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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Monitoring des HAPs et des PCBs dans le sol et les sédiments au Liban. Implantation d'une méthode optimisée et validée d'extraction et d'analyse / Monitoring of PAHs and PCBs in soil and sediments in Lebanon. Implantation of an optimized and validated method for extraction and analysis

Soukarieh, Banan 11 December 2018 (has links)
Actuellement, le public et surtout dans les pays industrialisés est de plus en plus conscient du fait que la dégradation de l’environnement peut dépasser les avantages du progrès rapide dans les domaines industriels et technologiques et que des dommages sérieux et irréversibles peuvent être imposés aux futures générations. L'occurrence des POPs dans l'environnement, qui résulte essentiellement des activités anthropogéniques, est l'une des préoccupations permanentes chez les scientifiques. Ces composés ont été trouvés dans toutes les matrices environnementales telles que l'air, le sol, l'eau et les sédiments et en raison de leurs propriétés lipophiles, ils risquent de rebondir dans la chaîne alimentaire humaine. Durant cette dernière décennie, le Liban a connu une grande explosion démographique qui a été accompagnée par des activités anthropogéniques diverses. La dégradation de la qualité de l’environnement est bien ressentie par la population locale et les conséquences sur la santé humaine sont lourdes et affreuses. Les travaux de cette thèse ont permis d’évaluer concrètement l’effet de POPs sur la qualité de l’environnement au Liban, ces travaux ont abouti à la détermination des niveaux de quelques POPs les plus globalement étudiés tels que les HAPs, les PCBs et les OCPs dans les différents compartiments environnementaux au Liban. A cette fin, des protocoles d'analyse comprenant une méthode GC/MS pour la séparation et la détection des HAPs, une méthode UAE pour l'extraction des HAPs à partir du sol et des sédiments et une méthode SPE pour l'extraction des HAPs à partir de l'eau ont été développés. Ces méthodes ont été ensuite appliquées pour évaluer les niveaux de 17 HAPs dans des sols de différents usages et pour étudier la distribution de HAPs dans la phase aqueuse et les sédiments sur les côtes libanais et dans des rivières côtières et internes. Les principaux résultats ont montré que les niveaux de contamination des sols par les HAPs décroissent dans l’ordre suivant: industriels, urbains, transport et agricoles et que les sols industriels et urbains étaient 777 et 256 fois plus toxiques que les sols ruraux de référence selon l'approche TEF. De plus, l'eau et les sédiments des sites côtiers affectés par l'industrie et le transport maritime ont montré une contamination plus élevée par les HAPs. Certains échantillons de sédiments ont montré des niveaux de quelques HAPs individuels supérieures à l'ERL, ce qui pourrait occasionnellement provoquer des effets écologiques négatifs. Les travaux de cette thèse incluent aussi la détermination des niveaux des PCBs et des OCPs dans les sédiments de la rivière Litani qui est une source d’une grande préoccupation environnementale actuelle au Liban. / Currently, the public and especially in industrialized countries is increasingly aware that environmental degradation can outweigh the benefits of rapid progress in the industrial and technological fields and that serious and irreversible damage can be imposed on the future generations. The occurrence of POPs in the environment, which results mainly from anthropogenic activities, is one of the permanent concerns of scientists. These compounds have been found in all environmental matrices such as air, soil, water and sediments and because of their lipophilic properties, they are likely to rebound in the human food chain. During the past decade, Lebanon has experienced a large population explosion that has been accompanied by various anthropogenic activities. The degradation of the quality of the environment is felt by the local population and the consequences for human health are heavy and horrendous. The work of this thesis allowed to evaluate concretely the effect of POPs on the quality of the environment in Lebanon, this work led to the determination of the levels of some POPs most widely studied such as PAHs, PCBs and OCPs in the different environmental compartments in Lebanon. To this end, analytical protocols including a GC/MS method for the separation and detection of PAHs, a UAE method for the extraction of PAHs from soil and sediments and an SPE method for the extraction of PAHs from water were developed. These methods were then applied to evaluate the levels of 17 PAHs in soils of different uses and study the distribution of PAHs in the aqueous phase and sediments on the Lebanese coasts and in coastal and inner rivers. The main results showed that soil contamination levels by PAHs decreased in the following order: industrial, urban, transport and agricultural and that industrial and urban soils were 777 and 256 times more toxic than rural reference soils according to the TEF approach. In addition, water and sediments from coastal sites affected by industry and shipping have shown higher contamination by PAHs. Some sediment samples showed concentrations of a few individual PAHs greater than the ERL, which could occasionally cause negative ecological effects. The work of this thesis also includes the determination of levels of PCBs and OCPs in the sediments of the Litani River which is a source of great environmental concern currently in Lebanon.
32

Obtenção de produtos a partir das cascas de Uncaria tomentosa (Willdernow ex Roemer & Schultes) D.C: otimização da extração e secagem em spray dryer utilizando planejamentos experimentais e avaliação da atividade anti-inflamatória / Obtaining products from the bark of Uncaria tomentosa (Willdernow ex Roemer & Schultes) D.C: optimization of extraction and drying in spray dryer using experimental designs and evaluation of anti-inflammatory activity

