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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.
161

The Use and Knowledge of Olive Oil and Other Lipids in a Collegiate Student Population

Benyazza, Samir 21 May 2010 (has links)
Purpose: Evidence suggests that olive oil consumption is associated with a decreased prevalence of cardiovascular disease and certain cancers. The purpose of this study was to assess the intake and knowledge of olive oil and other lipids in a collegiate population. Methods: Using an IRB-approved protocol, volunteered college students (N=56) from the college of Health and Human Sciences at Georgia State University completed a questionnaire on lipid and knowledge and eating behavior. Results were assessed to determine if students were able to accurately answer questions on the contents of different lipids, and also to determine the consumption behaviors of different lipids. Statistical comparisons were made between undergraduate and graduate students, and between students in different academic majors (nutrition, nursing, respiratory therapy, social work, criminal justice, and other). Results: It was hypothesized that eating behaviors would overemphasize unhealthy lipids. Lipids assessed included: olive oil, butter, canola oil, peanut oil, corn oil, margarine, sunflower oil, and soybean oil. There were no statistically significant differences between the ratios of consumed lipids labeled as ‘good’, and lipids labeled as ‘bad’. There were also no statistically significant differences in the presence of ‘good’ to ‘bad’ lipids in the subjects’ kitchens. Therefore, the results of this study were not able to disprove the null hypothesis. Nevertheless, using a Likert scale response scheme, there was a difference (p=0.041) between academic majors in the consumption of canola oil (an oil high in monounsaturated fatty acid), with Nursing majors reporting the highest consumption (X=3.73; SD=1.61) and Respiratory Therapy majors reporting the lowest consumption (X=1.89; SD=1.53). There was no statistically significant difference between graduate and undergraduate students in the presence of lipids in the kitchen. It was hypothesized that subject knowledge of lipid constituents would be poor. The majority of subjects either failed to respond correctly to the constituents of different lipids or reported that they did not know. Based on this result, the study is able to reject the lipid knowledge null hypothesis. There were clear differences in subgroup knowledge of commonly consumed lipids. Most notably, 100% of nutrition students responded correctly to the constituents of olive oil. Conclusions: This study focused on a group of college students in the College of Health and Human Sciences. One might assume that such a population would be sensitive and knowledgeable about key dietary factors that may influence disease risk. Nevertheless, these findings indicate that, except for isolated exceptions, the eating behaviors and lipid knowledge of these students in not at a level that could be considered health promoting. This suggests that, even with students in the health sciences, personal health classes are likely to be beneficial in reducing disease prevalence.
162

Amelioration of oxidative stress in human endothelial cells by caffeic acid phenethyl ester (CAPE) and fluorinated derivatives (FCAPES) and pharmacokinetic characterization of CAPE and FCAPE in rats

Wang, Xinyu, 1974 Aug. 12- 29 August 2008 (has links)
Tissue ischemia is a major cause of morbidity contributing to disease processes such as cardiovascular diseases, stroke, cancer, and traumatic injury and may lead to death. Failure to quickly reestablish flow to ischemic tissue results in tissue death. However, even timely return to normal flow has a downside in that the reintroduction of oxygen to ischemic tissue results in ischemia/reperfusion (I/R) injury that produces an oxidant stress. This pathological process requires new therapeutic strategies and agents to reduce the personal, social and economic loss. One of the most generally accepted mechanisms for the pathology of I/R injury is the production of the reactive oxygen species (ROS), suggesting antioxidants may ameliorate I/R injury. Caffeic acid phenethyl ester (CAPE), a plant derived polyphenolic compound, has been shown to protect organs from I/R induced damage in vivo, and this effect has been attributed to its antioxidant activity. To better understand the mechanism of CAPE protection, a model using menadione-induced oxidative stress in human endothelial cells to simulate I/R injury in vitro was developed. Gene expression analysis was performed with microarrays undergoing cytoprotection with CAPE. The dose-dependent cytoprotection of CAPE has been related to its induction of heme oxygenase-1 (HO-1). With the aim of improving the beneficial effect of CAPE and understanding structure activity relationship, six new catechol ring-fluorinated CAPE derivatives were synthesized and evaluated in the menadione-endothelial cell model. The data suggest good cytoprotective effects of CAPE and some analogues and indicate important structural features for cytoprotection. Further investigation of the mechanism of cytoprotection showed that cytoprotection profiles of CAPE and derivatives correlate better to their ability to induce HO-1 in human endothelial cells than free radical scavenging activity. One CAPE derivative (FCAPE) with cytoprotective effects similar to CAPE in vitro exhibited better stability in rat plasma. A validated ultra-performance liquid chromatography/tandem mass spectrometric method was developed that allowed for quantification of CAPE and FCAPE in plasma samples. Pharmacokinetic studies in male Sprague Dawley rats following intravenous bolus administration of 5, 10, and 20 mg/kg CAPE and 20 mg/kg FCAPE were performed. The results indicate that dose proportionality for CAPE does not exist in the dose range studied. Although the elimination half life was found not to be significant different between CAPE and FCAPE, significant difference was observed between the total body clearance of FCAPE and CAPE which may due to the difference in volume of distribution.
163

