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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

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.
112

An investigation of the role of the adhesive in the structure of pigment-adhesive films

Burke, James L. 01 January 1966 (has links)
No description available.
113

Isolation and Characterization of a new thermotolerant pigment- producing microalga: Salt stress enhances pigment and oil biosynthesis in Coelastrella sp.F50

Hu, Che-Wei 22 August 2012 (has links)
A new species of reddish-orange pigment-producing microalga was isolated from a shallow pond in tropical Taiwan. Morphological and molecular evidence including meridional ribs on the cell wall, pigment production, and 18S rDNA sequence analysis suggest that this microalga is a species in the genus Coelastrella. Salt stress accelerated biosynthesis of the reddish-orange pigments, and large quantity of oil accumulated as the cells stressed under nutrient deficiency. This microalga could sustain 45 ¢XC for more than 8 hours indicated by the stability of its chlorophylls, which is a necessary trait for large scale outdoor cultivation using photobioreactors in tropical areas. The reddish-orange pigments could be separated into many fractions by HPLC, and signals from carotenoids were detected in a few fractions using NMR, suggesting these pigments may function as antioxidants among other roles.
114

Some aspects of film formation from pigmented latex systems /

Ding, Tianhua, January 2003 (has links)
Thesis (Ph. D.)--Lehigh University, 2004. / Includes bibliographical reference and vita.
115

Investigation into the genetic basis of carotenoid and melanin colouration in red-billed queleas

Walsh, Neil January 2011 (has links)
No description available.
116

Photoadaptive strategies of Hawaiian macroalgae

Beach, Kevin Scott January 1996 (has links)
Thesis (Ph. D.)--University of Hawaii at Manoa, 1996. / Includes bibliographical references. / Microfiche. / xxi, 302 leaves, bound ill 29 cm
117

Titania pigment surface modification for improved plastic dispersion /

Capelle, Hendrik A. Unknown Date (has links)
In this study a variety of surface modifiers were absorbed onto titania pigment and their interaction examined. / Thesis (PhDAppliedScience)--University of South Australia, 2006.
118

Interaction of polymeric dispersants with Titania pigment particles /

Farrokhpay, Saeed. Unknown Date (has links)
The aim of the research presented in this thesis was to increase the understanding of the interaction between polymeric dispersants and titania pigment particles. In particular, the effects of dispersants of varied functionalities on the pigment dispersion behaviour in both aqueous suspension and dry paint film were investigated. / Thesis (PhDEng(MineralsandMaterials))--University of South Australia, 2004.
119

Implications of the phaeopigment, carbon and nitrogen content of sinking particles for the origin of export production /

Downs, Janet Newton, January 1989 (has links)
Thesis (Ph. D.)--University of Washington, 1989. / Vita. Includes bibliographical references (leaves [179]-194).
120

Enhanced performance and functionality of titanium dioxide papermaking pigments with controlled morphology and surface coating

Nelson, Kimberly Lynn January 2007 (has links)
Thesis (Ph.D.)--Chemical Engineering, Georgia Institute of Technology, 2008. / Committee Chair: Yulin Deng; Committee Member: Arthur Ragauskas; Committee Member: Jeff Empie; Committee Member: Jeffery Hsieh; Committee Member: Preet Singh

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