35 °C for 45 minutes, under stirring. The volatile fraction was analyzed in GC and were identified 77 compounds among acids (5), alcohols (14), aldehydes (9), ketones (12), lactones (3), terpenes (2) and esters (34). The ethyl hexanoate compound was the major compound in almost samples. The PCA from VCs enabled to realize grouping of samples into two groups according to region of origin. The fruits from Santa Maria showed a high content of esters and the fruits from Santa Rosa had higher concentrations of alcohols and aldehydes. An exploratory analysis of the variables of physico-chemical composition and volatile of the samples was observed using PCA. In the graphs analysis also realized a partial separation of samples according to their region: the samples SM2-10 and RS1-11 distanced themselves from the other and it indicates greater particularity in their chemical compositions. Therefore the fruits (Butia odorata) showed great variability in biometric characteristics, physico-chemical and volatile profiles according to region of origin. It indicates a strong influence of soil and climatic factors. In this study, the nutritional characteristics and high yield pulp of some Butia fruits demonstrated the high potential for fresh consumption or for the manufacture of processed products / O butiá (Butia odorata) tem recebido especial atenção da comunidade científica, em virtude de suas propriedades nutritivas e funcionais que estão sendo reveladas, além das suas características sensoriais peculiares, ainda pouco exploradas. Desta forma, o objetivo do presente trabalho foi caracterizar diferentes genótipos de frutos de butiazeiros coletados nas regiões de Santa Maria RS (SM) e Santa Rosa RS (SR) em três safras consecutivas, quanto as diversas propriedades físicoquímicas. Foram realizadas análises biométricas, de cor, dos parâmetros de qualidade, composição centesimal e ácidos graxos da polpa do butiá, além do desenvolvimento de método de isolamento por SPME com posterior quantificação (GC-FID) e identificação (GC/MS) dos compostos voláteis (CVs). Os resultados dos parâmetros biométricos revelaram rendimentos de polpa, entre 40,38 e 73,91%. A cor da polpa oscilou em tons de amarelo e laranja. Os SST variaram entre 12,39 e 15,50 °Brix, a acidez entre 0,69 e 2,26 g% em ácido cítrico e o pH entre 3,17 e 3,95. As frutas apresentaram umidade entre 78,04 e 85,85 g%; cinzas entre 0,47 e 0,77 g%, proteína entre 0,57 e 0,93 g%, fibra bruta entre 0,84 e 4,02 g% e lipídios de 0,12 a 2,27 g%. Os ácidos graxos encontrados em maior abundância foram o ácido palmítico, linoléico e linolênico. Na Análise dos Componentes Principais (PCA) empregando as variáveis físico-químicas observou-se a discriminação parcial entre as duas regiões, sendo as amostras da região de SR caracterizadas por elevados escores para lipídios e ácido palmítico, enquanto que as da região de SM apresentaram, em geral, maior umidade e teor de SST. O método desenvolvido emprega o uso da fibra DVB/CAR/PDMS para a extração dos CVs da polpa de butiá centrifugada, adicionada de 30% de NaCl, e mantendo o sistema a uma temperatura de 35 ºC por 45 minutos, sob agitação. A fração volátil foi analisada em GC e nela identificados 77 compostos entre ácidos (5), alcoóis (14), aldeídos (9), cetonas (12), lactonas (3), terpenos (2) e, principalmente, ésteres (34). Entre estes se destacou o hexanoato de etila como composto majoritário. A PCA dos CVs possibilitou ver o agrupamento das amostras em dois grupos conforme a região de origem, onde, em geral, os butiás de Santa Maria apresentaram elevado teor de ésteres, enquanto os de Santa Rosa obtiveram maiores concentrações de alcoóis e aldeídos. Uma análise exploratória entre as variáveis de composição físico-química e volátil das amostras estudadas foram observadas através de uma PCA. Na visualização dos gráficos notou-se também uma parcial separação das amostras quanto à região de origem, sendo que as amostras SM2-10 e SR1-11 distanciaram-se das demais, indicando maior particularidade em suas composições químicas. Sendo assim, os butiás apresentaram grande variabilidade em suas características biométricas, físicoquímicas e nos perfis voláteis em função da região de origem e safra e, portanto, apresentou forte influência de fatores edafoclimáticos. Sobretudo, as características nutricionais e o alto rendimento de polpa de alguns frutos de butiás evidenciaram, neste estudo, o alto potencial para consumo in natura ou mesmo para a fabricação de produtos processados.

CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / As variedades do mamÃo grupo Solo sÃo susceptÃveis a vÃrias doenÃas que restringem o mercado dos frutos in natura. A Embrapa vem desenvolvendo genÃtipos resistentes buscando caracterÃsticas agronÃmicas e sensoriais desejÃveis. Assim, objetivou-se caracterizar o perfil de volÃteis, compostos responsÃveis pelo aroma e sabor dos alimentos, e a qualidade sensorial de genÃtipos do grupo Solo, visando identificar novos cultivares com potencial para lanÃamento no mercado. Foram analisados quatro genÃtipos melhorados (CPMF L47-P8, CPMF L60-08, CPMF L47-P5 e CPMF H54-78) e uma variedade comercial (Sunrise). Para tanto, as condiÃÃes de extraÃÃo dos compostos pela tÃcnica HS-SPME foram otimizadas usando um Delineamento Composto Central Rotacional (DCCR), baseado em Metodologia de SuperfÃcie de Resposta, com duas variÃveis: tempo de equilÃbrio (0 a 30 min) e tempo de exposiÃÃo da fibra (20 a 60 min). As variÃveis dependentes foram nÃmero de picos, Ãrea total e intensidade do aroma. Os volÃteis foram extraÃdos com a fibra DVB/CAR/PDMS, separados e identificados por GC-MS. A anÃlise sensorial foi realizada com consumidores de mamÃo, por meio de testes afetivos de aceitaÃÃo global e aparÃncia, diagnÃstico de atributos (cor da polpa, aroma, sabor e textura) e intenÃÃo de compra. Os dados das anÃlises de compostos volÃteis foram submetidos à AnÃlise de Componentes Principais (ACP) e AnÃlise de Agrupamento HierÃrquico (clusters), e os da anÃlise sensorial foram submetidos à ANOVA e teste de Tukey. As duas matrizes de dados foram correlacionadas pela RegressÃo por MÃnimos Quadrados Parciais (PLS). As melhores condiÃÃes para a extraÃÃo dos volÃteis do mamÃo por HS-SPME foram 15 min de equilÃbrio e 60 min de exposiÃÃo da fibra. Nessas condiÃÃes foram identificados 70 compostos volÃteis, sendo os aldeÃdos os mais abundantes (em Ãrea), seguidos dos terpenos, Ãsteres, Ãlcoois e lactonas. Os genÃtipos CPMF L60-08 e CPMF L47-P5 apresentaram perfis de volÃteis semelhantes entre si e à variedade Sunrise, mas os genÃtipos CPMF H54-78 e CPMF L47-P8 apresentaram perfis de volÃteis Ãnicos. Quanto Ãs caracterÃsticas sensoriais, os genÃtipos CPMF L47-P8 e CPMF L47-P5 apresentaram-se semelhantes entre si, com textura mais firme e menor intensidade da cor da polpa, aroma e sabor que Sunrise, com menor aceitabilidade. O genÃtipo CPMF H54-78 apresentou boas caracterÃsticas sensoriais na degustaÃÃo, porÃm foi rejeitado quanto à aparÃncia externa. O genÃtipo CPMF L60-08 apresentou alta similaridade com a variedade comercial e mesma aceitabilidade, apesar da cor da polpa menos intensa. Os resultados da correlaÃÃo multivariada confirmam a superioridade do genÃtipo CPMF L60-08, o qual apresentou alta correlaÃÃo com a variedade Sunrise e com os atributos sensoriais. O presente trabalho recomenda o genÃtipo CPMF L60-08 como o promissor para substituir a variedade Sunrise (nÃo resistente a pragas e doenÃas), preservando o sabor e aroma caracterÃstico de mamÃo. / As variedades do mamÃo grupo Solo sÃo susceptÃveis a vÃrias doenÃas que restringem o mercado dos frutos in natura. A Embrapa vem desenvolvendo genÃtipos resistentes buscando caracterÃsticas agronÃmicas e sensoriais desejÃveis. Assim, objetivou -se caracterizar o perfil de volÃteis, compostos responsÃveis pelo aroma e sabor dos alimentos, e a qualidade sensorial de genÃtipos do grupo Solo, visando identificar novos cultivares com potencial para lanÃamento no mercado. Foram analisados quatro genÃtipos melhorados (CPMF L47-P8, CPMF L60-08, CPMF L47-P5 e CPMF H54- 78) e uma variedade comercial (Sunrise).Para tanto, as condiÃÃes de extraÃÃo dos compostos pela tÃcnica HS-SPME foram otimizadas usando um Delineamento Composto Central Rotacional (DCCR), baseado em Metodologia de SuperfÃcie de Resposta, com duas variÃveis: tempo de equilÃbrio (0 a 30 min) e tempo de exposiÃÃo da fibra (20 a 60 min). As variÃveis dependentes