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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.
411

Kondiční závislost druhotných ornamentů a výběr partnera u koroptve polní Perdix perdix) / Condition dependence of secondary ornamentation and mate choice in Grey Partridges

Gabrielová, Barbora January 2012 (has links)
This study focuses on relationships between individual condition, measures of ornament expression and mate choice in the Grey Partridge (Perdix perdix). It is based on the correlative data as well as results of manipulative experiments. I found positive correlation between the size of melanin- and carotenoid-based ornaments in partridges. The size and the redness of the carotenoid skin patch, and the size of the melanin-based feather ornamentation were associated with several measures of immunity and overall body condition (complement activity, ratio of immature erythrocytes, heterophil/leucocyte ratio, response to novel antigen). Furthermore, data from natural populations indicate that the expression of carotenoid-based ornamentation is associated with sexual attractiveness (measured as the ability to obtain a social mate) in partridges. Data from captive individuals indicate that carotenoid supplementation improves the redness of carotenoid-based ornament, while the stimulation of the immune system under increasing concentrations of supplemented carotenoids has no measurable effect on condition and physiological state. This seems to contradict predictions of the 'Carotenoid maintenance hypothesis'. Overall, results better understanding the role of carotenoid and melanin-based ornamentation in signaling...
412

Biomarkers of Phytochemical Intake in Human Trials Focusing on Modifiable Dietary Behaviors

Hill, Emily B. January 2021 (has links)
No description available.
413

Structural and biochemical insights into catalytic mechanisms of carotenoid cleavage oxygenases

Sui, Xuewu 08 February 2017 (has links)
No description available.
414

Influence of environmental and chemical factors on cellular signaling in lens epithelial cells

Long, Amy Carise 24 August 2007 (has links)
No description available.
415

Effects of resistant starch and soluble fiber on the bioaccessibility of dietary carotenoids from spinach and carrot using simulated in vitro digestion

Hart, Ashley Yeong 20 June 2012 (has links)
No description available.
416

Bioavalability, Metabolism, and Bioefficacy of Tomato Carotenoids

Kopec, Rachel Elizabeth 20 December 2012 (has links)
No description available.
417

Excited state dynamics of carotenoids in solution and proteins / Excited state dynamics of carotenoids in solution and proteins

CHÁBERA, Pavel January 2010 (has links)
Time resolved spectroscopy is one of the crucial methods used to study processes on molecular level in biological systems. It is useful especially for monitoring fast processes that take a place in photosynthetic apparatus of photosynthetic organisms, such as electron and energy transfer. The integral parts of photosynthetic apparatus are carotenoids, whose role in the photosynthetic apparatus is not as well explored as it is for chlorophylls. It was proved that carotenoids actively participate in energy transfer processes in photosynthetic antennas. They have a crucial role in protection against excess energy damage. They are also electron donors in both antennas and reaction centers. The fact that photo-physical properties of carotenoids are much different from properties of others organic pigments, complicates studies of their functions in photosynthesis as well as in other biological systems. This thesis employs advanced methods of femtosecond spectroscopy to obtain more information about carotenoid functions in some biological systems and in solution with special focus on carotenoids containing carbonyl group.
418

Iskorišćenje sporednog produkta prerade paradajza kao sirovine za prehrambene proizvode sa dodatom vrednošću / Utilization of tomato processing byproduct as raw material for value-added food products