Reis, Rayssa Aparecida da Silva Paiva 06 December 2017 (has links)
A Uncaria tomentosa (Willd.) DC., comumente conhecida como unha de gato ou cat´s claw, é uma planta endêmica da Amazônia Peruana. Devido às suas propriedades terapêuticas, seus extratos e derivados são comercializados ao redor do mundo. As propriedades medicinais são atribuídas aos glicosídeos do ácido quinóvico, polifenois e especialmente aos alcalóides oxinólicos pentacíclicos. Assim, a mitrafilina é o principal alcalóide presente nos extratos da planta e, portanto, é o marcador químico de suas formulações comerciais. O processo de extração é uma etapa importante na padronização de seus extratos e, considerando a falta de estudos a respeito de sua influência sob o perfil fitoquímico, amostras de casca de unha de gato foram extraídas por meio de maceração dinâmica e extração assistida por micro-ondas. O objetivo desse estudo foi avaliar a influência dos fatores envolvidos no processo extrativo a respeito de sua composição química, atividade anti-inflamatória e antioxidante. Devido ao grande número de fatores de extração a serem avaliados, um planejamento experimental do tipo Placket Burman foi selecionado e os fatores escolhidos nessa etapa foram: porcentagem de planta em solvente, temperatura e tempo de extração. Adicionalmente, através de um planejamento Box Behnken, as condições ótimas de extração foram delineadas na segunda etapa do estudo. O tempo e a porcentagem de planta em solvente foram fatores significantes para a extração assistida por micro-ondas. Entretanto, o conteúdo de mitrafilina nesses extratos foi reduzido - comparativamente ao seu conteúdo total presente nas amostras analisadas - e, portanto, mais estudos são necessários para otimizar o seu rendimento. Além disso, o extrato otimizado foi avaliado quanto à capacidade anti-inflamatória, em um teste de edema de pata induzido por carragenina e apresentou uma capacidade inibitória na concentração de 0,57 mg de mitrafilina/ Kg de rato. Por conseguinte, tais achados confirmaram a sua atividade anti-inflamatória. Os resultados obtidos a partir da extração por maceração dinâmica sugerem que o alcalóide é facilmente extraído, pois não foi afetado por nenhuma das variáveis experimentais. Adicionalmente, os extratos apresentaram maior conteúdo de mitrafilina - comparativamente aos resultados observados na extração por micro-ondas. Entretanto, devido ao menor tempo empregado na extração assistida por micro-ondas, outros estudos são necessários a fim de otimizar a extração desse alcalóide por esse método. O extrato otimizado sob as condições de maceração dinâmica foi seco em spray drying e, utilizando um planejamento de mistura do tipo simplex-centroid, o efeito de diferentes misturas de três adjuvantes foi avaliado: Dmanitol, maltodextrina e Aerosil. Embora os extratos secos com Aerosil e maltodextrina tenham prevenido a degradação de mitrafilina - quando comparado ao extrato seco sem excipiente - a secagem resultou em elevada perda no conteúdo de alcalóide e também propriedades farmacotécnicas inadequadas. Tais observações sugerem que, mesmo em condições amenas de secagem, há a degradação do alcalóide. Portanto, tais resultados reforçam a necessidade de avaliações complementares a fim de prevenir a ocorrência de tais eventos / The Uncaria tomentosa (Willd.) DC. commonly known as unha-de-gato or cat´s claw is an endemic plant from the Peruvian Amazon. Due its therapeutic properties, the crude drug and a variety of extracts are commercialized worldwide. The healing properties are attributed to the glycosides of quinovic acid, polyphenols, and especially to the pentacyclic oxindole alkaloids. Thereby, mitraphylline is the main alkaloid present in the bark extract of U. tomentosa, and therefore, is the chemical marker of commercial formulations derived from the plant. The extraction process is an important step in the standardization of plant extract and considering the lack of studies that relate the influence of extractive processes in phytochemical profile of the cat´s claw extracts, the bark samples were extracted by dynamic maceration and microwave assisted extraction. The study aimed evaluate the influence of the extraction factors on the chemical composition, antioxidant and anti-inflammatory activities of the extracts from cat \'s claw barks. Due to the wide number of possible extraction factors to be evaluated and the lack of knowledge about the importance of this factor effects on U. tomentosa extract, the Placket Burman factorial design was selected and the experimental factors chosen in this step were: % plant solvent ratio, temperature and extraction time. Through a Box Behnken planning the optimal extraction conditions of cat´s claw bark will be outlined in the second stage of this work. The time and % plant solvent ratio were significant factors for microwave assisted extraction. However, the contents extracted of mitraphylline have been reduced - compared to the total yield of the plant - and, therefore, more studies are needed to optimize the alkaloid yield. The extract from the optimized conditions, was evaluated in carrageenan-induced rat paw oedema, and presented inhibitory capacity in concentration of 0.57 mg of mitraphylline / kg of rat. Therefore, these findings confirm its anti-inflammatory activity. The results obtained in the extractions by dynamic maceration, suggest that the alkaloid is easily extracted and is not affected by experimental variables. In addition, compared to microwave extraction, this methodology allowed extracts with higher content of mitraphylline. However, in view of the shorter extraction time employed in microwave extraction, other reviews are needed to increase the extraction of mitraphylline, by this method. The extract optimized by the conditions under dynamic maceration was dried in spray drying and using a simplex-centroid mixture design, the effect of different mixtures of three adjuvants - D- mannitol, maltodextrin and Aerosil- were evaluated. Although dried extracts with the aid of Aerosil and maltodextrin slightly prevented the degradation of mitraphylline - as compared to the dry extract without excipient - the drying process resulted in high loss in the total content of this alkaloid and inadequate physical properties. Such observation suggests that, even under the mild drying conditions, there is degradation of the alkaloid. Therefore, these results reinforce the need for auxiliary evaluations to prevent the occurrence of such events.
33

