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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.
21

Sustainable restoration of mine sites

Krisnayanti, Dewi January 2009 (has links)
A sustainable approach to restoration of the post-mining landscape involves creating conditions where a viable growth medium can be established with the minimal amount of fertiliser inputs over a period of time. Ideally, this growth medium should comprise a combination of minerals, organic matter, and biological components with have the capacity to retain and release nutrients over time. When combined with a re-vegetation scheme appropriate to the biogeographic area, a self-sustaining ecosystem can be established. Regulatory requirements for mine restoration typically require the use of topsoil, which is often in limited supply. However, overburden is commonly present in vast quantities and has the potential to be used as a restoration substrate with appropriate amendments. There are significant gaps in our understanding of factors relating to the use and amendment of overburden as a growing medium. The main objective of this study was to investigate and quantify the effects of inorganic and organic amendments and weathering on nutrient availability and plant growth in topsoil and overburden material obtained from the OceanaGold Globe Progress mine at Reefton, New Zealand. A series of glasshouse experiments were carried out on topsoil, fresh overburden and mullock (old waste rock) amended with biosolids, green manure, sawdust, lime and mineral fertiliser nutrients (nitrogen (N) and phosphorus (P)). R esults demonstrated that 300 kg N ha⁻¹ was sufficient to overcome N deficiency in topsoil, while 100 kg P ha⁻¹ was required to overcome P deficiency. Addition of biosolids to topsoil and overburden increased plant biomass production, without increasing heavy metal concentrations. Amendment of overburden significantly affected weathering rates by accelerating the formation of secondary minerals. In particular, lupin green manure accelerated the formation of organic iron (Fe) and aluminium (Al) organic complexes, resulting from the decomposition of the green manure and release of Fe from primary minerals. Results revealed that wineberry and red beech required 200 kg N ha⁻¹ for optimum growth. Overall, the findings of this research identified key parameters for effective utilisation of overburden as a restoration substrate. A sustainable restoration method for managing the topsoil and/or any overburden or waste rock material remaining at mine sites can be achieved by careful selection of organic amendments and allowing an initial weathering period.
22

Preventing the spread of the invasive plant Lupinus polyphyllus.

Brobäck, David January 2015 (has links)
Invasive species are an increasing problem worldwide, threatening indigenous communities and species. Many human-made environments promote introductions of alien species and one such habitat is road verges. The invasive plant Lupinus polyphyllus is benefiting from these habitats and is today widespread along road verges in many parts of Sweden. However, it has been shown to be a problematic species, as it supresses native plants. Many of these plants originate from semi-natural grasslands, but have found a refuge in road verges. The Swedish Transport Administration has tried to control L. polyphyllus, but it is unclear to what extent it is possible. To manage an invasive species, it is often preferable to prevent further extension by limiting its dispersal, which can be done by reducing seed production. To find out how to prevent L. polyphyllus from spreading, I investigated how resprouting capacity and seed production was affected by cutting of L. polyphyllus at different times throughout the season, and at different heights. Plants in all plots resprouted after being cut, but resprouted leaf stalks grew taller in the plants cut early at the flowering stage, compared to the later cutting treatments. These were also the only ones producing new flowers and fruits, perhaps due to stored resources in roots or the fact that they were cut before the summer solstice. Plants cut higher above the ground produced more flowers and fruits and produced taller leaf stalks and might have used photosynthesizing aboveground parts to acquire resources for regeneration. Fruits were produced but not ripe before the mid-summer cutting. These seeds were still able to germinate after maturing on cut plants. However, they were more mould-infected than seeds maturing on non-cut plants. Seeds from cut plants were also lighter. Thus, seeds produced by the mid-summer cutting might disperse and germinate but may perhaps suffer from lower survival due to more frequent mould infections. The late-cut plants had already produced mature seeds, and thus, were probably able to disperse. Also, the later cutting treatments produced more seeds over the entire season. This indicates that to hinder dispersal by limiting seed production, it is best to cut Lupinus polyphyllus as early as possible, in the flowering stage, when seeds are not produced and to cut them entirely to the ground.
23

The impact of the invasive Garden lupine (Lupinus polyphyllus) on plant communities along species rich road verges / Den invasiva blomsterlupinens (Lupinus polyphyllus) påverkan på artrika vägkanters växtsamhällen

