O Rio Grande do Sul é o maior produtor de uvas do Brasil, e as cultivares de Vitis labrusca representam mais de 90% da produção, dentre as quais se destacam as variedades Isabel e Bordô, que se caracterizam por conter altas concentrações de polifenóis, principalmente antocianinas, que exibem propriedades antioxidantes e que podem ser usados como corantes em alimentos. Entretanto, a utilização destes compostos em alimentos se torna difícil devido à sua alta instabilidade, e uma das formas de proteger estes compostos das condições adversas do meio é a microencapsulação. O bagaço da uva, proveniente da fabricação de sucos e vinhos, contém uma elevada concentração de polifenóis, e é composto em grande parte pela casca da uva. Dessa forma, este trabalho de Tese, teve como primeiro objetivo a extração dos polifenóis da casca das uvas Isabel e Bordô, e seu microencapsulamento utilizando diferentes materiais de parede, o qual foi dividido em três etapas. Na primeira etapa, foi realizada a separação dos compostos fenólicos mediante extração aquosa em meio ácido da casca de uva Isabel. A seguir, o extrato foi submetido à atomização para obtenção das micropartículas, utilizando goma arábica, β-ciclodextrina e hidroxipropil-β-ciclodextrina como agentes encapsulantes, combinadas em concentrações máximas de 5%. Os pós obtidos foram avaliados quanto aos fenóis totais, antocianinas monoméricas totais, flavonoides, flavanols, atividade antioxidante (DPPH, CUPRAC e HRSA), cor, umidade, atividade de água, solubilidade, higroscopicidade, temperatura de transição vítrea e microestrutura. De forma geral, os pós obtidos apresentaram alta higroscopicidade e baixa temperatura de transição vítrea, além de aglomeração das partículas. O tratamento elaborado com 3% de goma arábica e 2% de β-ciclodextrina foi considerado o melhor, com maior retenção de flavonoides (67,2%), flavanols (51,1%), atividade antioxidante por DDPH (55%) e CUPRAC (58,8%), menor higroscopicidade (17,33%) e maior temperatura de transição vítrea (32,85 °C). Na segunda etapa, o extrato fenólico aquoso acidificado da casca de uva Bordô foi atomizado e liofilizado para a obtenção das micropartículas, utilizando goma arábica, goma guar parcialmente hidrolisada e polidextrose, em um total de 10% de material de parede. Os pós obtidos foram avaliados quanto ao conteúdo de fenóis totais, antocianinas monoméricas totais, atividade antioxidante (DPPH, CUPRAC, HRSA), cor, umidade, atividade de água, solubilidade, higroscopicidade, temperatura de transição vítrea, tamanho de partícula e microestrutura. Foram obtidas altas retenções, maiores que 80% para fenóis totais e antocianinas monoméricas totais, e entre 45 e 84% para atividade antioxidante em todos os tratamentos estudados. Os pós atomizados tiveram menor umidade, atividade de água e tamanho de partícula, maior solubilidade e temperatura de transição vítrea, além de melhores características morfológicas do que os pós liofilizados. O pó obtido por atomização com 5% de goma guar parcialmente hidrolisada e 5% de polidextrose foi considerado o melhor tratamento, visto que teve maior retenção de fenóis totais (89,0%), antocianinas monoméricas totais (99,5%) e atividade antioxidante por DPPH (57,3%) e CUPRAC (83,2%). Na terceira etapa, dispersões de extrato de casca de uva Bordô com 5% de goma guar parcialmente hidrolisada e 5% de polidextrose, que foi considerado o melhor tratamento dentre todos os elaborados com uva Isabel e Bordô, foram atomizadas e liofilizadas para obtenção das micropartículas, que foram submetidas a testes acelerados de armazenamento (umidades relativas de 75 e 90% em temperaturas de 35, 45 e 55 °C) e de simulação de digestão gastrointestinal (divididos em duas fases: fase gástrica e fase intestinal). Foram avaliados os conteúdos de fenóis totais, antocianinas monoméricas totais e atividade antioxidante por ABTS. Quanto às provas aceleradas, a temperatura teve um efeito significativo na diminuição no conteúdo de fenóis, com retenções de 82,5% a 93,5%. Na redução do conteúdo de antocianinas monoméricas totais foi significativo o efeito da temperatura, umidade relativa e tempo, com retenções de 3,9 a 42,3%. A redução do teor de antocianinas monoméricas totais exibiu cinética de primeira ordem, e os valores de z e Ea indicaram que o pó liofilizado é mais instável às mudanças de temperatura, quando utilizadas temperaturas mais elevadas. Por outro lado, os valores de D e t1/2 foram muito próximos entre os dois pós, o que indica pouca diferença de estabilidade entre eles nas temperaturas utilizadas neste estudo. Os parâmetros termodinâmicos indicaram que a reação foi endotérmica e não espontânea. A atividade antioxidante teve comportamento similar ao dos fenóis totais, com retenção final de 38,5 a 59,5%. Quanto à simulação da digestão gastrointestinal os dois pós tiveram liberação de fenóis de aproximadamente 80% na fase gástrica, e aumento significativo da liberação na fase intestinal, onde, na última hora de experimento, o pó atomizado teve 90,6% de liberação e o liofilizado 94,9%. Comportamento similar foi observado para a atividade antioxidante, onde o pó atomizado e o pó liofilizado tiveram percentuais próximos a 50% na fase gástrica e aumento significativo na fase intestinal, onde na última hora do experimento o pó atomizado teve 69,4% da atividade antioxidante e o pó liofilizado 67,8%. Entretanto, as antocianinas monoméricas tiveram redução significativa de aproximadamente 50% do seu conteúdo na fase intestinal, onde, na última hora de experimento, o pó atomizado teve 39% de liberação e o liofilizado 39,8%. O método de obtenção das micropartículas não influenciou na estabilidade dos pós, tanto nos testes acelerados de armazenamento quanto na simulação da digestão gastrointestinal. Como segundo objetivo foi avaliado o efeito da irradiação UV-C em uvas Bordô, como tratamento pós-colheita. Foram estudadas duas safras de anos diferentes, sendo que na primeira as uvas foram submetidas a 0, 0,5, 1, 4, 10 e 30 minutos de irradiação (120 W) e armazenadas a 22 °C, enquanto que na segunda safra as uvas foram submetidas à irradiações com UV-C (120 W) por 0, 0,5 e 4 minutos, combinada com ultrassom (40 kHz) por 5 minutos e armazenadas a 22 °C. Na primeira safra, as uvas não apresentaram aumento dos compostos bioativos e da atividade antioxidante. Entretanto, na segunda safra, os resultados indicaram o aumento significativo no conteúdo de fenóis totais, antocianinas monoméricas totais e na atividade