Éco-extraction et encapsulation de pigments caroténoïdes et anthocyanes à partir de plantes tropicales / Eco-extraction and encapsulation of carotenoid and anthocyanin pigments from tropical plants

Nguyen, Thi Thu 18 April 2018 (has links)
Cette thèse porte sur l’éco-extraction et l’encapsulation de pigments naturels pour une exploitation et application dans les industries alimentaire, cosmétique et pharmaceutique. Dans ce but, l'extraction assistée par micro-ondes (MAE) ou par ultrasons (UAE) et celle par liquides ioniques (LI) ont été évaluées pour l'extraction de caroténoïdes et d'anthocyanes de plantes vietnamiennes. Les résultats obtenus montrent que le MAE a été un système permettant d'accélérer et d'améliorer tous les types d'extraction testés alors que les ultrasons se sont montrés particulièrement efficaces lorsque les pigments étaient présents à la surface des tissus végétaux. Cependant, l’UAE améliore également les résultats par rapport à des extractions sans assistance. Les LI classiques ne sont pas adaptés pour l’extraction des pigments caroténoïdes et anthocyaniques qui sont généralement non volatils et thermosensibles car il n'a pas été possible de séparer les pigments extraits des LI dans des conditions douces. Pour remédier à ce problème, des LI réversibles ont été évalués. Le DBU/ 1-hexanol était efficace pour extraire les caroténoïdes relativement accessibles, mais, en raison d'une viscosité élevée, il perdait son efficacité pour d'autres tissus. La deuxième partie de cette thèse concerne l’encapsulation d’anthocyanes d’hibiscus dans des levures. Nous avons d’abord travaillé avec des levures entières. Les résultats ont montré que les cellules de levure étaient un bon matériau pour l'encapsulation des anthocyanes. Cependant, pour les levures non désactivées, les enzymes ont provoqué une perte indésirable de couleur des anthocyanines pendant le stockage. Les microparticules de levures traitées thermiquement ont montré un effet protecteur élevé pendant le stockage. Puis, comme les anthocyanes étaient majoritairement encapsulées dans le réseau pariétal des levures, nous avons utilisé les écorces de levures séparées du reste des cellules. Les microparticules des écorces de levure ont apporté une bonne protection pour les anthocyanes contre l'humidité, la chaleur et la lumière. En comparant avec les microparticules de maltodextrine, celles des écorces de levure étaient plus stables dans des conditions d'humidité élevée. En général, les microparticules de levure ont montré une capacité à protéger les anthocyanes et à garder la couleur rouge de la poudre d’anthocyanes encapsulées. Ces résultats montrent que la poudre d’anthocyanes encapsulées dans des levures ou écorces de levure a un avenir prometteur pour être appliquée dans les industries alimentaire, cosmétique et pharmaceutique. / This thesis deals with extraction processes using assistance technologies or green solvents and encapsulation systems of natural pigments in order to exploit and apply them in the food, cosmetic and pharmaceutical industries. In this goal, microwave-assisted extraction (MAE), ultrasonic-assisted extraction (UAE) and Ionic liquids (IL) were evaluated for the extraction of carotenoids and anthocyanins from Vietnamese plants. The results obtained show that the MAE was always a rapid and helpful system for all types of extraction tested whereas ultrasounds were particularly efficient when pigments are present on the surface of plant tissues. However, UAE was also improving results compared to conditions without assistance. Traditional IL are not suitable for the extraction of carotenoid and anthocyanin pigments that are generally non-volatile and heat-sensitive because it has not been possible to separate pigments extracted from IL under mild conditions. Therefore switchable IL were evaluated. DBU/ 1-hexanol was efficient to extract carotenoids that were relatively accessible, but, due to its high viscosity, it lost efficacy for other tissues. The second part of this thesis concerns the encapsulation of Hibiscus anthocyanins in yeasts. We have first worked with whole yeast cells. The results showed that yeast cells were a good material for the encapsulation of anthocyanins. However, yeast enzymes caused undesirable colour loss of anthocyanin during storage. Microparticles of heat-treated yeasts showed a high protective effect during storage. Then, as it was interesting to keep the pigments in the cell wall and deactivate the yeast enzymes, we used yeast hulls. Yeast hull particles brought a good protection to anthocyanins against moisture, heat and light. In comparison with maltodextrin microparticles, yeast hull ones were more stable in high humidity. In general, yeast microparticles have shown an ability to protect anthocyanins and to keep the red color of encapsulated anthocyanin powder. These results show that yeast encapsulated anthocyanins powder has a promising future to be applied in the food, cosmetic and pharmaceutical industries.
34

Isolamento de polissacarí­deos não amiláceos da banana (musa cavendishii L. variedade Nanicão) e seu potencial uso como ingrediente funcional. / Isolation of non-starch polysaccharides from banana Cavendishii L. variety Nanicão) and its potential use as a functional ingredient.

