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1

Gallagher, Anthony. "Detection of clustered and occluded oranges from a color image of an orange tree." Honors in the Major Thesis, University of Central Florida, 1998. http://digital.library.ucf.edu/cdm/ref/collection/ETH/id/33.

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This item is only available in print in the UCF Libraries. If this is your Honors Thesis, you can help us make it available online for use by researchers around the world by following the instructions on the distribution consent form at http://library.ucf.edu/Systems/DigitalInitiatives/DigitalCollections/InternetDistributionConsentAgreementForm.pdf You may also contact the project coordinator, Kerri Bottorff, at kerri.bottorff@ucf.edu for more information.
Bachelors
Engineering
Electrical and Computer Engineering
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2

Laws, Eric L. "An Investigation of Color Memory as a Function of Hue, Saturation, Lightness and Observer Imagery Vividness for Blue, Green and Orange Test Hues." Diss., Virginia Tech, 2000. http://hdl.handle.net/10919/26367.

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Fifty-two college-aged observers participated in an experiment assessing color memory via a PowerPoint '97 computer display program which varied one of the three dimensions of hue, saturation and lightness at a time. Consistent with previous research, errors were greater for the lightness conditions followed by saturation, and least for hue conditions Additionally, a signal detection analysis indicated that d-prime was greatest for the hue conditions, less for saturation and lowest for lightness conditions. There were also significant but unpredicted differences in response criterion which may reflect task difficulty. Scores on the Vividness of Visual Imagery Questionnaire (Marks, 1973) were, in general, not correlated with performance on these color memory tasks, inconsistent with previous research. The role of complexity of neuronal circuitry, the significance for opponent-process, trichromatic and retinex color vision theories and the relationship to Sokolov's model of color memory were discussed. Also, it was concluded that investigators of color memory using a computer display are well-advised to calibrate the monitor with a colorimeter because the internal computer units may be unreliable indexes of changes in hue, saturation and lightness.
Ph. D.
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3

Price, David James 1959. "The effects of ozone oxidation on dissolved organic matter, color, and trihalomethane formation potential of Orange County, California groundwater." Thesis, The University of Arizona, 1990. http://hdl.handle.net/10150/278305.

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Laboratory studies using ozone oxidation were conducted on samples of groundwater. The effects of ozonation on natural organic matter (NOM), color, and trihalomethane formation potential (THMFP) were examined. The fourteen groundwater samples had dissolved organic carbon (DOC) concentrations between 0.9 and 14.4 mg/L and color levels between 13 and 210 pcu. Small doses of ozone appeared to result in an oxidative polymerization phenomenon whereby the apparent molecular weight (AMW) of the organics increased. Higher doses of ozone led to lower AMW organic matter. Ozonation was successful at destroying color and ultraviolet absorbance at 254 nm. Ozonation showed limited ability to remove THMFP. Ozone treatment prior to chlorination resulted in increased brominated THMs.
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4

Napier, Alexandra Bamberger. "Identification and confirmation of molecular markers and orange flesh color associated with major QTL for high beta-carotene content in muskmelon." [College Station, Tex. : Texas A&M University, 2006. http://hdl.handle.net/1969.1/ETD-TAMU-1136.

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5

Jomori, Maria Luiza Lye. "Métodos de desverdecimento pós-colheita de tangor ´Murcott` e laranja ´Valência`." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/11/11136/tde-29062011-150721/.

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A procura de frutas com boas características para exportação in natura tem aumentado, sendo em grande parte dependente da melhoria da qualidade da fruta. Neste sentido, a adequação das operações ligadas à produção e pós-colheita é fundamental para tornar a fruta cítrica brasileira mais competitiva no mercado externo. Em decorrência de grande parte da área citrícola brasileira localizar-se em regiões de clima tropical, os frutos cítricos alcançam à plena maturação interna, enquanto que a casca permanece parcialmente verde, tornando-os inaceitáveis para a comercialização in natura em mercados exigentes. Assim, há necessidade do estudo de métodos e condições mais apropriadas para o desverdecimento dos frutos em pós-colheita para as nossas variedades e condições climáticas. Este estudo teve como objetivo avaliar o uso da técnica de desverdecimento pós-colheita de tangor Murcott e de laranja Valência, por meio da aplicação de etileno, na forma líquida e gasosa (em câmara). Utilizaram-se concentrações de 0 a 8000 mg L-1 de ethephon aplicadas por imersão (3 minutos) e 0,0; 0,25; 0,5; 0,75 e 1,0 L m-3 de etileno aplicadas em câmaras por 24 a 120 horas de exposição e 15 a 30ºC e 90% UR. Foram definidas as melhores condições de desverdecimento e, posteriormente, parte dos frutos ficou por 3 dias a 25ºC e 80% UR, simulando a comercialização, e outra parte dos frutos foi submetida à refrigeração (5ºC e 90% UR) por período de 30 dias (+3 dias a 25ºC e 80% UR, simulando a comercialização). Foi avaliado também o efeito do desverdecimento em câmara após o armazenamento refrigerado dos frutos. Os frutos foram avaliados logo após os tratamentos, após a primeira simulação de comercialização, após a refrigeração e após a segunda simulação de comercialização. A condição de 0,5 L m-3 de etileno por 96 horas de exposição a 25ºC foi a mais eficiente para incrementar a coloração dos frutos. As taxas respiratórias e produção de etileno aumentaram em função da concentração usada de etileno. O incremento na atividade da clorofilase foi acompanhado pela queda no teor de clorofila, enquanto que o teor de carotenóides se manteve constante. Quanto às características internas não foram observadas alterações significativas em função dos tratamentos. Verificou-se que o armazenamento refrigerado após o desverdecimento não interfere no desenvolvimento da coloração da casca dos frutos, não afetando a qualidade dos mesmos. Além disso, o processo de desverdecimento após a refrigeração é eficaz para a mudança da coloração dos frutos das duas variedades estudadas.
The demand for fresh fruits with good characteristics to exportation has increased, being mostly dependent on the improvement of fruit quality. In this sense, the adequacy of the operations related to production and post-harvest is crucial to make the Brazilian citrus fruit more competitive in foreign markets. Due to the large part of Brazilian citrus growing area is located in the tropical, citrus fruit reaches full internal maturity, while the peel remains partially green, making them unacceptable for the demanding fresh fruit markets. Thus, there is a necessity to study methods and more suitable conditions for the degreening of post-harvest fruit in our climatic conditions and varieties. This study was based on the technique of post-harvest degreening of \'Murcott\' and \'Valencia\', involving the application of ethylene in liquid and gaseous form (chamber). The concentrations used were 0 to 8000 mg L-1 of ethephon by immersion (3 minutes) and 0.0, 0.25, 0.5, 0.75 and 1.0 L m-3 of ethylene applied inside the chamber for 24 to 120 hours of exposure and 15 to 30ºC and 90% RH. The best conditions for degreening were defined and later, part of the fruits was for 3 days at 25ºC and 80% RH, simulating the commercialization, and the other part was stored under refrigeration (5ºC) with 90% RH for 30 days, and after that, 3 days at 25ºC and 80% RH, simulating the commercialization. The effect of cold storage of the fruit before the degreening inside the chamber was also evaluated. The fruits were evaluated right after the applications, the first simulation of commercialization, the cooling and the second simulation. The condition of 0.5 L m-3 for 96 hours at 25ºC was the most efficient way to improve fruit color. Respiratory rate and ethylene production increased with the dosage of ethylene used. The increased activity of chlorophyllase was followed by decrease in chlorophyll content, while the carotenoid content remained constant. As for the internal features, significant changes in the treatments were not observed. It was found that refrigerated storage after degreening do not interfere on the development of the fruits peal color, neither affecting their quality. Beyond that the process of degreening after cooling is effective for changing the color of both studied varieties.
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6

Ikeda, Yosuke 1966. "Reestablishing sufficient peel color in regreened Valencia oranges." Thesis, The University of Arizona, 1992. http://hdl.handle.net/10150/278218.