Knudsen, Carola January 2021 (has links)
The Swedish Transport Administration works continuously with biological diversity. The project, “Species-rich road verges”, begun in 1995. A species-rich road verge is a road verge area that houses objects worthy of protection. It is common for a species-rich road verge to contain meadow species but on the other hand, road verges also function as new habitat for invasive species. Invasive species often tend to show faster growth and higher reproductive potential than non-invasive species and are considered to homogenize ecosystems because many native species often have difficulty competing with them. The invasive Garden lupine (Lupinus polyphyllus) can be particularly problematic at species-rich road verges, where it competes with the native flora. The purpose of the study was to investigate whether the presence of L. polyphyllus in species-rich road verges decreases plant diversity and species richness, if it changes the species composition and if it affects the vegetation height. The study also wanted to investigate if the presence of L. polyphyllus in species-rich road verges presence affects the thickness of the litter, the pH-value in the soil and the ecological indicator values. This study was conducted at 12 species rich road verges in Värmland and Örebro counties in Sweden, where vascular plants in a box of 1 m2 were inventoried along the road verges in pairs, each pair containing a plot where L. polyphyllus was present (“lupine plot”) and a plot where L. polyphyllus was absent (“control plot”). At each species-rich road verge as many pairs as the length of the road verge allowed was inventoried. Vegetation height, litter thickness and pH- value were also measured and ecological indicator values was calculated for each plot. The results suggest that the presence of L. polyphyllus decreases species richness and diversity and changes the species composition in species-rich road verges so that it becomes homogenized. Vegetation height was affected when L. polyphyllus was present, even when the species itself was not taken into the calculation. The results of this study indicate that it is important to come up with effective strategies to control and stop the spread of the invasive L. polyphyllus in species-rich road verges. / Trafikverket arbetar kontinuerligt med biologisk mångfald. Projektet Artrika vägkanter började 1995. En artrik vägkant är ett vägkantsområde som hyser skyddsvärda arter. Det är vanligt att en artrik vägkant innehåller ängsarter. Vägkanter fungerar också som en ny livsmiljö för invasiva arter. Invasiva arter tenderar ofta att visa snabbare tillväxt och högre reproduktionspotential än icke-invasiva arter och anses homogenisera ekosystem då de konkurrerar ut många inhemska arter. Den invasiva blomsterlupinen (Lupinus polyphyllus) kan vara särskilt problematisk vid artrika vägkanter där den konkurrerar med den inhemska floran. Syftet med studien var att undersöka om förekomsten av L. polyphyllus i artrika vägkanter minskar växternas artrikedom och diversitet, om artsamman- sättningen förändras, om vegetationshöjden påverkas samt om abiotiska faktorer påverkas. Studien genomfördes vid 12 artrika vägkanter i Värmland och Örebro län i Sverige, där kärlväxter i en ruta på 1 m2 inventerades längs de artrika vägkanterna i par, med en lupinruta kontra en kontrollruta. Vid varje artrik vägkant inventerades så många par som vägkantens längd tillät. Vegetationshöjd, förnans tjocklek och pH-värde mättes också vid varje ruta och ekologiska indikator värden beräknades för varje ruta. Resultaten tyder på att blomsterlupinen minskar artrikedom och mångfald och att artsammansättningen i lupin rutor förändras jämfört med kontroll rutor och blir mer homogen. Vegetationshöjden påverkades av L. polyphyllus och var signifikant högre i lupinrutor jämfört med kontrollrutor även då arten L. polyphyllus inte räknades med i analysen. Resultaten av denna studie indikerar att det är viktigt att arbeta fram effektiva strategier för att kontrollera och stoppa spridningen av den invasiva L. polyphyllus i artrika vägkanter.
24

Les racines cachées de la phytoremédiation : décryptage métabolomique des mécanismes d’exsudation racinaire pour la tolérance à l’arsenic

