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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.
111

Esterase inhibition by grapefruit juice and its components leads to newly identified drug interactions

Li, Ping, January 2006 (has links)
Thesis (Ph. D.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains xvii, 122 p. : ill. Includes abstract. Includes bibliographical references (p. 46-53).
112

The Circle of Life in Network Marketing Relationships : A Case Study of Tahitian Noni International

Bråneryd, Camilla, Friberg, Tobias January 2008 (has links)
The marketing industry is moving towards customer centric marketing where it is important to establish and maintain relationships with customers. This need is even more crucial for a network marketing company which relies solely on relationships. The purpose of this thesis is to identify how a network marketing company establishes and maintains relationships with independent product consultants (IPC). This study was conducted by interviewing seven IPCs from the network marketing company Tahitian Noni International (TNI). The investigation shows that the main reasons for joining are either the business opportunity or the product. The relationship is maintained through various communication channels.
113

Effects of thermal processing on antioxidant, phenolic and anthocyanin levels in blackcurrant juice

Skahill, Bridget A. January 2009 (has links)
Thesis (M.S.)--Rutgers University, 2009. / "Graduate Program in Food Science." Includes bibliographical references (p. 53-56).
114

The breakdown of ascorbic acid at different temperatures and amounts of dissolved oxygen in orange juice

Ogsäter, Jens January 2014 (has links)
Vitamin C is an essential water soluble vitamin found mainly in fruits, vegetables and their derivatives. Orange juice is a popular thirst quencher and a convenient way to reach the daily recommended intake of vitamin C. The aim of this thesis was to determine how the vitamin C content in orange juice is affected by storage temperature and oxygen content in the product. Bottles of orange juice were stored at different temperatures. Regular orange juice was compared to juice where dissolved oxygen in product water had been decreased before mixing the juice. One other aim was to determine the efficiency of a stress test room where a higher temperature was supposed to simulate longer storage time. The study showed a larger non-linear loss of vitamin C over time in the bottles stored at the higher temperatures. The samples with less dissolved oxygen showed a higher vitamin C content after five and six months of storage in room temperature. For a storage time up to one week the loss of vitamin C in the stress test does not appear to be equal to the corresponding storage time in room temperature.KeywordsOrange juice, / Vitamin C är en livsnödvändig vattenlöslig vitamin som främst förekommer i grönsaker, frukter och produkter framställda från dessa. Apelsinjuice är en populär törstsläckare och ett enkelt sätt att få i sig sin dagliga dos C-vitamin. Syftet med denna rapport är att undersöka hur halten C-vitamin i apelsinjuice från Kiviks Musteri ändras beroende på lagringstemperatur och syrehalt i produktvatten. Apelsinjuice tillverkad från kranvatten jämfördes med juice tillverkad med vatten där syrehalten minskats genom kokning. Ett annat syfte var att fastställa effektiviteten för ett lagringsrum som simulerade en längre lagringsperiod genom att höja temperaturen. Resultaten visade att det var en större ickelinjär förlust av C-vitamin i flaskor som lagras vid en högre temperatur. Juiceflaskor med mindre mängd löst syre visade en lägre förlust av C-vitamin efter fem respektive sex månaders lagring i rumstemperatur. Förlusten av C-vitamin i juice lagrad en vecka i rummet med högre temperatur var ej den mängd som förutspåddes enligt företagets modell.
115

The pharmacokinetic interaction between cyclosporine and methoxsalen / Máralien Bouwer

Bouwer, Máralien January 2003 (has links)
Cyclosporine forms the cornerstone of therapy to prevent rejection after organ transplantation. However, the clinical use of the drug is compromised by a narrow therapeutic window and a wide inter- and intra-individual variation in metabolism. Cyclosporine is metabolised by the CYP3A4 isoenzymes in both the liver and intestine, while it has been reported that the metabolism of the drug can be inhibited by certain furocoumarin derivatives in grapefruit juice. Methoxsalen (8-methoxypsoralen) is a furocoumarin and a potent inhibitor of the cytochrome P450 system in both the liver and intestine. The study was conducted to investigate the possibility whether methoxsalen may inhibit the metabolism of cyclosporine and thereby increase the bioavailability of the drug. The interaction is of clinical relevance since both drugs are used in the treatment of psoriases. The study, conducted in 12 healthy male volunteers, was a three-way comparative bioavailability study with a wash out period of one week between treatments. The patients received 40 mg methoxsalen, 200 mg cyclosporine or a combination of the two on three separate occasions. Blood samples of 10 ml were collected by venupuncture at the following times: 0, 0.5, 1, 1.5, 2, 2.5, 3.4, 5,6, 8, 12 and 24 hours after drug administration. Methoxsalen was analysed by a high pressure liquid chromatograph method (HPLC) with UV detection (LOQ = 10 ng/ml), while cyclosporine was analysed using a fluorescence polarisation immunoassay (FPIA) technique. There was a statistical significant difference in AUCo-00 and Cmax ' for cyclosporine when methoxsalen was added to the drug regimen. When the methoxsalen levels were compared with those in the presence of cyclosporine, the levels were lower, although the difference was not statistical significant. We conclude that methoxsalen increase the levels of cyclosporine by inhibiting the P450 system enzymes in the liver and intestine. However, the absorption of methoxsalen is highly variable in the same individual which needs to be considered before this interaction can be regarded as being of any clinical relevance. / Thesis (M.Sc.(Pharmacology))--North-West University, Potchefstroom Campus, 2004.
116

