Made available in DSpace on 2014-08-20T14:22:07Z (GMT). No. of bitstreams: 1 Dissertacao_Debora_Leitzke_Betemps.pdf: 1110781 bytes, checksum: 2e516a9e01a150ed3520ffe92559384d (MD5) Previous issue date: 2010-03-29 / Althought there are researches that report the influence of rootstock about the scion cultivar, changing their behavior in relation to development, productivity, resistance, nutrition, maturation time and the quality of the fruits, these results are not conclusive. Objective of the study was evaluate the effect of rootstock Aldrighi, Capdeboscq, Flordaguard, Nemaguard, Okinawa and Umezeiro about quality of peaches cultivar Maciel. The fruits of the cultivar Maciel are from two orchards located in the Agricultural Center of Palma UFPel/Capão do Leão and in the experimental Estation of the Federal University of Rio Grande do Sul UFRGS/Eldorado do Sul. After the harvest, the fruits carried the following Physico-chemical analysis: acidity, skin color, total soluble solids, pH, 'Ratio' and firmness. For phytochemical analysis, fruits were separated into peel and flesh, stored in ultra-freezer, and later held the analysis of individual and total phenols, total and individual carotenoids and antioxidant activity. For Palma‟s fruits, the rootstock evaluated influenced considerably the acidity parameters, firmness, color of coating, pH, and ratio. These effects were not observed in the experimental Estation UFRGS with the same cultivar. The values of phenols and carotenoids total and individual were influenced by the rootstocks both the flesh and the peel, for the two localities. The Okinawa‟ had the highest average of total phenols in the peel for both places, Flordaguard‟ the flesh showed the highest average for the CAP‟s fruit and Nemaguard‟ to the fruits EE/UFRGS. The quantification of phenolic compounds, the gallic acid is the highest expression followed by p-hydroxybenzoic, p-coumaric and caffeic. For carotenoids in the flesh Okinawa‟ showed the highest average not differing from Aldrighi‟ while in the largest EE/UFRGS results were found in the Capdeboscq‟, Nemaguard‟ and Umezeiro‟. For carotenoids, β-cryptoxanthin, is the majority pigment, still presenting licopen and β-caroten in minors amounts. Nemaguard, Aldrighi and Umezeiro‟ present a higher value for antioxidant capacity. In the analysis of correlation between phytochemical were watched a weak and positive correlation for the flesh of the fruits and for the peel a correlation weak and negative. It is conclude that the rootstock might affect in an undirected form some phytochemical and physico-chemical, for both localities in which fruits were characterized. / Embora existam pesquisas que relatem a influência do porta-enxerto sobre a cultivar copa, alterando o seu comportamento em relação ao desenvolvimento, produtividade, resistência, nutrição, época de maturação e qualidade dos frutos, os resultados ainda não são conclusivos. Objetivou-se com o trabalho avaliar o efeito dos porta-enxertos Aldrighi, Capdeboscq, Flordaguard, Nemaguard, Okinawa e umezeiro sobre a qualidade de pêssegos da cultivar Maciel. Os frutos foram provenientes da safra de 2008 de dois pomares, sendo um localizado no Centro Agropecuário da Palma UFPel/Capão do Leão (CAP/UFPel) e outro na Estação Experimental da Universidade Federal do Rio Grande do Sul UFRGS/Eldorado do Sul (EE/UFRGS). Após a colheita dos frutos procederam-se as seguintes análises físico-químicas: acidez (AT), coloração da epiderme, sólidos solúveis totais (SST), pH, relação SST/AT e firmeza de polpa. Para as análises fitoquímicas os frutos foram separados em casca e polpa e armazenados em ultra-freezer e posteriormente realizou-se a análise de fenóis totais e individuais, carotenóides totais e individuais e atividade antioxidante. Para os frutos provenientes do CAP/UFPel, os porta-enxertos avaliados influenciaram significativamente a acidez, firmeza, cor de recobrimento, pH e ratio. Estes efeitos não foram observados com os frutos provenientes da EE/ UFRGS com esta mesma cultivar onde somente a firmeza apresentou efeito significante dos porta-enxertos. Os valores de fenóis e carotenóides totais e individuais foram influenciados pelos porta-enxertos tanto na polpa quanto na casca, para as duas localidades.O Okinawa‟ obteve as maiores médias de fenóis totais na casca para as duas localidades, na polpa Flordaguard‟ apresentou as maiores médias para os frutos do CAP/UFPel e Nemaguard‟ para os frutos da EE/UFPel. Na quantificação de compostos fenólicos, o ácido gálico foi o de maior expressão seguido dos ácidos hidroxibenzóico, cumárico e cafeíco. Para carotenóides totais, na polpa, Okinawa‟ e Aldrighi‟ apresentaram as maiores médias não diferindo entre si no CAP/UFPel enquanto que na EE/UFRGS os maiores resultados foram quantificados em Capdeboscq‟, Nemaguard‟ e Umezeiro‟. Na quantificação dos carotenóides individuais, o β-criptoxantina é o pigmento majoritário apresentando ainda licopeno e β-caroteno em quantidades menores. Nemaguard, Aldrighi e Umezeiro‟ apresentaram maiores valores para capacidade antioxidante para a polpa dos frutos do CAP/UFPel sendo que Nemaguard‟ e Aldrighi‟ mantiveram este resultado para polpa da EE/UFRGS. Na análise de correlação entre os fitoquímicos, observou-se uma correlação fraca e positiva para a polpa dos frutos e para casca uma correlação fraca e negativa. Conclui-se que o porta-enxerto pode afetar de forma indireta alguns parâmetros físico-químicos e fitoquímicos, para as duas localidades na qual os frutos foram caracterizados.