antioxidante para as uvas irradiadas por 0,5 minutos com UV-C e para as irradiadas com UV-C por 4 minutos em combinação com ultrassom por 5 minutos, com aumentos de 1,2 a 2,0 vezes em relação ao controle, não havendo mudanças significativas na cor das uvas irradiadas. / The state of Rio Grande do Sul, Brazil, is the greatest producer of grapes in the country. Vitis labrusca cultivars constitute more than 90% of production, underscoring Isabel and Bordô varieties, featuring high concentrations of polyphenols, especially antioxidant anthocyanins used as food coloring. Since the use of the compounds in food is rather difficult due to their unstableness, microencapsulation is one of the methods to protect the compounds from adverse environmental condition. Grape pomace, the residue from the manufacture of juice and wine, has high polyphenol concentration and is mainly formed by grape skin. Current thesis aims at extracting polyphenols from the skin of Isabel and Bordô grape varieties and their micro-encapsulation by different wall materials. Research was divided into three stages. The first stage comprised the separation of phenolic compounds by water extraction in the acid medium of the skin of the Isabel grape variety. The extract was spray-dried for microparticles by means of gum arabic, β-cyclodextrin and hydroxypropyl-β-cyclodextrin as encapsulating agents at maximum 5% concentrations. Powders were assessed for total phenols, total monomer anthocyanins, flavonoids, flavanols, antioxidant activity (DPPH, CUPRAC and HRSA), color, humidity, water activity, solubility, hygroscopicity, glass transition temperature and micro-structure. As a rule, the powders featured high hygroscopicity, low glass transition temperature and particle agglomeration. Treatment with 3% of gum arabic 3% and 2% of β-cyclodextrin was the best, with the highest retention rate of flavonoids (67.2%), flavanols (51.1%), antioxidant activity, and with DDPH (55%) and CUPRAC (58.8%), lowest hygroscopicity (17.33%) and highest glass transition temperature (32.85 °C). In the second stage the acidified water phenolic extract from the Bordô grape skin was spray-dried and freeze-dried for microparticles with gum arabic, partially hydrolyzed guar gum and polydextrose, with a total 10% of wall material. Powders were assessed for total phenols, total monomer anthocyanins, antioxidant activity (DPPH, CUPRAC, HRSA), color, humidity, water activity, solubility, hygroscopicity, glass transition temperature, particle size and micro-structure. High retentions occurred, with more than 80% for total phenols and total monomer anthocyanins; and between 45 and 84% for antioxidant activity in all treatments under analysis. Atomized powders had lower humidity, water activity and particle size, greater solubility, higher glass transition temperature, and better morphological characteristics than the freeze-dried powders. The powder obtain by spray-dried with 5% of partially hydrolyzed guar gum and 5% of polydextrose was the best treatment due to greater retention of total phenols (89.0%), total monomer anthocyanins (99,5%) and antioxidant activity for DPPH (57.3%) and CUPRAC (83.2%). The third stage comprised dispersions of the extract of the Bordô grape skin with partially hydrolyzed guar gum 5% and polydextrose 5%, or rather, the best treatment among those prepared with Isabel and Bordô grapes. Dispersions were spray-dried and freeze-dried to obtain microparticles which underwent fast storage tests (relative humidity rates 75 and 90% at 35, 45 and 55 °C) and gastrointestinal digestion simulations (divided into two phases: gastric and intestinal phases). Total phenols, total monomer anthocyanins and antioxidant activity for ABTS were evaluated. Fast tests revealed that temperature had a significant effect on the decrease in phenol contents, with 82.5 - 93.5% retentions. Temperature, relative humidity and time were significant on the reduction of total monomer anthocyanin contents, with 3.9 – 42.3% retentions. Decrease in total monomer anthocyanin rates revealed a first order kinetics, whilst z and Ea rates indicated highly unstable freeze-dried powder for changes in temperature when higher temperatures are employed. On the other hand, D and t1/2 rates were very close between the two powders, revealing slight stability difference between the two at temperatures employed in current study. Thermodynamic parameters demonstrated an endothermic and non-spontaneous reaction. Antioxidant activity behaved similarly to total phenols with a final retention between 38.5 and 59.5%. In the case of gastrointestinal digestion simulation, the two powders released 80% phenols during the gastric phase and a significant increase in release during the intestinal phase in which spray-dried and freeze-dried powders had 90.6% and 94.9% release during the last hour of the experiment. A similar behavior was detected for antioxidant activity in which spray-dried and freeze-dried powders featured 50% during the gastric phase and a significant increase during the intestinal one, with 69.4% and 67.8% of antioxidant activity respectively by the spray-dried and freeze-dried powders during the last hour of the experiment. However, monomer anthocyanins had a significant 50% reduction of contents in the intestinal phase in which the spray-dried and freeze-dried powders had 39% and 39.8% release respectively during the last hour of the experiment. The methods for obtaining microparticles failed to affect the stability of the powder in fast storage tests and in gastrointestinal simulation tests. Current research also evaluated the effect of UV-C irradiation on Bordô grapes for post-harvest treatment. Two harvests in two different years were analyzed: grapes of the first harvest underwent 0, 0.5, 1, 4, 10 and 30 minutes irradiation (120 W) and stored at 22 °C, whereas grapes of the second harvest underwent UV-C irradiations (120 W) during 0, 0.5 and 4 minutes, coupled to ultrasound (40 kHz) for 5 minutes and stored at 22 °C. The former did not have any increase in bioactive compounds and antioxidant activity. Results of the latter, however, demonstrated a significant increase in total phenols, total monomer anthocyanins and antioxidant activity for grapes irradiated during 0.5 minutes with UV-C and for those irradiated with UV-C for 4 minutes plus ultrasound for 5 minutes. There was 1.2 - 2.0 times increase when compared to control, with no change in color in the irradiated grapes.

Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2018-07-13T19:29:17Z No. of bitstreams: 2 Dissertação - Maria Carolina de Almeida - 2017.pdf: 6786764 bytes, checksum: 4574a29178a9cb373e63d3280e95024e (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-07-17T13:38:02Z (GMT) No. of bitstreams: 2 Dissertação - Maria Carolina de Almeida - 2017.pdf: 6786764 bytes, checksum: 4574a29178a9cb373e63d3280e95024e (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-07-17T13:38:02Z (GMT). No. of bitstreams: 2 Dissertação - Maria Carolina de Almeida - 2017.pdf: 6786764 bytes, checksum: 4574a29178a9cb373e63d3280e95024e (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-05-05 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / The objective of this work was to compare the efficiency of conventional treatments such as activated carbon (AC) Adsorption and the advanced oxidation process (AOP), UV-C/H2O2, for degradation of diethyl phthalete (DEP) and coupling UV-C/H2O2/AC in laboratory effluent, ultrapure water and faucet water doped with DEP and laboratory effluent with multicomponents (DEP and phenol). The chemical characterization (Boehm method, pHPZC, IRTF, elemental analysis) and physical (volume of micropores and mesopores, mean micropore width by the Dubini-Radushkevich method were used as a predecessor to the kinetic adsorption study, Surface area and microporous specific volume by the alpha method, microporous and total surface, BET surface area by BET method, cumulative mesopore distribution and pore volume, cumulative area and surface area and pore size by BJH method) of AC. The factorial design with eleven tests and three independent variables (AC mass, temperature and pH) was applied, resulting in response surfaces for adsorption capacity, DEP elimination rate and equilibrium time without significant difference between the studied variables. Mathematical modeling of adsorption kinetics using the pseudo-first, pseudo-second order and intraparticle models was performed and the pseudo-second order model was fitted to the experimental kinetic adsorption data. It was followed by the study of the adsorption isotherms for the lower, intermediate and longer equilibrium experimental conditions. It was performed the mathematical modeling of the adsorption isotherms using the Langmuir and Freundlinch models, and adjusted to the Freundlinch model to the experimental data of the adsorption isotherms with higher determination coefficients (R2), confirming the predominant chemorandomization adsorption phenomenon. The treatment of AOP UV-C/H2O2 was then applied alone. The factorial design with eleven tests and three independent variables (H2O2 concentration, temperature and pH) was applied, resulting in surfaces of responses to DEP elimination rate with significant difference between the variables studied for pH, positive effect of H2O2 concentration (p < 0.5). The mathematical modeling of the kinetics of AOP using the first order models was carried out, and the kinetic experimental data of the photodegradation with high coefficients of determination (R2> 0.9) were fitted to the model. The degradation kinetics of DEP by AOP coupling and AC, UV-C/H2O2/AC were followed. The factorial design with eleven tests and three independent variables (H2O2 concentration, temperature and pH) and with 0.4 g of AC, resulting in surfaces of responses to elimination rate of DEP with significant difference between the variables studied for pH, positive effect of H2O2 concentration (p <0.5). The mass of AC was determined in 0.4 g for all eleven tests, because it was the mass applied at the highest rates of elimination of DEP by kinetics of Adsorption, which was confirmed by repeatability at the central points of the factorial design (C9, C10 and C11). The catalytic activity of the carbons for the Adsorption process in the presence of tertbutanol was high, however, after the determination of the kinetic parameters, the contribution was higher for photooxidation of DEP by the action of the AOP (homogeneous system). / O objetivo desse trabalho foi comparar a eficiência de tratamentos convencionais como a adsorção com carvão ativado (CA) e o processo oxidativo avançado (POA), UV-C/H2O2, para degradação de dietil ftlato (DEP) e a acoplagem UV-C/H2O2/CA em efluente de laboratório, água ultrapura e água de torneira dopados com DEP e efluente de laboratório com multicomponentes (DEP e fenol). De modo predecessor ao estudo cinético da adsorção, aplicado isoladamente, realizou-se a caracterização química (método de Boehm, pHPZC, IRTF, análise elementar) e física (volume de microporos e mesoporos, largura média de microporos pelo método de Dubini-Radushkevich, superfície exterior e volume específico microporoso pelo método alfa, superfície microporosa e total, área de superfície de BET pelo método de BET, distribuição dos mesoporos cumulativo e volume do poro, área cumulativa e área superficial e tamanho do poro pelo método BJH) do CA. O delineamento fatorial com onze ensaios e três variáveis independentes (massa de CA, temperatura e pH) foi aplicado, resultando em superfícies de respostas para capacidade de adsorção, taxa de eliminação de DEP e tempo de equilibrio sem diferença significativa entre as variáveis estudadas. Foi realizada a modelagem matemática das cinéticas de adsorção utilizando os modelos de pseudo-primeira, pseudosegunda ordem e intrapartícula, e ajustou-se ao modelo de pseudo-segunda ordem aos dados experimentais cinéticos de adsorção. Seguiu-se com o estudo das isotermas de adsorção paras as condições experimentais de menor, intermediário e de maior tempo de equilíbrio. Foi realizada a modelagem matemática das isotermas de adsorção utilizando os modelos de Langmuir e Freundlinch, e ajustou-se ao modelo de Freundlinch aos dados experimentais das isotermas de adsorção com maior coeficientes de determinação (R2), confirmando o fenômeno de adsorção predominante quimiosorção. Seguiu-se a aplicação do tratamento de POA UVC/ H2O2, isoladamente. O delineamento fatorial com onze ensaios e três variáveis independentes (concentração de H2O2, temperatura e pH) foi aplicado, resultando em superfícies de respostas para taxa de eliminação de DEP com diferença significativa entre as variáveis estudadas para o pH, e efeito positivo da concentração de H2O2 (p<0,5). Foi realizada a modelagem matemática das cinéticas de POA utilizando os modelos de primeira ordem, e ajustaram-se ao modelo os dados experimentais cinéticos da fotodegradação com elevados coeficientes de determinação (R2>0,9). Seguiu-se para o estudo das cinética de degradação de DEP pela acoplagem POA e CA, UV-C/H2O2/CA. O delineamento fatorial com onze ensaios e três variáveis independentes (concentração de H2O2, temperatura e pH) e com 0,4 g de CA, resultando em superfícies de respostas para taxa de eliminação de DEP com diferença significativa entre as variáveis estudadas para o pH, efeito positivo da concentração de H2O2 (p<0,5). A massa de CA foi determinada em 0,4 g para todos os onze ensaios, porque foi a massa aplicada nas maiores taxas de eliminação de DEP pelas cinéticas de adsorção, que se confirmou, pela repetitibilidade, nos pontos centrais do delineamento fatorial (C9, C10 e C11). A atividade catalítica dos carvões para o processo de adsorção em presença de tércio butanol foi elevada, contudo a contribuição, após a determinação das constantes cinéticas, revelou-se maior para foto-oxidaçao de DEP pela ação do POA (sistema homogêneo).