Rayo Mendez, Lina Maria 19 July 2018 (has links)
Neste trabalho, polissacarídeos não amiláceos (PNAs) da banana madura com potencial de propriedades imunomoduladoras foram obtidos por meio da remoção dos açúcares solúveis (glicose, frutose e sacarose) do purê de banana submetido a duas técnicas de extração: sólido-líquido (ESL) com agitação mecânica e assistida por ultrassom (EAU) usando etanol a 99,5 g/100 g como solvente. Para o estudo em batelada, diferentes razões da matéria-prima/solvente (1:5, 1:7 e 1:10) g/mL, tempos de extração (30, 60 e 90) min e duas temperaturas de (25 e 65) °C foram estudados. No estudo cinético, o impacto da redução da razão matéria-prima/solvente de 1:5 para 1:3 g/mL foi estudado até 90 min, nas mesmas condições estudadas na extração em batelada. O teor de açúcares solúveis (AS) medido nos extratos foi superior na temperatura de 65°C, porém às razões de 1:7 e 1:10, não resultou em maior quantidade de AS nos extratos, portanto, menores quantidades de etanol podem ser usadas diminuindo custos. Com o emprego da técnica EAU à 25 °C e tempo de extração de 30 min, foi observado que uma redução da razão matéria-prima/solvente até 1:3 g/mL produz maior rendimento de processo. No entanto, foi observado que maiores tempos de extração promoveram degradação da parede celular da matéria-prima. Entre os modelos cinéticos testados, o ajuste do modelo de Patricelli aos dados experimentais indicou que a ESL é regida pela fase de lavagem em que ocorreu 85 % da extração dos AS. Frações molares de glicose, ácidos galacturônicos, manose, arabinose, xilose, galactose de conteúdo monossacarídeo foram observadas nos rafinados, indicando possivelmente serem parte de polissacarídeos do tipo ?-glicanos, xilomananos glucomananos, arabinogalactanos e arabinoxilanos. / In this work, non-starch polysaccharides (PNAs) of ripe bananas with potential for immunomodulatory properties were obtained by means removing the soluble sugars (glucose, fructose and sucrose) from banana puree submitted to two extraction techniques: solid-liquid (SLE) with mechanical stirring and ultrasonic assisted (UAE) using 99.5 g/ 100 g ethanol as solvent. For the batch study, different ratios of the raw material/ solvent (1:5, 1:7 and 1:10) g/ mL, extraction times of (30, 60 and 90) min and two temperatures of (25 and 65 ) °C were studied. In the kinetic study, the impact of reducing the raw material/ solvent ratio from 1:5 to 1:3 g/ mL was studied up to 90 min, under the same conditions studied in batch extraction. The soluble sugar content (AS) measured in the extracts was higher at temperature of 65 °C, however, at the ratios of 1:7 and 1:10, did not result in higher amount of AS in the extracts, therefore, smaller amounts of ethanol can be costs. With the use of the UAE technique at 25 °C and extraction time of 30 min, it was observed that a reduction of the raw material / solvent ratio up to 1:3 g / mL produces a higher process yield. However, it was observed that longer extraction times promoted degradation of the cell wall of the raw material. Among the kinetic models tested, the adjustment of Patricelli model to the experimental data indicated that the SLE the predominance is by the washing phase in which 85% of the AS extractions occurred. Glucose molar fractions, galacturonic acids, mannose, arabinose, xylose, galactose of monosaccharide content were observed in the raffinates, indicating possibly being part of polysaccharides as ?-glycan, xylomannans, glucomannans, arabinogalactans and arabinoxylans.
35

Bioactive extracts of Olea europaea waste streams : a thesis presented in partial fulfilment of the requirements for the degree of Master of Technology in Food Technology at Massey University

Mossop, Nicholas Paul January 2006 (has links)
The production of olive oil has seen an increase in recent years due to a broader understanding of the health benefits of the Mediterranean Aliment Culture. With this expanding industry we also see an increase in the waste products associated with olive oil production. Given the high polluting content of the waste streams and the economic costs associated with its removal and processing, waste remediation and disposal has become a significant point of interest for both producers and local bodies. In this project, wastes of the olive oil production industry are examined for their use as the raw material for a novel product used in the control of horticulturally important diseases, examining the effect of extraction protocols on the activity of the final product. Active fractions of the olive oil wastes were identified from literature and protocols for their extraction and recovery developed; incorporating both standard solvent extraction and novel ultrasound-assisted extraction. Criteria for the analysis of extract quality were outlined and potential target applications identified. The biophenolic compounds of olive wastes were identified as providing the majority of the active fraction, so protocols were developed for the recovery of these compounds. Standard solvent extraction and ultrasound-assisted extraction were examined for their effectiveness of biophenolic recovery and their effect on product quality. Certain horticulturally important diseases were identified as potential targets, and bioassays undertaken to determine the ability of a crude extract to inhibit and control these diseases. It was found that the action of ultrasound during extraction provides a greater degree of recovery of biophenolic compounds, with minimal loss of product quality; as determined by bioassays and total biophenol determination. This increase in recovery is due primarily to the destruction of cellular material resulting in higher rates and absolute yields of recovery. This work provides evidence of the occurrence of some interesting phenomenon in the recovery of biophenols from olive wastes that deserves further examination. The crude olive leaf extract was shown to have an inhibitory effect on bacteria and effectively no inhibitory effect on fungal species in the total biophenol ranges tested. Erwinia amylovora and Staphylococcus aureus both showed a large susceptibility to the olive leaf extract. Results showed a higher degree of susceptibility of Gram positive bacteria and a potential resistance in soil microbes. For bacterial species, total biophenol concentrations of 0.15 to 3.50 mg GAE/ml provided inhibitory effects, while with the fungal species tested, no inhibitory effects were found at total biophenol concentrations of up to 2.50 mg GAE/ml. Some evidence exists that there is an opportunity for the economic recovery of olive biophenols for use as a novel product, but more work is required to determine specific applications and/or targets of use, as well as optimisation of the extraction and purification protocol. A sample removed from interfering compounds will allow the examination of activity of particular compounds and hence a better understanding of the action of the olive waste extract.
36