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Improvements in the external color of Regreened 'Valencia' oranges were studied using ethylene gas. Twelve hour cycles of gassing were followed by the restoration of normal air concentrations with high humidity. Two temperatures, 14°C and 22°C were used with ethylene concentrations of 5, 10 μl/l as well as normal generated ethylene concentration in air for two weeks. The reflectance of the fruit was measured to indicate chlorophyll concentration changes. Chroma measurements were used to mimic the human eye response. The oranges treated at 22°C with either 5 or 10 μl/l ethylene gas lost their chlorophyll (greenness) and gained orange pigment (redness). Brightness increased more in the 10 μl/l ethylene than in the 5 μl/l concentrations. At 5 μl/l little evidence of stem-end decay was observed which indicates senescence was not accelerated. Some stem-end decay was observed in oranges treated with 10 μl/l of ethylene at 22°C an indication that shelf life had been reduced because of the treatments.
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7

Krifi, Boubaker. "Incidence des facteurs d'environnement (lumière, aération, agitation) sur la stabilité de la couleur du jus d'oranges sanguines." Vandoeuvre-les-Nancy, INPL, 1994. http://www.theses.fr/1994INPL123N.

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Cette étude a porté sur l'incidence de divers facteurs (lumière, aération, agitation) sur la stabilité des pigments responsables de la couleur des jus d'oranges sanguines. Nos observations ont été focalisées sur les effets de la lumière et de l'aération sur les pigments anthocyaniques et caroténoïdes des jus fraichement préparés à partir de fruits ainsi que des jus issus de la dilution de concentrés industriels d'âges différents. Il apparait que les caroténoïdes en même temps que des substances liposolubles non identifiées tendent à s'opposer aux effets de la lumière et de l'autoxydation sur la dégradation des pigments anthocyaniques. D’autre part l'acide ascorbique est le principal facteur responsable de la consommation de O2 par le jus d'oranges sanguines. Ce processus apparait comme la résultante de deux processus d'autoxydation en grande partie indépendants, l'un rapide imputable à l'acide ascorbique, l'autre beaucoup plus lent qui intéresse un ensemble de constituants des jus. L'autoxydation de l'acide ascorbique entraine à la fois la déprotection des caroténoïdes et la dégradation des pigments anthocyaniques par l'intermédiaire de ses produits d'oxydation
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8

Pitombo, Ronaldo Nogueira de Moraes. "Comportamento higroscópico do suco de laranja liofilizado." Universidade de São Paulo, 1990. http://www.teses.usp.br/teses/disponiveis/9/9131/tde-15032010-152158/.

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0 comportamento higroscópico do suco de laranja liofilizado, e aditivado com malto-dextrinas e lactose, e de misturas mecânicas do suco liofilizado com os aditivos secos, foi estudado através da cinética e das isotermas de sorção de água, em diferentes temperaturas. Avaliou-se as características espectrais no visível e ultravioleta, e o teor de vitamina C, de amostras de suco de laranja liofilizado expostas a diferentes umidades relativas e temperaturas. Estudou-se a influência do valor de pH e natureza do tampão sobre a retenção do limoneno emulsionado em soluções de lactose, liofilizadas. A liofilização praticamente não alterou o teor de vitamina C e as características espectrais do suco de laranja, mas aumentou o valor monomolecular da malto-dextrina (dextrose equivalente de 9 a 12%). A lactose liofilizada apresentou-se no estado amorfo. Os teores de umidade de equilíbrio das misturas aditivadas liofilizadas, foram menores que os das misturas mecânicas. Os aditivos reduziram a sorção de umidade em função do tempo. A retenção do limoneno foi influenciada pela sua concentração inicial, sendo que ocorreu a major perda, durante a liofilização na major concentração utilizada.
The higroscopic behavior of freeze-dried orange juice, with added maltodextrins and lactose and mechanical mixtures with this additives was studied through the kinetics and isoterms of water sorption in different temperatures. It was evaluated the spectral characteristics, in the visible and ultraviolet range, and the vitamin C content from samples of freeze-dried orange juice exposed at different relative humidities and temperatures. It was studied the influence of pH and buffer composition, on the limonene retention of freeze-dried emulsions. The spectral characteristics and vitamin C content showed no alterations after liofilization the maltodextrin (9-12 % dextrose equivalent monomolecular value increased. Freezedried lactose was amorphous. The equilibrium humidity content of the samples with additives were reduced when compared with mechanical mixtures. The additives also reduced the rate of water sorption. The limonene retention during freeze-drying was influenced by the initial concentration of the emulsion. The greater concentration studied showed the lower retention value.
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9

Lindqvist, Jonatan. "Är hälsa orange? : En kvalitativ studie av Norrbottens Läns Landstings byte av färg på Vårdcentralers logotyper i Norrbotten." Thesis, Umeå universitet, Institutionen för kultur- och medievetenskaper, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-87554.

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Colours have been proven to have both a great physical and psychological impact on human beings. This essay investigates the rebranding of 37 Health Care Centers, located in Norrbotten, Sweden, and how 10 interviewees have experienced the new choice of colour on the logotypes of these Health Care Centers. The theoretical framework used in this research process, consists of theories related to rebranding, the communication process, encoding/decoding and Goethe’s Theory of Colours. To gather information about how the 10 inhabitants have experienced the new choice of colour, a semistructured form of interview was used. In addition to these interviews, three people employed by Norrbotten County Council (NLL) were interviewed, to get to know more about the rebranding process and the message behind the chosen colours of the logotype. Results show that the inhabitants had an overall positive reaction to the new colour choices, but that younger target groups lacked information about the new logotype and the rebranding. Due to these results, recommendations were made that NLL should expand the quantity of media channels to reach these younger target groups, and thereby be able to attract more patients to their Health Care Centers. NLL would also profit from investigating the inhabitants experiences related to the new colour choices themselves, but in a larger scale, to achieve greater knowledge of how to proceed with colour choices in the future.
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10

Liu, MingHui. "Navel orange blemish identification for quality grading system : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Computer Science at Massey University, Albany, New Zealand." Massey University, 2009. http://hdl.handle.net/10179/1175.