Understanding the composition of camel milk coupled with studying the effects of thermal and non-thermal treatments on its components and bacterial inactivation were the general objectives of this dissertation. In the first study (Chapter 2), the gross composition of camel milk including milk protein, fat, casein, total solids, lactose, ash, and mineral content were analyzed. In addition, fatty acid profile, amino acid profile, protein fractions, and volatile compounds were evaluated as well. Our results revealed that camel milk has its unique nutrients profile. These findings make it easier for the researchers and consumers to understand some of the nutritional attributes of camel milk.The impact of non-thermal ultrasound treatment (900 W, 20 kHz, 100% power level) on some milk-borne microorganisms and the components of camel milk was studied in Chapter3. We reported that continuous ultrasound processing was efficient in inactivating Escherichia coli (E.coli) O157: H7 and Salmonella Typhimurium (S. Typhimurium) in camel milk without detrimental effects on milk fatty acids profile, lipid peroxides, and protein fractions except for some changes in milk volatile compounds (VC). In Chapter 4, another non-thermal technique, ultraviolet-C (UV-C) light, was applied to camel milk to study the effects of different UV-C light doses on the viability of E. coli O157:H7 and S. Typhimurium and the chemical changes to milk components. The main findings of this study were: (i) UV-C treatment at a dose of 12.45 mJ/cm2 resulted in only 3.9-log10 for both bacterial strains which did not meet the Food and Drug Administration (FDA) requirements for the 5-log pathogen reduction; (ii) the UV-C treatment at the above dose, had limited effects on camel milk components. Thermal pasteurization of milk was first introduced to prevent milk-borne infectious diseases, however, its effects on camel milk components and quality are still unknown. Therefore, in Chapter 5, we investigated the efficacy of three previously reported thermal methods: PAST-1 (65ºC/30 min), PAST-2 (72ºC/5 min), and PAST-3 (80ºC/5 min) on bacterial inactivation and some camel milk components such as the fatty acid profile, lipid peroxidation, VC, and milk protein fractions. Complete elimination (6 log10 CFU/ml reduction) of E. coli O157: H7 was achieved using all pasteurization methods, however, only 3.4 log10 CFU/ml reduction of the total viable counts was reported using PAST-1 and PAST-3 methods. We also reported that the PAST-1 and PAST-3 methods did not affect the chemical composition of camel milk. In conclusion, we assessed the main components of camel milk along with the amino fatty acid profile, acid profile, volatile compounds, and protein fractions. Thermal methods were more effective than the non-thermal methods in terms of microbial inactivation and most camel milk components were not significantly influenced by thermal and non-thermal methods.

L’objectif général de cette thèse est d’étudier et d’analyser l’effet du rayonnement UV-C comme méthodealternative aux produits chimiques dans la lutte et le contrôle de la prolifération des micro-organismesphotosynthétiques dans les grottes touristiques. Dans un premier temps, l’effet des UV-C a été analysé surdifférentes souches cavernicoles de micro-algues cultivées au laboratoire. Des analyses à l’échelle moléculaire,cellulaire et à l’échelle du biofilm d’algues ont permis de mettre en évidence un ensemble de dommages causépar l’irradiation aux UV-C (diminution de la viabilité et de l’activité photosynthétique, dégradation desmembranes, décoloration des cellules par destruction des pigments chlorophylliens, fragmentation de l’ADN,diminution de la surface d’occupation des biofilms d’algues cultivés sur support solide). Ceux-ci sont soit directs(réactions de photooxydation) soit indirects (liés à un stress oxydatif important). L’ensemble de ces résultats ontservi à la sélection de différentes durées d’exposition aux UV-C (traduites en doses d’UV-C) efficaces en termesd’éradication et de décoloration des micro-algues. Ces doses d’UV-C ont dans un deuxième temps été testées enconditions réelles sur le site d’étude de la grotte des Moidons (Jura, France). Une étude préalable à ces tests a étémenée afin de comprendre les dynamiques et les facteurs favorisant l’installation et la prolifération des biofilmsde micro-organismes photosynthétiques dans la grotte. L’étude des facteurs environnementaux mesurés àl’échelle du biofilm (quantité de lumière, type de support, localisation dans la grotte) ainsi que ceux mesurés àl’échelle de la cavité (circulation horizontale et verticale des eaux, vitesse des courants d’air, temps d’allumagedes lampes et temps de présence des visiteurs) ont permis de distinguer des zones de colonisation préférentielle.Plusieurs biofilms ont ensuite été sélectionnés pour tester l’efficacité des UV-C. Selon les caractéristiques desbiofilms (intensité de colonisation) et en fonction de leur emplacement dans la grotte (variations des facteurspréalablement déterminés), nous avons pu mettre en évidence une efficacité des UV-C variable dans le temps.Avec l’appui de résultats complémentaires obtenus sur deux souches de champignons et sur plusieurs types dematières picturales, l’ensemble des données collectées au cours de la thèse souligne l’intérêt et l’applicabilité destraitements aux UV-C dans divers contextes de conservation des matériaux du patrimoine / The aim of this thesis is to study and analyze the effect of UV-C radiation as an alternative method tochemicals to combat phototrophic microorganisms’ proliferation in show caves. First, the effect of UV-C wasanalyzed on several cave-dwelling unicellular green algae sub-cultured in laboratory conditions. Analysis at themolecular, cellular and biofilm scale highlighted several damages (decrease of viability and photosyntheticactivity, membrane degradation, chlorophyll bleaching, DNA fragmentation, decrease of the biofilms’ colonizedarea…) both direct (photooxydation reaction) or indirect (oxidative stress). These results helped to selectefficient UV-C exposure times (traduced in UV-C doses) both to eradicate and bleach green micro-algae.Second, these efficient UV-C doses were used to test the efficiency of UV-C treatments on natural phototrophicbiofilms proliferating in the Moidons Cave (Jura, France). Previous study to the UV-C tests was performed tounderstand the dynamics and factors that promote algal proliferation in this cave. Factors measured at the biofilmscale (quantity of light, type of the physical support, localization in the cave…) and at the cavity scale(horizontal and vertical circulation of waters, air currents, illumination time and visitors’ presence time) allowedto distinguish several preferential areas where growth-supporting conditions were present for algal proliferation.Then, several biofilms were selected to test the efficiency of UV-C treatments. According to the characteristicsof the biofilms (colonization intensity) and their localization in the cave (variations of the factors promotingcolonization) UV-C efficiency varied over time. Supplementary results obtained on filamentous fungi andmineral pigments used for prehistoric paintings, emphasize the interest and the applicability