Belović Miona 10 October 2016 (has links)
<p>U okviru disertacije su razvijeni postupci za iskori&scaron;ćenje sporednog produkta prerade paradajza (tropa) kao polazne sirovine za proizvodnju prehrambenih proizvoda sa dodatom vredno&scaron;ću. Sprovedena istraživanja kretala su se u dva smera: proizvodnja lipofilnih i hidrofilnih ekstrakata od liofilizovanog tropa paradajza, primenom rastvarača koji su dozvoljeni za upotrebu u prehrambenoj industriji (n-heksana i 95% etanola) i njihova karakterizacija u pogledu sadržaja i sastava fitohemikalija i biolo&scaron;ke aktivnosti in vitro; razvoj formulacija i tehnolo&scaron;kih postupaka za kreiranje gotovih proizvoda sa povećanim sadržajem prehrambenih vlakana i njihova karakterizacija u smislu nutritivnih, reolo&scaron;kih i senzorskih svojstava. Proizvedena su tri proizvoda sa povećanim sadržajem prehrambenih vlakana: kečap od svežeg tropa paradajza, kečap od liofilizovanog tropa paradajza u prahu i marmelada od liofilizovanog tropa paradajza u prahu.<br />Proizvedeni lipofilni i hidrofilni ekstrakti pokazali su sposobnost redukcije jona gvožđa, kao i antiradikalsku aktivnost na DPPH, azot (II)-oksid i superoksid-anjon radikale. Karotenoidi detektovani u lipofilnim ekstraktima (likopen i &beta;-karoten) povezani su sa vi&scaron;om antiradikalskom aktivno&scaron;ću na superoksid-anjon radikal, dok su fenolna jedinjenja detektovana u hidrofilnim ekstraktima (hidroksicinamati, flavonoli i dihidrohalkoni) bila efikasnija u redukciji jona gvožđa. Etanolni ekstrakt tropa paradajza pokazao je inhibitornu aktivnost na angiotenzin-konvertujući enzim pri koncentraciji ekstrakta od 10 mg/ml.<br />Kečap proizveden od svežeg tropa paradajza, kečap proizveden od liofilizata tropa paradajza i marmelada proizvedena od liofilizata tropa paradajza su bili okarakterisani povećanim sadržajem prehrambenih vlakana (preko 3 g na 100 g proizvoda), na osnovu kog mogu da se deklari&scaron;u kao izvor vlakana. Marmelada je proizvedena od liofilizovanog tropa paradajza bez dodatka hidrokoloida, sa 20% manjim sadržajem &scaron;ećera u odnosu na komercijalne proizvode.<br />Reolo&scaron;ka svojstva kečapa proizvedenog od svežeg tropa paradajza su prevashodno zavisila od koncentracije nerastvorljivih čestica. Rezultati senzorske ocene sprovedene uz primenu panela treniranih ocenjivača, ukazuju da su miris na paradajz i aroma paradajza bili najvažniji za jasno razlikovanje kečapa proizvedenog od svežeg tropa paradajza od komercijalnih proizvoda.<br />Kečap i marmelada proizvedeni od liofilizovanog tropa paradajza se, kao reolo&scaron;ki sistemi, mogu opisati modifikovanom frakcionom Kelvin-Voigt-ovom jednačinom kao viskoelastična tela. Ispitivanje model sistema sastavljenih od različitih odnosa liofilizata tropa paradajza i vode tretiranih na temperaturi od 60&deg;C i 100&deg;C ukazalo je da su vrednosti modula elastičnosti (G&rsquo;) zavisile od koncentracije liofilizata tropa i da su G&rsquo; vrednosti niže na 100&deg;C u odnosu na 60&deg;C. Test dopadljivosti kečapa i marmelade od liofilizovanog tropa paradajza, sproveden primenom hedonske skale od 1 do 7, ukazuje da su oba proizvoda prihvaćena od strane potro&scaron;ača (prosečna ocena za ukupnu dopadljivost veća od 4).</p> / <p>This dissertation describes processes for utilization of tomato processing byproduct (tomato pomace) as raw material for value-added food products. Research was conducted in two directions: one is production of lipophilic and hydrophilic tomato pomace extracts using solvents that are allowed for use in the food industry (n-hexane and 95% ethanol) and their characterization in terms of content and composition of phytochemicals and their in vitro biological activity; the other one is development of formulations and technological processes for the creation of tomato pomace based products with increased content of dietary fiber and their characterization in terms of nutritional, rheological and sensory properties. Three products with increased dietary fiber content were produced: ketchup was produced from fresh tomato pomace, and ketchup and jam were produced from lyophilized tomato pomace powder.<br />Produced lipophilic and hydrophilic extracts showed ferric ion reducing ability, as well as DPPH, nitric oxide and superoxide anion radical scavenging activity. Carotenoids detected in lipophilic extracts (lycopene and &beta;-carotene) were correlated with higher superoxide anion radical scavenging activity, while phenolic compounds detected in hydrophilic extracts (hydroxycinnamates, flavonols and dihydrochalcones) were more effective in ferric ion reduction.<br />Ketchup produced from fresh tomato pomace, ketchup produced from lyophilized tomato pomace, and jam produced from lyophilized tomato pomace were characterized by increased content of dietary fiber (more than 3 g per 100 g of product). Jam was produced from the lyophilized tomato pomace without addition of hydrocolloids, with 20% lower sugar content in comparison with commercial products. Rheological properties of ketchup produced from fresh tomato pomace primarily depended on the insoluble particles content. The results of sensory analysis indicate that tomato odor and flavor were the most important for clear separation of ketchup produced from fresh tomato pomace from commercial products.<br />Ketchup and jam produced from lyophilized tomato pomace could be described, as rheological systems, by the application of modified fractional Kelvin-Voigt model as viscoelastic solids. The examination of model systems comprised of different lyophilized tomato pomace:water ratios heat treated at 60&deg;C and 100&deg;C indicated that storage modulus (G&rsquo;) values depended on the concentration of lyophilized tomato pomace and that G&rsquo; values were lower at 100&deg;C than at 60&deg;C. Preference test for ketchup and jam, conducted by application of 7-point hedonic scale, indicated that both products were accepted by the consumers (average score for overall acceptability higher than 4).</p>
419