Initial adhesion of EPS producing bacteria Burkholderia cepacia – the impact of cranberry juice

Yang, Xuejiao Unknown Date
No description available.
117

Spray drying of fruit juice with vegetable fibre as a carrier

Cheuyglintase, Kloyjai January 2009 (has links)
The production of free flowing powder by spray drying of sugar-acid rich foods requires an appropriate carrier. High molecular weight materials such as maltodextrins are commercially used as a drying aid because of their high glass transition temperature (Tg). Alternatively, fibre-rich by-products from fruit and vegetable juice processing might provide high molecular weight elements that are suitable as a drying support. This study aimed to understand the variables affecting the spray-dried product of fruit juice so that non-sticky fibre-based juice powder could be obtained. Freeze dried carrot fibre was centrifically-milled to 50-100 µm sizes. Three sugar determination methods; enzymatic, enzyme membrane and HPLC with RID, were compared. The freeze drying performance of fructose, fructose + carrot fibre and fructose + carrot fibre + malic acid had the glass transition temperatures measured by differential scanning calorimetry (DSC) at 0.1 °C min-1. The results from the freeze drying were used as a key for the possibility of spray dried apple juice + carrot fibre. Similar methods were used to study freeze dried fructose + maltodextrin (DE max 9.8) and fructose + maltodextrin + malic acid. Dried sucrose, glucose and fructose were used to study glass transition temperature of melted amorphous sugars and mixtures by the visual experiment and DSC at 0.1°C min-1 of heating and cooling scans. The Gordon-Taylor equation was used to predict the Tg of anhydrous two-sugar mixtures from experimental and literature data. The Coachman and Karaze equation was used to predict Tg of three-sugar mixtures and compared to the experimental data. Spray dried powders of fructose + carrot fibre of 30, 40, 50, 60 and 70% w/w and apple juice concentrate + carrot fibre of 30, 40, 50, 60, 70% w/w at 165/75°C inlet/outlet temperature in a laboratory scale drier were compared to that of fructose + maltodextrin (DE max 9.8) and apple juice concentrate + maltodextrin of 50, 60 and 70% w/w (dry basis). Dielectric analysis in the range 200 Hz -1 MHz between 10-105 °C were applied to find the onset Tg (based on DSC results) from freeze dried mixtures of 14, 21, and 28% w/w (dry basis) carrot fibre+ fructose. The enzymatic method was found to be the most accurate method for sugar determination of fruit juice but the HPLC method was the most practical one. The results of Tg values of sugars and mixtures melted showed that the Tg values from heating and cooling scans of fructose, glucose and sucrose were in good agreement with literature. Fructose acted as a plasticizer; an increase in the fructose fraction decreased the Tg of sugar mixtures. Sucrose increased the Tg of the mixtures while the Tg of the three-sugar mixtures was less variable when there was a moderate to high proportion of glucose. The visual Tg values of sugars and mixtures were 7-28 °C higher than the onset DSC heating and cooling Tg values. This result suggested that more than one method should be used to study the glass transition of substances. The Gordon-Taylor equation did not fit well the Tg values of the dry sugars and their mixtures from this experiment. The variations might have been due to the degradation of sugar samples on the melting process. The Coachman and Karaze equation gave a good prediction of the three-sugar mixtures from this experiment. The carrot fibre was found to be crystalline. Carrot fibre increased the Tg of freeze dried fructose and decreased stickiness of fructose. Increasing malic acid fraction decreased Tg of the mixtures. Freeze dried fructose + maltodextrin showed higher hygroscopicity than freeze dried fructose + carrot fibre. It was not possible to determine Tg of fructose + maltodextrin + malic acid due to the swelling and hygroscopicity of the freeze dried samples. Tg values of freeze dried fructose + carrot fibre and fructose + maltodextrin were found to high enough to allow spray drying of these mixtures. The minimum fraction of carrot fibre to facilitate spray drying of fructose and apple juice concentrate was found to be 30%. Mixtures with maltodextrin at a fraction lower than 50% could not be successfully spray dried. When spray drying fructose + carrot fibre, apple juice + carrot fibre, fructose + maltodextrin and apple juice + maltodextrin at the appropriate ratios most of the powder stuck to the drier walls. The powder swept from the wall was free flowing with moisture content of approximately 2-4%. The Tg values of these powder indicated the wall build-up might be avoided in larger scale drying. Tg values of spray dried powder from the mixtures with fibre and maltodextrin were found to be not very different. The yield from mixtures with carrot fibre was three times higher than those of mixtures with maltodextrin. This cast doubts that Tg alone could be a good indicator for the stickiness of spray dried material. The microscope images and DSC scans of spray dried powders of fructose + carrot fibre and apple juice + carrot fibre showed crystalline material. The particle of spray dried fructose + maltodextrin and apple juice + maltodextrin were mostly amorphous. The crystals are more physically and chemically stable than the amorphous form. Thus carrot fibre is a good additive in spray drying of fruit juice. Dielectric analysis at low frequency was able to possible detect Tg of single and double components. For food polymer with many components it was found that Tg value was not consistently dependent on frequency. In conclusion, carrot fibre was a more effective carrier for spray drying than maltodextrin when compared on a mass basis and spray drying condition. Since edible fibre is an essential element needed by the human body, spray drying of fruit juice using fibre as a carrier showed the great potential of fibre in the application of fruit juice spray drying. In the case of clear juice, after reconstitution, the fibre can be easily separated from the juice as there seemed to be no chemical binding between the juice and the fibre during the spray drying process.
118