Quantum Chemical Topology (QCT) descriptors, calculated from ab initio wave functions, have been utilised to model pKa and mutagenicity for data sets of pharmaceutically relevant compounds. The pKa of a compound is a pivotal property in both life science and chemistry since the propensity of a compound to donate or accept a proton is fundamental to understanding chemical and biological processes. The prediction of mutagenicity, specifically as determined by the Ames test, is important to aid medicinal chemists select compounds avoiding this potential pitfall in drug design. Carbocyclic and heterocyclic aromatic amines were chosen because this compounds class is synthetically very useful but also prone to positive outcomes in the battery of genotoxicity assays.The importance of pKa and genotoxic characteristics cannot be overestimated in drug design, where the multivariate optimisations of properties that influence the Absorption-Distribution-Metabolism-Excretion-Toxicity (ADMET) profiles now features very early on in the drug discovery process.Models were constructed using carboxylic acids in conjunction with the Quantum Topological Molecular Similarity (QTMS) method. The models produced Root Mean Square Error of Prediction (RMSEP) values of less than 0.5 pKa units and compared favourably to other pKa prediction methods. The ortho-substituted benzoic acids had the largest RMSEP which was significantly improved by splitting the compounds into high-correlation subsets. For these subsets, single-term equations containing one ab initio bond length were able to accurately predict pKa. The pKa prediction equations were extended to phenols and anilines.Quantitative Structure Activity Relationship (QSAR) models of acceptable quality were built based on literature data to predict the mutagenic potency (LogMP) of carbo- and heterocyclic aromatic amines using QTMS. However, these models failed to predict Ames test values for compounds screened at GSK. Contradictory internal and external data for several compounds motivated us to determine the fidelity of the Ames test for this compound class. The systematic investigation involved recrystallisation to purify compounds, analytical methods to measure the purity and finally comparative Ames testing. Unexpectedly, the Ames test results were very reproducible when 14 representative repurified molecules were tested as the freebase and the hydrochloride salt in two different solvents (water and DMSO). This work formed the basis for the analysis of Ames data at GSK and a systematic Ames testing programme for aromatic amines. So far, an unprecedentedly large list of 400 compounds has been made available to guide medicinal chemists. We constructed a model for the subset of 100 meta-/para-substituted anilines that could predict 70% of the Ames classifications. The experimental values of several of the model outliers appeared questionable after closer inspection and three of these have been retested so far. The retests lead to the reclassification of two of them and thereby to improved model accuracy of 78%. This demonstrates the power of the iterative process of model building, critical analysis of experimental data, retesting outliers and rebuilding the model.

A própolis é uma substância resinosa, formada por produtos coletados de plantas e substâncias produzidas pelas abelhas, cuja textura e coloração varia dependendo da fonte de coleta e respectiva fenologia. É utilizada na colméia para diversas finalidades: vedar aberturas, forrar a entrada da colméia e envolver invasores. O interesse por própolis tem crescido muito, devido à comprovação experimental de suas atividades biológicas, tais como citotóxica, anti-herpes, anti-HIV, antitumoral, antimicrobiana e antioxidante. A composição química da própolis é complexa, compreendendo, além de cera de abelha, flavonóides, ácidos fenólicos, terpenóides, substâncias voláteis, entre outros constituintes. A composição depende de vários fatores, principalmente da região onde é produzida. Neste trabalho, estabeleceu-se o perfil químico de amostras de própolis brasileiras, baseando-se nos teores de substâncias fenólicas totais, flavonóides totais e ceras de amostras de distintas regiões do território brasileiro: Ponta Grossa (PR), Bauru e Pariquera-Açu (SP), Lavras e Mira Bela (MG), Pirenópolis (GO), Cabo Verde (BA), Maceió (AL) e Picos (PI). Os teores de fenóis totais foram determinados pelo no método de Folin Ciocalteau, utilizando-se ácido p-cumárico como referência. A dosagem de flavonóides totais baseou-se em dois métodos espectrofotométricos complementares: cloreto de alumínio e dinitrofenil-hidrazina, usando-se quercetina e pinocembrina, respectivamente, como referências. Os teores de ceras foram obtidos por extração com clorofórmio, tratamento com metanol e pesagem do resíduo. Os resultados demonstraram grande diversidade química entre as amostras estudadas, inclusive entre amostras do mesmo estado. Tal é o caso das amostras de Lavras e Mira Bela, e Bauru e Pariquera-Açu. Os teores de fenóis totais variaram de 0,91% a 41,63%, sendo o maior percentual referente à amostra de própolis vermelha (Maceió). Esses resultados são superiores aos obtidos com própolis do Uruguai, Argentina, Paraguai, China e países da Europa, e também de própolis verde brasileira. Os valores obtidos para flavonóides totais variaram entre 0,31% e 4,43%, valores próximos aos encontrados por outros pesquisadores de própolis brasileiras, porém inferiores aos relatados para própolis européia, que variam entre 1,1% e 22,3%. Os teores de ceras determinados, variando entre 5,37% e 45,88%, são superiores aos relatados para outras amostras de própolis brasileiras, sendo comparáveis apenas às própolis chinesas, cujo teor é de aproximadamente 30%. Com base nos teores dosados, foi feita análise de componentes principais (PCA). As amostras de Maceió, Cabo Verde, Pirenópolis e Bauru emergiram isoladamente das demais. Pariquera-Açu e Mira Bela sobressaíram-se no outro extremo do gráfico, devido a baixos teores