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Each year, the world’s top orange producers output millions of oranges for human consumption. This production is projected to grow by as much as 64 million in 2010 and so the demand for fast, low-cost and precise automated orange fruit grading systems is only deemed to become more increasingly important. There is however an underlying limit to most orange blemish detection algorithms. Most existing statistical-based, structural-based, model-based and transform-based orange blemish detection algorithms are plagued by the following problem: any pixels in an image of an orange having about the same magnitudes for the red, green and blue channels will almost always be classified as belonging to the same category (either a blemish or not). This however presents a big problem as the RGB components of the pixels corresponding to blemishes are very similar to pixels near the boundary of an orange. In light of this problem, this research utilizes a priori knowledge of the local intensity variations observed on rounded convex objects to classify the ambiguous pixels correctly. The algorithm has the effect of peeling-off layers of the orange skin according to gradations of the intensity. Therefore, any abrupt discontinuities detected along successive layers would significantly help identifying skin blemishes more accurately. A commercial-grade fruit inspection and distribution system was used to collect 170 navel orange images. Of these images, 100 were manually classified as good oranges by human inspection and the rest are blemished ones. We demonstrate the efficacy of the algorithm using these images as the benchmarking test set. Our results show that the system garnered 96% correctly classified good oranges and 97% correctly classified blemished oranges. The proposed system is easily customizable as it does not require any training. The fruit quality bands can be adjusted to meet the requirements set by the market standards by specifying an agreeable percentage of blemishes for each band.
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Noirot, Cécile. "Colorations rouge et orange de verres et glaçures sur céramique : étude du redox et de la cristallisation du cuivre." Electronic Thesis or Diss., Sorbonne université, 2022. http://www.theses.fr/2022SORUS427.

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Le cuivre est un élément multivalent qui donne aux verres ou aux glaçures une coloration bleue (ions Cu2+), rouge, ou orange (nano ou micro-cristaux de cuivre métallique Cu0 ou de cuprite Cu2O). Ces colorations sont utilisées depuis le début de la manufacture verrière, et se retrouvent dans de nombreux verres archéologiques et historiques, ainsi que dans les glaçures sur céramique. Le contrôle du redox et de la cristallisation lors de l’élaboration des verres rouges ou orange repose cependant sur des recettes en grande partie empiriques. Elles nécessitent la réduction du cuivre à l’aide d’agents réducteurs et/ou d’une atmosphère de fusion réductrice. D’autre part, les procédés de fabrications anciens sont mal connus. L’objectif de cette thèse est d’étudier l’état redox et la cristallisation du cuivre dans les verres silicatés à différentes étapes de l’élaboration de verres rouges et orange. Ainsi, on vérifie que lors de fusions sous air, l’étain permet la réduction du cuivre. On montre que cette réduction continue en même temps que la cristallisation de Cu0 pendant une deuxième étape de recuit. En atmosphère réductrice, on constate que la réduction et la cristallisation peuvent avoir lieu conjointement dans un verre à l’état liquide, mais aussi lors d’un recuit sans fusion réductrice préalable. L’étude est élargie à l’analyse de six tesselles de mosaïque romaines (4eme siècle) rouges et orange. Les parties rouges, colorées par Cu0, et orange, colorées par Cu2O mélangé avec Cu+, coexistent sous forme de rayures dans deux tesselles. L’analyse des compositions établit que les rayures correspondent au même verre de base auquel Cu, Sn et Pb ont été ajoutés, à de plus fortes concentrations pour les parties oranges. Les colorations par Cu2O ne sont pas utilisées en production modernes mais courantes dans les verres archéologiques, et corrélées avec de fortes proportion en cuivre, et souvent en plomb. A partir de nos résultats et d’un bilan de la littérature, un groupe de compositions [haut Cu/ bas Pb] est proposé, et le rôle du plomb dans la formation de Cu2O et la forme de cristaux est discuté. On montre que de fortes concentrations en cuivre et en plomb modifient peu le redox du cuivre. Nos résultats attestent que le choix de la durée et de la température de fusion de verres riches en cuivre et en plomb sont des leviers de contrôle du redox pour obtenir la cristallisation de Cu2O
Copper is a multivalent element that colours glasses in blue (Cu2+), red or orange (nano or micro-crystals of metallic copper Cu0 or cuprite Cu2O). These colourations have been used since the dawn of human glass-making and are thus found in numerous archaeological and historical glasses as well as in ceramic glazes. The control of redox and crystallization in the making of these red and orange glasses however rely on somewhat empirical recipes. They require the reduction of copper from added agents or the heating treatment atmosphere. Besides, there are still many unknowns about ancient processes for the production of red and oranges. The purpose of this thesis is to study redox and crystallization of copper in silicate glasses in different steps of the red and orange glasses elaboration. It is thus verified that tin reduces copper when melting in air. We show that this reduction also happen along with crystallization of Cu0 during a second annealing step. In a reducing atmosphere, we observed that reduction and crystallization can happen concurrently in a liquid glass but also during an annealing without previously melting the glass in a reducing atmosphere. The study was broadened to the analysis of six red and orange Roman mosaic tesserae (4th century). The red parts, coloured by Cu0, and the orange one, coloured by Cu2O mixed with Cu+, coexist as stripes in two tesserae. Compositional analyses establish that the stripes correspond to the same base glass to which Cu, Sn and Pb were added, in higher proportions for the orange parts. Colourations by Cu2O are not used in modern production but common in archaeological glasses, and correlated to high copper and often high lead contents. From our results and a literature review, a [high Cu/low Pb] compositional group is put forward, and the role of lead in Cu2O crystallisation is discussed. We show that high copper and lead contents have little impact on copper redox. Our results indicate that the tuning of melting time and temperature of copper and lead-rich glasses is a way to control redox to attain the crystallization of Cu2O
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El-Matni, Lambert Nada. "Etude d'une forme orale a liberation specifique au niveau du colon par action de la flore microbienne." Paris 11, 1998. http://www.theses.fr/1998PA114810.

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13

Strich, Samuel. "Oral drug delivery systems based on polysaccharides for colon targeting." Electronic Thesis or Diss., Université de Lille (2022-....), 2023. http://www.theses.fr/2023ULILS081.