Frémont, Adrien 01 1900 (has links)
Les sols représentent une ressource non renouvelable qui soutient 95% de la production alimentaire mondiale. Cependant, les sols sont de plus en plus impactés par la pollution chimique anthropique, menaçant la santé humaine et l’environnement. Parmi les polluants les plus répandus dans les sols, l'arsenic est aussi l’un des plus dommageables pour la santé humaine, touchant près de 200 millions de personnes dans le monde. Pour limiter la contamination des sols, les approches conventionnelles de remédiation reposent principalement sur l'excavation et l'enfouissement des sols contaminés, mais sont incompatibles avec les grandes surfaces concernées par la contamination chimique, pouvant s’étendre sur des millions d’hectares. Une solution novatrice utilise les plantes et les microorganismes associés pour extraire, dégrader ou stabiliser les contaminants in situ dans une approche dite de phytoremédiation. L'exsudation d'une grande diversité de métabolites des racines dans le sol environnant serait un mécanisme essentiel qui permet aux plantes de tolérer et de détoxifier les contaminants du sol. Cependant, l’environnement chimique de la rhizosphère et les interactions complexes entre les exsudats racinaires et les contaminants restent largement inconnus. L'objectif de cette thèse est de faire progresser la compréhension de l'exsudation racinaire en réponse à la contamination et de son impact sur le devenir de l'arsenic dans la rhizosphère. Le Chapitre 1 rapporte un nouveau système de croissance à petite échelle, hautement reproductible, développé pour capturer et caractériser les exsudats racinaires. En utilisant une analyse métabolomique non ciblée basée sur la chromatographie liquide couplée à la spectrométrie de masse, l’espèce légumineuse Lupinus albus a été examinée pour identifier les différences significatives dans l’exsudation d’un large spectre de composés dans la rhizosphère. Cette approche a révélé les classes prédominantes de composés exsudés et leurs variations en réponse à la contamination, notamment les coumarines, connues pour être impliquées dans les stratégies d'acquisition de nutriments chez les plantes, ainsi que l'exsudation inattendue de phytochélatines, connues pour participer à la complexation et à la détoxification intracellulaire de l'arsenic. Pour confirmer l'exsudation des phytochélatines, une expérience supplémentaire a été menée et a permis de valider l'exsudation des phytochélatines comme mécanisme potentiel de tolérance à l'arsenic dans la rhizosphère. Le Chapitre 2 examine plus en détail les mécanismes d'exsudation des phytochélatines et leurs interactions avec l'arsenic chez Lupinus albus. Grâce à l'inhibition chimique des principales voies de synthèse et d'exsudation des phytochélatines, ce chapitre fournit les premières observations de l’exsudation active de complexes arsenic-phytochélatine chez les plantes, pouvant jouer un rôle critique dans la détoxification de l'arsenic. À partir de ces observations, le chapitre 2 propose une révision du modèle actuel d'efflux d'arsénite des racines et met en évidence l'exsudation de complexes arsenic-phytochélatine comme mécanisme jusque-là inconnu de détoxification chez les plantes. Dans le Chapitre 3, les différentes stratégies employées en réponse à la contamination à l'arsenic chez Lupinus albus et Salix miyabeana sont explorées en profondeur par différents essais en pots et à plus grande échelle, directement sur le terrain. Ces deux espèces, illustrant différents traits fonctionnels importants pour la phytoremédiation, révèlent des adaptations distinctes ainsi que des stratégies d’exsudation conservées en réponse à l'arsenic. Les résultats présentés dans ce chapitre révèlent en particulier le rôle central de l'exsudation de phytochélatines dans la rhizosphère de ces deux espèces, pourtant éloignées phylogénétiquement. Notamment, la découverte de complexes phytochélatine-arsenic dans la rhizosphère des deux espèces souligne l'importance des mécanismes extracellulaires dans la détoxification de l'arsenic chez les plantes. De plus, les mesures sur le terrain soutiennent les implications de l'exsudation des phytochélatines en tant qu’adaptation à l'exposition à l'arsenic en conditions réelles. En résumé, ce chapitre fournit de nouvelles perspectives sur l'interaction complexe entre les plantes et les sols lors de la phytoremédiation de l'arsenic. Dans l'ensemble, cette thèse présente de nouvelles stratégies d'exsudation chez deux espèces phytoremédiatrices majeures et apporte de nouvelles connaissances sur la façon dont l'investissement de ressources dans la rhizosphère peut aider les plantes à tolérer, voire à surmonter, l'effet de la pollution anthropique sur l'environnement. Comprendre ces interactions naturelles est essentiel pour aider à concevoir des stratégies de gestion durables des terres, visant à réduire l'impact à long terme des activités humaines sur les sols. / Soils represent a non-renewable resource supporting 95% of global food production. However, soils face increasing threats from anthropogenic chemical pollution, creating an environmental burden impacting human and environmental health worldwide. Arsenic is one of the most widespread soil contaminants, thought to affect over 200 million people globally and posing substantial threats to public health. To limit contamination of soils, conventional remediation approaches rely on soil excavation and burial, but are incompatible with the extensive problem of soil contamination, often impacting millions of hectares. An innovative solution is to use phytoremediation to harness plants' natural abilities to extract or degrade soil contaminants. The exudation of a wide diversity of metabolites from roots into the surrounding soil is thought to be an essential mechanism used by plants to modify challenging soil environments. However, the extent and variation of root exudation remains largely uncharacterised for many important crops. The objective of this thesis is to advance the understanding of root exudation in response to contamination and how it impacts the fate of arsenic in the rhizosphere. Chapter 1 reports a novel small-scale but highly reproducible growth system developed to capture and characterise root exudates. Using untargeted liquid chromatography-tandem mass spectrometry-based metabolomic analysis, the leguminous crop white lupin (Lupinus albus) was scrutinised to identify significant differences in exuded compounds within the rhizosphere. This approach revealed the predominant classes of exuded compounds in response to contamination, including coumarins, known to be involved in plant nutrient acquisition strategies, as well as unexpected phytochelatin exudation, known to participate in intracellular arsenic complexation and detoxification. A validatory experiment was conducted and confirmed the exudation of phytochelatins as a potential arsenic tolerance mechanism for rhizosphere detoxification. Chapter 2 further investigates the mechanisms of phytochelatin exudation and their interactions with arsenic in Lupinus albus. Through chemical inhibition of key root exudates synthesis and exudation mechanisms, this chapter provides the first evidence that plants actively exude arsenic-phytochelatin complexes, which may function as a critical step for arsenic detoxification and tolerance. From this evidence, Chapter 2 provides a tentative revision of the current model of arsenite efflux from roots and demonstrates that arsenic-phytochelatin exudation may be an active mechanism conferring arsenic tolerance. In Chapter 3, the different strategies employed in response to arsenic contamination in Lupinus albus and Salix miyabeana were extensively scrutinised in larger-scale pot and field trials, to capture the diversity of rhizosphere metabolites within constructed and real-world soils. These species, illustrating different important functional traits for phytoremediation, revealed distinct as well as more conserved root exudate adaptations to arsenic. Most importantly, the findings presented in this chapter reveal a conserved and pivotal role for extracellular phytochelatin exudation in the rhizosphere of these distantly related phytoremediating species. The discovery of phytochelatin-arsenic complexes in the rhizosphere of both species underscores the importance of extracellular mechanisms in plant arsenic detoxification. Furthermore, field assessments supported the real-world implications of phytochelatin exudation as an adaptive response to arsenic exposure. In summary, this chapter provides novel insights into the complex interplay between plants and soils in arsenic phytoremediation. Overall, this thesis presents novel exudation strategies in two major phytoremediation species and brings new knowledge on how investment of resources in the rhizosphere can help plants tolerate, or even overcome, the effect of anthropogenic pollution upon the natural environment. Understanding these mechanisms is vital to devise sustainable land management strategies to reduce the long-term impact of human activity on soils around the world.
25