de compostos fenólicos e altos índices de ceras. As amostras de Picos, Lavras e Ponta Grossa agruparam-se em função de teores de fenóis totais expressivos e de ceras relativamente altos. Foram analisadas as frações clorofórmicas e metanólicas de todas as amostras por HPLC-MS e CG-EM. Essas análises revelaram que as amostras de Bauru, Lavras e Cabo Verde têm composição típica de própolis verde, com muitos fenilpropanóides prenilados e derivados de ácido cafeoilquínico. A composição da própolis de Maceió diferiu muito das demais, incluindo a presença de chalconas. Tais substâncias nunca foram relatadas em própolis anteriormente. As própolis de Pirenópolis e Picos assemelham-se pela presença de muitos flavonóides glicosilados, substâncias nunca reportadas anteriormente para própolis. As amostras de Ponta Grossa, Pariquera-Açu e Mira Bela têm perfil químico intermediário entre a própolis verde e própolis com flavonóides glicosilados. Essas afinidades químicas ficaram bem evidenciadas por meio de análise de agrupamento, usando-se as substâncias identificadas como variáveis e o método de agrupamento UPGMA. Os resultados evidenciam que os tipos de própolis brasileiras não se restringem a doze, como proposto anteriormente. As análises químicas revelaram três tipos adicionais: Maceió, Pirenópolis / Picos e Ponta Grossa / Pariquera-Açu / Mira Bela. A enorme diversidade da composição da própolis produzida no Brasil realça a importância da realização de estudos para a determinação de perfis químicos e fontes botânicas de resinas. Esses conhecimentos são essenciais para o uso adequado de produtos da própolis no mercado nacional e internacional. / Propolis is a resinous substance comprising exsudates collected from plants and substances produced by bees, with texture and colour varying according to the plant source of resin and respective phenology. This product is used in the hive with various purposes: to seal holes and line the hive entrance and to embalm the bodies of killed invaders. The interest in propolis has increased recently, mainly due to experimental evidences of its biological activities, such as cytotoxic, anti-herpes, anti-HIV, antitumoral, anti-microbial and antioxidant. The chemical composition of propolis is complex, including, in addition to beeswax, flavonoids, phenolic acids, terpenoids and volatile substances, among other constituents. The composition depends on many factors, mainly the region, where it was produced. In the present work the chemical profile of the Brazilian propolis was established based on the content of total phenolic substances, total flavonoids and waxes of samples from distinct regions of the Brazilian territory: Ponta Grossa (PR), Bauru and Pariquera-Açu (SP), Lavras and Mira Bela (MG), Pirenópolis (GO), Cabo Verde (BA), Maceio (AL) and Picos (PI). The contents of total phenols were obtained by the Folin-Ciocalteau method, using p-coumaric acid as reference. Determination of total flavonoids was based on two spectrophotometric complementary methods: alluminum chloride and dinitrophenyl-hydrazine, using quercetin and pinocembrin, respectively, as references. Determination of wax contents was carried out by extraction with chloroform, treatment with methanol and weight of the residue. The results revealed a wide chemical variety among the samples, even between samples from the same state, as are the cases of samples from Lavras and Mira Bela and from Bauru and Pariquera-Açu. Total phenol contents varied in the range 0,91%-41,63%, highest figures corresponding to red propolis from Maceio. The contents determined are higher than those obtained with propolis from Uruguai, Argentina, Paraguai, China and Europe, and also with Brazilian green propolis. Regarding values of total flavonoids, they ranged from 0,31% to 4,43%, similar to results reported by other researchers with Brazilian propolis, but lower than contents of European propolis, which has varied in the range 1,1%-22,3%. Wax contents varied from 5,37% to 45,88%, such figures being higher than values of Brazilian propolis reported by other authors, but comparable with Chinese propolis, which content is close to 30%. Based on the results obtained a Principal Components Analysis (PCA) was carried out. Samples from Maceio, Cabo Verde, Pirenópolis and Bauru emerged isolated. Pariquera-Açu and Mira Bela standed out as a group in the other end of the graphic, due to low contents of phenolic compounds and high levels of waxes. The samples from Picos, Lavras and Ponta Grossa comprised another group, based on salient contents of total phenols and relatively high contents of waxes. Chloroform and methanolic fractions from each sample were analyzed by HPLC-MS and GC-MS. These analyses showed that samples from Bauru, Lavras and Cabo Verde have composition typical of green propolis, with many prenylated phenylpropanoids and cafeoylquinic acid derivatives. The composition of the Maceio propolis differed very much, standing out by having exclusive constituents, such as chalcones, a class of flavonoids never reported for propolis. Propolis from Pirenopolis and Picos are alike due to many glycosilated flavonoids, substances also never reported for propolis. Samples from Ponta Grossa, Pariquera-Açu and Mira Bela have chemical profiles intermediate between green propolis and those with glycosilated flavonoids. The commented chemical affinities were evident in clustering analysis carried out with the identified substances as variables and UPGMA method. These results constitute evidence that Brazilian propolis cannot be grouped in only twelve types, as has been suggested. The present chemical analyses revealed three additional types: Maceió, Pirenópolis/Picos e Ponta Grossa/Pariquera-Açu/Mira Bela. The huge diversity of the composition of propolis produced in Brazil highlight the importance of studies for determination of chemical profiles and resin botanical sources. Such findings are essential for adequate use of propolis products both in the national and international market.

