A atmosfera terrestre contém nitrogênio e oxigênio, sendo este último, um composto altamente reativo e fundamental ao desenvolvimento e manutenção da vida. Além desses gases, diversos outros compostos em pequenas concentrações, os quais podem atuar como reagentes e/ou catalisadores também a compõe. Os compostos gasosos variados e material particulado (orgânico e inorgânico) de diferentes dimensões lançados constantemente à atmosfera são provenientes de fontes diversas. Tais fontes podem ser de origem natural ou antrópica e ainda, podem ser pontuais, difusas, primárias, secundárias, móveis e/ou estacionárias. Os processos envolvendo transformações químicas na atmosfera são extremamente importantes porque tendem a manter a sua composição em estado estacionário. A vegetação, que constitui uma fonte natural, é responsável pela emissão de grandes quantidades de compostos carbonados para a atmosfera. Dentre os vários compostos orgânicos emitidos da superfície do planeta, destacam-se em particular, alguns gases traços, denominados compostos orgânicos voláteis (COVs). A emissão dos compostos orgânicos voláteis pela vegetação ocorre, em escala global, predominantemente nos trópicos ou nos meses de verão em outras regiões. As reações fotoquímicas dos compostos orgânicos voláteis desempenham um papel diferenciado e importante na química da troposfera, podendo alterar de forma significativa a concentração de ozônio em áreas tanto urbanas quanto rurais. O presente projeto contempla o estudo de alguns dos inúmeros compostos orgânicos voláteis de origem biogênica (COVBs) emitidos pela vegetação constituinte, das regiões da Floresta Amazônica, da Mata Atlântica e da floresta Tropical da Guiana Francesa, comparando-se os dados de saída gerados pelos Modelos MOZART-4 e CAM-Chem. A escolha dos sítios experimentais para realização deste estudo se deu em parte em função da importância dos locais em termos de biodiversidade, extensão territorial, influência na climatologia (local e/ou regional), bem como também em função da acessibilidade, proximidade a centros urbanos e alterações devido à influência humana. O procedimento metodológico adotado para coleta das amostras de COVBs se deu por meio da técnica conhecida como acumulação de vórtices turbulentos (Relaxed Eddy Accumulation - REA), a qual faz uso de um dispositivo coletor denominado acumulador compacto de vórtices turbulentos (Compact Relaxed Eddy Accumulator - CREA). As amostras gasosas de COVBs foram coletadas por meio de cartuchos comerciais apropriados, compostos por diferentes materiais adsorvedores que apresentavam afinidade química também diferenciada para os variados compostos aos quais foram expostos. Estudos primários para determinação da natureza dos cartuchos que foram utilizados neste projeto foram realizados, a fim de se obter dispositivos adequados a este propósito. Os resultados evidenciam, como esperado, que a presença de isopreno é predominante em todos os sítios experimentais, sendo sua concentração média diária máxima de 5,0 ± 0,3 μg/cm3 registrada na Amazônia e de 8,0 ± 0,4 μg/cm3 (concentração diária) na floresta da Guiana Francesa, seguido pelo alfa-pineno cuja concentração máxima obtida foi de aproximadamente 1,6 ± 0,08 μg/cm3 no último sítio experimental, ambos detectados na estação seca. A emissão de isopreno e dos monoterpenos ocorreu de forma mais acentuada na época seca em comparação ao período úmido. Contudo, observou-se em algumas situações uma pequena discrepância. De maneira geral os resultados gerados pelos modelos estão subestimados, como exceção do parâmetro de radiação fotossinteticamente ativa (PAR), o que indica que a defasagem entre os resultados observados e os simulados pode estar relacionada parâmetros de OH-, NOx e em algumas reações químicas fotoquímicas envolvendo o ozônio. / The Earth\'s atmosphere contains nitrogen and oxygen, the last one being a highly reactive compound and fundamental to the development and maintenance of life. Besides these gases, many other compounds in small concentrations, which can act as reactants and /or catalysts can be found in the atmosphere. Various gaseous compounds and particulate matter (organic and inorganic) of different dimensions constantly released into the atmosphere come from various sources. Such sources can be natural or anthropogenic and still be punctual, diffuse, primary, secondary, mobile and or stationary. Processes involving chemical transformations in the atmosphere are extremely important because they tend to maintain their steady-state composition. The vegetation, which is a natural source, is responsible for producing large amounts of carbon compounds in the atmosphere. Among the various organic compounds emitted from the planet\'s surface, stand out in particular, some trace gases, called volatile organic compounds (VOCs). The emission of volatile organic compounds by vegetation occurs on a global scale, predominantly in the tropics or in the summer months in other regions. The photochemical reactions of volatile organic compounds play an important and unique role in the chemistry of the troposphere, which can significantly change the concentration of ozone in both urban and rural areas. This project involves the study of some of the numerous biogenic volatile organic compounds (BVOC) emitted by vegetation from the Amazon Forest, the Mata Atlântica forest and the Tropical forest of French Guiana, comparing the output data generated by MOZART -4 and CAM-Chem models. The choice of experimental sites for this study was in part due to the importance of local biodiversity , territorial extent , influence the weather (local and/or regional), and also because of accessibility, proximity to urban centers and changes due to human influence . The methodological procedures for collecting samples of VOCs was through the technique known as eddy accumulation (Relaxed Eddy Accumulation - REA), which uses an equipment known as compact relaxed eddy accumulator (CREA). The gas samples were collected from BVOCs through appropriate commercial cartridges, composed of different materials showed that chemical affinity adsorbents also differentiated for the various compounds which were exposed. Primary studies to determine the nature of cartridges that were used in the field campaigns were conducted in order to obtain devices suitable for this purpose. The results show, as expected, the presence of isoprene as a prevalent compound in all experimental sites, with maximum daily average concentration of 5,0 ± 0,3 μg/cm3 registered on the Amazon basin and 8,0 ± 0,4 μg/cm3 (daily concentration) in the forest of French Guiana, followed by alpha-pinene, whose maximum concentration obtained was approximately 1,6 ± 0,08 μg/cm3 in the last experimental site, both detected in the dry season. The emission of isoprene and monoterpenes occurred sharply in the dry season compared to the wet season. However, it was observed in some situations a small discrepancy. In general, the results generated by the models are underestimated, as an exception of photosynthetically active radiation parameter (PAR), indicating that the gap between the observed and simulated results can be related to OH- and NOx parameters and some chemical reactions involving photochemical ozone.

No description available.