Value-added processing of blackcurrants:use of membrane technologies for clarification and concentration of blackcurrant juice and extraction of anthocyanins from blackcurrant marc

Pap, N. (Nora) 06 November 2018 (has links)
Abstract Blackcurrants (Ribes nigrum L.) are widely consumed due to their favourable taste and health-promoting effects. The berries and extracts from different parts of the plant show anticarcinogenic, antioxidative and anti-inflammatory properties, and are effective in reducing the risk of cardiovascular disease and in promoting brain health. These health-promoting benefits are due to high concentrations of valuable compounds such as anthocyanins and flavonols in blackcurrants. However, these compounds are sensitive to heat and processing and some are lost when the berries are processed into products such as jams, purees and juices. Industrial processing of juices is a multistep process that typically includes enzyme treatment, pressing, pasteurisation, clarification and usually also thermal concentration. Alternative minimal processing technologies are required to preserve the health-promoting compounds in products by avoiding the use of high temperatures and extensive clarification. Integrated membrane technology, i.e. combined ultrafiltration and reverse osmosis, was used in this thesis for the production of blackcurrant juice concentrate. Pre-treatment methods, such as enzymatic treatment, ultrafiltration, enzymatic treatment combined with ultrafiltration and centrifugation to increase the filtration efficiency in reverse osmosis were evaluated. Processing was modelled to define the resistances, using the resistance-in-series model. The preservation and concentration of anthocyanins and flavonols were analysed. The results indicated that the main resistance in the reverse osmosis process was polarisation resistance, while membrane resistance was lower and fouling resistance was one order of magnitude lower than the other resistances. The filtration efficiency results showed that the highest flux was achieved by ultrafiltered blackcurrant juice, but that the resulting juices were substantially lower in anthocyanins and flavonols, which were retained on the ultrafiltration membrane. Therefore, replacing ultrafiltration with centrifugation as the clarification method for juices is recommended. Value-added processing of blackcurrant was conceptualised by valorisation of the marc left in the berry pressing process for extraction of anthocyanin compounds. Conventional extraction was compared with microwave-assisted extraction (MAE), with the latter optimised using response surface methodology to achieve maximum efficiency in extracting anthocyanins. The optimum parameters found for MAE were: microwave power 700 W, extraction time 10 minutes, pH 2 adjusted with hydrochloric acid and a solid to solvent ratio of 0.05. Conventional extraction showed the best results when carried out at 80 °C for 300 minutes in aqueous solution with pH 2 adjusted by hydrochloric acid. Under these conditions, recovery of anthocyanins was still 10% lower than with MAE for only 10 minutes of extraction time. / Tiivistelmä Mustaherukoita käytetään paljon niiden hyvän maun ja terveyttä edistävien vaikutusten ansiosta. Marjoilla ja marjakasvin eri osien uutteilla on osoitettu olevan antikarsinogeenisia, antioksidatiivisia ja tulehduksia estäviä ominaisuuksia ja ne ovat tehokkaita pienentämään sydän- ja verisuonisairauksia. Ne edistävät myös aivojen terveyttä. Marjojen arvokkailla yhdisteillä kuten antosyanideillä ja flavonoleilla on terveyttä edistäviä vaikutuksia. Mustaherukassa on runsaasti näitä yhdisteitä. Hillojen, soseiden ja mehujen prosessoinnissa menetetään näitä hyödyllisiä yhdisteistä, koska ne ovat herkkiä lämmölle ja prosessoinnin vaikutuksille. Mehujen prosessoinnissa käytetään entsyymikäsittelyjä, puristusta, pastörointia, selkeytystä ja usein myös lämpökonsentrointia. Tuotteiden terveyttä edistävien yhdisteiden säilyttämiseksi tarvitaan uudenlaisia hellävaraisia prosessointitekniikoita ilman korkeita lämpötiloja ja voimakasta selkeyttämistä. Tässä työssä tutkittiin yhdistettyjen kalvotekniikoiden kuten ultrasuodatuksen ja käänteisosmoosin käyttöä mustaherukkatiivistemehun prosessoinnissa. Esikäsittelymenetelmiä, mm. entsyymikäsittelyä, ultrasuodatusta, entsyymikäsittelyn ja ultrasuodatuksen yhdistelmää sekä sentrifugointia, arvioitiin käänteisosmoosin suodatustehokkuuden parantamisessa. Suodatusvastuksen määrittämiseksi prosessi mallinnettiin käyttäen sarja -vastus mallia. Antosyanidien ja flavonolien säilyminen ja konsentroituminen prosesseissa määritettiin. Tulokset osoittivat, että suurin vastus käänteisosmoosissa aiheutui polarisaatiovastuksesta, kun taas kalvon vastus oli pienempi. Mallinnus osoitti myös, että likaantumisen aiheuttama vastus oli yhtä magnitudia alhaisempi kuin muut vastukset. Suodatusteho osoitti, että suurin virtaus saavutettiin ultrasuodatetulla mustaherukkamehulla. Ultrasuodatetussa mehussa oli kuitenkin huomattavasti vähemmän antosyaniineja ja flavonoleja, mikä johtui näiden yhdisteiden tarttumisesta ultrasuodatuskalvoon. Näin ollen, tämän työn tulokset suosittelevat ultrasuodatuksen korvaamista sentrifugoinnilla mehun kirkastusprosessissa. Mustaherukkamehun tuotannossa muodostuu sivutuotteena ns. puristekakkua, joka sisältää runsaasti antosyaaneja. Työssä kehitettiin antosyaanien talteenottoa tästä sivutuotteesta vertaamalla tavanomaista uuttotekniikkaa mikroaaltoavusteiseen uuttoon. Prosessi optimoitiin vastepintamenetelmällä mahdollisimman suuren antosyaanien uuttotehokkuuden saavuttamiseksi. Optimaaliset parametrit saatiin mikroaaltoavusteisessa uutossa teholla 700 W, uuttoajalla 10 minuuttia, kiintoaines-liuotin -suhteella 0,05 pH-arvossa 2, mikä saavutettiin lisäämällä suolahappoa. Tavanomaisessa uutossa parhaat antosyaanisaannot saavutettiin suolahappo-vesiliuoksella pH-arvossa 2 uuttamalla 300 minuuttia lämpötilassa 80 °C. Antosyaanisaanto oli kuitenkin tavanomaisessa uutossa optimiolosuhteissa 10% pienempi kuin mikroaaltoavusteisessa uutossa 10 minuutin uuttoajalla.
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Isolamento de polissacarí­deos não amiláceos da banana (musa cavendishii L. variedade Nanicão) e seu potencial uso como ingrediente funcional. / Isolation of non-starch polysaccharides from banana Cavendishii L. variety Nanicão) and its potential use as a functional ingredient.

