The whey generated during cheese curd manufacture is a byproduct of great importance for cheese industry. Since a large volume of whey is produced and it is rich in several nutrients, the utilization of this product gains importance. The objective of this work was to develop a biotechnological process for obtaining compounds of higher aggregated values by promoting fermentation of whey from cheese curd manufacture. Several fermentations utilizing whey as a substrate were undertaken by using the yeast kluyveromices lactis in the initial concentrations of 9.0 g/L and 19.0g/L, and with the non-sterilized whey in its natural form as obtained in the process of manufacture of cheese curd. In relation to physico-chemical characteristics, increase in protein and lactose consumption was observed in all the fermentations undertaken and these values were relatively more when yeast concentration used for fermentation was of 9.0 g/L. The microbial growth curves were constructed for all the fermentations and fermented samples withdrawn characterizing each phase (14, 30 and 62 hours of fermentation) were analyzed in a gas chromatographic system coupled with several detectors for the presence of volatile compounds. The results demonstrated that between 200 to 252 volatile constituents were captured by dynamic headspace method, between 141 to 235 by liquid-liquid extraction and between 149 to 301 by simultaneous distillation and extraction method. In the volatiles extracted from different fermented products, the presence of compounds such as 2-hexadecenal, octadecanoico acid, hexadecanamide, 3-hexenol was revealed and these are relatively costly compounds as their market price varies from 70.06 to 194.50 US$/100 mL. It could be concluded from the results obtained in this study that the whey fermentation by usage of kluyveromices lactis is a promising biotechnological process for obtaining volatile compounds of higher commercial values. / O soro de queijo é um subproduto de importante relevância na indústria queijeira. Tendo em vista o elevado volume produzido e sua composição nutricional, o aproveitamento deste produto é de suma importância. O objetivo deste trabalho foi desenvolver um processo biotecnológico para obtenção de compostos de alto valor agregado através da fermentação do soro de queijo coalho. Foram realizadas fermentações com o soro utilizando a levedura kluyveromices lactis nas concentrações iniciais de 9,0 g/L e 19,0g/L e com o soro in natura (não esterilizado). Em relação às características físico-químicas observou-se que houve acentuado consumo de proteínas e lactose e aumento no teor de acidez total em todas as fermentações realizadas, sendo obtido valores maiores durante a fermentação do soro com a levedura na concentração inicial de 9,0 g/L. Determinou-se a curva de crescimento microbiano para todas as fermentações, onde coletou-se uma amostra de fermentado de cada fase (14, 30 e 62 horas de fermentação) para serem analisadas por cromatografia gasosa acoplada com diversos detectores para identificação de compostos voláteis. Os resultados demonstraram que de 200 a 252 constituintes voláteis foram capturados pelo método de extração headspace dinâmico, entre 141 a 235 pelo método líquido-líquido e entre 149 a 301 pelo método de destilação e extração simultânea. Nos voláteis extraídos dos produtos fermentados identificou-se a presença de compostos tais como 2-hexadecenal, ácido octadecanóico, hexadecanamida, 3-hexenol e outros, os quais apresentam custo extremamente elevado no mercado mundial variando de 70,06 a 194,50 US$/100 mL. Contudo, verificou-se através deste trabalho que a fermentação do soro de queijo coalho usando a kluyveromices lactis consiste em um processo biotecnológico promissor para a obtenção de compostos voláteis de grande valor comercial.