M. Tech (Department of Chemistry, Faculty of Applied and Computer Sciences) Vaal University of Technology. / In this study, analytical method for determining the chlorinated phenols in water was developed using High Performance Liquid Chromatography. The following four compounds which are 2, 4, 6- Trichlorophenol (2, 4, 6 TCP), 3-chlorophenol (3CP), 2, 4- Dichlorophenol (2, 4 DCP) and 4-chloro-3-methylphenol (4C3MP) were identified and quantified with a High Performance Liquid Chromatography (HPLC). The validation parameters tested were,: linearity, trueness, precision, detection limit of quantitation, sensitivity, specificity, selectivity. The linear calibration ranges of five standard solution from 1-10 ppm. The linearity ranges between 0.9298-0.9813. The activated carbon based on the waste macadamia nutshell activated carbon (MAC) was investigated for its potential uses as an adsorbent for chlorinated phenols removal and compared with grafted macadamia nutshell activated carbon (GMAC). The adsorbent was characterized with Fourier transform infrared spectrophotometer (FTIR), scanning electron microscope (SEM) and thermo gravimetric analysis (TGA). The parameters such as pH, temperature, contact time, concentration and adsorbent were investigated by adsorption technique. The strata C18E has been used before for the same reason and therefore the research was based on mimic the functional group of solid phase extraction (SPE) into macadamia activated carbon (MAC). The functional groups in SPE C18E are benzene and octadecyl. MAC was grafted with strata C18E functional groups to compare its potential with the SPE. The pseudo-first-order and pseudo-second-order kinetic models were applied to verify the experimental data. The pseudo-second order exhibited the best fit for the kinetic studies for MAC adsorption. Chemical removal of chlorinated phenols from wastewater is necessary to reduce harmful products on the environment and human health. Chlorinated phenols have been previously listed as some of the highest priority contaminants and as well as mainly important capability carcinogenic toxins released from chemical plants. Their availability in water supplies was perceived by their bad taste and smell. The acceptable chlorinated phenols concentration in portable water is 1 (mg/l) base on the approval of world health organization. The permanent checking of chlorinated phenols in environmental samples has a greater significance and stresses highly effectiveness, common selectively and great sensitively methods. The maximum uptake of Phenol using weighed mass of MAC was found to be 78 % and for GMAC was 84% for both 2,4,6TCP. t=250 min, pH=5, Co=1mg/l, T = 25 oC and m = 0.3 g/l were the optimum condition for Phenol-MAC system and GMAC system. Over all analysis of equilibrium model analysis indicates the fitness of Langmuir isotherm model to Phenol MAC adsorption system, suggesting a monolayer adsorption of phenol on the surface of MAC. Phenol adsorption capacity of MAC was found to be decreasing with increase in temperature suggesting that the adsorption process was exothermic in nature, which was further supported by the negative values of change in enthalpy. Characterization of MAC and GMAC confirmed the mesoporous texture, highly carbonaceous nature and a higher effective surface area of 912 m2/g. The highest phenol uptake capacity of GMAC was found to be 8.0049 mg/g. The optimal conditions for various process parameters are t = 250 min, pH=5, Co=1mg/l, T = 25 oC and m = 0.3 g/l were the optimum condition for Phenol-GMAC system. Like Phenol-MAC system, the kinetics studies confirmed that Phenol-GMAC adsorption system can be described by pseudo- second-order kinetics model. Equilibrium model analysis indicates the fitness of Langmuir isotherm model to Phenol-MAC adsorption system, suggesting a monolayer adsorption of phenol on the surface of GMAC. Phenol adsorption capacity of GMAC was found to be decreasing with increase in temperature suggesting that the adsorption process was exothermic in nature, which was further supported by the negative values of change in enthalpy. The negative values of Gibb’s free energy suggested that adsorption of phenol onto GMAC was a spontaneous process.

Improving diversity of food systems by targeting whole grain cereals, pseudo-cereals, and millets is essential to enhance nutritional qualities beyond macro and micronutrient balance and to address emerging global food and nutritional security-linked public health challenges. However, human health relevant nutritional parameters of whole grains vary widely among species, genotypes, growing conditions, and further due to different processing methods. Therefore, it is important to screen human health relevant nutritional parameters of these whole grains prior to targeting them for wider public health solutions linked to non-communicable chronic diseases (NCD). Based on this rationale, oats from different processing stages and from different production systems, buckwheat, teff, pearl millet, and different genotypes of sorghum were analyzed for health relevant phenolic bioactive linked antioxidant and anti-hyperglycemic properties using in vitro assay models. Overall, high phenolic-linked antioxidant and anti-diabetic properties were observed in whole grain oats, rolled oat, buckwheat, teff, and select sorghum genotypes.