Made available in DSpace on 2014-08-20T13:42:06Z (GMT). No. of bitstreams: 1 Tese_ Amauri_Costa_da_Costa.pdf: 821830 bytes, checksum: 461372c264b8901d1eddb80605e2c297 (MD5) Previous issue date: 2010-07-06 / Enzymatic browning and softening are the main changes on fresh-cut peaches. Initially we studied the combination of antioxidant molecules and protective texture control enzymatic activities of peroxidase (POD) and polyphenoloxidase (PPO), enzymatic browning and softening the flesh of peaches cv. Esmeralda, minimally processed and refrigerated. For this we tested the use of L-cysteine (Cis), L-ascorbic acid (AA) and calcium chloride (CC), alone or in combination: (i) water (control); (ii) AA+CC; (iii) Cis+CC; e, (iv) Cis+AA+CC. After treatment, the slices were packed in packages sealed with PVC film 30μm and stored for six days at 4±1ºC and 85±3 RH. The samples were evaluated under physical-chemical, enzymatic and sensory every two days. Treatment Cis+AA+CC had the highest values of L* and h°, ie was more effective in preventing browning. Treatments with L-cysteine showed a lower PPO activity and treatment Cis+AA+CC was the most effective in containing the POD activity, indicating that the best performance of this treatment is associated with lower activity of these enzymes. The sensory evaluation indicated that the treatment Cis+AA+CC was the most efficient, providing the maintenance of the sensory characteristics acceptable of fresh-cut peaches, cv. Esmeralda. In sequence was tested using ultraviolet radiation type C (UV-C) radiation as a means of increasing the conservation value of these fruits as well as to increase the synthesis of compounds of nutritional value and functional. That were applied to the following treatments: (i) fruit without UV-C, peeled, sliced and stored under refrigeration (control); (ii) fruits treated with UV-C and immediately peeled, sliced and stored under refrigeration (UV-C 0); (iii) fruits treated with UV-C and kept at room temperature 24h before processing (UV-C 24), (iv) fruits treated with UV-C and kept at room temperature 48h before processing (UV-C 48); and (v) fruit without treatment with UV-C, processed and treated with metabisulphite K (MB K). Evaluations, color (L* and hue angle), firmness, ascorbic acid and phenolic compounds, antioxidant activity and transcriptional expression of genes supposedly related to physiological changes were taken immediately after processing and every 24h for six days. The application of UV-C resulted in a significant improvement in the storage potential of the peaches. But for that to happen, it was necessary to wait 24 to 48h before processing. With this procedure there was a stimulus to the transcription of genes in the metabolism of ethylene, cell wall synthesis and oxidation of phenolic compounds. Still, there was less browning of fruits treated with UV-C, indicating that this change is not only dependent on the concentration of total phenolics and PPO activity. / O escurecimento enzimático e o amolecimento são as principais alterações em pêssegos minimamente processados. Inicialmente estudou-se a combinação de moléculas antioxidantes e protetores de textura no controle da atividade das enzimas polifenoloxidase (PPO) e peroxidase (POD), do escurecimento enzimático e do amolecimento da polpa de pêssegos, cv. Esmeralda, minimamente processados e refrigerados (MPR). Para isso testou-se o uso de L-cisteína (Cis), ácido L-ascórbico (AA) e cloreto de cálcio (CC), isolados ou em combinação: (i) água (controle); (ii) AA+CC; (iii) Cis+CC; e, (iv) Cis+AA+CC. Após o tratamento, as fatias foram acondicionadas em embalagens rígidas envoltas com filme PVC 30μm e armazenadas durante seis dias a 4±1ºC e 85±3 UR. As amostras foram avaliadas sob aspectos físico-químicos, enzimáticos e sensoriais a cada dois dias. O tratamento Cis+AA+CC apresentou os maiores valores de L* e hº, ou seja, foi o mais eficaz na prevenção do escurecimento. Os tratamentos com L-cisteína apresentaram menor atividade da PPO e o tratamento Cis+AA+CC foi o mais efetivo na contenção da atividade da POD, indicando que o melhor desempenho desse tratamento está associado à menor atividade dessas enzimas. A avaliação sensorial indicou que o tratamento Cis+AA+CC foi o mais eficiente, proporcionando a manutenção de características sensoriais aceitáveis aos pêssegos MPR, cv. Esmeralda. Em sequência testou-se o uso de radiação ultravioleta tipo C (UV-C) como meio de aumentar o potencial de conservação desses frutos, assim como para aumentar a síntese de compostos de interesse nutricional e funcional. Para isso foram aplicados os seguintes tratamentos: (i) frutos sem UV-C, pelados, fatiados e armazenados sob refrigeração (AR) (controle); (ii) frutos tratados com UV-C e imediatamente pelados, fatiados e armazenados em AR (UV-C 0); (iii) frutos tratados com UV-C e mantidos 24h à temperatura ambiente (TA) antes do processamento (UV-C 24); (iv) frutos tratados com UV-C e mantidos 48h a TA antes do processamento; e (v) frutos sem tratamento com UV-C, processados e tratados com metabissulfito de K (MB K). As avaliações, coloração (L* e ângulo hº), firmeza de polpa, teor de ácido ascórbico e compostos fenólicos, atividade antioxidante e a expressão transcricional de genes supostamente relacionados às alterações fisiológicas, foram realizadas imediatamente após o processamento e a cada 24h por seis dias. A aplicação da radiação UV-C provocou uma significativa melhora no potencial de conservação dos pêssegos. Mas para que isso ocorresse, foi necessário se aguardar de 24 à 48h antes do processamento. Com esse procedimento houve estímulo à transcrição de genes do metabolismo do etileno, da parede celular e da síntese e oxidação de compostos fenólicos totais (CFT). Mesmo assim, houve menor escurecimento dos frutos tratados com UV-C, indicando que essa alteração não é apenas dependente da concentração de CFT e da atividade da PPO.