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / This work describes the chemical study of renewable natural resources of the State of Sergipe, Brazil, in that we analyzed the leaves and branches of mangabeira, Hancornia speciosa Gomes (Apocynaceae).This work is divided into 3 chapters. In the first part of the research was investigated the volatile chemical composition from leaves varying the drying time and harvest time. Analysis by GC/MS and GC/FID showed that there was a significant increase in the content of some oxygenated monoterpenes according to the drying of leaves, such as -terpineol (0,08±0,20 - 3,89±1,78 in fresh leaves to 0,93±0,03 - 5,21±0,65 in dried leaves), linalool (2,95±1,45 - 12,46±2,24 in fresh leaves to 2,78±1,08 - 17,16±2,83 in dried leaves), geraniol (1,04±0,34 - 12,80±1,23 in fresh leaves to 25,67±6,45- 46,56±4,67 in dried leaves), as well and a decrease in the relative percentage of alcohols such as (Z)-3-hexenol (46,81±3,27 - 78,45±7,75 in fresh leaves to 10,70±4,87 - 19,15±4,28 in dried leaves) and 1-hexanol (1,65±0,33 - 10,15±0,80 in fresh leaves to 0,07±0,05 - 4,59±1,55 in dried leaves).In the months with higher rainfall and temperature we observed a higher yield of essential oils from leaves of H. speciosa. In the second part of the work, the phytochemical study of the leaves and branches of this species allowed the isolation of 3 mixtures. Those containing a mixture of triterpenes -amyrin, -amirin and lupeol were isolated from the hexane partition of methanolic extract of the leaves, while a mixture of 9 3--O-acyl lupeol esters and another mixture of n-alkanes were isolated from hexane extract of the branches.Structure determination of the isolated compounds was based on analysis of spectroscopic methods. In the third part, we evaluated the antioxidant activity of essential oils from fresh and dried leaves, and the methanol extract of leaves and branches and their partitioned extracts, which was seen to goodability to scavenge free radicals butanol partition of the mathanol extract of leaves. We also investigate the cytotoxic activity of hexane and methanol extracts of leaves and branches against cancer cell lines MDA-MB-435 (melanoma) and SF-295 (brain) and HCT-8 (human colon carcinoma), which was not observed an inhibitory effect. / O presente trabalho descreve o estudo químico dos recursos naturais renováveis do estado de Sergipe, onde foram analisadas as folhas e ramos da mangabeira, Hancornia speciosa Gomes (Apocynaceae). Na primeira parte do trabalho foi investigada a composição química dos voláteis das folhas variando-se o tempo de secagem e a época de colheita. As análises através de CG/EM e CG/DIC permitiram verificar que, com a secagem das folhas, houve um aumento significativo nas percentagens relativas de alguns monoterpenos oxigenados como -terpineol (0,08±0,20 - 3,89±1,78 nas folhas frescas para 0,93±0,03 - 5,21±0,65 nas folhas secas), linalol (2,95±1,45 - 12,46±2,24 nas folhas frescas para 2,78±1,08 - 17,16±2,83 nas folhas secas), geraniol (1,04±0,34 - 12,80±1,23 nas folhas frescas para 25,67±6,45- 46,56±4,67 nas folhas secas), assim como um decréscimo nas percentagens de alcoóis como (Z)-3-hexenol (46,81±3,27 - 78,45±7,75 nas folhas frescas para 10,70±4,87 - 19,15±4,28 nas folhas secas) e 1- hexanol (1,65±0,33 - 10,15±0,80 nas folhas frescas para 0,07±0,05 - 4,59±1,55 nas folhas secas). Nos meses com valores de índice de pluviometria e temperatura elevados observou-se um maior rendimento de óleo essencial de H. speciosa. Na segunda parte do trabalho, o estudo fitoquímico das folhas e dos ramos desta espécie permitiu a identificação de 3 misturas. Destas uma mistura de triterpenos contendo -amirina, - amirina e lupeol foi identificada da partição hexânica do extrato metanólico das folhas, enquanto uma mistura contendo 9 ésteres 3--O-acil lupeol e uma outra mistura contendo 12 n-alcanos foram identificadas do extrato hexânico dos ramos. A determinação estrutural das substâncias foi baseada na análise dos dados espectroscópicos obtidos. Na terceira parte do trabalho, foram realizados testes de atividade antioxidante com os óleos essenciais das folhas frescas e secas, e com o extrato metanólico das folhas e dos ramos e suas respectivas partições, onde foi observada a boa capacidade de sequestrar radicais livres da partição butanólica do extrato metanólico das folhas. Além da investigação da citotoxicidade dos extratos hexânicos e metanólicos das folhas e dos ramos frente às linhagens de células tumorais MDA-MB435 (mama - humano) e SF-295 (glioblastoma - humano) e HCT-8 (colon), onde não foi observado um efeito inibitório.