O ozônio (O3) é um dos poluentes que representa grande preocupação em termos de qualidade do ar na Região Metropolitana de São Paulo (RMSP). No ano de 2012 foram observados 98 dias de ultrapassagens do padrão horário da qualidade do ar para este poluente na RMSP. A exposição aos poluentes atmosféricos como O3 e outros está associada ao prejuízo da saúde respiratória. O enfoque deste estudo é determinar os principais Compostos Orgânicos Voláteis (COV) precursores de O3 para auxiliar no controle deste poluente. Neste trabalho foram realizadas 78 amostragens durante a semana de hidrocarbonetos no ano de 2006 e 66 amostragens de hidrocarbonetos, 62 de aldeídos e 42 de etanol durante o ano de 2011/2012, 7:00 h às 9:00 h, na estação CETESB IPEN/USP. Medidas de COV também foram realizadas no ano de 2006 e 2008, na Estação CETESB Cerqueira César. Adicionalmente, foram efetuados testes de emissões veiculares durante o ano de 2009 de 5 veículos a diesel, 3 a etanol, 2 a gasolina C e 1 motocicleta. O modelo de trajetórias OZIPR foi utilizado para determinar os principais precursores de O3. Durante o ano de 2011/2012, na Estação CETESB IPEN/USP, a classe de aldeídos representou 35,3% dos COV analisados em concentração na atmosfera, seguido pelo etanol 22,6%, compostos aromáticos 15,7%, alcanos 13,5%, cetonas 6,8%, alcenos 6,0% e alcadienos < 0,1%. Considerando a concentração dos compostos e sua reatividade, as simulações executadas com o modelo OZIPR mostraram que o acetaldeído contribuiu com 61,2% da formação do O3 na atmosfera da RMSP no ano de 2011/2012. Dos COV analisados, a classe dos aldeídos contribui com 74% da produção de O3, aromáticos 14,5%, alcenos 10,2%, alcanos 1,3% e alcadienos (isopreno) 0,03%. O estudo de emissão veicular mostrou que 39% dos aldeídos foram provenientes de veículos a etanol, 28% a diesel, 26% a gasolina C e 7% de motocicletas. As emissões dos COV por veículos a gasolina contribuíram com 44% da formação de O3, a diesel 22%, a etanol 19% e motocicletas 15%. / Ozone (O3) is a pollutant that represents great concern in terms of air quality in the metropolitan area of São Paulo (MASP). In 2012 were observed 98 days of exceedances of the standard time air quality for this pollutant in the MASP. Exposure to air pollutants such as O3 and others is associated with the injury of respiratory health. The focus of this study is to determine the main Volatile Organic Compounds (VOCs) precursors of O3 to auxiliary in control this pollutant. In this work were made 78 samples during the week of hydrocarbons in 2006 and 66 samples of hydrocarbons, 62 of aldehydes and 42 of ethanol during the year 2011/2012, 7:00 am to 9:00 am, at the CETESB IPEN/USP station. Measurements of VOCs also were realized in 2006 and 2008, in the CETESB Cerqueira Cesar station. Additionally, were performed tests vehicle emissions during the year 2009 of 5 diesel vehicles, 3 ethanol, 2 gasool and 1 motorcycle. The OZIPR trajectory model was used to determine the main O3 precursors. During the year 2011/2012, in the CETESB IPEN/USP station the class of aldehydes represented 35.3% of VOCs analyzed in concentration in the atmosphere, followed by ethanol 22.6%, aromatics 15.7%, alkanes 13.5%, ketones 6.8%, alkenes 6.0% and alkadienes <0.1%. Considering the concentration of the compounds and their reactivity, the simulations executed with the model showed that acetaldehyde OZIPR contributed with 61.2% to the formation of O3 in the atmosphere of MASP in the year 2011/2012. VOCs analyzed, the class of aldehydes contributed with 74% of the production of O3, aromatics 14.5%, alkenes 10.2%, alkanes 1.3% and alkadienes (isoprene) 0.03%. The study of vehicular emission showed that 39% of aldehydes were obtained from ethanol vehicles, 28% diesel, 26% gasoline and 7% of motorcycles. Emissions of VOCs by gasoline vehicles contributed with 44% of the formation of O3, diesel 22%, ethanol 19% and motorcycles gasoline 15%.

Viruses can affect plant-insect interactions by altering emission of plant volatile organic compounds (VOCs). Previous work in the lab suggested that VOCs emitted by tomato (Solanum lycopersicum) plants infected with cucumber mosaic virus (CMV) were more attractive to bumblebees (Bombus terrestris) in free choice assays. I extended this work using Arabidopsis thaliana mutants with lesions in genes encoding factors in RNA silencing. In conditioning assays, I confirmed that plant VOC emission is controlled in part by the microRNA regulatory pathway. I used gas chromatography coupled to mass spectrometry and principal component analysis to confirm that CMV infection caused changes in VOC emission by tomato. VOCs collected from non-flowering mock-inoculated and CMV-infected plants were qualitatively distinct from each other. CMV-infected plants also released greater quantities of VOCs than mock-inoculated plants. CMV appears to be both ‘turning up the volume’ of plant volatile emission, whilst ‘tuning’ volatile blend composition so as to diminish levels of a repellant signal. These data are likely to explain how bumblebees can discriminate between VOCs emitted by mock-inoculated and CMV-infected plants. To determine if CMV infection of tomato plants affects plant reproductive success, I carried out a series of bumblebee pollination experiments. Bumblebees pollinate tomato by ‘buzzing’ (sonicating) the flowers, which releases pollen and enhances self-fertilization and seed production as well as pollen export. First, I established that CMV-infected tomato plants produced fruits with a lower seed yield than mock-inoculated plants. When single bumblebees were allowed to buzz-pollinate flowers in a small flying arena, the fruit that developed from buzz-pollinated flowers on virus infected plants had significantly more seeds than fruit from non-visited flowers. Subsequent experiments were performed in a large flying arena. Bumblebees consistently spent longer foraging on the mock-inoculated tomato plants but seed yield was increased by bumblebee pollination in both mock-inoculated as well as virus-infected tomato plants. However, although buzz-pollination significantly enhanced seed yield from CMV-infected plants compared to fruit from non-buzz-pollinated flowers, the yield was higher in buzz-pollinated fruits from mock-inoculated plants. Similar experiments were carried out utilizing a transgenic line of tomato that constitutively expresses the green fluorescent protein in order to estimate the level of cross-pollination from either CMV-infected plants to mock-inoculated plants or vice versa. More pollen from virus-infected plants was transferred to mock-inoculated plants than the reciprocal cross. However, some caution is needed in the interpretation of the larger scale experiments because the tomato plants were affected by a fungal infection. I investigated if the defensive plant hormone salicylic acid (SA) affects bee-perceivable VOC emission. Exogenous SA treatment renders non-flowering tomato plants more attractive to bumblebees in free choice experiments in which bees could only perceive VOCs, but bumblebees spent less time visiting SA-treated flowering tomato plants in the glasshouse (when the bumblebees were allowed unimpeded access to the flowers). Taken together, these data provide evidence that virus infection can affect host-pollinator interactions. Speculatively, CMV infection may change the fitness of susceptible plants via changes in production of pollinator-attractive VOCs and this may affect the balance of resistant or susceptible plants within the host population.