Antioksidacinio poveikio preparatų su juodųjų serbentų (Ribes nigrum L.) uogų ekstraktu tyrimas ir vertinimas / Development and evaluation of antioxidant preparations containing black currant (Ribes nigrum L.) berries extract

Kasparavičienė, Giedrė 26 January 2006 (has links)
Growing numbers of morbidity and mortality due to the cancer and coronary heart disease is recognized as the increasing challenge in the world. The initial stage of these diseases, early diagnosis and treatment are the main objectives of current researches. According to Lithuanian Health Information Centre morbidity and mortality due to these diseases in Lithuania exceed average of European Union. The oxidative stress occurs in cells as a result of normal physiological processes and environmental interactions, and the complex antioxidant defense system are of particular importance in protecting biological systems against oxidative damage by free radicals. Recently polyphenols and anthocyanins containing foods and preparations have attracted attention due to their health promoting benefits. Anthocyanins make one of the main groups of flavonoids, and represent polyphenolic compounds, that are found in vegetables and fruits, particularly in berries. An important effect of anthocyanins is the scavenging of oxygen-derived free radicals. They can interfere with few different free radical-producing systems, and can increase the function of the endogenous antioxidants. The aim of the research is to choose sources for the products with antioxidant activity from plants cultivated in Lithuania, evaluate quality and antioxidant activity of black currant, red currant and chokeberry products, to develop and evaluate technologies of phytopharmaceuticals with antioxidant activity... [to full text]
164

Polyphénols de l'alimentation : extraction, pouvoir antioxydant et interactions avec des ions métalliques

Achat, Sabiha 24 November 2013 (has links) (PDF)
Les polyphénols sont des métabolites secondaires de végétaux abondants dans l'alimentation. Les extraire dans des conditions efficaces et mieux comprendre leurs propriétés physico-chimiques modulant leurs activités possibles dans le tractus digestif, constituent des enjeux scientifiques importants qui sont à la base de ce travail. La première partie porte sur l'enrichissement de l'huile d'olive en polyphénols par transfert direct de ces derniers des feuilles d'olivier à l'huile, sous irradiation ultrasonore en comparaison avec une macération conventionnelle. Après optimisation des paramètres d'extraction, la technique sous-ultrason à 16°C s'est révélée plus efficace que le procédé conventionnel du laboratoire (réacteur de 3 L) à l'échelle pilote industriel (réacteur de 30L). Dans la seconde partie, la réactivité de polyphénols communs et représentatifs des principales classes(rutine, quercétine, catéchine, acide chlorogénique et phénols de l'olive) avec le radical DPPH* et les ions de métaux de transition d'intérêt biologique(FeII, FeIII, CuI, CuII), a été étudiée par spectroscopie UV-visible (études cinétiques), par CLUP-SM (analyse de produits d'oxydation) et au moyen des tests colorimétriques permettant de préciser l'état redox des ions métalliques. L'étude de l'activité antiradicalaire (test DPPH*) en milieu micellaire aqueux a confirmé la capacité antioxydante des polyphénols sélectionnés en présence et en absence de la protéine sérum albumine bovine (SAB) etd'un modèle d'amidon (β-cyclodextrine). L'étude de la capacité des composés phénoliques à complexer les ions métalliques, en solution faiblement acide (pH= 5-6), a suggéré que les flavonols et acides hydroxycinnamiques sont susceptibles de complexer Fe III dès le compartimen tgastrique quand le pH est faiblement acide (1-2 h après le repas). Par contre, l'interaction avec Fe II et les ions du cuivre est probablement négligeable.L'interaction Fe III - polyphénol conduit à des complexes stables (sans oxydation notable du polyphénol) mais peut être inhibée par les interactionspolyphénol-protéine
165

The association between black tea consumption and iron status of African women in the North West Province : THUSA study / L. Muller