L'objectif de cette thèse est d'étudier le vieillissement thermique et prédire la durée de vie d'un jonc composite utilisé comme raidisseur de câbles électriques aériens. En effet, en conditions normales de fonctionnement, la température des câbles est de l'ordre de 80-90°C et, pendant les opérations de maintenance, des pics jusqu'à des températures de l'ordre de 220°C peuvent aussi être enregistrés. L'analyse microstructurale des coupes radiales du jonc après vieillissement dans l'air entre 160 et 220°C met en évidence son endommagement. Lorsque la matrice époxy n'est pas bien réticulée, l'endommagement consiste en une fissuration spontanée (sous l'effet de contraintes induites par le retrait chimique de la matrice) suivie de la thermo-oxydation du cœur du jonc. En revanche, lorsque la matrice est bien réticulée, cet endommagement est remplacé par la formation et l'accumulation de microcavités de gaz dans le cœur du jonc, résultant de la thermolyse de la matrice. A terme, ces microcavités coalescent pour former de larges fissures apparentes. Cette dégradation provoque la baisse progressive du module élastique et, au-delà d'un taux d'endommagement (porosités, fissures) critique, la chute catastrophique des propriétés à la rupture. Sur la base de ces résultats, des relations microstructure/propriétés mécaniques sont établies. Des tests complémentaires par thermogravimétrie couplée à la spectroscopie de masse haute résolution sont réalisés sur des films de matrice pure entre 160 et 240°C sous atmosphère inerte, afin d'élucider le mécanisme de thermolyse et l'origine de la cavitation. La décomposition des liaisons instables du réseau époxy conduit à la formation de trois principaux composés organiques volatils dont de l'eau. Lorsque la concentration de ce dernier dépasse son seuil de solubilité dans la matrice, les premières cavités apparaissent. Sur la base de ces résultats, un schéma mécanistique et un modèle cinétique de thermolyse sont proposés et vérifiés avec succès par gravimétrie. / This thesis is devoted to the study of thermal ageing and lifetime prediction of a composite rod used to stiffen electrical overhead power lines. The operating temperature of the wire is usually ranged between 80 and 90°C and, during maintenance, temperature can rise up to 220°C for short durations. Microstructural analysis of radial composite cross-sections after ageing between 160 and 220°C in air evidences its damage. When the epoxy matrix is under-crosslinked, the damage consists in a spontaneous cracking (due to stresses induced by the chemical shrinkage of the matrix) followed by the thermal oxidation of the rod core. However, when the matrix is better crosslinked, this damage is replaced by the formation and accumulation of microcavities of gases in the rod core, resulting from the matrix thermolysis. Eventually, these microcavities get connected to form wide apparent cracks. This degradation leads to the progressive decrease of the elastic modulus and, beyond a critical damage (porosities, cracks) fraction, a catastrophic fall of fracture properties. Based on these results, microstructure/properties relationships are established. Complementary tests by thermogravimetry coupled with high resolution mass spectrometry are carried on neat matrix films between 160 and 240°C under inert atmosphere to elucidate the thermolysis mechanism and the origin of the cavitation. The decomposition of unstable linkages in the epoxy network leads to the formation of three major volatile organic compounds including water. When the concentration of this later exceeds its solubility threshold in the matrix, the first microcavities appear. Based on these results, a mechanistic scheme and a kinetic model of thermolysis are proposed and successfully checked by gravimetry.