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10 millions dans le monde, 3 millions en Europe, 250000 en France. Ces nombres représentent la prévalence des maladies inflammatoires chroniques de l'intestin (MICI), respectivement dans chaque région citée. Le plus souvent diagnostiquées entre 15 et 35 ans, les MICI regroupent la Maladie de Crohn (MC) et la Rectocolite Hémorragique (RCH), et se caractérisent par une inflammation de la paroi du tube digestif, évoluant par poussées.Le ciblage de la partie distale du tractus gastro-intestinal (TGI), ou côlon, permet d'envisager une libération locale et optimale de substance active au niveau des zones lésées, tout en diminuant les effets indésirables des traitements. Différentes stratégies sont employées pour le ciblage du côlon par voie orale, parmi lesquelles : *) l'utilisation de prodrogues, **) Les systèmes pH-dépendants, ***) Les systèmes temps-dépendants, et ****) les systèmes sensibles au microbiote intestinal.De toutes, l'approche basée sur l'activité du microbiote reste la plus fiable. Les quelques mille milliards de bactéries par gramme de selle présentes dans le côlon peuvent, via leur activité enzymatique, dégrader les polysaccharides de structure complexe. Afin de pallier les limites des approches pH- et temps-dépendantes, les systèmes à double stimuli intéressent aussi de plus en plus les équipes de recherches. En combinant plusieurs approches différentes mais complémentaires, il est possible d'améliorer significativement la libération de la substance active in situ.Notre projet a consisté à fabriquer, pelliculer, et développer des mini-comprimés de 5 mm de diamètre pour le ciblage du côlon. Au terme d'une étape de criblage de films polymériques, permettant d'identifier le mélange le plus résistant dans le haut TGI, un pelliculage associant éthylcellulose et shellac a été retenu. Différents ratios de mélanges ont été exploités. Des tests de libération in vitro ont été menés sur une durée totale de 32h, impliquant différents milieux digestifs reconstitués. Les expériences en milieu colique ont été réalisées avec et sans selles de patients sous atmosphère anaérobie, permettant de travailler au plus près des conditions physiopathologiques.Incontestablement, la protection de la substance active a été totale dans le haut TGI. Les formes galéniques pelliculées ont aussi présenté un profil de libération contrôlée dans le côlon.La formulation finale allie plusieurs propriétés :- Une prise en eau et une dissolution contrôlées grâce à l'éthylcellulose- Une dissolution pH-dépendante liée à la shellac- Une sensibilité au microbiote grâce à la présence d'un polysaccharideLes données obtenues se sont avérées encourageantes. La libération de la substance active en milieu colique peut être modulée selon la quantité de polysaccharide ajouté. Cette phase d'optimisation a été un enjeu capital
10 million people worldwide, over 1.5 million in North America and 2 million in Europe. Those are the numbers of people affected by inflammatory bowel disease (IBD) in each region quoted, respectively. Including both Crohn's disease (CD) and ulcerative colitis (UC), inflammatory bowel disease has emerged as a public health challenge worldwide in the past decades. Often diagnosed between 15 and 35 years old, IBD are characterized by moderate to severe symptoms, and have in common relapsing-remitting cycles of mucosal inflammation.To date, there is no cure for IBD. Defined as colon targeting, targeted drug delivery systems is a way to get selective and efficient delivery of pharmacologically active compounds to the predetermined targeted region in therapeutic concentrations along with minimizing side effects of the drug. Current strategies for colon targeting rely on : *) prodrugs, **) pH-dependant systems, ***) time-dependant systems, ****) microbially triggered systems.Of all approaches, microbiota sensitive systems are currently known as the best ones for colonic drug delivery. It is also possible to combine several complementary approaches (pH- and microbiota sensitive) to significantely favor localized drug release.Our project aimed to develop 5 mm mini-tablets for colon targeting. First, a comparison of different film coatings was made to highlight the most interesting drug release profiles. Then, an innovative formulation, combining synthetic and natural polymers as well as polysaccharides, was evaluated. Different blend ratios were selected as well for films as for coated mini-tablets. In vitro drug release was carried out in simulated digestive fluids for a 32 h duration, including:- 0.1 N HCl or simulated gastric fluid (2 h)- PBS 6.8 or simulated intestinal fluid (6 h)- Colonic simulated medium with and without patients' faeces (24 h).Colonic simulated medium inoculated with patients' faeces allowed for working closer to pathophysiological conditions. Relevant results were obtained and paved the way for a promising monolayer technology. None or negligible drug release occurred up to 8 h, in the upper GIT. Also, drug could be totally protected in the lower gastrointestinal tract.Ethylcellulose, as a thermoplastic polymer, prevented from premature dissolution.Shellac, as a natural resin, provided pH-dependant properties.The adjunction of a polysaccharide acted as a substrate of microbiota.Interestingly, colonic release profiles could be optimized depending on the amount of polysaccharide added into the system
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Semde, Rasmané. "Etude des pectines en vue de leur utilisation pour la délivrance spécifique des médicaments dans le colon après administration orale." Doctoral thesis, Universite Libre de Bruxelles, 1999. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/211954.

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15

Ferraro, Fabiana. "Enzyme-sensitive coatings for colon targeting : species-independent drug delivery systems." Electronic Thesis or Diss., Université de Lille (2022-....), 2023. http://www.theses.fr/2023ULILS035.

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Le but de cette thèse est de préparer et caractériser de nouvelles formes galéniques permettant une libération ciblée du côlon. Ce projet s’inscrit dans le cadre du projet Interreg des 2 mers “Site-specific Drug Delivery” (https://www.interreg2seas.eu/fr/Site-Drug). La libération ciblée d’un principe actif au côlon peut présenter des avantages majeurs pour une thérapie médicamenteuse, par exemple si des maladies inflammatoires du côlon doivent être traitées localement. Des formes galéniques conventionnelles mènent à une libération rapide et complète du principe actif dans l’estomac et l’intestin grêle et –généralement- une absorption rapide dans la circulation sanguine. Par conséquent, les concentrations systémiques en principe actif et les effets indésirables associés peuvent être considérables. Par ailleurs, les concentrations résultantes en principe actif au site d’action (le côlon enflammé) sont faibles, résultant en une faible efficacité thérapeutique. Une forme galénique idéale pour traiter localement les maladies coliques devrait empêcher de manière efficace la libération de la substance active dans l’estomac et l’intestin grêle. En revanche, une fois le côlon atteint, la libération doit débuter et être contrôlée dans le temps (incluant -si désiré- une libération rapide et complète). Dans le cas de traitement des maladies inflammatoires du côlon (ex : maladie de Crohn et recto colique hémorragique), le principe actif est, ainsi, libéré à son site d’action, offrant des effets thérapeutiques optimaux et des effets secondaires minimisés. Différents types de systèmes de délivrance de principe actif ont été décrits dans la littérature visant à libérer de manière site-spécifique le principe actif au côlon. Souvent, le principe actif est piégé dans une matrice polymérique, ou un réservoir de principe actif (ex : des minigranules, gélules ou comprimés chargés en principe actif) est enrobé d’un film polymérique. Les polymères idéaux utilisés à cette fin sont peu perméables pour le principe actif dans la partie haute du tube digestif, mais deviennent perméables dès que le côlon est atteint. Afin de permettre une telle augmentation en principe actif, différents systèmes ont été proposés, basés notamment sur : (i) des changements de pH le long du tractus gastro-intestinal, (ii) une dégradation du polymère par des enzymes préférentiellement localisés dans le côlon, ou (iii) des changements structuraux dans les réseaux polymériques après un certain délai, tels que la formation de fissures dans des pelliculages peu perméables. Néanmoins, une attention particulière doit être payée car les conditions pathophysiologiques dans le côlon de patients souffrant de maladies inflammatoires du côlon peuvent être significativement différentes de celles chez des sujets sains(i) le pH du contenu du tractus gastro-intestinal,(ii) la qualité et la quantité de la microflore (secrétant les enzymes),(iii) les temps de transit dans les différentes sections du tractus gastro-intestinal. Ainsi, une forme galénique qui libère avec succès un principe actif dans le côlon d’un sujet sain peut échouer chez un patient. De même, la variabilité inter et intra-individuelle des effets thérapeutiques peut être considérable, si la forme galénique n’est pas adaptée de manière appropriée à l’état pathologique. L’objectif de ce projet de thèse est de développer de nouvelles formes galéniques ciblant la libération du principe actif au côlon et qui soient adaptés à l’état pathologique. La libération du principe actif sera déclenchée par des enzymes localisés au niveau du côlon, indépendamment de l’état pathologique.2. Méthodologie. Les systèmes ont été préparés par pelliculage fonctionnel de micro granules chargés en principe actif [...]
The aim of this thesis is to produce and characterize novel drug delivery systems for colon targeting.This project is part of the Interreg des 2 mers “Site-specific Drug Delivery” (https://www.interreg2seas.eu/fr/Site-Drug). The site-specific delivery of drugs to the colon presents major therapeutical advantages, for example in the treatment of inflammatory bowel diseases which required a local action. Conventional oral dosage forms lead to a fast and complete drug release in the stomach and small intestine and, generally, a systemic absorption into the bloodstream. Therefore, systemic concentrations of drugs and associated adverse effects can be considerable. Furthermore, the resulting concentrations of drug at the site of action (the inflamed colon) are low, resulting in low therapeutic efficacy. An ideal dosage form for the local treatment of colonic diseases should effectively prevent the release of the active substance in the stomach and small intestine. On the other hand, once the colon is reached, the release must begin and be controlled over time (including -if desired- a rapid and complete release). In the case of treatment of inflammatory diseases of the colon (e.g. Crohn's disease and haemorrhagic ulcerative colitis), the active ingredient is thus released at its site of action, offering optimal therapeutic effects and minimized side effects. Different types of drug delivery systems have been described in the literature aiming at site-specific release to the colon. Often, the drug is trapped in a polymeric matrix, or a drug reservoir (e.g. minigranules, capsules or tablets loaded with active ingredient) is coated with a polymeric film. The ideal polymers used for this purpose have low permeability for the drug in the upper part of the gastrointestinal tract, but become permeable as soon as the colon is reached. In order to allow such control delivery, various systems have been proposed, based in particular on: (i) changes in pH along the gastrointestinal tract, (ii) degradation of the polymer by enzymes preferentially located in the colon, or (iii) structural changes in the polymeric networks after a certain delay, such as the formation of cracks in low permeability films. Nevertheless, special attention should be paid because the pathophysiological conditions in the colon of patients with inflammatory bowel diseases may be significantly different from those in healthy subjects.(i) the pH of the contents of the gastrointestinal tract,(ii) the quality and quantity of microflora (secreting enzymes),(iii) transit times in different sections of the gastrointestinal tract. Thus, a galenic formulation which successfully releases an active ingredient in the colon of a healthy subject may fail in a patient. Similarly, the inter- and intra-individual variability of therapeutic effects can be considerable, if the dosage form is not appropriately adapted to the pathological state. The objective of this thesis project is to develop new galenic forms targeting the release of the active ingredient in the colon and which are adapted to the pathological state. The release of the drug will be triggered by enzymes located in the colon, regardless of the pathological state.1. Methods. The systems were prepared by functional coating of microgranules loaded with 5-ASA as drug. These systems have been characterized physico-chemically in different media simulating the gastrointestinal tract, this includes in particular exposure to media containing stools from patients with inflammatory bowel diseases as well as stools from animal models of these diseases (TNBS rats) and dog stools (healthy) under anaerobic conditions, in collaboration with INSERM U995 (Dr. Christel Neut). The main characterization technique used concerns the study of the release kinetics of systems exposed to these different release media [...]
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Dossou-Yovo, Flore. "Modification de la biodisponibilité orale des médicaments : interactions « Herb-Drugs » « Drugs- Drugs»." Thesis, Paris, CNAM, 2014. http://www.theses.fr/2014CNAM0936/document.