Cheung Hiu-Ming. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 140-150). / Abstracts in English and Chinese. / ABSTRACT --- p.i / ACKNOWLEDGEMENTS --- p.vi / LIST OF FIGURES --- p.xiii / LIST OF TABLES --- p.xv / Chapter CHAPTER 1 --- LITERATURE REVIEW --- p.1 / Chapter 1.1 --- Introduction --- p.2 / Chapter 1.2 --- Soybeans --- p.3 / Chapter 1.2.1 --- Chemistry and nutritional value of soybeans --- p.3 / Chapter 1.2.2 --- Protein composition of soybeans --- p.4 / Chapter 1.2.3 --- Volatile compounds in soybeans --- p.4 / Chapter 1.3 --- Food fermentation --- p.5 / Chapter 1.4 --- Chaw tofu --- p.6 / Chapter 1.4.1 --- Preparation of tofu --- p.7 / Chapter 1.4.2 --- Preparation of chaw tofu --- p.7 / Chapter 1.4.3 --- Microorganisms involved in fermentation of chaw tofu --- p.8 / Chapter 1.4.4 --- Volatile components in chaw tofu --- p.11 / Chapter 1.4.5 --- Proteolytic activity of chaw tofu --- p.12 / Chapter 1.5 --- Stinky brine broth --- p.13 / Chapter 1.5.1 --- The pH value of stinky brine broth --- p.13 / Chapter 1.5.2 --- The salt percentage of stinky brine broth --- p.14 / Chapter 1.5.3 --- Volatile components of stinky brine broth --- p.14 / Chapter 1.5.4 --- Parameters affecting ammonia production of stinky brine --- p.15 / Chapter 1.6 --- Other fermented soy products --- p.16 / Chapter 1.6.1 --- Microorganisms involved in the fermentation --- p.16 / Chapter 1.6.1.1 --- Fermentation of soybean by bacteria --- p.17 / Chapter 1.6.1.1.1 --- Natto --- p.17 / Chapter 1.6.1.1.2 --- Kinema --- p.18 / Chapter 1.6.1.1.3 --- Soy daddawa --- p.19 / Chapter 1.6.1.1.4 --- Hawaijar --- p.20 / Chapter 1.6.1.1.5 --- Thua nao --- p.21 / Chapter 1.6.1.2 --- Fermentation of soybean by moulds --- p.21 / Chapter 1.6.1.2.1 --- Tempe --- p.21 / Chapter 1.6.1.2.2 --- Sufu --- p.22 / Chapter 1.6.1.2.3 --- Soy sauce --- p.22 / Chapter 1.6.1.2.4 --- Soy paste --- p.23 / Chapter 1.6.2 --- Formation of volatile compounds during Bacillus fermentation --- p.24 / Chapter 1.6.3 --- Biochemical changes during fermentation --- p.21 / Chapter 1.7 --- Methods of flavor analysis --- p.30 / Chapter 1.7.1 --- Headspace Analysis --- p.31 / Chapter 1.7.2 --- Aroma characterization --- p.32 / Chapter CHAPTER 2 --- IDENTIFICATION OF ODOROUS COMPOUNDS IN COMMERCIAL CHAW TOFU BASED ON ODOR ACTIVITY EVALUATION --- p.42 / Chapter 2.1 --- Introduction --- p.43 / Chapter 2.2 --- Materials & Methods --- p.46 / Chapter 2.2.1 --- Experimental samples --- p.46 / Chapter 2.2.2 --- Headspace-Gas Chromatography-Mass Spectrometry (GC-MS) --- p.46 / Chapter 2.2.3 --- Conditions of the Gas Chromatography-Mass Spectrometry (GC-MS) --- p.47 / Chapter 2.2.4 --- Compound identifications --- p.48 / Chapter 2.2.5 --- Quantification of compounds --- p.48 / Chapter 2.2.6 --- Statistical analysis --- p.48 / Chapter 2.2.7 --- Calculation of odor activity value (OAV) --- p.49 / Chapter 2.3 --- Results & Discussion --- p.50 / Chapter 2.3.1 --- Odor activity value (OAV) --- p.51 / Chapter 2.3.2 --- Volatile compounds in fresh samples --- p.51 / Chapter 2.3.2.1 --- Comparison of odorous compounds in fresh samples among different locations --- p.52 / Chapter 2.3.3 --- Volatile compounds in deep-fat fried samples --- p.53 / Chapter 2.3.3.1 --- Comparison of odorous compounds in deep-fat fried samples among different locations --- p.54 / Chapter 2.3.4 --- Comparison between fresh and deep-fat fried samples --- p.55 / Chapter 2.3.5 --- Odorous compounds of chaw tofu based on OAVs --- p.56 / Chapter 2.3.6 --- Possible ways for formation of odorous compounds --- p.58 / Chapter 2.3.6.1 --- Protein degradation --- p.58 / Chapter 2.3.6.2 --- Lipid degradation --- p.59 / Chapter 2.3.7 --- Comparison between volatile compounds in chaw tofu and others fermented soybean products --- p.60 / Chapter 2.4 --- Conclusion --- p.61 / Chapter CHAPTER 3 --- IDENTIFICATION OF ODOROUS COMPOUNDS IN COMMERCIAL CHAW TOFU BASED ON GAS CHROMATOGRAPHY-OLFACTOMETRY --- p.67 / Chapter 3.1 --- Introduction --- p.68 / Chapter 3.2 --- Materials & Methods --- p.71 / Chapter 3.2.1 --- Experimental samples --- p.71 / Chapter 3.2.2 --- Gas Chromatography-Mass Spectrometry-Flame Ionization Detection-Olfactometry (GC-MS-FID-O) --- p.71 / Chapter 3.2.3 --- Conditions of the Gas Chromatography-Mass Spectrometry --- p.72 / Chapter 3.2.4 --- Detection of odor active compounds --- p.73 / Chapter 3.2.5 --- Compound identifications --- p.73 / Chapter 3.3 --- Results & Discussion --- p.74 / Chapter 3.3.1 --- "Fecal, rancid and putrid odor" --- p.74 / Chapter 3.3.2 --- "Cabbages, sulfurous and meaty odor" --- p.76 / Chapter 3.3.3 --- Green odor --- p.77 / Chapter 3.3.4 --- Other odor contributing compounds --- p.77 / Chapter 3.3.5 --- Odor generate during deep-fat frying --- p.78 / Chapter 3.3.6 --- Comparison between GC-O and OAVs --- p.79 / Chapter 3.3.7 --- Comparison between volatile compounds in chaw tofu and others fermented soybean products --- p.80 / Chapter 3.4 --- Conclusion --- p.82 / Chapter CHAPTER 4 --- EVALUATION OF CHAW TOFU MODEL FERMENTATION BROTH --- p.86 / Chapter 4.1 --- Introduction --- p.87 / Chapter 4.2 --- Materials & Methods --- p.90 / Chapter 4.2.1 --- Model fermentation broth preparation --- p.90 / Chapter 4.2.2 --- Tofu sample preparation --- p.91 / Chapter 4.2.3 --- Gas Chromatography-Mass Spectrometry --- p.91 / Chapter 4.2.3.1 --- Conditions of Gas Chromatography-Mass Spectrometry (GC-MS) --- p.92 / Chapter 4.2.3.2 --- Compound identification --- p.93 / Chapter 4.2.3.3 --- Quantification of compounds --- p.93 / Chapter 4.2.4 --- Viable cell counts --- p.93 / Chapter 4.2.5 --- pH value and soluble content --- p.94 / Chapter 4.2.6 --- Proteolytic activity --- p.94 / Chapter 4.2.7 --- Statistical analysis --- p.95 / Chapter 4.3 --- Results & Discussion --- p.96 / Chapter 4.3.1 --- Headspaces analysis --- p.96 / Chapter 4.3.1.1 --- Changes in volatile composition in model fermentation broths --- p.97 / Chapter 4.3.1.2 --- Comparison of volatile compositions between the broths --- p.98 / Chapter 4.3.1.3 --- Comparison of volatile