Guava (Psidium guajava L.) consumption, either industrialized or in natura, has increased significantly. It is rich in fiber, total polyphenols, vitamin C, and carotenoids, particularly lycopene. Since guava is highly perishable, it is necessary to investigate new processing methods focusing on products that are different from conventional ones. Accordingly, fermented beverages can be an alternative to obtain by-products with longer shelf-life and higher value added. These beverages could also have a great and wide consumer acceptance. In addition there is the possibility of using the by-products, such as in the production of flour due to its physicochemical composition and functional properties. Therefore, the objectives of this study were to produce fermented beverages using guava and to evaluate the bioactive and volatile compound contents as well as to use the by-products from the beverage s production to obtain flour for the production of cookies. The wine and sparkling guava beverages produced showed reasonable concentration of bioactive and volatile compounds with physicochemical parameters similar to those of traditional beverages. In terms of sensory attributes, the sparkling guava beverages achieved better acceptability indicating that the base wine can be used to produce the sparkling wine, which is evidenced by their physicochemical parameters. The analysis of the volatile composition of the sparkling guava revealed the presence of many odoriferous compounds. The use of byproducts, such as guava peel flour, proved feasible, and its use to partially replace wheat flour in the preparation of cookies showed several important nutritional benefits such as an increase in dietary fiber and mineral content, low moisture content, and increased levels of active compounds, besides reducing environmental impact. / A goiaba (Psidium guajava L.) tem apresentado largo consumo, quer in natura, quer na forma industrializada. É uma fruta rica em fibras, polifenóis totais, vitamina C e carotenóides, em especial o licopeno. Por ser altamente perecível, faz-se necessário o estudo de novas formas de processamento para obtenção de produtos diferentes dos convencionais. Neste sentido, as bebidas fermentadas apresentam-se como alternativa para a obtenção de produtos derivados com maior período de vida útil e maior valor agregado. Certamente estas bebidas poderiam ter uma ótima aceitação entre os consumidores, além da possibilidade do aproveitamento dos resíduos dessa produção na forma de farinha devido sua composição físico-química e propriedades funcionais. Sendo assim, este trabalho teve como objetivo elaborar bebidas fermentadas a partir de goiaba, avaliando os teores de compostos bioativos e compostos voláteis bem como fazer um aproveitamento dos resíduos proveniente da produção das bebidas na obtenção de farinha para a produção de biscoitos tipo cookies. O fermentado e o espumante de goiaba apresentaram razoáveis teores de compostos bioativos e voláteis, com parâmetros físico-químicas semelhantes aos das bebidas tradicionais. Sensorialmente, o espumante de goiaba apresentou melhor aceitabilidade indicando assim que o fermentado de goiaba obtido pode ser usado como vinho base para a elaboração de espumante de goiaba, comprovado pelos parâmetros físico-químicos apresentados. A análise da composição volátil do espumante de goiaba revelou muitos compostos com potencial odorífero. O aproveitamento dos resíduos do processamento de goiaba como farinha da casca demonstrou ser viável e seu uso na substituição parcial da farinha de trigo na preparação de biscoitos tipo cookies demonstrou ter muitas vantagens nutricionais, fornecendo um incremento de fibra alimentar, conteúdo de minerais, baixo teor de umidade e aumento nos teores de compostos ativos, além de reduzir a contaminação ambiental.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study evaluated the UV-C irradiation in tissues of rachis with and without berries, and berries with stems of Vitis vinifera and Vitis labrusca. In berries of cv. Isabella, the volatile compounds were analyzed on days 2, 5 and 10 of storage at 20 ºC and the effect of UV-C irradiation on the 5th day of storage. The experiments were based on four treatments of UV-C radiation (0, 1, 2 and 3 kJ m-2) with four cv. (Niagara white, Trebbiano, Cabernet sauvignon and Isabella) and evaluation times (three in berries and four rachis). The rachis with and without berries and the berries with stems remained stored at 20 ºC to evaluate physiological parameters. Ethylene production rate, respiratory rate and total polyphenols were evaluated in all tissues. Only in the rachis was determined by weight