Lina Maria Rayo Mendez 19 July 2018 (has links)
Neste trabalho, polissacarídeos não amiláceos (PNAs) da banana madura com potencial de propriedades imunomoduladoras foram obtidos por meio da remoção dos açúcares solúveis (glicose, frutose e sacarose) do purê de banana submetido a duas técnicas de extração: sólido-líquido (ESL) com agitação mecânica e assistida por ultrassom (EAU) usando etanol a 99,5 g/100 g como solvente. Para o estudo em batelada, diferentes razões da matéria-prima/solvente (1:5, 1:7 e 1:10) g/mL, tempos de extração (30, 60 e 90) min e duas temperaturas de (25 e 65) °C foram estudados. No estudo cinético, o impacto da redução da razão matéria-prima/solvente de 1:5 para 1:3 g/mL foi estudado até 90 min, nas mesmas condições estudadas na extração em batelada. O teor de açúcares solúveis (AS) medido nos extratos foi superior na temperatura de 65°C, porém às razões de 1:7 e 1:10, não resultou em maior quantidade de AS nos extratos, portanto, menores quantidades de etanol podem ser usadas diminuindo custos. Com o emprego da técnica EAU à 25 °C e tempo de extração de 30 min, foi observado que uma redução da razão matéria-prima/solvente até 1:3 g/mL produz maior rendimento de processo. No entanto, foi observado que maiores tempos de extração promoveram degradação da parede celular da matéria-prima. Entre os modelos cinéticos testados, o ajuste do modelo de Patricelli aos dados experimentais indicou que a ESL é regida pela fase de lavagem em que ocorreu 85 % da extração dos AS. Frações molares de glicose, ácidos galacturônicos, manose, arabinose, xilose, galactose de conteúdo monossacarídeo foram observadas nos rafinados, indicando possivelmente serem parte de polissacarídeos do tipo ?-glicanos, xilomananos glucomananos, arabinogalactanos e arabinoxilanos. / In this work, non-starch polysaccharides (PNAs) of ripe bananas with potential for immunomodulatory properties were obtained by means removing the soluble sugars (glucose, fructose and sucrose) from banana puree submitted to two extraction techniques: solid-liquid (SLE) with mechanical stirring and ultrasonic assisted (UAE) using 99.5 g/ 100 g ethanol as solvent. For the batch study, different ratios of the raw material/ solvent (1:5, 1:7 and 1:10) g/ mL, extraction times of (30, 60 and 90) min and two temperatures of (25 and 65 ) °C were studied. In the kinetic study, the impact of reducing the raw material/ solvent ratio from 1:5 to 1:3 g/ mL was studied up to 90 min, under the same conditions studied in batch extraction. The soluble sugar content (AS) measured in the extracts was higher at temperature of 65 °C, however, at the ratios of 1:7 and 1:10, did not result in higher amount of AS in the extracts, therefore, smaller amounts of ethanol can be costs. With the use of the UAE technique at 25 °C and extraction time of 30 min, it was observed that a reduction of the raw material / solvent ratio up to 1:3 g / mL produces a higher process yield. However, it was observed that longer extraction times promoted degradation of the cell wall of the raw material. Among the kinetic models tested, the adjustment of Patricelli model to the experimental data indicated that the SLE the predominance is by the washing phase in which 85% of the AS extractions occurred. Glucose molar fractions, galacturonic acids, mannose, arabinose, xylose, galactose of monosaccharide content were observed in the raffinates, indicating possibly being part of polysaccharides as ?-glycan, xylomannans, glucomannans, arabinogalactans and arabinoxylans.
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DESENVOLVIMENTO E APLICAÇÃO DE METODOLOGIA ANALÍTICA (CLAE/FL) PARA DETERMINAÇÃO DE FLUOROQUINOLONAS EM SEDIMENTO ESTUARINO DA ILHA DO MARANHÃO / DEVELOPMENT AND APPLICATION OF ANALYTICAL METHODS (HPLC / FL) FOR DETERMINATION OF FLUOROQUINOLONES IN ESTUARINESEDIMENT OF ISLAND OF MARANHÃO