compositions among the three deep-fat fried fermented tofu with different broths --- p.101 / Chapter 4.3.1.4 --- Comparison of volatile compositions of deep fat fried fermented tofu with that of the commercial chaw tofu --- p.102 / Chapter 4.3.2 --- Liquid samples analysis --- p.104 / Chapter 4.3.2.1 --- "Changes in viable cell counts, pH values, protease activities and soluble solid contents within model fermentation broths during fermentation" --- p.106 / Chapter 4.3.2.2 --- Viable cell counts --- p.107 / Chapter 4.3.2.3 --- Soluble solid content --- p.108 / Chapter 4.3.2.4 --- Proteolytic activity --- p.106 / Chapter 4.3.2.5 --- pH value --- p.110 / Chapter 4.4 --- Conclusion --- p.112 / Chapter CHAPTER 5 --- GENERAL CONCLUSION --- p.127 / APPENDIX --- p.130 / IDENTIFICATION OF MICROORGANISMS PRESENTED IN THE MODEL CHAW TOFU FERMENTATION BROTHS BY MICROBIAL IDENTIFICATION SYSTEM (MIDI) --- p.130 / Materials & Methods --- p.130 / Model fermentation broth preparation --- p.130 / Viable cell counts --- p.131 / Microbial Identification System (MIDI) --- p.131 / Results --- p.133 / Suggestion on further investigation --- p.134 / REFERNECES --- p.141

Lam, Hon Yiu. / "November 2011." / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 122-135). / Abstracts in English and Chinese. / Abstract (in English) --- p.i / Abstract (in Chinese) --- p.iv / Acknowledgement --- p.vi / Contents --- p.vii / List of Abbreviations --- p.xiii / List of Figures --- p.xiv / List of Tables --- p.xvii / Chapter 1 --- Literature review / Chapter 1.1 --- Introduction --- p.1 / Chapter 1.2 --- Flavor of fish --- p.3 / Chapter 1.2.1 --- Carbonyls (aldehydes and ketones) and alcohols --- p.4 / Chapter 1.2.2 --- Sulfur-containing compounds --- p.5 / Chapter 1.2.3 --- Thermally-induced flavor --- p.5 / Chapter 1.2.4 --- Deteriorated fish flavor --- p.6 / Chapter 1.2.5 --- Autoxidation --- p.7 / Chapter 1.2.6 --- Bromophenols --- p.8 / Chapter 1.3 --- Bromophenols in aquaculture --- p.8 / Chapter 1.3.1 --- General properties of bromophenols --- p.9 / Chapter 1.3.2 --- Biosynthetic pathway of bromophenol in marine algae --- p.12 / Chapter 1.3.3 --- Thresholds of bromophenols --- p.14 / Chapter 1.3.4 --- Toxicity of bromophenols --- p.17 / Chapter 1.4 --- Giant Grouper --- p.19 / Chapter 1.4.1 --- Living Habitat of Giant Grouper --- p.19 / Chapter 1.4.2 --- Biological features of Giant Grouper --- p.23 / Chapter 1.4.3 --- Aquaculture of Giant Grouper --- p.23 / Chapter 1.5 --- Flavor analysis and extraction methods --- p.23 / Chapter 1.5.1 --- Solvent extraction --- p.25 / Chapter 1.5.2 --- Simultaneous Steam Distillation/Extraction --- p.25 / Chapter 1.5.3 --- Headspace sampling --- p.27 / Chapter 1.5.4 --- Gas Chromatography/Olfactometry (GCO) --- p.28 / Chapter 1.5.5 --- Food chemistry and Odor Threshold Value --- p.30 / Chapter 2 --- Distribution of bromophenols in selected Hong Kong dried seafood / Chapter 2.1 --- Introduction --- p.33 / Chapter 2.2 --- Materials and Methods --- p.34 / Chapter 2.2.1 --- Sample preparation --- p.34 / Chapter 2.2.2 --- "Preparation of the internal standard, Pentachloroanisole" --- p.35 / Chapter 2.2.3 --- Simultaneous steam distillation-solvent extraction (SDE) --- p.35 / Chapter 2.2.4 --- Gas chromatography-mass spectrometry (GC-MS) --- p.36 / Chapter 2.2.5 --- Compound identification --- p.37 / Chapter 2.2.6 --- Quantification of compounds --- p.37 / Chapter 2.2.7 --- Recovery --- p.37 / Chapter 2.2.8 --- Odor activity value (OAV) --- p.38 / Chapter 2.2.9 --- Statistical Analysis --- p.38 / Chapter 2.3 --- Results and discussion --- p.39 / Chapter 2.3.1 --- Distribution of bromophenols in dried seafoods --- p.39 / Chapter 2.3.2 --- Bromophenol contents in dried seaweeds --- p.51 / Chapter 2.3.3 --- Bromophenol contents in dried crustacean --- p.52 / Chapter 2.3.4 --- Bromophenol contents in dried mollusks --- p.53 / Chapter 2.3.5 --- Bromophenol contents in dried-salted fishes --- p.54 / Chapter 2.3.6 --- Relationship between living habitat and bromophenol contents --- p.55 / Chapter 2.3.7 --- Flavor impact of bromophenols in dried seafood --- p.57 / Chapter 2.3.8 --- Comparison of bromophenol content in purchased dried laminaria with Qingdao seaweed powder and bloodworms --- p.64 / Chapter 2.4 --- Conclusion --- p.67 / Chapter 3 --- Bromophenol content retention and fish quality in giant grouper / Chapter 3.1 --- Introduction --- p.70 / Chapter 3.2 --- Materials and Methods --- p.71 / Chapter 3.2.1 --- Abbreviation of treatment groups --- p.71 / Chapter 3.2.2 --- Sample preparation --- p.72 / Chapter 3.2.3 --- Ingredients --- p.72 / Chapter 3.2.4 --- Production of fish feed --- p.73 / Chapter 3.2.5 --- Preparation of the internal standard，Pentachloroanisole --- p.73 / Chapter 3.2.6 --- Simultaneous steam distillation-solvent extraction (SDE) --- p.75 / Chapter 3.2.7 --- Gas chromatography-mass spectrometry (GC-MS) --- p.75 / Chapter 3.2.8 --- Bromophenol identification and quantification --- p.76 / Chapter 3.2.9 --- Recovery of bromophenols --- p.76 / Chapter 3.2.10 --- Muscle color determination --- p.76 / Chapter 3.2.11 --- Texture analysis --- p.77 / Chapter 3.2.12 --- Moisture determination --- p.78 / Chapter 3.2.13 --- Ash determination --- p.78 / Chapter 3.2.14 --- Fat determination --- p.78 / Chapter 3.2.15 --- Protein determination --- p.79 / Chapter 3.2.16 --- Statistical Analysis --- p.80 / Chapter 3.3 --- Results and discussion --- p.80 / Chapter 3.3.1 --- Muscle color of giant grouper --- p.81 / Chapter 3.3.2 --- Texture of giant grouper --- p.85 / Chapter 3.3.3 --- Proximate analysis of giant grouper --- p.86 / Chapter 3.3.4 --- Bromophenol depuration of giant grouper --- p.92 / Chapter 3.4 --- Conclusion --- p.101 / Chapter 4 --- Volatile compounds in giant grouper / Chapter 4.1 --- Introduction --- p.102 / Chapter 4.2 --- Materials and Methods --- p.103 / Chapter 4.2.1 --- Sample preparation --- p.103 / Chapter 4.2.2 --- "Preparation of the internal standard, 2,4,6Trimethylpyridine (TMP)" --- p.104 / Chapter 4.2.3 --- Dynamic