Muller, Lizanne January 2005 (has links)
Motivation: A variety of factors including food shortage, poor hygiene and low education levels affects the nutritional status of black women. Women also have a high risk for the development of iron deficiency because they lose iron through menstruation, the birth process and a low intake of iron containing foods. All of these factors contribute to an increased risk for the development of iron deficiency anaemia in women. Objectives: The primary purpose of the study was to investigate the association between tea consumption and iron status of African females in the North West Province. To reach this purpose the specific aims were to (1) assess the iron status of women, (2) determine tea intake, and (3) determine the relationship between tea consumption and iron status, taking into account inhibiting and enhancing factors of iron absorption. Methods: A cross-sectional sample of apparently healthy females was taken from five different strata of urbanisation. The subjects were then further divided into two groups, namely younger women (younger than 45.9 years) and older women (older than 46 years). A sample of 920 subjects was used. Data were obtained from dietary, demographic and additional questionnaires, as well as from the taking of blood samples. This study was a sub-study of the THUSA study. Results: A total of 920 subjects participated of which 69.24% were younger women and 30.76% were older women. Due to missing data, the number of subjects for each parameter differed. The mean serum ferritin as well as haemoglobin concentrations were within normal ranges for both groups. The mean dietary iron intake for both groups was below recommendations. No significant correlations were found between serum ferritin or haemoglobin and total tea intake as well as a variety of other dietary factors. The low haemoglobin concentration group of the younger and older women combined had a slightly higher intake of animal protein and ascorbic acid than the high haemoglobin concentration group. On the other hand, the high serum ferritin concentration group had a significantly higher intake of animal protein than the low serum ferritin concentration group. Conclusion: The results of this study indicated that tea does not have an inhibitory effect on the iron status of the female population of the North West Province. However, the investigation of other studies conducted on the same topic had mixed results. Two of seven studies investigated and this study indicated that tea had no inhibitory effect on iron absorption. These two studies, as well as this study were not done in a controlled environment where certain factors can be controlled for, for example, time of tea intake and milk consumption with tea. The other five studies were, however, conducted in an environment where subjects were given test meals, time of tea consumption was regulated and milk consumption with tea was recorded. The conclusion can, therefore, be made that further studies on the South African population in a controlled environment are necessary to give accurate recommendations to the population. / Thesis (M.Sc. (Dietetics))--North-West University, Potchefstroom Campus, 2005.
166

Oxidative Stress and the Risk of Osteoporosis: The Role of Dietary Polyphenols and Nutritional Supplements in Postmenopausal Women

Kang, Nancy 20 November 2012 (has links)
Previous findings have indicated that oxidative stress plays a role in the development of osteoporosis and that individual polyphenols, by virtue of their antioxidant properties, may mitigate these damaging effects. Nutritional supplements, greens+ bone builderTM, containing polyphenols and other micronutrients beneficial for bone health are of recent interest as complementary strategies in the management of osteoporosis. A randomized controlled study was conducted to explore the combined effects of the nutrients found within the supplement on bone health for 8 weeks. Total polyphenol content and antioxidant capacity increased whereas oxidative stress parameters and the bone resorption marker, crosslinked C-telopeptide of type I collagen decreased after supplementation. There was no significant change in the bone formation marker, procollagen type I N-terminal propeptide. This thesis shows an association of polyphenols with other micronutrients acts through their antioxidant capacity to decrease oxidative stress parameters and bone resorption, thus potentially reducing the risk for osteoporosis.
167

Oxidative Stress and the Risk of Osteoporosis: The Role of Dietary Polyphenols and Nutritional Supplements in Postmenopausal Women

Kang, Nancy 20 November 2012 (has links)
Previous findings have indicated that oxidative stress plays a role in the development of osteoporosis and that individual polyphenols, by virtue of their antioxidant properties, may mitigate these damaging effects. Nutritional supplements, greens+ bone builderTM, containing polyphenols and other micronutrients beneficial for bone health are of recent interest as complementary strategies in the management of osteoporosis. A randomized controlled study was conducted to explore the combined effects of the nutrients found within the supplement on bone health for 8 weeks. Total polyphenol content and antioxidant capacity increased whereas oxidative stress parameters and the bone resorption marker, crosslinked C-telopeptide of type I collagen decreased after supplementation. There was no significant change in the bone formation marker, procollagen type I N-terminal propeptide. This thesis shows an association of polyphenols with other micronutrients acts through their antioxidant capacity to decrease oxidative stress parameters and bone resorption, thus potentially reducing the risk for osteoporosis.
168

Evaluation of food matrix interactions and in vitro gastrointestinal digestion on the bioefficacy of polyphenols from blueberries (Vaccinium sp.)

