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

The blueberry : composition, anthocyanins, and polyphenolics /

Lee, Jungmin. January 2004 (has links)
Thesis (Ph. D.)--Oregon State University, 2004. / Printout. Includes bibliographical references. Also available via the World Wide Web.
32

Combinatory effects of the bioflavonoid apigenin with chemotherapeutic drugs on prostate, colon, and lung cancer cell lines

Lopez, Lesly Anne J. January 1900 (has links)
Thesis (M.S.)--West Virginia University, 2005. / Title from document title page. Document formatted into pages; contains viii, 14, [22] p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references.
33

Effects of shelf-life on phytonutrient composition in stored non-alcoholic beer

Majoni, Sandra. January 2006 (has links) (PDF)
Thesis PlanA (M.S.)--University of Wisconsin--Stout, 2006. / Includes bibliographical references.
34

Manipulation of Starch Digestibility in Particle Form

Dobson, Corrine 31 October 2019 (has links)
This work investigates ways to prevent and manage hyperglycemia using preventive nutrition. Uncontrolled and chronic hyperglycemia is a global health issue leading to many health problems including diabetes. This thesis details the manipulation of highly retrograded starch particles in order to produce particles that are digested slowly to release glucose at a prolonged and moderate rate to prevent this. The first section of this study utilized acid hydrolysis to alter starch structure and change digestibility. The hydrolysis treatment showed that hydrolysis of native starch prior to particle formation changed the structure in a way that increased digestibility. The second section of this work introduced polyphenols into the particles which only a marginal effect on digestion. Overall the actual process of retrograding and making the particles themselves appeared to create particles that were more resistant to digestion. These could be used in a product to deliver a moderate glycemic response.
35

Synthesis of Resveratrol Ester Derivatives

Ressler, Daniel 01 December 2013 (has links) (PDF)
The goal of this research project was to synthesize derivatives of transresveratrol. In order for resveratrol to be activated and used by the body it needs to bind to Human Serum Albumin (HSA), a protein in blood plasma. The derivatives were synthesized to improve the ability of resveratrol to enter cells as well as improve their ability to bind to HSA. The three derivatives that were synthesized have converted one of the hydroxyl groups on resveratrol to an ether with a methylene chain terminated by a carboxylic acid. By varying the lengths of the methylene chain we varied the water solubility of the resveratrol derivative. This brought the research closer to the goal of determining how this would affect the binding ability to HSA. Currently three derivatives have been synthesized and purified once by column chromatography.
36

Effect of Rooibos preparation on the total polyphenol content and antioxidant capacity of herbal tea and its consumer characteristics

Piek, Hannelise January 2016 (has links)
Thesis (MTech (Consumer Science: Food and Nutrition))--Cape Peninsula University of Technology, 2016. / Background: The different types and forms of rooibos and the ways in which it is prepared and flavoured for consumption influences its total polyphenol content and total antioxidant capacity (TAC) and hence depends on its consumer practices. Design: Phase 1 of the study entailed the selection and preparation of different rooibos types and forms; rooibos brewed for different times; and with different household and commercially added flavourings to determine the total polyphenol content, TAC, flavonol and flavanol content; and subsequent identification of the optimal cup of rooibos based on the first two biochemical parameters. For Phase 2 a questionnaire was used to obtain information on the profile of the adult rooibos herbal tea consumer, as well as of those consuming the optimal cup of rooibos. Results: The following prepared rooibos samples delivered the higher biochemical parameter content: green / unfermented (type representative); green / unfermented leaves and powdered extract (form representatives); that brewed for 10 minutes or longer; and those with added honey. The optimal cup of rooibos was identified as the one brewed for 10 minutes or longer. The older respondents and those with a lower level of education consumed a higher daily amount of rooibos (p < 0.05) and those who brewed rooibos in a teapot consumed the optimal cup (p < 0.05). However, very few respondents consumed the advised number of cups per day (< 1%) and the identified optimal cup (15.9%). Conclusions: Rooibos consumers in this study did not consume it in sufficient amounts and did not brew it for long enough to fully gain from its attributed health benefits.
37