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L’administration par voie orale des médicaments reste encore de nos jours la voie royale de la prise des médicaments car moins onéreuse et plus adaptée au confort du patient. Mais cette voie reste toujours inaccessible pour certains médicaments comme les médicaments biologiques et les bio similaires voir certains anticancéreux et antirétroviraux.Le but de ce travail est d’améliorer la biodisponibilité par voie orale des médicaments à faible biodisponibilité par la mise au point d’un promoteur d’absorption. Pour y arriver nous avons adopté comme stratégie de développer un promoteur qui agit à la fois sur le passage passif et sur le passage actif des médicaments. Les études in vitro ont été réalisées en chambre de perméation d’Ussing adaptées par la société Biomécatronics SAS (BéthuneFrance). Dans la première partie de ce travail (Brevet), nous avons montré que l’utilisation d’une composition pharmaceutique et/ou diététique comprenant un extrait de plante(Hibiscus sabdariffa) pouvait augmenter la biodisponibilité in vitro des médicaments et des xénobiotiques qui passent par la voie paracellulaire comme le cisplatine (21 fois),l’oxaliplatine (11fois), la fluorescéine isothiocyanate-Dextran 4000 (3 fois), mais également les médicaments connus pour leur transport actif par la voie transcellulaire comme l’Efavirenz (7 fois) et l’Atazanavir (4 fois). Dans la seconde partie de ce travail, nous avons cherché à vérifier si notre promoteur d’absorption des médicaments a un effet sur la couche de mucus intestinale.Cette couche peut être un facteur limitant de passage des médicaments au travers de la barrière intestinale.Dans un premier temps (article 1), nous avons induit l’augmentation de la couche mucus au niveau du colon de rat après un prétraitement pendant une semaine avec le métronidazole. Puis nous avions confirmé (article 2) que l’administration par voie orale de deux antibiotiques le Cotrimoxazole (CTX) et le métronidazole (MTZ) pendant une semaine augmente la couche de mucus au niveau du côlon ; aussi nous avons montré qu’il existe une relation entre l’augmentation de la couche de mucus et la diminution de la conductance qui est l’index de transport passif des ions, des électrolytes et de certaines molécules à faibles poids moléculaires.De plus l’augmentation de la couche de mucus au niveau de l’intestin est responsable de la diminution du passage transépithélial des deux antirétroviraux dont l’utilisation est recommandée en première ligne par l’OMS (le.Ritonavir et l’Atazanavir) surles sujets porteurs du VIH (virus de l’immunodéficience humain). Après les traitements auMTZ et au CTX la sécrétion de l’Atazanavir augmente respectivement dans le côlon proximal de 2 et 4 fois et dans le côlon distal de 3 et 5 fois. On obtient également une sécrétion du Ritonavir de 5 et 10 fois dans le proximal et de 2 et 5 fois plus dans le distal.Le travail se poursuit par l’étude de l’effet de notre promoteur d’absorption des médicaments sur la couche de mucus intestinal.En conclusion, ce travail montre que l’on peut augmenter la biodisponibilité in vitroen utilisant les promoteurs de l’absorption des xénobiotiques qui agissent à la fois au niveau du transport passif et actif
Oral dosing is still seen as the silver bullet of drug administration, as it is cheaper andbetter adapted to patient comfort. However, oral route is still inaccessible to many drugssuch as biologics and biosimilars respectively certain anticancer drugs and antiretrovirals(ARV).The aim of this present study was to find new drugs enhancers that improve the oralbioavailability of drugs and xenobiotics. All the studies were realized in vitro using Ussingchambers technic. To achieve the set objective we used the strategy to develop drugenhancer which can modulate at the same time transcellular and paracellular pathways.In the first part of this study (patent) we have shown that the use of a pharmaceutical and /or a dietetic formulation containing a plant extract (Hibiscus sabdariffa) could increase thebioavailability in vitro in rats not only of cisplatin (21 fold), oxaliplatin (11 fold) andFluorescein Isothiocyanate-Dextran 4000 (FD4, 3 fold). All that drugs were transportedthrough intestinal barrier using paracellular pathway. In addition the study showed thatthis formulated enhancer can increased the bioavailability of Efavirenz (7 fold) andAtazanavir (4 fold) which are active transported.In order to assess the effect of new drugs enhancer on mucus thickness that limits thetransport of xenobiotic through intestinal barrier, we decide to evaluate his effect on passiveand active transport of drugs.In the second part of this study we have shown that after a week of pre-treatment of ratswith Metronidazole (MTZ, publication 1) and Cotrimoxazole (CTX, publication 2), the twomost commonly used antibiotics in the prophylaxis against opportunistic infections in HIV /AIDS, both increase colonic mucus thickness that affect directly passive intestinalpermeability by reducing conductance an index of passive transport through intestinalepithelium. In addition those antibiotics also entail a change in the transepithelialconductance and ARV fluxes. After MTZ and CTX treatment the secretion of Atazanavir(ATZ) increases respectively in the proximal colon by 2 to 4 fold and in the distal colon by 3to 5 fold respectively. Ritonavir (RTV) is poorly absorbed in control, after a week of pretreatmentwith MTZ and CTX one rather notices a secretion of RTV 5 to 10 fold higher in theproximal and 2 to 5 fold higher in the distal colon. The next study will be conducted toevaluate the effect of new drugs enhancer on mucus thickness layer.In conclusion, oral bioavailability of drugs and xenobiotics can be enhanced bypharmaceutical composition that contains herbal extract which increase passive and activetransport of drugs through intestinal barrier
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Kalmegh, Prajakta. "Image mining methodologies for content based retrieval." Thesis, Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/39587.