Identification de facteurs opératoires influents en vue d'une production microbienne optimale de torularhodine et de sa fonctionnalisation enzymatique, à partir d'études cinétiques / Identification of major operating factors for an optimal torularhodin production by yeast and its enzymatic modifying based on kinetic studies

Alves Da Costa Cardoso, Ligia 14 November 2008 (has links)
Ce travail a eu pour objectif de déterminer les conditions optimales de production d’un caroténoïde original, la torularhodine, par Sporobolomyces ruberrimus, cultivée en réacteur discontinu. Cette souche est capable d’utiliser le glycérol technique comme source de carbone et d’énergie pour sa croissance et pour la production de caroténoïdes. D’abord, il s’est agi d’identifier les facteurs opératoires majeurs qui sont susceptibles d’avoir une influence sur la production de la torularhodine, au travers d’une étude préliminaire. L’identification expérimentale de ces facteurs d’action - la température, le taux d’oxygène dissous et la supplémentation en acide oléique - a été validée statistiquement, à des degrés divers, avant d’engager une étape d’optimisation par la construction d’un plan d’expériences multicritère. Celui-ci a conduit à l’établissement de modèles polynômiaux du second degré pour représenter l’effet conjugué des facteurs retenus et permettre la prédiction des valeurs de µmax et de concentration de torularhodine rapportée à la biomasse. Cette étude a alors été consacrée à un essai de fonctionnalisation de la torularhodine, à partir de sa fonction carboxylique, en vue de la stabilisation de la molécule dont l’activité antioxydante est élevée. L’acylation enzymatique de la lysine par la torularhodine a été envisagée. Les conditions d’acylation par la lipase B de C. antarctica ont été déterminées avec un caroténoïde modèle, la bixine. Le produit dérivé obtenu après transacylation a été purifié et a montré une activité antiradicalaire supérieure à celle de la bixine. Ces résultats permettent d’envisager la synthèse de peptides acylés avec ce type de caroténoïdes / The aim of this work was to determine the optimum of an original carotenoid, the torularhodin, produced by Sporobolomyces ruberrimus, in batch culture. A very interesting characteristic of this strain is its ability to consume raw glycerol as a carbon and energy source for microbial growth and carotenoid production. In the fist part of this study, the identification of operating parameters that have an influence on the optimum torularhodin production, was achieved. Experimental assays reinforced by a statistical study allowed to identify temperature, dissolved oxygen pressure and oleic acid supplementation, as the major parameters of influence, and then the integration of these data was performed for the construction of a multiobjective optimization based on a multicriteria experimental design. The establishment of a mathematical model of a second degree polynomial type was developed for the prediction of the values of µmax and of the torularhodin concentration reported to biomass. In the last part, considering that torularhodin has an important antioxidant property and it exhibits a free carboxyl acid function which can be used as acyl agent, a study of its structure modifying by an enzymatic way as a stabilization pattern was started. The experimental conditions of lysine acylation by the lipase B of Candida antarctica were determined using a model carotenoid, the bixin. The resulting product of the synthesis of bixin derivative was purified and showed an antiradical activity of 2.5 times higher than that of bixin. This result showed the ability of the acylation reaction of peptides with this kind of carotenoids
420

Analýza parametrů, u nichž se předpokládá souvislost se suchovzdorností, u různých genotypů čiroku / Analysis of parameters presumably associated with drought-resistance in various sorghum genotypes

Panchártek, Daniel January 2013 (has links)
The aims of this work were 1) to assess whether sorghum (Sorghum bicolor (L.) Moench) genotypes originating from the India can be grown and analyzed in the climatic conditions of central Europe and 2) to find out the utilization potential of selected non- destructive and destructive methods based mostly on the chlorophyll a fluorescence measurements and the determination of photosynthetic pigments' content for the differentiation of sorghum genotypes based on their presumed drought tolerance. Field experiments made during 2 years compared 15 genotypes of this species (2 stay-green parental lines, 2 senescent parental lines and 11 introgression lines with stay-green loci), 2 of these genotypes were further analyzed in greenhouse conditions where the water deficit was induced by a cessation of watering for 12 days. The field-grown plants showed some differences between individual genotypes in all measured parameters; however, for the majority of the genotypes these differences were not statistically significant. The stay-green parental genotype B35 differred the most from the other ones in both field seasons, but the other stay-green genotypes usually did not differ from the senescent genotypes. No significant differences between both greenhouse-tested genotypes (presumably contrasting in their...

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