DNA damage response (DDR) represents a vital signaling network that protects genome integrity and prevents development of cancer. Therefore the study of DDR is of a crucial clinical importance and DDR proteins are promising therapeu- tic targets. Although the great advances have been made mapping out interac- tions between individual DDR proteins, better understanding of complex behav- ior of this network is still needed. One approach, which might help us in this task, is to describe the dynamics of key proteins under different conditions. The first objective of this study was to investigate whether the temporal dynamics of selected DDR proteins differ upon different genotoxic insults, particularly upon γ- irradiation and UV-C irradiation. We showed that under certain insult some DDR proteins exhibit a monotone continuous activation pulse, while the activation of others triggers a series of pulses. We observed a previously described pulsative dynamics of p53 after γ-irradiation in MCF7 cells. Interestingly, we detected a monotone increase of p53 in U2OS after γ-irradiation and similar dynamics upon UV-C irradiation. We suggest that p53 dynamics depends on the presence or ab- sence of effective negative feedback loops between the upstream p53-activating kinases and Wip1 phosphatase. In the second...

Aluminum Gallium Nitride (AlGaN) / Gallium Nitride (GaN) based deep ultraviolet (DUV) light emitting didoes (LEDs) with emission wavelengths between 200-280 nm enable key emerging technologies such as water/air purification and sterilization, covert communications and portable bio-agent detection/identification systems for homeland security, and surface and medical device sterilization. These devices produce a large amount of undesired heat due to low quantum efficiencies in converting electrical input to optical output. These low efficiencies are attributed to difficulties in the growth&doping of AlₓGa₁₋ₓN materials and UV absorbing substrates leading to excessive joule heating, which leads to device degradation and a spectral shift in the emission wavelength. With this regard, effective thermal management in these devices depends on the removal of this heat and reduction of the junction temperature. This is achieved by decreasing the package thermal resistance from junction-to-air with cost-effective solutions. The use of heat sinks, thermal interface materials, and high conductivity heat spreaders is instrumental in the reduction of the overall junction-to-air thermal resistance. This thesis work focuses on thermal modeling of flip-chip packaged deep UV LEDs to gain a better understanding of the heat propagation through these devices as well as the package parameters that have the biggest contributions to reducing the overall thermal resistance. A parametric study focusing on components of a lead frame package is presented to ascertain the thermal impacts of various package layers including contact metallizations, thermal spreading sub-mounts, and thermal interface materials. In addition the use of alternative thermal interface materials such as phase change materials and liquid metals is investigated experimentally.

Made available in DSpace on 2014-06-11T19:26:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-03-03Bitstream added on 2014-06-13T20:34:24Z : No. of bitstreams: 1 tremocoldi_ma_me_botfca.pdf: 616438 bytes, checksum: 67f1da03c193fb8aca4f0e4cbb1ebdac (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O presente trabalho teve por objetivo determinar a atividade antioxidante, compostos fenólicos totais e cor em abacate ‘Hass’ submetido ao tratamento térmico, radiação gama e ultravioleta. Após a colheita, os frutos foram selecionados para tornar o lote homogêneo. Foi realizada a caracterização do fruto verde e amadurecido quanto a acidez titulável, pH, umidade, teor de lipídios, cinzas (minerais), proteína (nitrogênio bruto), açúcar total e coloração. Foram realizados 3 experimentos com frutos recém colhidos. Experimento I: imersão dos frutos em água a 45ºC por 5, 10, 15 e 20 minutos; Experimento II: radiação gama nas doses 0,2; 0,4; 0,6 e 1,0kGy e Experimento III: radiação ultravioleta (UVC) por 5, 10, 15 e 20 minutos. Após os tratamentos, os frutos foram armazenados em temperatura ambiente (21ºC±1 e 70±5% de UR) e refrigerado (10ºC±1 e 90±5% de UR). Os frutos foram analisados quanto à capacidade antioxidante pelo método DPPH e compostos fenólicos totais aos 0, 3, 9 e 12 dias. A coloração foi avaliada aos 0, 3, 6, 9, 12 e 15 dias. Os resultados foram submetidos à análise de variância e as médias comparadas pelo teste de Tukey ao nível de 1% de probabilidade. Nas condições em que os experimentos foram realizados, pode-se concluir que os frutos do tratamento testemunha e mantidos sob refrigeração apresentaram maior capacidade antioxidante e teor de compostos fenólicos totais ao longo do período de armazenamento; o tratamento térmico por 5 e 10 minutos foi efetivo na manutenção da capacidade antioxidante e dos compostos fenólicos; a dose de 0,6kGy não foi efetiva na manutenção da capacidade antioxidante; a radiação ultravioleta (UV-C) não manteve a capacidade antioxidante dos frutos, no entanto ocasionou aumento na quantidade de compostos fenólicos; o tratamento térmico e a radiação ultravioleta não afetaram a coloração da polpa / This study aimed to determine the antioxidant activity, total phenolic compounds and color in avocado 'Hass' submitted to heat treatment, gamma and ultraviolet radiation. After harvest, fruits were selected to make the homogeneous portion. The characterization was performed of the green fruit and mature as acidity, pH, moisture, lipids, ash (minerals), protein (nitrogen gross), total sugar and coloring. 