headspace (purge-and-trap) --- p.104 / Chapter 4.2.4 --- Simultaneous steam distillation-solvent extraction (SDE) --- p.105 / Chapter 4.2.5 --- Gas chromatography-mass spectrometry (GC-MS) --- p.105 / Chapter 4.2.6 --- Compound identification --- p.106 / Chapter 4.2.7 --- Quantification of compounds --- p.106 / Chapter 4.2.8 --- Recovery --- p.107 / Chapter 4.2.9 --- Odor activity value (OAV) --- p.108 / Chapter 4.2.10 --- Statistical analysis --- p.108 / Chapter 4.3 --- Results and discussion --- p.108 / Chapter 4.3.1 --- Comparison of extraction between dynamic headspace and SDE --- p.108 / Chapter 4.3.2 --- Flavor profile of giant grouper --- p.113 / Chapter 4.3.2.1 --- carbonyls and alcohol --- p.113 / Chapter 4.3.2.2 --- Other aroma volatile compounds in giant grouper --- p.116 / Chapter 4.3.3 --- Giant grouper tainted by water contamination --- p.116 / Chapter 4.4 --- Conclusion --- p.118 / Chapter 5 --- General conclusion --- p.119 / References --- p.122 / Appendix --- p.136

腐乳是中國傳統豆類發酵製品，具有綿軟的口感和特殊的風味。其是豆腐通過真菌固態發酵，并加入鹽，米酒和香料等進行後期熟化而成的產品。本文的研究分為兩部份，第一部份對腐乳發酵過程中的毛胚，鹽胚，熟化第一天，熟化一個月以及熟化六個月的腐乳樣本進行採樣，并採用傳統微生物培養法和克隆文庫法對每個階段真菌和細菌的生態結構和動態變化進行研究。第二部份重點比較了四株腐乳產品中分離的微生物和購自台灣生物資源保存及研究中心的四株細菌的產揮發性含硫化合物能力，并挑選了最高產的一株微生物進行紫外誘變，最後獲得理想的突變株。本研究的結論如下： / 1. 真菌和細菌的總數均是在毛胚階段為最高，在進入熟化階段后開始下降。在傳統微生物培養方法下分別分離出了三株真菌和九株細菌，通過18S rDNA和16 rDNA測序，發現絲孢酵母屬（Trichosporon spp.）是真菌中的優勢菌種，蠟狀芽孢桿菌（Bacillus cereus）和解澱粉芽孢桿菌（Bacillus amyloliquefaciens）為細菌中的優勢菌種； / 2. 本研究建立了五個真菌18S rDNA克隆文庫和五個細菌16 rDNA克隆文庫用于研究真菌和細菌的生態結構和動態變化。通過聚合酶鏈式反應-限制性片段長度多態性（PCR-RFLP）的研究，分別在真菌和細菌克隆文庫中發現23和38種圖譜類型，并計算其相應比例。在進行真菌細菌測序之後，對優勢菌群進行了定性和定量分析； / 3. 在對比傳統微生物培養方法和克隆文庫技術的結果后發現，二者的結果存有差異，有些在克隆文庫中鑒定到的微生物在傳統培養方法中未能分離鑒定，而有些微生物則只能在傳統培養方法中被分離鑒定。因此，本研究中將這兩種方法結合有助於我們更為全面、客觀地研究腐乳發酵過程中真菌和細菌的生態結構和多樣性。 / 4. 對四株腐乳中分離純化的微生物和四株外來購入細菌的產揮發性含硫化合物能力進行比較，結果發現，從腐乳產品中分離純化的B-1菌株擁有最高的產揮發性含硫化合物能力，通過紫外誘變后，突變株#3在產揮發性含硫化合物以及L-蛋氨酸代謝酶活力都比初始菌株有了顯著的提升。B-1菌經測序比對后鑒定為絲孢酵母（Trichosporon sp.）。 / 本研究結果對于傳統腐乳發酵的有效控制和現代腐乳生產工藝的建立有一定指導意義，並且對於腐乳產品中的風味物質，特別是揮發性含硫化合物的產生和優化提供信息。 / Sufu (fermented soybean curd) is a soft creamy cheese-type product with a pronounced flavor and is made by fungal solid state fermentation of tofu (soybean curd) followed by aging in brine containing salt and alcohol. In first part of this research, the eco-structure and the dynamic changes of microbes during sufu production process (Pehtze, Salted pehtze, 0 Month sufu, 1 Month sufu and 6 Month sufu sample) were studied by combined microbiology techniques, including plate culture, 16S rDNA and 18S rDNA clone library and restriction fragment length polymorphism (RFLP) analysis. The second part of this research focus on the comparison of volatile sulfur-containing compounds (VSCs) production ability within isolated strains in sufu product and bacteria purchased commercially, the strain that possessed highest ability was selected and followed by a UV mutation experiment, finally obtained the desired mutant. The results of this research are as followed: / 1. The population of both fungi and bacteria were all at highest number in Pehtze stage and started to decrease in ripening stages. A combined total of three and nine living strains of fungi and bacteria were obtained from the plate culture, respectively. Through 18S rDNA and 16S rDNA sequencing, Trichosporon spp. was the dominant fungi and Bacillus cereus and Bacillus amyloliquefaciens were the dominant bacteria; / 2. Five 18S rDNA clone libraries and five 16S rDNA clone libraries from different stages of sufu production were constructed to analyze the structure and dynamic changes of fungi and bacteria. A total of 23 and 38 RFLP patterns were found, and the ratio of each pattern were calculated. After sequencing, qualitative and quantitative analysis on the dynamic changes of dominant strains was performed; / 3. After comparing the results of plate culture and clone library, it was found that there were some differences between the two. Some strains were only found in clone library while some only found in plate culture approach. Therefore, the combination of the two microbiology methods will help us to objectively and completely analyze the structure and dynamic changes of microbes in the sufu production process; / 4. The ability to produce VSCs within four strains (B-1, B-2, B-3 & B-4) isolated from a commercial sufu manufacturing process and four commercial strains (B. acetylicum, L. Lactics, S. thermophilus and L. Paracasei) were compared. Results showed that B-1 possessed both the highest VSCs production ability and L-methionine metabolism enzymatic activities among the eight strains. After UV light mutagenesis of B-1 strain, its mutant #3 significantly increased in DMDS and DMTS production and all four L-methionine-related enzymatic activities in reference to that of the starting strain (B-1). B-1 was identified as Trichosporon sp. by sequencing. / These results would make a profound significance on the control of traditional sufu production and the development of new technology for modern sufu manufacturing. They will also help to provide some important information of optimal production of VSCs in sufu ripening and the overall flavor in sufu product. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Huang, Ruolan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 106-117). / Abstracts also in Chinese. / Abstract --- p.i / 摘要 --- p.iii / Acknowledgement --- p.v / Table of contents --- p.vi / List of Figures --- p.x / List of Tables --- p.xiii / Chapter Chapter 1 --- : Introduction --- p.1 / Chapter 1.1 --- Sufu --- p.1 / Chapter 1.1.1 --- Classification --- p.1 / Chapter 1.1.1.1 --- Classified by processing technology --- p.1 / Chapter 1.1.1.2 --- Classified by color and flavor --- p.1 / Chapter 1.1.1.3 --- Other classifications --- p.2 / Chapter 1.1.2 --- Typical commercial manufacturing process --- p.2 / Chapter 1.1.2.1 --- Production process of naturally fermented sufu --- p.2 / Chapter 1.2.2.2 --- Production process of traditional mold-based sufu --- p.5 / Chapter 1.2.2.3 --- Production process of traditional bacteria-based sufu --- p.5 / Chapter 1.2.2.4 --- Acceleration of sufu ripening process --- p.6 / Chapter 1.1.3 --- Important ingredients in sufu production --- p.6 / Chapter 1.1.4 --- Flavor components in sufu --- p.7 / Chapter 1.1.4.1 --- Volatile flavor components --- p.7 / Chapter 1.1.4.2 --- Essential odor in sufu product --- p.8 / Chapter 1.1.4.3 --- Volatile sulfur compounds in sufu --- p.9 / Chapter 1.1.4.4 --- Using Head Space-Solid phase Microextraction (HS-SPME) to analyze the volatile sulfur components --- p.9 / Chapter 1.1.5 --- Relationship between microbes and sufu --- p.12 / Chapter 1.1.5.1 --- Microbes involved in fermentation process --- p.13 / Chapter 1.1.5.2 --- Microbial changes during the production of sufu --- p.14 / Chapter 1.1.6 --- Study on microbial ecology in food product --- p.15 / Chapter 1.1.6.1 --- PCR-based molecular techniques --- p.16 / Chapter 1.1.6.2 --- Non-PCR based molecular techniques --- p.16 / Chapter 1.1.6.3 --- The common techniques used in microbial ecology research --- p.17 / Chapter 1.1.6.4 --- Microbial ecology study by molecular biological techniques --- p.18 / Chapter 1.2 --- Objectives --- p.19 / Chapter Chapter 2 --- : Analysis of fungi diversity during sufu fermentation process --- p.21 / Chapter 2.1 --- Introduction --- p.21 / Chapter 2.2 --- Materials and methods --- p.21 / Chapter 2.2.1 --- Sample collection and preparation --- p.22 / Chapter 2.2.2 --- Plate count of fungi during sufu fermentation process --- p.22 / Chapter 2.2.3 --- Change of pH values and moisture content --- p.22 / Chapter 2.2.4 --- Total DNA extraction from fungi --- p.23 / Chapter 2.2.5 --- Preparation of competent cell --- p.23 / Chapter 2.2.6 --- 18S rDNA PCR amplification and construction of 18S rDNA clone library --- p.24 / Chapter 2.2.7 --- RFLP analysis of 18S rDNA clone library --- p.25 / Chapter 2.2.8 --- DNA sequencing for fungi identification --- p.26 / Chapter 2.2.9 --- Analysis of the diversity of 18S clone library --- p.26 / Chapter 2.2.10 --- Frequency percentage analysis --- p.27 / Chapter 2.2.11 --- Enzyme Solutions --- p.27 / Chapter 2.2.12 --- Determination of protease activity --- p.28 / Chapter 2.2.13 --- Determination of lipase activity --- p.29 / Chapter 2.2.11 --- Microtox test --- p.30 / Chapter 2.2.12 --- Statistical analysis --- p.30 / Chapter 2.3 --- Results and discussion --- p.30 / Chapter 2.3.1 --- Fungi growth on plate counting result --- p.30 / Chapter 2.3.2 --- Changes in pH and moisture content of sufu during production --- p.33 / Chapter 2.3.3 --- Construction and selection of 18S rDNA clone library --- p.35 / Chapter 2.3.4 --- Fungal diversity based on 18S rDNA clone library analysis --- p.38 / Chapter 2.3.5 --- Protease and lipase activities in Actinomucor elegans and Trichosporon japonicum --- p.45 / Chapter 2.3.5.1 --- Protease activity --- p.46 / Chapter 2.3.5.2 --- Lipase activity --- p.47 / Chapter 2.3.6 --- Toxicity of Actinomucor elegans and Trichosporon japonicum --- p.49 / Chapter 2.3.7 --- Analysis of fungi eco-structure and function during sufu fermentation process --- p.50 / Chapter 2.3.8 --- The influence of PCR bias and artifact --- p.53 / Chapter 2.2 --- Summary --- p.55 / Chapter Chapter 3 --- : Analysis of bacteria diversity during sufu fermentation process --- p.57 / Chapter 3.1 --- Introduction --- p.57 / Chapter 3.2 --- Materials and methods --- p.57 / Chapter 3.2.1 --- Sample collection and preparation --- p.57 / Chapter 3.2.2 --- Plate count of bacteria during sufu fermentation process --- p.57 / Chapter 3.2.3 --- Total DNA extraction from bacteria --- p.58 / Chapter 3.2.4 --- Preparation of competent cell --- p.58 / Chapter 3.2.5 --- 16S rDNA PCR amplification and construction of 16S rDNA clone library --- p.58 / Chapter 3.2.6 --- RFLP analysis of 16S rDNA clone library --- p.59 / Chapter 3.2.7 --- DNA sequencing for bacteria identification --- p.60 / Chapter 3.2.8 --- Analysis of the diversity of 16S rDNA clone library --- p.60 / Chapter 3.3 --- Results and discussion --- p.60 / Chapter 3.3.1 --- Bacteria growth on plate counting result --- p.60 / Chapter 3.3.2 --- Construction and selection of 16S rDNA clone library --- p.63 / Chapter 3.3.3 --- 16S rDNA clone library analysis of bacteria diversity --- p.65 / Chapter 3.3.4 --- Analysis of bacteria eco-structure and function during sufu fermentation process --- p.74 / Chapter 3.4 --- Summary --- p.77 / Chapter Chapter 4 --- : Screening the mutant possess higher capacity of forming volatile sulfur compounds (VSCs) from non-starter microbes of sufu product --- p.80 / Chapter 4.1 --- Introduction --- p.80 / Chapter 4.2 --- Materials and methods --- p.82 / Chapter 4.2.1 --- Strains and culture conditions --- p.82 / Chapter 4.2.2 --- Head space-solid phase microextraction (HS-SPME) analysis --- p.83 / Chapter 4.2.3 --- Gas Chromatography-Mass Spectrometry (GC-MS) analysis --- p.84 / Chapter 4.2.4 --- UV mutation --- p.85 / Chapter 4.2.5 --- Ellman’s method --- p.86 / Chapter 4.2.6 --- Preparation of cell-free extracts (CFE) for enzymatic assays --- p.86 / Chapter 4.2.7 --- Enzymatic assay --- p.86 / Chapter 4.2.7.1 --- L-methionine aminotransferase activity assay --- p.86 / Chapter 4.2.7.2 --- L-methionine demethiolase activity assay --- p.87 / Chapter 4.2.7.3 --- α-keto acid decarboxylase activity assay --- p.87 / Chapter 4.2.7.4 --- C-S lyase activity --- p.88 / Chapter 4.2.8 --- Statistical analysis --- p.88 / Chapter 4.3 --- Results and discussion --- p.89 / Chapter 4.3.1 --- Optimization of SPME extraction condition --- p.89 / Chapter 4.3.2 --- Selecting the start strain --- p.90 / Chapter 4.3.4.1 --- Comparison of VSCs production ability --- p.90 / Chapter 4.3.4.2 --- Comparison of enzymatic activity in L-methionine metabolism --- p.92 / Chapter 4.3.3 --- Optimization of UV exposure time --- p.95 / Chapter 4.3.4 --- Screening the mutants --- p.96 / Chapter 4.3.4.1 --- Comparison of VSCs production ability among the mutants --- p.96 / Chapter 4.3.4.2 --- Comparison of the L-methionine related enzymatic activities among the mutants --- p.99 / Chapter 4.3.4.3 --- Identified of strian B-1 --- p.101 / Chapter 4.4 --- Summary --- p.102 / Chapter Chapter 5 --- : General conclusions and future work --- p.103 / References --- p.106