foram nÃmero de picos, Ãrea total e intensidade do aroma. Os volÃteis foram extraÃdos com a fibra DVB/CAR/PDMS, separados e identificados por GC-MS. A anÃlise sensorial foi realizada com consumidores de mamÃo, por meio de testes afetivos de aceitaÃÃo global e aparÃncia, diagnÃstico de atributos (cor da polpa, aroma, sabor e textura) e intenÃÃo de compra. Os dados das anÃlises de compostos volÃteis foram submetidos à AnÃlise de Componentes Principais (ACP) e AnÃlise de Agrupamento HierÃrquico (clusters), e os da anÃlise sensorial foram submetidos à ANOVA e teste de Tukey. As duas matrizes de dados foram correlacionadas pela RegressÃo por MÃnimos Quadrados Parciais (PLS). As melhores condiÃÃes para a extraÃÃo dos volÃteis do mamÃo por HS-SPME foram 15 min de equilÃbrio e 60 min de exposiÃÃo da fibra. Nessas condiÃÃes foram identificados 70 compostos volÃteis, sendo os aldeÃdos os mais abundantes (em Ãrea), seguidos dos terpenos, Ãsteres, Ãlcoois e lactonas. Os genÃtipos CPMF L60-08 e CPMF L47-P5 apresentaram perfis de volÃteis semelhantes entre si e à variedade Sunrise, mas os genÃtipos CPMF H54-78 e CPMF L47-P8 apresentaram perfis de volÃteis Ãnicos. Quanto Ãs caracterÃsticas sensoriais, os genÃtipos CPMF L47-P8 e CPMF L47-P5 apresentaram-se semelhantes entre si, com textura mais firme e menor intensidade da cor da polpa, aroma e sabor que Sunrise, com menor aceitabilidade. O genÃtipo CPMF H54-78 apresentou boas caracterÃsticas sensoriais na degustaÃÃo, porÃm foi rejeitado quanto à aparÃncia externa. O genÃtipo CPMF L60-08 apresentou alta similaridade com a variedade comercial e mesma aceitabilidade, apesar da cor da polpa menos intensa. Os resultados da correlaÃÃo multivariada confirmam a superioridade do genÃtipo CPMF L60-08, o qual apresentou alta correlaÃÃo com a variedade Sunrise e com os atributos sensoriais. O presente trabalho recomenda o genÃtipo CPMF L60-08 como o promissor para substituir a variedade Sunrise (nÃo resistente a pragas e doenÃas), preservando o sabor e aroma caracterÃstico de mamÃo.

Ce travail de thèse a pour premier objectif le développement de méthodologies d’extraction (HS-SPME) et d’analyse (GC-MS, GC-MS-MS) des hydrocarbures pétroliers volatils (aromatiques et aliphatiques) dans la phase dissoute et la phase sédimentaire. Le deuxième objectif concerne le développement d’un nouvel outil d’échantillonnage passif des HAP dissous (POCIS-« like »). Les méthodologies développées ont été par la suite appliquées pour la caractérisation des hydrocarbures dans les effluents industriels pétroliers au cours d'expérimentations en conditions semi-contrôlées dans le cadre de deux projets de recherche (TOTAL, EMESTOX). Enfin un couplage de l’échantillonnage passif/ponctuel et biologique a été mis en oeuvre pour le suivi des HAP dans deux écosystèmes aquatiques français : le bassin d’Arcachon et l’estuaire de la Gironde. / Hydrocarbons originating from telluric discharges and accidental spills constitute a major source of pollution in the aquatic systems. These compounds are present at trace levels in the dissolved phase due to their hydrophobicity and/or their volatility, and are characterized by variable concentrations in the water body depending on discontinuous inputs, dilution phenomena, tidal cycles…Therefore, in order to raise the analytical and environmental challenges generated by the hydrocarbons in the aquatic systems, the present phD work focused on: i) methodological developments for the extraction and analysis of volatile petroleum hydrocarbons (aromatics and aliphatics) for both the dissolved and the sedimentary phases, in order to characterize the presence and fate of a petroleum contamination in these media, and ii) developments of new passive sampling tools for the sampling of polycyclic aromatic hydrocarbons (PAHs) which have proved their toxic character, while integrating the variability in the contaminant concentrations in the dissolved phase.