loss on days 1, 3 and 5, reducing sugars, non-reducing sugars on the 5th day. Berries and the juice from the cv. Isabella the 5th day of storage at 20 °C the total soluble solids (TSS), titratable acidity (TA), anthocyanins, total phenols, sugars and the ratio (TSS/ TA) were measured. In berries of cv. Isabella on days 2, 5 and 10 storage and berries irradiated with UV-C in amounts of 0, 1, 2 and 3 kJ m-2, volatiles were extracted by solid phase microextration. After desorption, the volatile compounds were separated by gas chromatography, identified by mass spectrometry and quantified by flame ionization detector. For the sensory analysis of the juice discriminatory tests for paired comparison of difference and test ranking were used. The physiological response of UV-C irradiation depends on the cv. and the irradiated tissue. Only the rachis of grape Vitis labrusca ‗Niagara white behaves climateric during storage in post-harvest and may reduce the self life of table grapes. This study found a possible hormetic dose of 3 kJ m-2 only for the cv. Isabella berry. 84 volatile compounds were detected over the days of storage. After 5 days storage, berries irradiated with UV-C 66 volatiles were found. And the dose of 3 kJ m-2 increased the concentration of esters and aldehydes, and 43,8% increase in the total polyphenols in berry. In the paired comparison test of difference, the judges showed greater intensity in the aroma of the juice from grapes irradiated. In the ranking test, the judges were unable to discriminate between different doses of irradiation, though differing dose control (0 kJ m-2) of the irradiated treatments. The analytical test enabled by gas chromatography to determine statistical differences between the different doses detected volatiles, especially at a dose of 3 kJ m-2, in which panelists found no difference. / Este trabalho avaliou a irradiação UV-C em tecidos vegetais de ráquis com e sem bagas, e bagas com pedúnculo de Vitis vinifera e Vitis labrusca. Nas bagas da cv. Isabel, foram analisados os compostos voláteis nos dias 2, 5 e 10 de armazenamento a 20 ºC e sobre o efeito da irradiação UV-C no 5º dia de armazenamento. Os experimentos basearam-se em quatro tratamentos de irradiação UV-C (0, 1, 2 e 3 kJ m-2), com quatro cv. (Niágara branca, Trebbiano, Isabel e Cabernet sauvignon) e tempos de avaliação (três nas bagas e quatro nas ráquis). As ráquis com e sem bagas e as bagas com pedúnculo permaneceram armazenadas a 20 ºC para avaliar parâmetros fisiológicos. Em todos os tecidos foram avaliadas a taxa de produção de etileno, taxa respiratória e polifenóis totais. Apenas na ráquis foi determinado a perda de peso nos dias 1, 3 e 5, além de açúcares redutores e não redutores no 5º dia. Nas bagas e no suco da cv. Isabel do 5º dia de armazenamento a 20 ºC foram mensurados os sólidos solúveis totais (SST), acidez total titulável (ATT), antocianinas totais, polifenóis totais, açúcares totais e a relação (SST/ATT). Nas bagas da cv. Isabel dos dias 2, 5 e 10 de armazenamento e nas bagas irradiadas com UV-C nas doses de 0, 1, 2 e 3 kJ m-2, foram extraídos os compostos voláteis por microextração em fase sólida. Após a dessorção, os compostos voláteis foram separados em cromatógrafo a gás, identificados pelo espectrômetro de massas e quantificados por detector de ionização em chamas. Para a análise sensorial do suco, foram utilizados os testes discriminativos de comparação pareada de diferença e teste de ordenação. A resposta fisiológica da irradiação UV-C depende da cv. e do tecido irradiado. Apenas a ráquis da uva Vitis labrusca ‗Niágara branca se comporta de forma climatérica durante o armazenamento na pós-colheita, podendo reduzir a vida de prateleira da uva de mesa. Neste estudo foi encontrada uma possível dose hormética de 3 kJ m-2 somente para a baga da cv. Isabel. Foram detectados 84 compostos voláteis ao longo dos dias de armazenamento. No 5º dia de armazenamento, das bagas irradiadas com UV-C, foram encontrados 66 compostos voláteis, sendo que a dose de 3 kJ m-2 aumentou a concentração de ésteres e aldeídos, além de elevar em 43,8% os polifenóis totais na baga. No teste de comparação pareada de diferença, os provadores indicaram maior intensidade no aroma do suco proveniente de uvas irradiadas. No teste de ordenação, os julgadores não conseguiram discriminar as diferentes doses de irradiação, mas diferenciaram a dose controle (0 kJ m-2) dos tratamentos irradiados. O teste analítico por cromatografia gasosa permitiu determinar diferença estatística entre as doses nos diferentes compostos voláteis detectados, principalmente na dose de 3 kJ m-2, na qual os julgadores não encontraram diferença.