In Hinblick auf den stetig steigenden Bedarf der chemischen Industrie an Grundstoffchemikalien und der teilweise unsicheren Versorgung mit Erdöl und Erdgas ist es notwendig alternative Rohstoffe und Verwertungspfade für die Bereitstellung von Basischemikalien zu finden. Ziel der vorliegenden Arbeit war die Untersuchung der Hydrogenolyse von Lignin in niedermolekulare Produkte unter Verwendung geeigneter Salzschmelzen. Es konnte gezeigt werden, dass Lignin in Zinkchlorid/Kaliumchloridschmelzen in niedermolekulare Produkte abgebaut werden kann. Hierbei erwiesen sich der Einsatz eines entsprechenden Eutektikums und einer Alternativschmelze mit niedrigem Schmelzpunkt als hilfreich. Durch den Einsatz verschiedener Apparaturen wurden Untersuchungen in statischer und dynamischer Atmosphäre durchgeführt. Es ergaben sich während der Untersuchung Abhängigkeiten der Hydrogenolyse von verschiedenen Reaktionsparametern. Optima der Umsetzung hinsichtlich der Reaktionsparameter Temperatur, Zeit und Ligninanteil in der Schmelze wurden herausgearbeitet. Die Ausbeute an gewünschten Flüssigprodukten wurde, im Untersuchungsbereich, an diesen Punkten maximiert. Gleichzeitig war die Rückstands- und Gasbildung eingeschränkt. Es konnten Erkenntnisse eines komplexen Systems der Abhängigkeiten der Ausbeuten an Reaktionsprodukten von den Parametern der Untersuchung gewonnen werden. Die Hydrogenolyse von Lignin führte zur Aromatisierung fester Residuen sowie zur Abreicherung von Sauerstofffunktionalitäten. Komplexe Reaktionsmechanismen bewirkten den Abbau von Methoxyl-, Carboxyl- und Hydroxylgruppen der Ligninstruktur. Carbeniumionmechanismen konnten als wichtige Reaktionen zur Spaltung von Ether Arylbindungen identifiziert werden. Die Freisetzung von Monomeren und die Polymerisation anderer Intermediäre sind durch Sekundärreaktionen denkbar. Die gebildeten Flüssigprodukte bestanden hauptsächlich aus Monoaromaten (v.a. Guajakole und Kresole) und wenigen Polyaromaten. Die Selektivität der Bildung einzelner Verbindungen war gering, d.h. die Flüssigprodukte sind eine heterogene Mischung mit geringen Konzentrationen der Einzelsubstanzen. Die Unterschiede in der Struktur der Ausgangslignine bildeten sich auch in der Zusammensetzung der Flüssigprodukte ab. / In view of the steadily increasing demand of the chemical industry to base chemicals and the partial uncertain supply of crude oil and gas, it is necessary to find alternative raw materials and conversion routes for the provision of basic chemicals. The aim of the present work was to investigate the hydrogenolysis of lignin in low molecular weight products using appropriate molten salt media. It could be demonstrated that lignin can be convert in low molecular weight products using zinc chloride/potassium chloride molten salt media. The use of an appropriate eutectic melt and of an alternative melt with low melting point proved helpful. By the use of different apparatus investigations in static and dynamic atmosphere could be carried out. During the investigation dependencies of the hydrogenolysis of various reaction parameters are submitted. Optima of the hydrogenolysis regarding to reaction temperature, time and lignin content at the melt could be identified. The yields were maximized at these points in the range of investigation. Concurrently formation of gases and residues were suppressed. Some evidence of a complex system of the dependencies of the yields of reaction products are obtained from the parameters of the investigation. Hydrogenolysis of lignin leads to aromatic solid residues and to a loss of oxygen containing structures. Structures containing methoxyl-, carboxyl- and hydroxyl groups are degraded by various complex reaction mechanisms. Mechanisms of the formation of carbonium ions were identified as important reactions of the cleavage of ether aryl bonds. Secondary reactions caused the liberation of monomers and polymerisation of some intermediaries. The resulting liquid products consist mainly of monoaromatics (guaiacols and cresols) and less of polyaromatics. The selectivity of the formation of single compounds was low, i.e. the liquid products constitute a heterogenous mixture with low concentrations of the single compounds. The structural differencies of the feedstock lignins also showed at the composition of the liquid products.