Les matériaux actuellement utilisés comme capteurs passifs de polluants atmosphériques, la mousse de polyuréthane et la résine XAD®-2, ne sont optimisés ni pour l'adsorption de composés polaires ni pour le captage de particules. Pour remédier à ces limitations, la mousse de carbure de silicium (SiC) est proposée comme alternative. Plusieurs campagnes de mesures ont été mises en place pour comparer SiC et XAD®-2. Les composés recherchés étaient des HAP, des PCB et des pesticides.Une méthode d'analyse combinant ASE, SPE et SPME a été développée et optimisée pour ces polluants. Celle-ci permet d'atteindre de faibles limites de détection et quantification pour les composés recherchés.Les campagnes réalisées montrent que la mousse de SiC est toujours plus efficace que la résine XAD®-2 pour le piégeage de composés particulaires et polaires. De plus, la SiC peut être greffée avec du carbone ou des nanotubes de carbone pour augmenter sa surface spécifique, ce qui la rend également plus performante pour l'adsorption de composés volatils. Les débits d'échantillonnage moyens de la mousse ont été calculés et sont comparable aux valeurs rapportées dans la littérature pour la résine XAD®-2. / Materials currently used as passive samplers for atmospheric pollutants, polyurethane foam and XAD®-2 resin, are not suited ta trapping polar compounds nor particles. Ta overcome these limitations, silicon carbide (SiC) foam is presented as an alternative. Several sampling campaigns monitoring PAH, PCB and pesticides were done ta compare SiC and XAD®-2. An analytical method coupling ASE, SPE and SPME was developed and optimised for these pollutants. lt allowed low limits of detection and quantification ta be reached for all compounds of interest.Sampling campaigns showed that SiC foam is consistently more efficient than XAD®-2 resin at trapping particulate and polar compounds. Moreover, SiC foam can be grafted with carbon or carbon nanotubes ta increase its specific surface area, which also makes it better at adsorbing volatile compounds. Average sampling rates were calculated for SiC foam and they are comparable ta the values reported in the literature for XAD®-2 resin.

Organic emissions with focus on terpenes, from biomass drying and storage were investigated by Solid Phase Microextraction (SPME) and GC-FID and GC-MS. The remaining terpenes in the biomass (Spruce and pine wood chips) after drying were dependant on the drying temperature and drying medium used. The drying medium used was steam or hot air; the drying temperatures used were 140degreeC, 170degreeC and 200degreeC. Steam drying at 170degreeC left more of the terpenes remaining in the wood chips, not emitting them into the drying medium. The terpenes emitted from storage of forest residues and bark and wood chips increased up to three-four or four-five months of storage, and then dropped down to approximately the same low level as the first month. The leachate taken from the forest residue pile contained 27µg PAH per liter. The SPME response for a monoterpene (a-terpene) at different temperatures, amounts and humidities was quantified. The highest concentration calibrated was 250 ppm and the lowest 9.4 ppm. There is a better linear agreement at higher temperatures (70degreeC and 100degreeC) than lower temperatures (below 40degreeC). Organic emissions from biofuel combustion were measured at three medium sized (~ 1MW) biomass fired moving grate boilers fired with different fuels: dry wood fuel, forest residues and pellets. The PAH emissions varied by almost three orders of magnitude between the three boilers tested, 2.8-2500 microgram/m3. It was difficult to identify any general parameters correlating to the PAH emissions. The variation in PAH emission is most probably a result of boiler design and tuning of the combustion conditions. When comparing the contribution to self-heating from different wood materials by means of isothermal calorimetry with different metals added and stored at different temperatures, the differences were quite large. Some of the samples released as much as 600mW/kg, whereas others did not contribute at all to the self-heating. The storage temperature, at which the samples released the most heat, was 50C. There was a peak in heat release for most of the samples after 10-30 days. Stepwise increase in temperature did not favour the heat release in the sample Dry Mix; the heat released was even lower than when it was directly put in the different storage temperatures. When metal is added, there is an increase in heat release, the reference sample without metal released 200mW/kg compared to 600mW when copper was added.

No description available.