Neves, Mônica Araujo das 19 December 2014 (has links)
Made available in DSpace on 2016-08-19T12:56:49Z (GMT). No. of bitstreams: 1 Dissertacao Monica de Araujo Neves.pdf: 1987787 bytes, checksum: c4159e188bd8d08a6860a3f310618950 (MD5) Previous issue date: 2014-12-19 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Drugs in the planet have increased during last decades. Such compounds can cause adverse impact on ecosystems. Soon, more effective analytical methods are essential for the study of new pollutants, especially in magazines whose headquarters are very complex as mangrove sediments. Therefore, this study aimed to improve an analytical method to assess the occurrence of fluoroquinolone antibiotics, ciprofloxacin (CIP), levofloxacin (LEV) and norfloxacin (NOR), in sediment samples from the Paciência river located on the Maranhão island using the technique of ultrasound-assisted extraction, extraction phase solid and liquid chromatography (HPLC/FD). According to the study, the method was linear (r²> 0.99), recovery ranging from 73.73 to 88.85%, precise (RSD <20%), selective and sensitive (detection limit for CIP, LEV and NOR 9.32; 17.78 and 4.42 µg.kgˉ¹, respectively, and limit of quantitation of 20 µg.kgˉ¹ for all three drugs) for quantification of fluoroquinolones in estuarine sediments. Other relevant aspects of the method developed in this work were the simplicity, low cost and absence of interfering to a very complex environmental matrix as are the mangrove sediments. When evaluating the sediment at various points of the river there was contamination at three points by CIP ranging from 56.55 to 70.45 µg.kgˉ¹ These results are similar to those found around the planet to polluted regions and they are of concern due to the effects of these antibiotics in the ecosystem. / É crescente a utilização de fármacos no planeta nas últimas décadas. Tais compostos podem causar impacto negativo nos ecossistemas. Logo, métodos analíticos mais eficazes são fundamentais para o estudo de novos poluentes, especialmente em compartimentos cujas matrizes são muito complexas como sedimentos de manguezal. Sendo assim, este trabalho teve por objetivo aprimorar um método analítico para avaliar a ocorrência de antibióticos fluoroquinolônicos, ciprofloxacino (CIP), levofloxacino (LEV) e norfloxacino (NOR), em amostras de sedimento do rio Paciência localizadas na ilha do Maranhão utilizando a técnica de extração assistida por ultrassom, extração em fase sólida e a cromatografia líquida (CLAE/FL). Segundo o estudo, o método mostrou-se linear (r²>0,99), recuperação variando 73,73-88,85%, preciso (DPR < 20%), seletivo e sensível (Limite de detecção para CIP, LEV e NOR de 9,32; 17,78 e 4,42 µg.kgˉ¹, respectivamente e limite de quantificação de 20 µg.kgˉ¹ para todos os três analitos) para quantificação de fluoroquinolonas em sedimento estuarino. Outros aspectos relevantes do método desenvolvido nesse trabalho foram à simplicidade, o baixo custo e ausência de interferentes para uma matriz ambiental muito complexa como são os sedimentos de manguezal. Ao avaliar o sedimento em vários pontos do rio observou-se contaminação em três pontos por CIP variando entre 56,55 70,45 µg.kgˉ¹. Esses resultados são similares ao encontrados ao redor do planeta para regiões poluídas e são motivos de preocupação em função dos efeitos desses antibióticos no ecossistema.
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Optimizing the Extraction of Phenolic Antioxidant Compounds from Peanut Skins