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O presente estudo teve como objetivo quantificar as emissões de Compostos Orgânicos Voláteis do Aterro Controlado Morro do Céu localizado na cidade de Niterói, Rio de Janeiro, Brasil. Para tanto, vinte amostras foram coletadas, usando uma bomba de ar operada a bateria durante dois dias de dezembro de 2009. Uma câmara de fluxo cilíndrica de PVC de 30L foi inserida 5 cm no solo do aterro, e as amostras foram coletadas através de uma válvula na parte superior da câmera. Os resultados indicaram um valor de 1.980 Kg Km-2 h-1. O modelo Gaussiano de dispersão atmosférica ISCST3 foi utilizado para calcular a difusão e transporte dos poluentes a fim de estimar as concentrações de COV no bairro, usando dados topográficos, meteorológicos e de emissões. Valores de 525 &#956;g m-3 de COV foram encontrados a 500 metros do aterro. As emissões do aterro foram usadas em conjunto com dados meteorológicos, utilizando o modelo de trajetória OZIPR e o mecanismo químico SAPRC para demonstrar o impacto na formação do ozônio troposférico na região. É conhecido que o ozônio é formado pela reação entre COV, NOx e luz solar. A contribuição de valores elevados de COV provenientes das emissões do aterro conduzirá a uma nova situação com valores mais elevados de ozônio na região. Os resultados da modelagem indicaram um aumento maior que 1000% nos níveis de ozônio na região do aterro, se comparado com a modelagem do ozônio para a região metropolitana do Rio de Janeiro. Os resultados mostram ser necessário que maior atenção seja dada à política de gerenciamento de RSU no Brasil, incluindo a escolha adequada para o local de instalação, o monitoramento da área durante e após o período de operação e técnicas mais adequadas de disposição dos resíduos sólidos urbanos / The purpose of this work was to quantify the Volatile Organic Compounds emissions by a landfill (Morro do Céu), located in Niterói, Rio de Janeiro State, Brazil. Twenty 10-minute samples were collected using a battery-operated air pump operated at 500 mL min-1, over a period of four days in May and December, 2009. A cylindrical 30 L PVC flux chamber was used, the open, bottom side of which was inserted into the landfill soil to a depth of 5 cm. The samples were collected using a valve at the upper, closed side of the chamber. The results indicated an elevated value of 1,980 kg km-2 h-1. A Gaussian plume dispersion model, implemented by Aermod software, was used to calculate the diffusion and transport of pollutants, and the pollutant concentrations in the surroundings were estimated using the emission, meteorological, and topographical data. Maximum values of 525 &#956;g m-3 for VOC were found at approximately 500 m from the landfill. The landfill emissions were also compiled with meteorological data, using the OZIPR trajectory model coupled with SAPRC chemical mechanism, to demonstrate their impact on the formation of tropospheric ozone. It is well known that ozone is formed by the reactions of VOC, NOx and sunlight. The contribution of high VOC levels from the landfill emissions was expected to lead to higher ozone values. The results indicated a 1000% increase in ozone in the region of the landfill, compared to the ozone values for the metropolitan region of Rio de Janeiro. The results show that it is both necessary and desirable that greater attention be given to the political management of municipal solid waste in the Brazil, including the location choice, the monitoring of landfill areas during and after their period of operation and techniques more appropriate of disposition of municipal solid waste

O ozônio (O3) é um dos poluentes que representa grande preocupação em termos de qualidade do ar na Região Metropolitana de São Paulo (RMSP). No ano de 2012 foram observados 98 dias de ultrapassagens do padrão horário da qualidade do ar para este poluente na RMSP. A exposição aos poluentes atmosféricos como O3 e outros está associada ao prejuízo da saúde respiratória. O enfoque deste estudo é determinar os principais Compostos Orgânicos Voláteis (COV) precursores de O3 para auxiliar no controle deste poluente. Neste trabalho foram realizadas 78 amostragens durante a semana de hidrocarbonetos no ano de 2006 e 66 amostragens de hidrocarbonetos, 62 de aldeídos e 42 de etanol durante o ano de 2011/2012, 7:00 h às 9:00 h, na estação CETESB IPEN/USP. Medidas de COV também foram realizadas no ano de 2006 e 2008, na Estação CETESB Cerqueira César. Adicionalmente, foram efetuados testes de emissões veiculares durante o ano de 2009 de 5 veículos a diesel, 3 a etanol, 2 a gasolina C e 1 motocicleta. O modelo de trajetórias OZIPR foi utilizado para determinar os principais precursores de O3. Durante o ano de 2011/2012, na Estação CETESB IPEN/USP, a classe de aldeídos representou 35,3% dos COV analisados em concentração na atmosfera, seguido pelo etanol 22,6%, compostos aromáticos 15,7%, alcanos 13,5%, cetonas 6,8%, alcenos 6,0% e alcadienos < 0,1%. Considerando a concentração dos compostos e sua reatividade, as simulações executadas com o modelo OZIPR mostraram que o acetaldeído contribuiu com 61,2% da formação do O3 na atmosfera da RMSP no ano de 2011/2012. Dos COV analisados, a classe dos aldeídos contribui com 74% da produção de O3, aromáticos 14,5%, alcenos 10,2%, alcanos 1,3% e alcadienos (isopreno) 0,03%. O estudo de emissão veicular mostrou que 39% dos aldeídos foram provenientes de veículos a etanol, 28% a diesel, 26% a gasolina C e 7% de motocicletas. As emissões dos COV por veículos a gasolina contribuíram com 44% da formação de O3, a diesel 22%, a etanol 19% e motocicletas 15%. / Ozone (O3) is a pollutant that represents great concern in terms of air quality in the metropolitan area of São Paulo (MASP). In 2012 were observed 98 days of exceedances of the standard