Extractable and Non-Extractable Polyphenols from Apples: Potential Anti-inflammatory Agents

Gennette, MaKenzi 27 October 2017 (has links) (PDF)
With diet being such a huge factor in the development of diseases, emerging research has supported that apple consumption is a promising candidate for disease prevention due to the high phenolic content it possesses. These polyphenols can be found in two forms: extractable polyphenols (EP) and non-extractable polyphenols (NEP). Polyphenols have been shown to have strong anti-inflammatory and anti-oxidant properties, but up until this point, most researchers focus on EP fractions, while NEP are neglected. After the EP extraction using acetone and acetic acid (99:1) from the Apple Boost powder, three additional extraction methods were conducted on the remaining powder residue to extract the NEP. These extractions put the residue in three different environments for hydrolysis to compare their extraction abilities: enzyme, alkaline, and acid. After analyzing the EP and NEP total phenolic content (TPC) levels, oxygen radical absorbance capacity (ORAC) assay was conducted to measure anti-oxidation capacity of each extraction, and in vitro anti-inflammatory assay was performed to evaluate the anti-inflammation capacity of each extraction where inflammation was induced by LPS. The results showed that the NEP obtained from acid hydrolysis had the highest readings in both the TPC and ORAC assay, but did not show any anti-inflammatory effects in vitro. The EP extraction had the second highest readings in the TPC, ORAC and anti-inflammatory assays. The NEP enzyme extraction had the second lowest TPC and ORAC assay performance, but highest performance in the anti-inflammatory assay. The NEP alkaline extraction had the lowest TPC and performed poorly in both the anti-inflammatory assay and ORAC assay.
38

Phenolic and polyphenolic compounds of wheat (Triticum spp.) : extraction and antioxidative properties /

Liyanapathirana, Chandrika M., January 2005 (has links)
Thesis (Ph.D.)--Memorial University of Newfoundland, 2005. / Bibliography: leaves 203-239.
39

Physicochemical properties and phenolic composition of selected Saskatchewan fruits : buffaloberry, chokecherry and sea buckthorn

Green, Richard Christopher 31 July 2007
There is increasing interest in the commericalization of native fruits for utilization as foods and medicinal extracts. This study was undertaken to determine the physicochemical properties and phenolic composition of selected Saskatchewan native fruits, including buffaloberry (<i>Shepherdia argentea</i> Nutt.), chokecherry (<i>Prunus virginiana</i> L.) and sea buckthorn (<i>Hippophae rhamnoides</i> L.). The physicochemical analyses included carbohydrate content, CIELAB colour values, organic acid composition, phenolic content, % seed, soluble solids, pH, total solids, total titratable acidity and proximate composition. Fruit samples were collected and analyzed over four crop years. The proanthocyanidin content was also determined photometrically after acid depolymerization in acid-butanol. Buffaloberry contained a proanthocyanidin concentration of 505 ± 32 mg/100 g fresh fruit and this level was 10 fold higher than that of chokecherry and sea buckthorn. Chokecherry was found to contain an anthocyanin concentration of 255 ± 35 mg/100 g fresh fruit, as determined using the pH differential method. Two high performance liquid chromatography (HPLC) methods were developed for simultaneous determination of seven phenolic classes, including anthocyanins, hydroxybenzoic acids, hydroxycinnamic acids, flavanols, flavanones, flavones and flavonols in aqueous methanol extracts. Based on the semi-quantitative analysis of the total phenolic chromatographic index (TPCI), chokecherry contained the highest levels of phenolic compounds with a concentration of 3,327 ± 469 µg/g fresh fruit followed by buffaloberry (578 ± 73 µg/g fresh fruit) and sea buckthorn (477 ± µg/g fresh fruit). The antioxdant activity of the fruit extracts was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2´-azinobis-3-ethylbenzthiazoline-sulphonic acid (ABTS) radical scavenging assays. Buffaloberry and chokecherry produced the highest radical scavenging activity and were at least five fold greater than that of sea buckthorn. The major radical scavenging compounds in buffaloberry were ascorbic acid and proanthocyanidins. Radical scavenging activity of chokecherry fruit was largely attributable to its anthocyanins, flavonols and hydroxycinnamic acids. Prominent antioxidants in sea buckthorn included ascorbic acid, proanthocyanidins and flavonols. Certain individual compounds in the phenolic extracts were identified by HPLC-photodiode array and HPLC-mass spectrometry. Rutin was found in all of the extracts. Other phenolic compounds identified included catechin in sea buckthorn, and chlorogenic acid and quercetin in chokecherry. The chokecherry fruit pigments were comprised of two major anthocyanins and these were identified as cyanidin 3-glucoside and cyanidin 3-rutinoside. A preparative scale purification method for these anthocyanins using centrifugal partition chromatography (CPC) was determined. Under the CPC conditions employed, cyanidin 3-glucoside and cyanidin 3-rutinoside were purified to concentrations of 84 and 90%, respectively.
40