The pharmacokinetic interaction between cyclosporine and methoxsalen / Máralien Bouwer

Bouwer, Máralien January 2003 (has links)
Cyclosporine forms the cornerstone of therapy to prevent rejection after organ transplantation. However, the clinical use of the drug is compromised by a narrow therapeutic window and a wide inter- and intra-individual variation in metabolism. Cyclosporine is metabolised by the CYP3A4 isoenzymes in both the liver and intestine, while it has been reported that the metabolism of the drug can be inhibited by certain furocoumarin derivatives in grapefruit juice. Methoxsalen (8-methoxypsoralen) is a furocoumarin and a potent inhibitor of the cytochrome P450 system in both the liver and intestine. The study was conducted to investigate the possibility whether methoxsalen may inhibit the metabolism of cyclosporine and thereby increase the bioavailability of the drug. The interaction is of clinical relevance since both drugs are used in the treatment of psoriases. The study, conducted in 12 healthy male volunteers, was a three-way comparative bioavailability study with a wash out period of one week between treatments. The patients received 40 mg methoxsalen, 200 mg cyclosporine or a combination of the two on three separate occasions. Blood samples of 10 ml were collected by venupuncture at the following times: 0, 0.5, 1, 1.5, 2, 2.5, 3.4, 5,6, 8, 12 and 24 hours after drug administration. Methoxsalen was analysed by a high pressure liquid chromatograph method (HPLC) with UV detection (LOQ = 10 ng/ml), while cyclosporine was analysed using a fluorescence polarisation immunoassay (FPIA) technique. There was a statistical significant difference in AUCo-00 and Cmax ' for cyclosporine when methoxsalen was added to the drug regimen. When the methoxsalen levels were compared with those in the presence of cyclosporine, the levels were lower, although the difference was not statistical significant. We conclude that methoxsalen increase the levels of cyclosporine by inhibiting the P450 system enzymes in the liver and intestine. However, the absorption of methoxsalen is highly variable in the same individual which needs to be considered before this interaction can be regarded as being of any clinical relevance. / Thesis (M.Sc.(Pharmacology))--North-West University, Potchefstroom Campus, 2004.
119

Initial adhesion of EPS producing bacteria Burkholderia cepacia the impact of cranberry juice

Yang, Xuejiao 11 1900 (has links)
The impact of cranberry juice was investigated with respect to the initial adhesion of three isogenic Burkholderia cepacia bacteria with different extracellular polymeric substance (EPS) producing capacities: a wild-type cepacian EPS producer PC184, mutant bacteria PC184rml with reduced EPS production, and PC184bceK with a deficiency in EPS production. Adhesion experiments demonstrated that in the presence of cranberry juice, the adhesive capacity of PC184 was largely reduced, while cranberry juice had little impact on the adhesion of either mutant. Thermodynamic modeling supported results from adhesion experiments. For PC184, the surface free energy change Gadh switched from negative in the absence of cranberry juice to positive when cranberry juice was added. Surface force apparatus (SFA) and scanning electron microscopy (SEM) studies demonstrated strong adsorption of cranberry juice components to bacterial EPS. It was concluded that cranberry juice components could impact bacterial initial adhesion by adhering to EPS and impairing bacterial adhesive capacity. / Environmental Engineering
120

The vitamin C value of commercially canned tomato juice

Webb, Iva Nellie 06 1900 (has links)
Graduation date: 1936

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