Correa Betanzo, Julieta 16 May 2013 (has links)
Bluberries (Vaccinium sp.) are rich in polyphenols that are responsible for lowering the risk of developing several chronic degenerative diseases. However, the effect of food matrix interactions on the bioaccessibility and bioavailability of polyphenols is not well understood. In this research free and complexed polyphenols found in blueberry extracts were characterized and their antioxidant activity as well as antiproliferative activities against colon cancer cells (HT-29) and normal colon cells (CRL-1790) were evaluated. The blueberry food matrix and different carbohydrate-rich synthetic matrices were characterized and their biological activities assessed alone and in complexed state with polyphenols. The degradation of polyphenols during their transit through the gastrointestinal tract (GIT) was evaluated using an in vitro digestion model. Biological activities of blueberry polyphenols and their parent metabolites produced during colonic fermentation were estimated by in vitro antioxidant assays and cell proliferation analysis using HT-29 and CRL-1790 cell lines. HPLC analysis revealed the presence of 7 phenolic compounds and 13 anthocyanins in all samples. Although the concentration of the polyphenols varied among the samples, free and complexed polyphenols showed significant antioxidant and antiproliferative activities. Polyphenol complexes were analyzed using transmission electron microscopy (TEM) revealing the presence of electron dense complexes ranging from 100 – 200 nm. Pectinase treatment disrupted the structure of the complexes, suggesting the pectin nature of the polyphenol complexes. The antioxidant- and antiproliferative activities of the blueberry food matrix alone was below 10% compared to almost 90% and 70% of free and complexed polyphenols, respectively. Polyphenols and anthocyanins were highly stable during simulated gastric digestion step with approximately 93% and 99% of recovery, respectively. The intestinal digestion process decreased the polyphenol- and anthocyanin- contents by 49% and 15 % respectively. During colonic digestion, the complex polyphenol mixtures were degraded to a limited number of phenolic compounds. Only acetylated anthocyanins were detected in low amounts after the colonic digestion process. After simulated colonic digestion, the isolated catabolites showed lowered antioxidant activity and cell growth inhibition potential. Understanding the interactions that occur among polyphenols and different food matrices may help to produce more stable foods with better bioavailability. / The National Council of Science and Technology of Mexico (CONACYT)
169

The association between black tea consumption and iron status of African women in the North West Province : THUSA study / L. Muller

Muller, Lizanne January 2005 (has links)
Motivation: A variety of factors including food shortage, poor hygiene and low education levels affects the nutritional status of black women. Women also have a high risk for the development of iron deficiency because they lose iron through menstruation, the birth process and a low intake of iron containing foods. All of these factors contribute to an increased risk for the development of iron deficiency anaemia in women. Objectives: The primary purpose of the study was to investigate the association between tea consumption and iron status of African females in the North West Province. To reach this purpose the specific aims were to (1) assess the iron status of women, (2) determine tea intake, and (3) determine the relationship between tea consumption and iron status, taking into account inhibiting and enhancing factors of iron absorption. Methods: A cross-sectional sample of apparently healthy females was taken from five different strata of urbanisation. The subjects were then further divided into two groups, namely younger women (younger than 45.9 years) and older women (older than 46 years). A sample of 920 subjects was used. Data were obtained from dietary, demographic and additional questionnaires, as well as from the taking of blood samples. This study was a sub-study of the THUSA study. Results: A total of 920 subjects participated of which 69.24% were younger women and 30.76% were older women. Due to missing data, the number of subjects for each parameter differed. The mean serum ferritin as well as haemoglobin concentrations were within normal ranges for both groups. The mean dietary iron intake for both groups was below recommendations. No significant correlations were found between serum ferritin or haemoglobin and total tea intake as well as a variety of other dietary factors. The low haemoglobin concentration group of the younger and older women combined had a slightly higher intake of animal protein and ascorbic acid than the high haemoglobin concentration group. On the other hand, the high serum ferritin concentration group had a significantly higher intake of animal protein than the low serum ferritin concentration group. Conclusion: The results of this study indicated that tea does not have an inhibitory effect on the iron status of the female population of the North West Province. However, the investigation of other studies conducted on the same topic had mixed results. Two of seven studies investigated and this study indicated that tea had no inhibitory effect on iron absorption. These two studies, as well as this study were not done in a controlled environment where certain factors can be controlled for, for example, time of tea intake and milk consumption with tea. The other five studies were, however, conducted in an environment where subjects were given test meals, time of tea consumption was regulated and milk consumption with tea was recorded. The conclusion can, therefore, be made that further studies on the South African population in a controlled environment are necessary to give accurate recommendations to the population. / Thesis (M.Sc. (Dietetics))--North-West University, Potchefstroom Campus, 2005.
170