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The thesis presents a system for content based image retrieval and mining. The research presents a design of a scalable solution for efficient retrieval of images from large image databases using image features such as color, shape and texture. A framework for automatic labeling of images and clustering of meta data in database based on the dominant shapes, textures and colors in the image is proposed. The thesis also presents a new image tagging methodology to annotate the dominant image features to the image as meta data. The users of this system can input a query image and select similar image retrieval criteria by selecting a feature type from amongst color, texture or shape. The system retrieves images from the database that match the specified pattern and displays them by relevance. The user can enter a set of keywords or a combination of keywords that form the input text query. Images in the database that match the input text query are fetched and displayed. This ensures content based similar image search even for text based search. An efficient clustering algorithm is shown to improve the image retrieval by an order of magnitude.
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Eduardo, Da Silva Acarilia. "Nanotechnological delivery systems for the oral administration of active molecules : Polymeric microparticles and microemulsions applied to anti-inflammatory and anti-infectious drugs." Phd thesis, Université Paris Sud - Paris XI, 2013. http://tel.archives-ouvertes.fr/tel-00856598.

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This thesis was devoted to the development of innovative oral delivery systems for two different molecules. In the first part, microparticles (MPs) based on xylan and Eudragit® S-100 were produced and used to encapsulate 5-aminosalicylic acid for colon delivery. Xylan was extracted from corn cobs and characterized in terms of its physicochemical, rheological and toxicological properties. The polymeric MPs were prepared by interfacial cross-linking polymerization and spray-drying and characterized for their morphology, mean size and distribution, thermal stability, crystallinity, entrapment efficiency and in vitro drug release. MPs with suitable physical characteristics and satisfactory yields were prepared by both methods, although the spray-dried systems showed higher thermal stability. In general, spray-dried MPs would be preferable systems due to their thermal stability and absence of toxic agents used in their preparation. However, drug loading and release need to be optimized. In the second part of this thesis, oil-in-water microemulsions (O/W MEs) based on medium-chain triglycerides were formulated as drug carriers and solubility enhancers for amphotericin B (AmB). Phase diagrams were constructed using surfactant blends with hydrophilic-lipophilic balance values between 9.7 and 14.4. The drug-free and drug-loaded MEs presented spherical non-aggregated droplets around 80 and 120 nm, respectively, and a low polydispersity index. The incorporation of AmB was high and depended on the volume fraction of the disperse phase. These MEs did not reduce the viability of J774.A1 macrophage-like cells for concentrations up to 25 µg/mL of AmB. Therefore, O/W MEs based on propylene glycol esters of caprylic acid may be considered as suitable delivery systems for AmB.
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Sharp, Kathleen. "At the End of the Spectrum Next to Orange and Opposite Violet." 2017. http://scholarworks.gsu.edu/art_design_theses/228.

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Photography is an unstable medium, the repercussions of technological advancement are constantly redefining its capabilities. As an artist working in this medium, I have often found myself wrapped up in existential reflection over my work’s place within the discipline. With At the End of the Spectrum Next to Orange and Opposite Violet, I have narrowed my interests to focus on the phenomenon of light and the manipulation of color. I am creating work committed to the conceptual foundation that light constitutes the experience of a color. I have been working monochromatically to create images and videos in order to explore this idea of color as an experience. Throughout this document my research has opened a new way of thinking about the interactions of light, color, and the viewer.
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"Orange is my Favorite Color: An Autoethnographic Account of a Volunteer Educator in the American Prison System." Master's thesis, 2020. http://hdl.handle.net/2286/R.I.57390.

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abstract: The United States of America incarcerates more people than any other country in the world, with the rate of growth for the imprisonment for women being currently twice that of men. Despite these alarming numbers women are often deemed the forgotten population within the carceral system. Using feminist inquiry within an interpretivist framework, I employ an autoethnographic account to examine my experience as a volunteer educator within the American Prison system. The 'data' within the autoethnography include my thoughts, eventualities, and reflections that are analyzed through an iterative cycle. Due to the creative nature of this thesis, 'data' are represented through a series of concepts, including art, photographs, and shifting narratives that mediate the language between theory and the lived experiences of incarcerated women. The data within this thesis however are not mine alone, they are cogenerated with the women of the Perryville Correctional Facility. Using feminist-based practices the representations of incarcerated women come from the women themselves , thus serving as a method of survival, as a form of activism, and as a tool of healing and justice that is not linked to reform. This thesis serves to simultaneously challenge and contribute to the traditional scholarship surrounding female incarceration by centering the voices of incarcerated women, and in turn serving as a form of liberatory action.
Dissertation/Thesis
Masters Thesis Social Justice and Human Rights 2020
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Lee, Pei-Hsuan, and 李佩璇. "Theatrical Lighting Color Interaction within’ the Stage Composition-The Lighting Design of Orange Seller and the Elixir of Love." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/9cn95u.

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碩士
國立臺北藝術大學
劇場設計學系碩士班
104
This performance report aims to explore the theatrical lighting color interaction within’ the stage composition. Given that the development of theatrical lighting equipment is rapid, the light emitting diode (LED) is skillful using in the theatrical lighting. And the lighting designers often use the moving light in the performance. The color of theatrical lighting is getting more and more inexhaustible. Take two lighting design works for example - and . The former was a performance combine with chinese comedy and play which focusing on the experiment of color on stage. In the whole project, color is the main theme. I use the color to create the different atmosphere of the scene. The latter was a opera which focusing on the color connection of stage and lighting. Try to balance the stage composition.
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Yi-HuaHung and 洪逸樺. "Single-phased white-light-emitting luminescence using color-tunable Dy3+/Tb3+ co-doped LiLa(MoO4)2:Sm3+ red-orange phosphors." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/ajc67m.