La présence accrue de la chimie en flux continu dans les publications des dernières années a mené à un développement rapide de cette nouvelle technologie. La transposition de méthodes du ballon réactionnel au réacteur de chimie en flux continu permet au chimiste d’ajouter un outil à son répertoire, afin d’améliorer la productivité et le rendement dans la synthèse de composés d’intérêt. Bien que les réactions de Friedel-Crafts aient été déjà réalisées en chimie en flux continu, aucune méthode homogène robuste n’a été développée pour des composés dérivés du phénol. Les premières parties de ce mémoire portent sur le développement et l’optimisation des conditions réactionnelles de l’acylation de Friedel-Crafts en chimie en flux continu. Tout d’abord, une première méthode a été développée, en utilisant le chlorure d’aluminium et l’anisole. Cependant cette méthode est incompatible avec le phénol. Une deuxième méthode a été développée en utilisant l’acide méthanesulfonique comme acide de Brønsted et solvant réactionnel. Cette méthode est efficace et surtout compatible avec le phénol. Les dernières parties portent sur l’étendue de cette deuxième méthode. La méthode a été employée sur des dérivés du phénol, tels que les di- et tri-hydroxyphénols et des hydroxybicycles. D’autres cycles aromatiques, aussi bien activés que désactivés, contenant une fonction phénol ont aussi été testés. Par la suite, la méthode a été essayée avec des agents acylants différents, afin d’évaluer l’étendue de la réaction. / The increased presence of continuous flow chemistry in recent publications has led to rapid development of the technology. The transposition of methods from round-bottom flask to flow enables chemists to add a tool to their repertoire to improve productivity and yield in the synthesis of compounds of interest. Although Friedel-Crafts reactions have been explored in continuous flow, no robust homogenous method has been developed for phenol derivatives. The initial sections of the work focus on the development and optimization of reaction conditions for continuous flow Friedel-Crafts acylation. First, a method has been developed using aluminum chloride as a catalyst, and anisole for optimization purposes. This method is robust, but proved incompatible with phenols. A second method was then developed using methanesulfonic acid as both catalyst and reaction solvent. The method is effective and, more importantly, compatible with phenols. The final sections address the scope of this second method. The method was applied to various phenol derivates, such as di- and tri-hydroxyphenols and hydroxybicycles. Other aromatic rings, both activated and deactivated, containing a phenol function were also tested. The method was evaluated with different acylating agents, demonstrating the wide range of possibilities it offers.

La tesi di dottorato è stata sviluppata all'interno del progetto nazionale Valorvitis ed è suddivisa in due parti. La prima riguarda la caratterizzazione chimica di sei estratti di vinacce d’uva ottenute diverse varietà di uva: tre a bacca rossa( Pinot Noir, Barbera e Nebbiolo) e tre a bacca bianca (Moscato, Muller Thurgau e Chardonnay). Ogni estratto è stato caratterizzato per contenuto e composizione in composti fenolici. La seconda attività consiste nello studio di un metodo alternativo di estrazione-purificazione basato sull'impiego di Gas Aphron Colloidali (CGAs) con la finalità di ridurre i costi di processo, la quantità di solvente da utilizzare durante la fase di estrazione e, allo stesso tempo, aumentare il grado di purezza dell’estratto in termini di contenuto polifenolico. / The present PhD thesis work was carried out under the framework of the Valorvitis.Extracts have been obtained from different red (Pinot Noir, Barbera and Nebbiolo) and white (Moscato, Muller Thurgau and Chardonnay) grape marcs and quantitatively analysed for the content of total phenolics, tannins, anthocyanins, cinnamic acids, flavonoids, flavonols, sugars (glucose and fructose) and for the anti-oxidant power (AOP). A new extraction-purification process based on CGAs application has been investigated. CGAs were first reported by Sebba (1987) as micro bubbles, with dimension among 10–100 μm, composed of a gaseous inner core surrounded by a thin surfactant film, which are created by intense stirring of a surfactant solution above its critical micellar concentration. Surfactants are able to catch phenolics thanks to both electrostatic and hydrophobic interactions depending on the surfactant (ionic or non-ionic) and on the phenolic compound. In this project the low-cost non-ionic food grade surfactant Tween 20 was used.

Thesis (MscAgric (Viticulture and Oenology))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: Tannins and colour components in red wine are important quality parameters. These factors can be manipulated in the vineyard by grape growing techniques or in the cellar by different winemaking practices. Grape seeds make a significant contribution to tannin concentration in wine when compared to those from the skins and pulp. Tannins contribute to the ageing potential, organoleptic properties and stabilisation of red wine colour. The colour of a red wine is also influenced by malolactic fermentation, the biological process that transforms malic acid into lactic acid which normally leads to an increase in pH. The subsequent change in pH alters the anthocyanin equilibrium, the primary colour components in red wine. Oxygen contributes to the polymerisation of anthocyanins over time to form more stable pigments that are less sensitive to pH fluctuations and sulphur dioxide bleaching. Limited research has been done on the use of oxygen after alcoholic fermentation and the impact it has on the phenolic composition of red wines. Similarly, only a few studies have examined the impact of either the addition or removal of seeds to the phenolic composition of a red wine in combination with oxygen addition. Additionally, little published data seems to exist