Development of a functional beverage from the Kei apple fruit Dovyalis caffra / M-J. Gore

Gore, Mary Jane Cook January 2005 (has links)
Interest has grown over the last two decades in the health benefits of polyphenols, with particular relation to degenerative diseases. The Kei apple (Dovyalis caffra) is an indigenous plant to South Africa, thought to be rich in polyphenols. This study aimed to produce a functional beverage from the Kei apple, with demonstrable nutritional benefits, which should also be found acceptable by consumers due to its sensory attributes. A long term aim of the study is to assist in improving income of farmers in rural and urban areas by encouraging the participation of small holders in growing the Kei apple for subsequent economic benefit. A thorough literature review was conducted on functional foods, trends for beverages, legislation and on polyphenols as a class of functional ingredients, specifically focusing on fruits and the fate of polyphenols in the body. A review of fruit processing procedures, preservation techniques and legislation, followed by new product development (NPD) and the types of consumers desiring functional foods were investigated as well as the role of sensory evaluation and consumer research were examined. Methods Kei apples were collected from two areas of South Africa, namely Bloemhof in the North West Province in the 200212003 growing season and from the Eastern and Western Cape in the 200412005 growing season. The first set of Kei apples were used to produce a prototype functional beverage, from which future development would take place. The second set of Kei apples were used for pulping on an industrial scale and then a small-scale commercial production batch of the Kei apple beverages for consumer panel testing was produced. Various flavours were used to mask the strong characteristic taste and aroma of the Kei apple for the beverage and these were narrowed down to apple, vanilla and mint 8. vanilla. Consumer panel testing was undertaken with 152 consumers with a pre-tested questionnaire using hedonic scales for overall acceptance, ranking for preference, a Fwd Action Rating Scale (FACT) for consumption intent, and a ranking test for purchase intent. All evaluations were carried out under strictly controlled sensory evaluation requirement and respondents were asked to fill in anonymous questionnaires at North West University, Potchefstroom Campus. Results and Discussion Statistical analysis of the results were determined by the Statistic* programme, version 7. In summary for all of the consumer testing, it was found that consumers regarded the apple flavoured Kei apple beverage statistically significantly more acceptable than the other flavours. The apple flavoured beverage was found to be rated practically significantly higher for the attributes of taste and overall acceptance, as well as for consumption intent, purchase intent and preference. There was, however, no significant differences in any of the attributes or evaluated consumption and purchase intent between the vanilla and mint & vanilla. The total polyphenols, determined by UV spectrophotometry as gallic acid equivalents per litre (GAE/I), were found to be slightly less then expected, with the apple and mint & vanilla showing similar results (as GAEII) 101.7 versus 106.1 for the latter two, whilst vanilla was 143.0 which may have been attributed to the vanillic acid molecule itself which also has a phenolic structure. This lower-than-expected level of total polyphenols may have been due to degradation during processing. There was a clear difference in the polyphenol content between the different harvests from the two regions. The former showed greater acidity as determined by total citric acid 4.81% w/w and sugar 16.3% versus 2.54% w/w and 8.4% This may be due to various factors of climate, soil and ripeness. For comparison purposes, a commercial product from the USA, Ocean Spray ® Cranberry, was also found to have more polyphenols present than the Kei apple beverage. This was also demonstrated by the amount of ascorbic acid, free and bound. The Kei apple beverage subjected to pasteurization probably lost most of its vitamin C content due to the heat treatment and the exposure to oxygen during pulping. Conclusion and Recommendations The development of a functional beverage from the Kei apple is feasible. As with most new product developments, further formulation modifications which are not insurmountable are required. The consumer panel was positive towards the apple flavoured beverage and this flavour should be taken forward for future development. The key stumbling block to the success of this project is the lack of an effective organizing body that could liaise with the growers to form a cooperative and provide a consistent supply of Kei apples. The effect of variations in harvesting time, soil conditions and climate must also be evaluated. The improvement of income of farmers may only be achieved by the involvement of other stake holders and the formation of a Kei apple grower's co-operative / Thesis (M.Sc. (Nutrition))--North-West University, Potchefstroom Campus, 2006.

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