Physicochemical properties and phenolic composition of selected Saskatchewan fruits : buffaloberry, chokecherry and sea buckthorn

Green, Richard Christopher 31 July 2007 (has links)
There is increasing interest in the commericalization of native fruits for utilization as foods and medicinal extracts. This study was undertaken to determine the physicochemical properties and phenolic composition of selected Saskatchewan native fruits, including buffaloberry (<i>Shepherdia argentea</i> Nutt.), chokecherry (<i>Prunus virginiana</i> L.) and sea buckthorn (<i>Hippophae rhamnoides</i> L.). The physicochemical analyses included carbohydrate content, CIELAB colour values, organic acid composition, phenolic content, % seed, soluble solids, pH, total solids, total titratable acidity and proximate composition. Fruit samples were collected and analyzed over four crop years. The proanthocyanidin content was also determined photometrically after acid depolymerization in acid-butanol. Buffaloberry contained a proanthocyanidin concentration of 505 ± 32 mg/100 g fresh fruit and this level was 10 fold higher than that of chokecherry and sea buckthorn. Chokecherry was found to contain an anthocyanin concentration of 255 ± 35 mg/100 g fresh fruit, as determined using the pH differential method. Two high performance liquid chromatography (HPLC) methods were developed for simultaneous determination of seven phenolic classes, including anthocyanins, hydroxybenzoic acids, hydroxycinnamic acids, flavanols, flavanones, flavones and flavonols in aqueous methanol extracts. Based on the semi-quantitative analysis of the total phenolic chromatographic index (TPCI), chokecherry contained the highest levels of phenolic compounds with a concentration of 3,327 ± 469 µg/g fresh fruit followed by buffaloberry (578 ± 73 µg/g fresh fruit) and sea buckthorn (477 ± µg/g fresh fruit). The antioxdant activity of the fruit extracts was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2´-azinobis-3-ethylbenzthiazoline-sulphonic acid (ABTS) radical scavenging assays. Buffaloberry and chokecherry produced the highest radical scavenging activity and were at least five fold greater than that of sea buckthorn. The major radical scavenging compounds in buffaloberry were ascorbic acid and proanthocyanidins. Radical scavenging activity of chokecherry fruit was largely attributable to its anthocyanins, flavonols and hydroxycinnamic acids. Prominent antioxidants in sea buckthorn included ascorbic acid, proanthocyanidins and flavonols. Certain individual compounds in the phenolic extracts were identified by HPLC-photodiode array and HPLC-mass spectrometry. Rutin was found in all of the extracts. Other phenolic compounds identified included catechin in sea buckthorn, and chlorogenic acid and quercetin in chokecherry. The chokecherry fruit pigments were comprised of two major anthocyanins and these were identified as cyanidin 3-glucoside and cyanidin 3-rutinoside. A preparative scale purification method for these anthocyanins using centrifugal partition chromatography (CPC) was determined. Under the CPC conditions employed, cyanidin 3-glucoside and cyanidin 3-rutinoside were purified to concentrations of 84 and 90%, respectively.

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