on the effect of different pHs on red wine’s phenolic and colour development after oxygen addition. In our results we have shown that it is possible to stabilise wine colour by adding supplementary seeds before alcoholic fermentation. This led to an increase in colour intensity in certain cases. Some red wines produced without seeds had significantly lower colour intensities. This clearly suggests that catechins and proanthocyanidins are extracted from seeds and contribute to wine colour as they combine with other pigments to stabilise wine colour. Spectrophotometric and HPLC analyses have shown that the total phenolic content increased with seed concentration. However, we have observed that a wine may possibly become saturated with phenols when supplementary seeds are added. Anthocyanin concentrations often decreased when oxygen was added, while polymeric phenols and polymeric pigments sometimes increased. When applying different oxygen dosages to a red wine on commercial scale with microoxygenation, it was found that monomeric anthocyanins decreased as more oxygen was added and this decrease in anthocyanins led to the formation of stable polymeric pigments. This was reflected in the significant increase in colour intensity for the wines receiving oxygen. Small differences were detected in the total phenol and tannin concentration for the control and oxygenated wines. However, some of these phenolic and colour differences disappeared during subsequent ageing of the wine. When making wines of different initial pHs, we observed that the colour density decreased as the pH increased. The application of oxygen reduced the decrease in colour during MLF, especially at a lower pH. The addition of oxygen did not result in significantly different polymeric pigment concentrations in the various pH treatments, although the results could have been different if the wines were aged. However, pH differences in the range between 3.4 and 4.0 did not significantly influence the phenol composition of the wines under our conditions. This study led to a better understanding on the effect of oxygen additions under different conditions on red wine's phenolic and colour composition. / AFRIKAANSE OPSOMMING: Tanniene en kleur komponente teenwoordig in rooiwyn is belangrike kwaliteit parameters. Hierdie faktore wat wynkwaliteit beïnvloed kan gemanipuleer word in die wingerd deur verskeie verbouingstegnieke toe te pas en in die kelder deur die toepassing van verskillende wynbereidingsmetodes. Die bydrae van sade tot die finale tannienkonsentrasie in rooiwyn is groot in vergelyking met dié van die pulp en doppe. Tanniene dra by tot die verouderingspotensiaal, organoleptiese eienskappe en die stabilisasie van die wynkleur. Die kleur van ‘n rooi wyn word ook beïnvloed deur appelmelksuurgisting (AMG), die biologiese proses wat appelsuur omskakel na melksuur en ‘n gevolglike toename in die pH van die wyn veroorsaak. Hierdie verandering in die pH van die wyn beïnvloed die antosianien ewewig, die primêre kleur komponente teenwoordig in rooiwyn. Suurstof dra by tot die polimerisasie van antosianiene oor tyd om meer stabiele kleur pigmente te vorm met ‘n hoër kleurintensiteit wat minder sensitief is teenoor pH veranderinge en die bleikingseffek van swaweldioksied. Beperkte navorsing is gedoen op die gebruik van suurstof na alkoholiese gisting en die impak daarvan op die fenoliese samestelling van ‘n rooiwyn. Slegs ‘n paar studies het die invloed van die verwydering of byvoeging van sade in kombinasie met suurstoftoediening op ‘n rooiwyn se fenoliese samestelling ondersoek. Dit wil voorkom of beperkte gepubliseerde data beskikbaar is oor die effek wat verskillende pH’s het op rooi wyn se fenoliese en kleurontwikkeling na suurstof byvoeging. Ons resultate het aangedui dat dit wel moontlik is om in sekere gevalle die kleur van ‘n rooiwyn te stabiliseer deur addisionele sade by te voeg voor alkoholiese fermentasie. Hierdie byvoeging het ‘n toename in kleurintensiteit tot gevolg gehad. Sekere wyne wat gemaak is sonder sade het ‘n kenmerkend laer kleur intensiteit gehad. Hierdie bevinding is ‘n duidelike bewys dat katesjiene en prosianidiene geëkstraheer word vanuit die sade en bydra tot wynkleur deurdat hulle met ander pigmente verbind om die kleur sodoende te stabiliseer. Spektrofotometriese en hoë druk vloeistof chromatografie (HDVC) analises het gewys dat die totale fenoliese konsentrasie neem toe met ‘n toename in saad konsentrasie. Daar is egter waargeneem dat ‘n wyn moontlik versadig kan raak met fenole wanneer addisionele sade bygevoeg word. Antosianien konsentrasies het meestal afgeneem wanneer suurstof bygevoeg is, maar polimeriese fenole en polimeriese pigmente het partykeer toegeneem. Met die toediening van verskillende suurstof dosisse tot ‘n rooiwyn op kommersiële skaal het ons bevind dat monomeriese antosianiene afneem wanneer meer suurstof bygevoeg word. Hierdie afname in antosianiene het egter gelei tot die vorming van stabiele polimeriese pigmente. Dié bevinding was gereflekteer in die toename in kleurintensiteit van wyne wat met suurstof behandel is. Klein verskille was waargeneem vir die totale fenol en tannien konsentrasies tussen die kontrole en wyne behandel met suurstof. Sekere van hierdie fenoliese kleur verskille het egter afgeneem tydens die daaropvolgende veroudering van die wyne. Wyne wat gemaak is met verskillende aanvanklike pH’s se kleurintensiteit neem af soos die pH toeneem. Die toediening van suurstof het die kleurverlies tydens AMG verminder, veral by ‘n laer pH. Die toediening van suurstof het nie verskillende polimeriese pigment konsentrasies by verskillende pH’s veroorsaak nie, maar ‘n verskil kon moontlik waargeneem word indien die wyne verouder was. pH verskille tussen 3.4 en 4.0 het egter nie die fenoliese samestelling van die wyne onder ons omstandighede beduidend beïnvloed nie. Hierdie studie het gelei tot meer kennis oor die effek van suurstoftoedienings onder verskillende kondisies op rooiwyn se fenoliese en kleursamestelling.