<p>This thesis describes some new methods for analysis oforganic trace components from air and water by gaschromatography. The work is particularly focused on thedevelopment of new technologies for analyte enrichment, usingsorbent-based concepts. Short lengths of open tubular columnswere examined for their potential use as denuders.Polydimethylsiloxane-based stationary phases as well as anadsorbent-based column were evaluated in an equilibrium mode oftrapping. For the analytes selected, detection levels in theppb range were obtained (Paper I).</p><p>A new, fully automated set-up for analysis of organic tracecomponents in aqueous samples has been developed (Paper II).The work combines specific advantages of the solid phase microextraction (SPME) technology and stir bar sorptive extractionconcept. Ultra trace components, down to 0.1 ppt could bedetected. Finally a simple method for preparation a new type ofultra thick film open tubular trap is described (Paper III).The traps are characterized by an irregular coating, and it wasdemonstrated that the performance characteristics of thesetraps were practically as good as of traps with a smooth,regular coating. The technology can be utilized in many areas,e.g. environmental monitoring, process analysis and otherfields dealing with analysis of trace organic volatiles ingaseous samples.</p><p><b>Keywords:</b>Organic trace components, volatiles, denuders,sorbent trapping, thick film trapping, open tubular traps,SPME, automation, water analysis, gas analysis, environmentalanalysis.</p>

<p>In the work underlying this thesis solid-phase microextraction (SPME) was evaluated as a passive sampling technique for organophosphate triesters in indoor air. These compounds are used on a large scale as flame-retarding and plastizicing additives in a variety of materials and products, and have proven to be common pollutants in indoor air. The main objective of this work was to develop an accurate method for measuring the volatile fraction. Such a method can be used in combination with active sampling to obtain information regarding the vapour/particulate distribution in different indoor environments. SPME was investigated under both equilibrium and non-equilibrium conditions and parameters associated with these different conditions were estimated. </p><p>In <b>Paper I</b>, time-weighted average (TWA) SPME under dynamic conditions was investigated in order to obtain a fast air sampling method for organophosphate triesters. Among the investigated SPME coatings, the absorptive PDMS polymer had the highest affinity for the organophosphate triesters and was consequently used in all further work. Since the sampling rate is dependent on the agitation conditions, the linear airflow rates had to be carefully considered. Sampling periods as short as 1 hour were shown to be sufficient for measurements in the ng-μg m^-3 range when using a PDMS 100-μm fibre and a linear flow rate above 7 cm s^-1 over the fibre. </p><p>SPME under equilibrium conditions is rather time-consuming, even under dynamic conditions, for slowly partitioning compounds such as organophosphate triesters. Nevertheless, this method has some significant advantages. For instance, the limit of detection is much lower compared to 1 h TWA sampling. Furthermore, the sampling time can be ignored as long as equilibrium has been attained. In <b>Paper II</b>, SPME under equilibrium conditions was investigated and evaluated for organophosphate triester vapours. Since temperature and humidity are closely associated with the distribution constant a simple study of the effect of these parameters was performed. The obtained distribution constants were used to determine the air levels in a common indoor environment. SPME and parallel active sampling on filters yielded similar results, indicating that the detected compounds were almost entirely associated with the vapour phase</p><p>To apply dynamic SPME method in the field a sampler device, which enables controlled linear airflow rates to be applied, was constructed and evaluated (<b>Paper III</b>). This device was developed for application of SPME and active sampling in parallel.</p><p>A GC/PICI-MS/MS method was developed and used in combination with active sampling of organophosphate triesters in indoor air (<b>Paper IV</b>). The combination of MS/MS and the soft ionization achieved with methanol as reagent gas yielded high selectivity and detection limits comparable to those provided by GC with nitrogen-phosphorus detection (NPD). The method limit of detection, when sampling 1.5 m³ of air, was in the range 0.1-1.4 ng m^-3. In <b>Paper V</b>, the developed MS method was used in combination with SPME for indoor air measurements.</p><p>The levels detected in the investigated indoor environments range from a few ng to μg m^-3. Tris(2-chloropropyl) phosphate was detected at a concentration as high as 7 μg m^-3 in a newly rebuilt lecture room.</p>

An apple wine produced by Kiviks Musteri AB have an undesirable flavor of yeast. As a step in the development to reduce this off-flavour the wine flavor was analyzed by gas chromatography-mass spectrometry (GCMS) with headspace solid-phase microextraction (HS-SPME). Two other wines without the flavor of yeast where analyzed as references. Samples from the production step prior to clarification where also analyzed. Through matching against mass spectrum library, retention index and in some cases references a total of 37 volatile compounds were identified in the apple wines. Some uncertainty in the relative quantification of a few compounds was caused by insufficient clearance (deadsorption) of the SPME-fiber. When comparing the different wines the compounds were divided into groups: key compounds, ethyl esters, derivatives of 3-methyl-1-butanol, other compounds: group 1 and other compounds: group 2. In each group the percent area for each compound was calculated. Comparing the percent area of each wine showed that the samples prior to clarification contains a higher number of volatile compounds e.g. ethyl esters and 3-methylbutanol derivatives than the final wine products. The comparisons also revealed differences between the wines. The results from the analyses indicated that the compounds that hypothetically contribute to the yeast-flavor could be 2-phenylethanol; 3-methylbutanoic acid; 2-methyl-1-butanol; 2-phenylacetaldehyde och 2-methylthiolan-3-one. The results need to be verified e.g. by an odor panel if they are going to be useful for Kivik Musteri AB in its effort to solve the taste problem in the wine.