3 experiments were performed with freshly harvested fruits. Experiment I: immersion of fruits in water at 45 ° C for 5, 10, 15 and 20 minutes; Experiment II: gamma radiation doses 0.2, 0.4, 0.6 and 1.0 kGy and Experiment III: ultraviolet radiation (UV-C) for 5, 10, 15 and 20 minutes. After treatments, fruits were stored at room temperature (21±1ºC and 70±5% HR) and refrigeration (10ºC±1 and 90±5% HR). The fruits were analyzed for their antioxidant capacity by DPPH method and phenolic compounds at 0, 3, 9 and 12 days. The color was measured at 0, 3, 6, 9, 12 and 15 days. Data were subjected to analysis of variance and mean comparison using Tukey’s test at 1% probability. In conditions where the experiments were performed, one can conclude that the fruits of control treatment and kept under refrigeration had higher antioxidant capacity and content of phenolic compounds during the storage period, the heat treatment for 5 and 10 minutes was effective the maintenance of antioxidant capacity and phenolic compounds, the dose of 0.6 kGy was not effective in maintenance the antioxidant capacity, ultraviolet radiation (UV-C) did not maintain the antioxidant capacity of fruits, however caused an increase in the content of phenolic compounds, heat treatment and ultraviolet radiation did not affect the pulp color

Advanced oxidation technology (AOT) has been used to destroy microorganisms in ballast water by breaking down the cell membranes. The primary objective of this study was to determine the effects of a ballast water treatment system that uses a combination of UV-C (λ=254 nm), Vacuum-UV (VUV; λ=185 nm) and photocatalytic titanium dioxide (TiO2) on a freshwater algae, Pseudokirchneriella subcapitata, and a marine algae, Tetraselmis suecica. The coupling of a semiconductor, such as TiO2, with a UV source is known as an advanced oxidative technology (AOT). To test the effects of TiO2 and wave length on algae, dose-response experiments were conducted to determine the species median lethal dose (LC50) for each of the following treatments: UV-light emitted at 254 nm (UVλ=254 nm), UV-light emitted at 254 nm in the presence of TiO2 (AOTλ=254 nm), and UV-light emitted at λ=254 nm (90 %) and 185 nm (90 %) in the presence of TiO2 (AOTλ=185 + 254 nm). In both species, TiO2 significantly increased mortality, most likely due to the biologically harmful radicals generated at the TiO2 surface. The addition of the 185 nm wavelength significantly increased cell mortality in P. subcapitata, but not in T. suecica. Across all three treatments, P. subcapitata was more sensitive than T. suecica. The secondary purpose of this study was to assess the applicability of ImageJ, an image analysis software, for highthroughput data to analyze the effectiveness of ballast water treatment. ImageJ has been used to rapidly and accurately perform cell Live/Dead analysis; however, several hurdles were identified.

[EN] In modern agriculture, the widespread use of chemicals is common, but the possible presence of residues in food is an issue of increasing importance for public health opinion. The germicidal effect of UV-C irradiation has been successfully tested in different foods but not at an industrial scale as a method for surface disinfection at room temperature of fresh citrus fruit without leaving residues on the product, which is considered a good alternative for food preservation. Postharvest diseases affect the fruit from harvest to the consumer table, and cause significant economic losses to the citrus industry. Losses from disease are highly variable and depend on the production area, species, cultivar, age and condition of the trees; weather conditions throughout the season, the time and method of harvest, postharvest handling of the fruit, storage conditions and destination market. At the global level, important economic losses are caused by strict wound pathogens such as Penicillium digitatum (Pers.: Fr.) Sacc, and Penicillium italicum Wehmer that cause, respectively, citrus postharvest green and blue molds. UV-C irradiation has a maximum emission peak at 254 nm and has been found that this wavelength provides the greatest germicidal action, which has been extensively studied in various plant tissues. Depending on the intensity and wavelength, UV irradiation can induce a biological stress in plants and activate some defense mechanisms of plant tissues, with the consequent production of phytoalexins. Irradiation with UV-C is considered a potential additional tool in CINCEP strategies for the control of citrus decay, although UV-C alone cannot achieve the high efficacy of the fungicides used nowadays for disease control. The results obtained with the prototypes, showed that the best prototype is number III, in which the UV light is applied over rotating rollers. The results indicate that UV light has an indirect hormetic effect on the fruit in preventive trials. The combination with hot water also improves the results when applied in the sequence of hot water followed by application of UV-C in the rotating UV-C applicator prototype III, but not vice versa. Fruit ripening conditions along the season influence the efficacy of the applied dose of UV-C and higher doses can cause undesirable phytotoxic, which can be minimized by the combination with hot water. The studied doses that have been more effective for mandarins and oranges at different ripening stages are: 2.5kJ/m2 on fruit at commercial maturity and subjected to degreening, and the range 5 to 10kJ/m2 on fruit that has reached physiological maturity, which varies depending on the characteristics of the fruit along the season and always in combination with hot water. / [ES] En una agricultura moderna, difícilmente se puede prescindir del uso de productos químicos, pero la posible presencia de residuos en los alimentos es una cuestión que, cada vez, por mínima que ésta sea, preocupa más a la opinión pública, si resulta desfavorable para su salud. El efecto germicida de la irradiación UV-C se ha ensayado con éxito en diferentes alimentos, pero no a escala industrial en la manipulación de cítricos, como un método de desinfección superficial a temperatura ambiente que no deja residuos en el producto, por lo que se considera una buena alternativa para la conservación de alimentos. Las enfermedades de postcosecha, es decir, aquellas enfermedades que afectan a los frutos desde que son recolectados hasta que llegan al consumidor, provocan