Thesis (MScAgric (Viticulture and Oenology))--University of Stellenbosch, 2006. / The assessments of grape and wine quality are complex issues and the wine industry needs more objective analysis of grape and wine quality. The standard quality assessment protocol for grading grapes at most wine cellars in South Africa is based on viticultural practices and the determination of chemical parameters such as ºBrix, pH and titratable acidity (TA). Grape juice indices calculated by formulae such as ºBrix/pH, TA/pH, ºBrix/TA, ºBrix x (pH)2 have been used in the past but these approaches have had limited success. It was shown that the total anthocyanins and total phenolics of red grapes correlate with wine quality and provide additional objective measures of grape quality. Most methods for the quantification of total anthocyanins and total phenolics are complex and time consuming and therefore not easily implemented in the routine laboratory environment. Fourier transform infrared spectroscopy (FT-IR) is widely used in South African laboratories for the routine quantification of wine and grape parameters but the commercial calibration models supplied for the quantification of grape total anthocyanins and phenolics are not satisfactory. The focus of this study was to develop new FT-IR calibration models for the quantification of total anthocyanins and phenolics of grapes and to use the generated data during a preliminary evaluation of the implementation of these parameters as part of the grape quality control protocol at a commercial winery in South Africa. The potential of Fourier transform infrared spectroscopy (FT-IR) for the rapid quantification of total anthocyanins and total phenolics in red grapes was investigated and evaluated for prediction accuracy with independent validation sets. The design of calibration sets aimed at capturing most of the variation due to vintage (2004 and 2005), cultivar (Cabernet Sauvignon, Merlot, Pinotage, and Shiraz) and sugar concentration. Best prediction accuracies were obtained for calibration sets using grapes from a single vintage or cultivar or approximately the same sugar concentration. The highest prediction accuracies were obtained for total anthocyanins calibration sets of grapes with sugar concentrations ≥ 23.5ºBrix (SEP = 0.13 mg/g; R2 validation set = 0.77) and for total phenolics calibration sets of grapes with sugar concentrations < 23.5ºBrix (SEP = 0.13 OD280/g; R2 validation set = 0.74). Strong correlations were found between the spectral data and the total anthocyanins (SEP = 0.12 mg/g; R2 validation set = 0.84) and total phenolics concentration data (SEP = 0.10 OD280/g; R2 validation set = 0.76) for 2005 Merlot calibration sets indicating that the FT-IR spectra captured most of the variation. Overall the RPD (ratio of the standard deviation of the reference data to the standard error of prediction) values of all calibration models were below 3 indicating that calibration models are fit for screening purposes. Spectroscopic absorbance at 280 nm is not specific enough for the quantification of total phenolics and the use of an alternative reference method such as high performance liquid chromatography (HPLC) will be considered in the future. Principal component analysis (PCA) revealed that the major sources of variation in the FT-IR spectra of grapes could be ascribed to vintage and grape sugar concentration and this had an effect on the accuracy of the analytical data generated when using FT-IR spectroscopy. This report is the first to our knowledge where FT-IR has been used for the quantification of total anthocyanins and phenolics of grapes. The evaluation of the reference laboratory protocol for the quantification of total anthocyanins and total phenolics in grapes were evaluated in Chapter 4 and emphasized the importance of meticulous laboratory practices to obtain reliable reference data for calibration purposes. This large scale investigation of the total anthocyanins and phenolics concentrations in grapes is the first of its kind in South Africa and a quantitative database containing analytical data of the anthocyanins and total phenolics concentrations of 692 grape samples representing a wide range of grape maturities of Vitis vinifera cultivars Cabernet Sauvignon, Merlot, Pinotage and Shiraz from the 2004 and 2005 vintages was established based on the reference values. The data were used in a preliminary investigation of the implementation of total anthocyanins and total phenolics concentrations as part of grape quality classification at a commercial South African winery (Chapter 5). The results showed that the total anthocyanins and total phenolics concentration in grapes increased with increasing grape maturity (measured as sugar concentration). ANOVA and post-hoc analysis (Bonferroni testing) revealed significant differences between the total anthocyanins and total phenolics concentrations of the four Vitis vinifera cultivars investigated. Grapes harvested earlier in the season had significantly higher (p≤0.05) total anthocyanins and total phenolics concentrations than grapes harvested later in the season. This implies that grapes harvested earlier in the harvest season could produce wines with higher quality. Grapes from regularly irrigated vineyards had lower total anthocyanins and total phenolics concentrations compared to dryland vineyards. The current grape grading system in use at the industrial cellar did not correlate well with the total anthocyanins and total phenolics concentrations of grapes which highlighted the need for the inclusion of more objective measures during grape grading. The information captured in the database can be used as a starting point to establish profiles of the typical anthocyanins and total phenolics of South African grapes and data from more vintages should be included and continually updated. These findings highlight the important contribution of the results obtained in this preliminary study for the incorporation of total anthocyanins and phenolics concentrations as objective parameters of grape quality. Finally multivariate data analysis of the FT-IR spectra revealed important information regarding factors (both physical and chemical) that contribute to the variation of the spectra. The main variation between the 2004 and 2005 samples can probably be interpreted in terms of the water content of the samples.