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Sekhon, Rajandeep Singh. "Investigation of molecular mechanisms of regulation of maize pericarp color1 by an epigenetic modifier unstable factor for orange1." 2007. http://etda.libraries.psu.edu/theses/approved/WorldWideIndex/ETD-2306/index.html.

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24

Silungwe, Henry. "Variation B-carotene content and physicochemical properties of orange-fleshed sweet potato (Ipomoea batatas (L.) Lam) cultivars grown in Limpopo Province, South Africa." Thesis, 2017. http://hdl.handle.net/11602/866.

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PhD (Agric) (Food Science and Technology)
Department Food Science and Technology
In recent years, there has been a lot of interest in orange fleshed sweet potato (OFSP) [Ipomoea batatas (L.) Lam] cultivar, as a cheaper source of vitamin A. In Southern Africa, reports have shown that one in every three children has deficiency in vitamin A. This study investigated the variations in β-carotene (vitamin A precursor) content among selected OFSP cultivars grown in Limpopo Province, South Africa. In addition, the study investigated the effects of location on functional properties, total carotenoids and antioxidant profile of the sweet potato flour as well as their physicochemical, functional and nutritional properties. Four (4) sweet potato cultivars [Dagga, Bophelo, Impilo (orange fleshed) and Mvuvhelo (cream fleshed)] were obtained from two locations, namely, University of Venda (Univen) agricultural experimental farm and Tshiombo irrigation scheme (Tshiombo) and analysed for pasting, functional, physicochemical and nutritional properties. The sweet potato flours from these two locations were also analysed by computed tomographic (CT) scans for flour particle density. Mineral and microstructure of OFSP flours were analysed by scanning electron microscope (SEM). All measurements, except the tristimulus L* a* b* and other colour parameters from five replicates, were performed in triplicate. Statistical analysis was performed using a one-way analysis of variance and means were separated using Duncan’s multiple range test; P < 0.05 was considered to be statistically significant. Pearson’s correlation coefficients were used to determine the correlation among functional, physicochemical, nutritional and pasting properties of sweet potato flour. β-carotene content varied significantly between the two locations from 70.98 ± 0.8 μg/g (Tshiombo) to 86.09 ± 2.0 μg/g (Univen), among cultivars from 1.71 ± 0.0 μg/g (Mvuvhelo) to 201.50 ± 1.0 μg/g (Dagga) and among orange fleshed (Dagga, Bophelo and Impilo) flours from 28.38 ± 0.2 μg/g (Impilo) to 201.50 ± 1.0 μg/g (Dagga). There was a similar trend in the contents of α-carotene to that of β-carotene from the two locations, which ranged from 0.63 ± 0.0 mol/L (Tshiombo) to 1.01 ± 0.0 mol/L (Univen). Mvuvhelo had significantly the lowest α-carotene content (0.50 ± 0.0 mol/L) and Impilo the highest (1.28 ± 0.0 mol/L). The total carotenoids was highest for Impilo (7.56 μg/g) and lowest for Mvuvhelo (1.33 ± 0.1 μg/g) but did not vary significantly (P > 0.05) between ii the locations. The antioxidant activity, based on 2, 2-diphenyl-1picrylhydrazyl (DPPH) free radical scavenging activity, was significantly highest in Bophelo (63.37 ± 0.8 mMAAE ml-1) and lowest in Dagga (26.93 ± 1.4 mMAAE ml-1) flours. The ferric reducing antioxidant power (FRAP) varied significantly across the locations and among the cultivars and ranged from 14.45 ± 0.3 μMTE ml-1 (Tshiombo) to 17.40 ± 1.1 μMTE ml-1 (Univen). FRAP was significantly highest in Impilo (21.12 ± 2.1 μMTE ml-1) and lowest in Mvuvhelo (8.16 ± 2.0 μMTE ml-1). Total carotenoid content positively correlated with DPPH (0.486*), FRAP (0.830**), β-carotene (0.370*), and α-carotene (0.424*). The antioxidant content and the radical scavenging activity were significantly correlated (0.563**). Vitamin A content was significantly lowest (6.88 ± 0.38 μg/g retinol) in Dagga flour and highest (7.97 ± 0.25 μg/g) in Impilo flour. Protein content varied significantly across the two locations and ranged from 4.23% (Tshiombo) to 7.16% (Univen). Dagga had significantly the lowest (3.47%) protein content while Impilo had the highest (7.53%). The fat content of the flours varied significantly between the two locations ranging from 0.63% (Tshiombo) to 1.01% (Univen). The protein content was positively correlated 0.594** and 0.421* to vitamin A and fat contents respectively. The Bophelo colour luminosity was significantly lower (L* 76.2) than the other two OFSP, Dagga (L* 83.51) and Impilo (L* 82.07). Bophelo a* (14.09) also differed significantly across all sweet potato cultivars. All cultivars differed significantly in b* values. Colour intensity (ΔE*) ranged from 15.87 to 38.48 for Mvuvhelo and Bophelo, respectively. Chroma ranged from 87.52 to 84.95 for Dagga and Mvuvhelo respectively. Total starch content was significantly different in all sweet potato cultivars and ranged from 244.07 μg/100 g (Bophelo) to 325.04 mg/g (Dagga). Resistant starch differed significantly in all sweet potato cultivars ranging from 1.21 μg/100 g dwb (Bophelo) to 7.07 μg/100 g dwb (Impilo). Ash content was significantly different in all cultivars and ranged from 3.17% (Dagga) to 3.79% (Bophelo). Water holding capacity (WHC) varied significantly across the two locations and ranged from 1.44 g H2O/g DM (Tshiombo) to 1.72 g H2O/g DM (Univen). Bophelo had significantly the lowest (1.27 g H2O/g DM) WHC and Impilo the highest (1.99 g H2O/g DM). The ash content negatively correlated to total starch (-0.928**) but positively iii correlated to WHC (0.654**). Peak viscosity differed significantly across all cultivars under study and ranged from 126.54 RVU (Bophelo) to 302.36 RVU. (Dagga). There was significant difference in trough viscosity across all cultivars ranging from 55.97 RVU (Impilo) to 280.78 RVU (Dagga). There were significant differences in the final viscosity across all cultivars ranging from 78.99 RVU (Impilo) to 319.26 (Dagga). Peak time viscosity varied significantly across all cultivars ranging from 3.87 min (Impilo) to 8.47 min. (Bophelo). Dagga cultivar had significantly the highest pasting temperature (94.16oC) and Bophelo the lowest (77.75oC). The setback viscosity was significantly highest 51.10 RVU (Mvuvhelo) and lowest 23.01 RVU (Impilo). All cultivars from the two locations consistently showed high potassium content ranging from 0.46% (Impilo) to 1.38% (Dagga) as compared to other minerals such as magnesium, calcium and chlorine which ranged from 0.16% (Impilo) to 0.34%. (Dagga). The CT scans revealed that there was a possibility of evaluating the effect of location on the density of granules of sweet potato flour and also the inherent differences in granular distribution of various sweet potato cultivars. SEM revealed high amounts of potassium, magnesium and chlorine. A profile of physicochemical and functional properties of flour of some of the OFSP cultivars produced in Limpopo province, South Africa has been drawn. This study also highlights the nutritional quality of the flour from four sweet potato cultivars and provides a ranking of flour to help the producers in the selection process. Bophelo flour was ranked the highest in terms of β- and, α-carotenes, total