This diploma thesis is focused on the construction of the electrochemical cells for the lead determination using electrochemical generation of volatile compounds connected with the atomic absorption spectrometry as a detection technique. Three different electrochemical cells were constructed: membrane electrochemical cell (MEC), non-membrane electrochemical cell 1 (BEC1) and non-membrane electrochemical cell 2 (BEC2). Experimental conditions were optimized in continuous flow mode with cells BEC1 and BEC2. The optimization include flow rate of carrier gas, composition and concentration of the electrolytic solution, atomization temperature, generation current and voltage applied to the electrode material. A 1.0 mm diameter cadmium wire was used as cathode material and the anode material was composed of platinum wire of 0.5 mm in diameter. Under the optimal experimental conditions, the calibration was constructed and basic characteristics of proposed method were determined for the BEC1 and BEC2 cells: limit of detection, limit of quantification, repeatability, sensitivity, linear dynamic range and correlation factor of linear dynamic range. The cell MEC was found to be unsuitable for the lead determination by the electrochemical generation of volatile compounds. Using the BEC1 cell, the experimental...

Les accidents cardio-vasculaires représentent la première cause de décès en France. Parmi les facteurs de risque de ces pathologies figure la structure de l’apport lipidique, excédentaire en acides gras saturés, et déficitaire en acides gras polyinsaturés n-3. L’objectif de cette thèse est la mise au point d’un corps gras alimentaire, dont le profil lipidique permet de participer au rééquilibrage des apports en acides gras, avec comme cible la prévention des maladies cardio-vasculaires.Quatre études ont été réalisées pour répondre à cette problématique. Après la mise au point du profil en acides gras optimal, l’impact de la formulation de la phase concrète sur la texture du produit a été étudié afin de concilier les exigences nutritionnelles et les contraintes techniques de sa fabrication et de sa conservation.La mise au point de la formulation de la phase fluide a engendré une étude sur le développement de composés volatils délétères suite à l’addition d’une proportion importante d’huile de poisson dans la formule. Ce travail a mis en évidence deux phénomènes liés au dégagement de ces molécules, l’un attribué à l’oxydation des lipides, l’autre au contact avec l’eau.Le besoin de protéger les nutriments d’intérêt dans la matrice alimentaire a conduit à la mise au point d’une technologie de microencapsulation, originale de par son procédé de fabrication et sa finalité.Enfin, une étude de la biodisponibilité chez l’animal a montré que ce produit alimentaire est un vecteur efficace de ces nutriments d’intérêt que sont les acides gras polyinsaturés à longue chaîne. Apportés dans une telle matrice, ces composés ont modifié le profil lipidique des cellules circulantes et cérébrales, ce qui permet potentiellement d’améliorer le statut inflammatoire et coagulant des animaux / Cardiovascular events are the major cause of death in France. Among the known risk factors, lipid intake is of growing interest, saturated fatty acids being too much consumed, and n-3 polyunsaturated fatty acids not enough. The aim of this PhD study is to design a spread with a lipid profile that can improve the whole lipid intake, and with cardiovascular events prevention as main goal.Four studies were conducted regarding this issue. Following the design of the optimal fatty acid profile for the product, it appeared necessary to study the solid phase recipe impact on the product texture, to achieve both nutritional and technological restrains.The design of the liquid phase recipe generated a study on the development of deleterious volatile compounds following the addition of a high proportion of fish oil in the formula. This work highlighted two phenomena linked to the emission of these molecules, one related to lipid oxidation, and the other to a contact with water.A technology of microencapsulation, which is original because of its production process and aim, was designed to ensure the protection of the active nutrients in the product matrix.Finally, a bioavailability study in rats showed that this food product is a powerful way of providing these nutrients. Incorporated in such a matrix, these molecules modified the lipid profile of the circulating and cerebral cells membrane, potentially improving the inflammatory and clotting status of the animals