Insects associated with the lupin (Lupinus angustifolius) cultivars Fest and Uniharvest

Harris, B. M. January 1980 (has links)
The insect fauna of two Lupinus angustifolius cultivars (Fest and Uniharvest) was surveyed between October, 1978 and March, 1979. The main sampling methods were sweepnetting, use of the D-Vac, and pod removal. Glasshouse experiments were carried out with species showing pest potential (based on the survey). These species were Acyrthosiphon pisum (Harris), Nysius huttoni White, and Sidnia kinbergi (Stalenberg). While A. pisum and S. kinbergi had their pest potential confirmed, N. huttoni did not. Although the aphids Acyrthosiphon kondoi Shinji, Macrosiphum euphorbiae (Thompson) and Myzus persicae (Sulzer) were not studied in the laboratory, field data indicated their pest potential. Insects to show lesser pest potential were Calocoris norvegicus (Gmelin), Hylemyia deceptiva Malloch, and Hylemyia platura (Meigen). Important potential predators or parasites were Austromicromus tasmaniae (Walker), Coccinella undecimpunctata L., Tropiconabis capsiformis (Germar), some Araneae species and single unidentified species of Braconidae and Eulophidae. The cultivar Uniharvest was the preferred host presumably because it does not possess the toxic alkaloids of Fest. However, crop loss through insect damage appeared unimportant compared to the 10% loss of Uniharvest caused by the aphid-borne bean yellow mosaic virus.
26