pérdidas económicas importantes al sector citrícola. Las pérdidas provocadas por las enfermedades son muy variables y dependen del área productora, la especie, el cultivar, la edad y condición de los árboles; las condiciones climatológicas durante toda la campaña, la época y forma de recolección; el manejo de los frutos en postcosecha, las condiciones de almacenamiento y el mercado de destino. En el ámbito mundial destacan las pérdidas producidas por patógenos de herida estrictos como Penicillium digitatum (Pers.:Fr.) Sacc. o Penicillium italicum Wehmer, causantes, respectivamente, de las podredumbres verde y azul. La irradiación UV-C tiene su máximo pico de emisión a 254 nm y se ha comprobado que es en esta longitud de onda donde presenta su mayor acción germicida, por lo que ha sido ampliamente estudiada en varios tejidos vegetales. En función de la intensidad y longitud de onda, la irradiación UV puede inducir un estrés biológico en plantas y activar algunos mecanismos de defensa de los tejidos vegetales, con la consecuente producción de fitoalexinas. La irradiación con UV-C se considera una potencial herramienta adicional en la estrategia de tratamientos combinados para el control del podrido de los cítricos, aunque la radiación UV-C por sí mismo no puede alcanzar la alta eficiencia de control del podrido de los fungicidas utilizados en la actualidad. De los resultados obtenidos en los distintos prototipos, el que ha proporcionado mejores resultados ha sido el prototipo número III , en el que se aplica la UV-C sobre la rulada en movimiento. Los resultados obtenidos indican que el efecto de la UV produce un efecto de hormesis indirecto sobre el fruto en ensayos preventivos. La combinación con agua caliente mejora también los resultados en la estrategia combinada de agua caliente seguida de aplicación de UV-C, en el aplicador de UV sobre rulada (prototipo número III), y no viceversa. Las condiciones de maduración a lo largo de la campaña influyen en los resultados de las dosis aplicadas. A dosis más altas la UV puede provocar efectos no deseados, minimizando los daños con la aplicación combinada de agua caliente. Las dosis estudiadas que han dado buenos resultados en las distintas épocas de la maduración de las variedades de mandarina y naranja son las siguientes: 2,5 kJ/m2 en fruta con la madurez comercial, sometida a desverdización, y en un rango entre 5 y 10 kJ/m2 cuando el fruto alcanza la maduración fisiológica, que varía en función de las características de fruto a lo largo de la campaña, y siempre en combinación con agua caliente. / [CA] En una agricultura moderna, difícilment es pot prescindir de l'ús de productes químics, però la possible presència de residus en els aliments és una qüestió que, cada vegada, per mínima que aquesta siga, preocupa més a l'opinió pública, si resulta desfavorable per a la seua salut. L'efecte germicida de la irradiació UV-C s'ha assajat amb èxit en diferents aliments, però no a escala industrial en la manipulació de cítrics, com un mètode de desinfecció superficial a temperatura ambient que no deixa residus en el producte, per la qual cosa es considera una bona alternativa per a la conservació d'aliments.Les malalties de postcollita, és a dir, aquelles malalties que afecten als fruits des que són recol·lectats fins que arriben al consumidor, provoquen pèrdues econòmiques importants al sector citrícola. Les pèrdues provocades per les malalties són molt variables i depenen de l'àrea productora, l'espècie, el cultivar, l'edat i condició dels arbres; les condicions climatològiques durant tota la campanya, l'època i forma de recol·lecció; la manipulació dels fruits en postcollita, les condicions d'emmagatzematge i el mercat de destí. En l'àmbit mundial destaquen les pèrdues produïdes per patògens de ferida estrictes com Penicillium digitatum (Pers.:Fr.) Sacc. o Penicillium italicum Wehmer, causants, respectivament, de les podridures verda i blava. La irradiació UV-C té el seu màxim pic d'emissió a 254 nm i s'ha comprovat que és en aquesta longitud d'ona on presenta la seua major acció germicida, per la qual cosa ha sigut àmpliament estudiada en diversos teixits vegetals. En funció de la intensitat i longitud d'ona, la irradiació UV pot induir un estrès biològic en plantes i activar alguns mecanismes de defensa dels teixits vegetals, amb la consequ¿ent producció de fitoalexinas. La irradiació amb UV-C es considera una potencial eina addicional en l'estratègia de tractaments combinats per al control del podrit dels cítrics, encara que la radiació UV-C per si mateix no pot aconseguir l'alta eficiència de control del podrit dels fungicides utilitzats en l'actualitat. Dels resultats obtinguts en els diferents prototips, el que ha proporcionat millors resultats ha sigut el prototip número III, en el qual s'aplica la UV-C sobre rodets en moviment. Els resultats obtinguts indiquen que l'efecte de la UV produeix un efecte de hormesis indirecte sobre el fruit en assajos preventius. La combinació amb aigua calenta millora també els resultats en l'estratègia combinada d'aigua calenta seguida d'aplicació d'UV-C, en l'aplicador d'UV sobre rodets (prototip número III), i no viceversa. Les condicions de maduració al llarg de la campanya influeixen en els resultats de les dosis aplicades. A dosis més altes la UV pot provocar efectes no desitjats,minimitzants els danys amb l'aplicació combinada d'aigua calenta. Les dosis estudiades que han donat bons resultats en les diferents èpoques de maduració de les varietats de mandarina i taronja són les següents: 2,5 kJ/m2 en fruta amb maduresa comercial sotmesa a desverdització, i en un rang entre 5 i 10 kJ/m2 quan el fruit aconsegueix la maduració fisiològica, que varia en funció de les característiques de fruit al llarg de la campanya, i sempre en combinació amb aigua calenta. / Ibiza Mauri, S. (2016). DESARROLLO DE PROTOTIPOS PARA EL TRATAMIENTO POSTCOSECHA DE CÍTRICOS CON RADIACIÓN UV-C Y AGUA CALIENTE PARA EL CONTROL DE LA PODREDUMBRE VERDE CAUSADA POR PENICILLIUN DIGITATUM [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/62169