Jackfruit seeds are an under-utilized waste in many tropical countries. In this work, we demonstrated the potential of roasted jackfruit seeds to generate chocolate aroma for use as a cocoa substitute in foodstuffs. Twenty-seven different flours were produced from a hard pulp variety of jackfruit by drying (DJS), acidifying (AJS), or fermenting (FJS) the seeds prior to roasting under different time/temperature combinations. The chocolate aroma of groups of four flours were ranked by a sensory panel (n=162) and response surface methodology was used to identify optimum conditions for producing chocolate aroma. Pyrazines were analyzed instrumentally as markers of chocolate aroma, while moisture, pH, and color were also monitored. The best chocolate aroma was produced in three jackfruit seed flours: DJS, AJS, and FJS. Volatile and semi-volatile compound contents were evaluated by GC-MS, GC-O, and SPE-GC in these three jackfruit seed flours and their profiles were compared with the profile of cocoa powder. These flours were also evaluated for their solubility, swelling power, wettability, apparent density, viscosity, sensory preference, and intensity of chocolate aroma. The central composite design was used to optimize the solubility and swelling power. Water temperature and time to flour exposition were the response variables. Owing to their differing volatile compositions, two different flours (DJS and FJS) were applied in six cappuccino formulations with 50%, 75%, and 100% substitution of cocoa powder with jackfruit seed flours. The consumers acceptance of cappuccinos (n=126) and the quantitative descriptive analysis (QDA) were used to describe the preparations. Physicochemical properties in cappuccino formulations were also evaluated. The greatest relative concentration of pyrazines (p<=0.05) was formed in dry, acidified, and fermented flour when we used 156, 165, and 154°C, respectively. Clearly, fermentation is necessary to improve the chocolate aroma of jackfruit seeds, and it is possible to select the best roasting conditions for each treatment to optimize the sensory perception of chocolate aroma. These optimal treatment conditions were found to be 171°C for 47 min in DJS, 180°C for 40 min in AJS, and 154°C for 35 min in FJS. FJS had higher solubility and wettability than other flours. The viscosities of jackfruit seed flours were low with high solubility, properties that are desirable in cocoa powder (CP). Chocolate aroma was most intense for FJS. Therefore, jackfruit seed flours have technological properties and chocolate aroma similar to or better than CP and commercial chocolate (CC). For cappuccino formulations, 50% and 75% cocoa powder was replaced with dry jackfruit seed flour, and there was no change in sensory acceptability or technological properties. The principal component analysis of QDA explained 90% of variance. The primary characteristics of cappuccinos made with dry jackfruit seeds were cappuccino, chocolate, cinnamon, and coffee aromas, and cappuccino and chocolate tastes. Indeed, dry jackfruit seed flour is an innovative cocoa powder substitute; it could be used in food preparations, consequently utilizing this tropical fruit waste by incorporating it as an ingredient in a common product of the human diet. / As sementes de jaca são subaproveitadas em muitos países tropicais. Neste estudo, foi possível demonstrar que as sementes de jaca torrada possuem potencial para produzir aroma de chocolate e podem ser utilizada como um substituto do cacau em alimentos processados. Vinte e sete farinhas foram produzidas com a semente de jaca da variedade dura através de secagem (DJS), acidificação (AJS), ou fermentação (FJS) as sementes foram submetidas sob diferentes combinações de tempo e temperatura de torra. O aroma de chocolate quanto aos grupos de farinha foram avaliados sensorialmente por painel (n=162) e a metodologia superfície de resposta foi utilizada para identificar a melhor condição para produzir aroma de chocolate. As pirazinas foram instrumentalmente analisadas como marcadores do aroma de chocolate. Assim como, umidade, pH e cor também foram monitorados. O melhor aroma de chocolate foi produzido para as três farinhas de semente de jaca: DJS, AJS e FJS. Compostos voláteis e semi-volateis foram avaliados utilizando GC-MS; GC-O e SPE-GC nesses três tratamentos as farinhas de sementes de jaca seus perfis foram comparados com o perfil do cacau em pó. Essas farinhas foram também avaliadas quanto sua solubilidade, molhabilidade, densidade aparente, viscosidade, preferência sensorial e intensidade do aroma de chocolate. O delineamento com ponto central foi utilizado para otimizar a solubilidade e o poder de absorção. As variáveis respostas foram temperatura da água e tempo de exposição da farinha. Devido a sua composição diferenciada quanto aos compostos voláteis, duas diferentes farinhas (DJS e FJS) foram aplicadas em seis formulações de cappuccino com 