Ballard, Tameshia Shaunt'a 29 July 2008 (has links)
Peanut skins are a low-value byproduct of peanut blanching operations. They have been shown to contain significant levels of phenolic compounds with demonstrated antioxidant properties. The effects of two types of extraction methods: solid-liquid extraction (SLE) and microwave-assisted extraction (MAE) on the recovery of phenolic compounds from peanut skins were investigated. Response surface methodology was used to optimize extraction conditions based on total phenolic content (TPC), ORAC (oxygen radical absorbance capacity) activity and <i>trans</i>-resveratrol content. The protective effect of peanut skin extracts (PSE) against hydrogen peroxide (H₂O₂)-induced oxidative stress in human brain microvascular endothelial cells (HBMEC) and the effect of PSE on lipid oxidation in commercial peanut butter were also evaluated. In the SLE method, EtOH was found to be the most efficient extraction solvent followed by MeOH, water and EA. Despite EtOH extracts having a higher TPC, samples extracted with MeOH demonstrated slightly higher ORAC activity. Resveratrol was identified in MeOH extracts but was not found in EtOH, water or EA extracts. In the MAE procedure, the maximum predicted TPC under the optimized conditions was 144 mg phenols/g skins compared to 118 mg/g with SLE. The maximum predicted ORAC activity was 2789 μmol TE/g as opposed to 2149 μmol TE/g with the SLE method. MAE was able to extract more phenolic compounds (with higher antioxidant activity) in a faster time than the SLE procedure. In addition, resveratrol was identified in PSE derived from MAE although at relatively low levels. PSE were found to have some protective effects against oxidative stress in HBMEC. Higher doses of PSE appeared to have a slightly cytotoxic effect. However, the data were highly variable which made it difficult to arrive at any definitive conclusions regarding the potential benefits of PSE in preventing oxidative damage to cells. In the PB experiment, hexanal levels over the storage period were not high enough for the samples to be considered oxidized. However, hexanal values of PB samples treated with PSE were lower than the control throughout storage, which suggests that PSE may provide some protection against oxidation of PB. / Ph. D.
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Mise au point des espèces du genre Stephania au Cambodge : études systématique, phytochimique et pharmacologique / Update on the species of the genus Stephania in Cambodia : systematic, phytochemical and pharmacological studies

Dary, Chhavarath 18 July 2016 (has links)
L’objectif de la thèse est une mise au point des espèces de Stephania répertoriées au Cambodge par l’étude systématique, phytochimique et pharmacologique. Du point de vue systématique, les travaux ont permis de répertorier sept espèces et deux variétés de Stephania au Cambodge : S. cambodica, S. japonica var. discolor et var. timoriensis, S. oblata, S. pierrei, S. rotunda (espèce-type), S. suberosa, et S. venosa. La clef de détermination établie lors de ce travail de thèse permet d’identifier ces espèces. D’après les résultats phylogénétiques, seul S. pierrei est monophylétique, ce qui représente moins de 10% des espèces de Stephania. L’étude chimique de cinq espèces a été réalisée par des méthodes chromatographiques (CLHP, UCLHP) et des méthodes spectroscopiques. Différents alcaloïdes ont été proposés comme marqueurs : la palmatine, la roémérine et la tétrahydropalmatine pour S. cambodica et S. rotunda, la cépharanthine, la tétrahydropalmatine et la xylopinine pour S. suberosa, la cépharanthine pour S. pierrei, la crébanine, et la tétrahydropalmatine pour S. venosa. Neuf alcaloïdes ont été isolés à partir du tubercule de S. cambodica, dont un nouveau composé dénommé «angkorwatine ». Une méthode d’éco-extraction des alcaloïdes assistée par ultrasons a été mise au point et optimisée par un plan d’expérience pour cette espèce. Une méthode analytique par UCLHP a été développée et validée pour le contrôle qualité de S. cambodica. Les résultats montrent que les extraits hydroéthanoliques obtenus par macération à partir du tubercule de S. suberosa, S. venosa et S. rotunda présentent une activité anti-inflammatoire importante (in vitro) avec un ratio anti-inflammatoire élevé. / The thesis aims to provide update on species of the genus Stephania recorded in Cambodia by systematic, phytochemical and pharmacological studies.The systematic study allowed to list seven species and two varieties of Stephania in Cambodia: S. cambodica, S. japonica var. discolor and var. timoriensis, S. oblata, S. pierrei, S. rotunda (type species), S. suberosa and S. venosa. The presence of S. japonica var. timoriensis and S. oblata is reported for the first time in Cambodia. According to the phylogenetic results, only S. pierrei is monophyletic, which represents less than 10% of species in the genus Stephania. Chemical studies on the tubers of five species were carried out using chromatographic methods (HPLC, UHPLC) and spectroscopic methods. Different isolated alkaloids have been proposed as markers: palmatine, roemerine and tetrahydropalmatine for S. cambodica and S. rotunda, cepharanthine, tetrahydropalmatine, and xylopinine for S. suberosa, cepharanthine for S. pierrei, crebanine, and tetrahydropalmatine for S. venosa. Nine alkaloids belonging to five classes were isolated from the tuber of S. cambodica and a new compound namely "angkorwatine" was described. Ultrasound assisted extraction of alkaloids was developed and optimized by Design of Experiment for this species. This innovative extraction is a good alternative to conventional methods. An analytical UHPLC method was developed and validated for the quality control of S. cambodica. Results show that hydroethanolic extracts obtained by maceration of S. suberosa, S. rotunda and S. venosa exhibit significant anti-inflammatory activity with high anti-inflammatory ratio (selectivity index).

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