carotenoids and antioxidant capacity while Impilo was ranked highest in terms of functional properties and ash content. This study has highlighted significant differences in a number of parameters measured among the sweet potato cultivars. Therefore, in order to derive the maximum benefit from aIn recent years, there has been a lot of interest in orange fleshed sweet potato (OFSP) [Ipomoea batatas (L.) Lam] cultivar, as a cheaper source of vitamin A. In Southern Africa, reports have shown that one in every three children has deficiency in vitamin A. This study investigated the variations in β-carotene (vitamin A precursor) content among selected OFSP cultivars grown in Limpopo Province, South Africa. In addition, the study investigated the effects of location on functional properties, total carotenoids and antioxidant profile of the sweet potato flour as well as their physicochemical, functional and nutritional properties. Four (4) sweet potato cultivars [Dagga, Bophelo, Impilo (orange fleshed) and Mvuvhelo (cream fleshed)] were obtained from two locations, namely, University of Venda (Univen) agricultural experimental farm and Tshiombo irrigation scheme (Tshiombo) and analysed for pasting, functional, physicochemical and nutritional properties. The sweet potato flours from these two locations were also analysed by computed tomographic (CT) scans for flour particle density. Mineral and microstructure of OFSP flours were analysed by scanning electron microscope (SEM). All measurements, except the tristimulus L* a* b* and other colour parameters from five replicates, were performed in triplicate. Statistical analysis was performed using a one-way analysis of variance and means were separated using Duncan’s multiple range test; P < 0.05 was considered to be statistically significant. Pearson’s correlation coefficients were used to determine the correlation among functional, physicochemical, nutritional and pasting properties of sweet potato flour. β-carotene content varied significantly between the two locations from 70.98 ± 0.8 μg/g (Tshiombo) to 86.09 ± 2.0 μg/g (Univen), among cultivars from 1.71 ± 0.0 μg/g (Mvuvhelo) to 201.50 ± 1.0 μg/g (Dagga) and among orange fleshed (Dagga, Bophelo and Impilo) flours from 28.38 ± 0.2 μg/g (Impilo) to 201.50 ± 1.0 μg/g (Dagga). There was a similar trend in the contents of α-carotene to that of β-carotene from the two locations, which ranged from 0.63 ± 0.0 mol/L (Tshiombo) to 1.01 ± 0.0 mol/L (Univen). Mvuvhelo had significantly the lowest α-carotene content (0.50 ± 0.0 mol/L) and Impilo the highest (1.28 ± 0.0 mol/L). The total carotenoids was highest for Impilo (7.56 μg/g) and lowest for Mvuvhelo (1.33 ± 0.1 μg/g) but did not vary significantly (P > 0.05) between ii the locations. The antioxidant activity, based on 2, 2-diphenyl-1picrylhydrazyl (DPPH) free radical scavenging activity, was significantly highest in Bophelo (63.37 ± 0.8 mMAAE ml-1) and lowest in Dagga (26.93 ± 1.4 mMAAE ml-1) flours. The ferric reducing antioxidant power (FRAP) varied significantly across the locations and among the cultivars and ranged from 14.45 ± 0.3 μMTE ml-1 (Tshiombo) to 17.40 ± 1.1 μMTE ml-1 (Univen). FRAP was significantly highest in Impilo (21.12 ± 2.1 μMTE ml-1) and lowest in Mvuvhelo (8.16 ± 2.0 μMTE ml-1). Total carotenoid content positively correlated with DPPH (0.486*), FRAP (0.830**), β-carotene (0.370*), and α-carotene (0.424*). The antioxidant content and the radical scavenging activity were significantly correlated (0.563**). Vitamin A content was significantly lowest (6.88 ± 0.38 μg/g retinol) in Dagga flour and highest (7.97 ± 0.25 μg/g) in Impilo flour. Protein content varied significantly across the two locations and ranged from 4.23% (Tshiombo) to 7.16% (Univen). Dagga had significantly the lowest (3.47%) protein content while Impilo had the highest (7.53%). The fat content of the flours varied significantly between the two locations ranging from 0.63% (Tshiombo) to 1.01% (Univen). The protein content was positively correlated 0.594** and 0.421* to vitamin A and fat contents respectively. The Bophelo colour luminosity was significantly lower (L* 76.2) than the other two OFSP, Dagga (L* 83.51) and Impilo (L* 82.07). Bophelo a* (14.09) also differed significantly across all sweet potato cultivars. All cultivars differed significantly in b* values. Colour intensity (ΔE*) ranged from 15.87 to 38.48 for Mvuvhelo and Bophelo, respectively. Chroma ranged from 87.52 to 84.95 for Dagga and Mvuvhelo respectively. Total starch content was significantly different in all sweet potato cultivars and ranged from 244.07 μg/100 g (Bophelo) to 325.04 mg/g (Dagga). Resistant starch differed significantly in all sweet potato cultivars ranging from 1.21 μg/100 g dwb (Bophelo) to 7.07 μg/100 g dwb (Impilo). Ash content was significantly different in all cultivars and ranged from 3.17% (Dagga) to 3.79% (Bophelo). Water holding capacity (WHC) varied significantly across the two locations and ranged from 1.44 g H2O/g DM (Tshiombo) to 1.72 g H2O/g DM (Univen). Bophelo had significantly the lowest (1.27 g H2O/g DM) WHC and Impilo the highest (1.99 g H2O/g DM). The ash content negatively correlated to total starch (-0.928**) but positively iii correlated to WHC (0.654**). Peak viscosity differed significantly across all cultivars under study and ranged from 126.54 RVU (Bophelo) to 302.36 RVU. (Dagga). There was significant difference in trough viscosity across all cultivars ranging from 55.97 RVU (Impilo) to 280.78 RVU (Dagga). There were significant differences in the final viscosity across all cultivars ranging from 78.99 RVU (Impilo) to 319.26 (Dagga). Peak time viscosity varied significantly across all cultivars ranging from 3.87 min (Impilo) to 8.47 min. (Bophelo). Dagga cultivar had significantly the highest pasting temperature (94.16oC) and Bophelo the lowest (77.75oC). The setback viscosity was significantly highest 51.10 RVU (Mvuvhelo) and lowest 23.01 RVU (Impilo). All cultivars from the two locations consistently showed high potassium content ranging from 0.46% (Impilo) to 1.38% (Dagga) as compared to other minerals such as magnesium, calcium and chlorine which ranged from 0.16% (Impilo) to 0.34%. (Dagga). The CT scans revealed that there was a possibility of evaluating the effect of location on the density of granules of sweet potato flour and also the inherent differences in granular distribution of various sweet potato cultivars. SEM revealed high amounts of potassium, magnesium and chlorine. A profile of physicochemical and functional properties of flour of some of the OFSP cultivars produced in Limpopo province, South Africa has been drawn. This study also highlights the nutritional quality of the flour from four sweet potato cultivars and provides a ranking of flour to help the producers in the selection process. Bophelo flour was ranked the highest in terms of β- and, α-carotenes, total carotenoids and antioxidant capacity while Impilo was ranked highest in terms of functional properties and ash content. This study has highlighted significant differences in a number of parameters measured among the sweet potato cultivars. Therefore, in order to derive the maximum benefit from a given cultivar careful selection of sweet potato cultivars would be necessary.
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