50, 75 e 100% de substituição do pó de cacau por farinha de semente de jaca. A aceitação dos cappuccinos pelos consumidores (n=126) e a análise quantitativa descritiva (ADQ) foram utilizadas para descrever as preparações. Propriedades físico-químicas das formulações de cappuccino também foram avaliadas. A maior concentração relativa de pirazinas foi formada em farinhas seca, acidificada e fermentada quando utilizado 156, 165 e 154°C, respectivamente. Claramente a fermentação é necessária para melhorar o aroma de chocolate da farinha de semente de jaca, foi possível selecionar a melhor condição de torração para cada tratamento quanto à percepção sensorial do aroma de chocolate. Essas condições ótimas foram encontradas como 171°C para 47 minutos para farinha seca; 180°C durante 40 minutos para as sementes acidificadas e 154°C durante 35 minutos para as farinhas fermentadas com alta solubilidade e molhabilidade em comparação com as demais farinhas. A viscosidade da farinha de semente de jaca foi baixa com alta solubilidade o que é desejável para o cacau em pó (CP). O aroma de chocolate foi mais intenso para FJS. Assim, as farinhas de semente de jaca tiveram propriedades tecnológicas e aroma de chocolate similar ou melhor que CP e de chocolate comercial (CC). Para as formulações de cappuccino 50 e 75% de pó de cacau foram substituídas por farinha de semente de jaca seca, e não houve mudança na aceitabilidade sensorial e nas propriedades tecnológicas A análise de componentes principais para ADQ explicou 90% da variância. A principal característica dos cappuccinos feitos com semente de jaca seca quanto ao aroma foram cappuccino, chocolate, canela e café e cappuccino e chocolate para o sabor. Assim, a farinha de semente de jaca seca é um substituto inovador do pó de cacau, este pode ser utilizado em preparações alimentícias, consequentemente este resíduo agroindustrial pode ser incorporado como ingrediente comum na dieta humana.

This diploma thesis deasl with the chemical charakterization of wine from selected PIWI varieties. The theoretical part describes the general origin and reason for breeding PIWI varieties, a closer characterization of selected three PIWI varieties, Johaniter, Hibernal and Solaris. The next part is devoted to the description of analytical methods that were used to determine the chemical characteristics. The experimental part is developed to the determination of chemical characteristics, namely general characteristics such as alcohol, total phenols, phenolic substances, volatile substances and elemental composition. The results show that are differences between wines from selected PIWI varieties in therms of chemical composition. The most represented organic acid was in the range of 735,1-1286,2mg/l malic acid. This was followed by acetic in the range of 100-400mg/l. The antioxidant activity was determined in the range of 0,2988-0,9683 mmol/l of Trollox and content of total phenols 273,5-390,3mg/l. Of the phenolic substances, gallic acid was the most represented, ranging from 6,9-13,9mg/l. As another, abundant phenolic substances, catechin in the range of 1,6-6,0mg/l was detected. Of the determined elements, phosphorus in the range of 165,4-450,5mg/l was the most represented. Representatives of ethyl ester, ethyl acetate, decanoic acid ethyl acetate and hexanoic acid ethyl ester, were detected as the most abundant volatiles. From the measured data it was evident that wines from PIWI varieties different from standard varieties, especially in the profile of aromatic substances.

This thesis deals with the development of a method suitable for determination Te(IV) by UV-photochemical generation of volatile compounds (UV-PVG) in liquid samples. Atomic absorption spectrometry (AAS) and atomic fluorescent spectrometry (AFS) were used as detection methods. The basis of the apparatus for UV-PVG was a mercury lamp wrapped by PTFE capillary. Firstly, the experimental parameters were optimized for both methods. The optimized parameters were the type, concentration, pH and flow rate of the reaction medium, the length of the PTFE reaction coil, carrier gas flow rate (argon), supportive gas flow rate (hydrogen) and atomization temperature. The figures of merit with both detection methods were determined and compared after the method was optimized. Detection limits achieved for these two detection methods were 6,0 µg dm-3 for AFS and 1,50 µg dm-3 for AAS. Performed interference study confirmed a significant effect of many cations of transition metals and hydride forming elements on tellurium determination. The influence of nitric acid in the sample was studied separately. The suitability of the method for tellurium determination was confirmed by using a spiked certified reference material.