time air quality for this pollutant in the MASP. Exposure to air pollutants such as O3 and others is associated with the injury of respiratory health. The focus of this study is to determine the main Volatile Organic Compounds (VOCs) precursors of O3 to auxiliary in control this pollutant. In this work were made 78 samples during the week of hydrocarbons in 2006 and 66 samples of hydrocarbons, 62 of aldehydes and 42 of ethanol during the year 2011/2012, 7:00 am to 9:00 am, at the CETESB IPEN/USP station. Measurements of VOCs also were realized in 2006 and 2008, in the CETESB Cerqueira Cesar station. Additionally, were performed tests vehicle emissions during the year 2009 of 5 diesel vehicles, 3 ethanol, 2 gasool and 1 motorcycle. The OZIPR trajectory model was used to determine the main O3 precursors. During the year 2011/2012, in the CETESB IPEN/USP station the class of aldehydes represented 35.3% of VOCs analyzed in concentration in the atmosphere, followed by ethanol 22.6%, aromatics 15.7%, alkanes 13.5%, ketones 6.8%, alkenes 6.0% and alkadienes <0.1%. Considering the concentration of the compounds and their reactivity, the simulations executed with the model showed that acetaldehyde OZIPR contributed with 61.2% to the formation of O3 in the atmosphere of MASP in the year 2011/2012. VOCs analyzed, the class of aldehydes contributed with 74% of the production of O3, aromatics 14.5%, alkenes 10.2%, alkanes 1.3% and alkadienes (isoprene) 0.03%. The study of vehicular emission showed that 39% of aldehydes were obtained from ethanol vehicles, 28% diesel, 26% gasoline and 7% of motorcycles. Emissions of VOCs by gasoline vehicles contributed with 44% of the formation of O3, diesel 22%, ethanol 19% and motorcycles gasoline 15%.

A indústria alimentícia utiliza variados materiais para embalagens, sendo o polietileno de baixa densidade linear (PELBD) um dos materiais de maior importância, por possuir características únicas e adequadas à produção de embalagens. A geração de espécies químicas em embalagens de alimentos vem sendo foco de estudos no mundo. Este controle de compostos é denominado como estudo de Substâncias Não Intencionalmente Adicionadas (NIAS) e tem sua importância justificada pela preocupação com a saúde humana devido à capacidade de contaminação do alimento embalado. Para este estudo foram escolhidas duas resinas PELBD amplamente aplicadas na produção de embalagens alimentícias, analisadas na forma de pellets. As amostras foram nomeadas como PELBD1 e PELBD2 e analisadas antes e após exposição natural e acelerada (estufa a 50°C) de um, dois e três meses. Ambas apresentaram grande aumento no número de NIAS detectadas por Cromatografia Gasosa com detecção de Massas (GC-MS) após envelhecimentos, quando comparadas à resina virgem, chegando a 1100% em PELBD1 e 100% em PELBD2, com surgimento de substâncias oxigenadas e tóxicas. O aditivo antioxidante ativo foi sendo consumido e analisado via Cromatografia Líquida de Alta Eficiência (HPLC) ao longo das exposições, confirmando os efeitos do envelhecimento. Através do Infravermelho por transformada de Fourier (FTIR) foi verificada degradação inicial em PELBD1 exposto por três meses à estufa. Porém, até mesmo em períodos menores de exposição natural, a formação de grupos cromóforos foi comprovada pela análise de cor, onde houve pequeno e gradual aumento do amarelecimento e diminuição da brancura principalmente em PELBD1. Por Cromatografia de Permeação à Gel (GPC), as amostras apresentaram pequena tendência para diminuição de M̅z. Já nas análises de Reometria Rotacional com variação de Frequência (DSR), Índice de Fluidez (IF) e Calorimetria Exploratória Diferencial (DSC), foram observadas mínimas tendências de degradação. Pode-se concluir a partir destes resultados que a maior degradação e produção de NIAS ocorreram em ambiente acelerado. Esta pesquisa trouxe grandes contribuições para futuros trabalhos que envolvam o estudo de NIAS e suas condições de formação. / The food industry uses various packaging materials being linear low density polyethylene (LLDPE) one of the most important materials, have unique features suitable for the production and packaging. The generation of chemical species in food packages has been the focus of research in the world. This control compounds is referred to as study Non-Intentionally Added Substances (NIAS) and has its importance justified by concern human health because of capacity contamination the food packaging. For this study it was chosen two LLDPE resins widely applied in the production of food packaging, analyzed in the form of pellets. The samples were named as PELBD1 and PELBD2 and analyzed before and after natural and accelerated exposure (oven at 50°C) of a two and three months. Both showed huge increase in the number of NIAS detected by Gas Chromatography with Mass detection (GC-MS) after ageing, when compared to virgin resin, reaching of 1100% in PELBD1 and 100% in PELBD2 with the appearance of oxygen substances and toxic substances. The active antioxidant additive was being consumed and analyzed via High-Performance Liquid Chromatography (HPLC), during the exposures, confirming the effects of ageing. For Fourier Transform Infrared (FTIR) was observed in initial degradation PELBD1 exposed for three months in an oven. However, even at under natural exposure periods, the formation of chromophoric groups were confirmed by analysis of color where there was a slight and gradual increase in yellowing and brightness decreased mainly PELBD1. For the Gel Permeation Chromatography (GPC), the samples showed a slight tendency to decrease M̅z. Already in the analysis of Rheometry Rotational Varying Frequency (DSR), Melt Flow Index (MFI) and Differential Scanning Calorimetry (DSC), were observed minimum trends of degradation. It can concluded from these results that the greatest degradation and NIAS production occurred in an accelerated environment. This research has brought great contributions to future work involving the study of NIAS and their conditions of training.