Ésteres produzidos por via biotecnológica são considerados e classificados como naturais e sua demanda tem aumentado. Várias leveduras podem produzir ésteres e seu método de seleção é altamente importante para inúmeros tipos de indústrias. Trinta e quatro cepas de leveduras, isoladas de vinhos tintos em barris de carvalho elaborados na Serra Gaúcha e de queijos artesanais do Sul do Brasil, foram utilizadas neste trabalho. Cada cepa foi inoculada na superfície de meio sólido inclinado rico em glicose e nitrogênio, diretamente no frasco utilizado para a microextração em fase sólida (SPME) seguida pela injeção num cromatógrafo gasoso com detecção por espectrometria de massas (GC/MS) e quantificação utilizando detector de ionização de chama (GC-FID). O método foi desenvolvido e validado, sendo que a fibra DVB/PDMS/CAR, temperatura de extração de 80˚C e 20 minutos de aquecimento da amostra antes da extração foram as condições ótimas estabelecidas. A metodologia de superfície e resposta foi usada para a otimização da produção de acetato de etila pela levedura Zygosaccharomyces bailii BCV 08, e um planejamento fatorial 22 foi aplicado para determinar as melhores condições de temperatura de cultivo (X1, 20 até 36 ˚C) e agitação (X2, 0 a 200 rev/min). Os melhores resultados foram obtidos com a temperatura de 28 ˚C e 0 rev/min, onde houve um aumento de 60% na produção de acetato de etila. Foram avaliados os efeitos das fontes de carbono (glicose e frutose) e do mosto de uva sobre a produção de acetato de etila. A máxima concentração de acetato de etila produzida foi de 71,11 mg/L, utilizando o mosto de uva como meio. Experimentos utilizando biorreatores de 4L levaram à produção máxima de 133,74 mg/L de acetato de etila, 14,57 mg/L de hexanoato de etila, 4.093,74 mg/L de octanoato de etila e 3.775,28 mg/L de decanoato de etila. / Esters produced by biotechnological means are legally labeled as natural and there is an increasing demand for these products. Several yeasts can accumulate esters, and their selection is highly interesting for many industries. Thirty-four yeast strains isolated from red wine oak barrels of Serra Gaúcha winemaking region and from homemade cheeses of Southern Brazil were used in this research. The yeasts were inoculated in agar slants of a solid medium rich in glucose and nitrogen, directly inside the extraction transparent glass vials, using a headspace solid phase microextraction (SPME) method followed by injection of gas chromatography with mass spectrometric detection (GC/MS), and quantification by flame ionization detector (GC/FID). The analytical method was developed and validated, and the DVB/PDMS/CAR fiber, extraction temperature of 80˚C, and 20 minutes of sample heating time volatilization prior to the extraction step were the best conditions. A response surface methodology was used to optimize the production of ethyl acetate by Zygosaccharomyces bailii BCV 08, which was selected, and a 22 full factorial central composite design was applied to determine the best conditions for the cultivation temperature (X1, 20 to 36 ˚C) and stirring speed (X2, 0 to 200 rev/min). The best results were found with temperature of 28 ˚C and medium agitation of 0 rev/min, with a 60% increase in ethyl acetate production. We evaluated the effect of the carbon sources (glucose and fructose) and grape must on ethyl acetate formation; the maximal yield was reached with grape must and the highest concentration of ethyl acetate produced was 71.11 mg/L. Employing experiments on bioreactors of 4L, it was possible to improve the esters production by this yeast; a maximal production of 133.74 mg/L of ethyl acetate, 14.57 mg/L of ethyl hexanoate, 4093.74 mg/L of ethyl octanoate, and 3775.28 mg/L of ethyl decanoate was reached.