Effect of irrigation on growth and nitrogen accumulation of Kabuli chickpea (Cicer arietinum L.) and narrow-leafed lupin (Lupinus angustifolius L.)

Kang, Sideth January 2009 (has links)
A field experiment was conducted to examine the responses in growth, total dry matter (TDM), seed yield and nitrogen (N) accumulation of Kabuli chickpea cv. Principe and narrow-leafed lupin cv. Fest to different irrigation levels and N fertilizer on a Templeton silt loam soil at Lincoln University, Canterbury, New Zealand in 2007/08. The irrigation and fertilizer treatments were double full irrigation, full irrigation, half irrigation and nil irrigation and a control, full irrigation plus 150 kg N ha⁻¹. There was a 51 % increase in the weighed mean absolute growth rate (WMAGR) by full irrigation over no irrigation. The maximum growth rates (MGR) followed a similar response. The growth rates were not significantly decreased by double irrigation. Further, N fertilizer did not significantly improve crop growth rates. With full irrigation MGRs were 27.6 and 34.1 g m⁻² day⁻¹ for Kabuli chickpea and narrow-leafed lupin, respectively. Seed yields of fully-irrigated crops were trebled over the nil irrigation treatment. With full irrigation, seed yield of chickpea was 326 and that of lupin was 581 g m⁻². Seed yield of the two legumes was reduced by 45 % with double irrigation compared with full irrigation. Nitrogen fertilizer did not increase seed yields in either legume. Increased seed yield with full irrigation was related to increased DM, and crop growth rates, seeds pod⁻¹ and seeds m⁻². Crop harvest index (CHI) was significantly (P < 0.05) increased by irrigation and was related to seed yield only in narrow-leafed lupin. With full irrigation, the crops intercepted more than 95 % of incoming incident radiation at leaf area indices (LAIs), 2.9 and 3 or greater in Kabuli chickpea and narrow-leafed lupin, respectively. In contrast, without irrigation the two legumes achieved a maximum fraction of radiation intercepted of less than 90 %. With full irrigation, total intercepted photosynthetically active radiation (PAR) was increased by 28 % and 33 % over no irrigation for Kabuli chickpea and narrow-leafed lupin, respectively. Fully-irrigated Kabuli chickpea intercepted a total amount of PAR of 807 MJ m⁻² and fully-irrigated narrow-leafed lupin intercepted 1,042 MJ m⁻². Accumulated DM was strongly related to accumulated intercepted PAR (R² ≥ 0.96**). The final RUE was significantly (P < 0.001) increased by irrigation. With full irrigation the final RUE of Kabuli chickpea was 1.49 g DM MJ⁻¹ PAR and that of narrow-leafed lupin was 2.17 g DM MJ⁻¹ PAR. Total N accumulation of Kabuli chickpea was not significantly affected by irrigation level. Kabuli chickpea total N was increased by 90 % by N fertilizer compared to fully-irrigated Kabuli chickpea which produced 17.7 g N m⁻². In contrast, total N accumulated in narrow-leafed lupin was not increased by N fertilizer but was decreased by 75 % with no irrigation and by 25 % with double irrigation (water logging) compared to full irrigation with a total N of 45.9 g m⁻². Total N was highly significantly related to TDM (R² = 0.78** for Kabuli chickpea and R² = 0.99** for narrow-leafed lupin). Nitrogen accumulation efficiency (NAE) of narrow-leafed lupin was not affected by irrigation or by N fertilizer. However, the NAE of Kabuli chickpea ranged from 0.013 (full irrigation) to 0.020 (no irrigation) and 0.017 g N g⁻¹ DM (full irrigation with N fertilizer). The N harvest index (NHI) was not affected by irrigation, N fertilizer or legume species. The NHI of Kabuli chickpea was 0.50 and that of narrow-leafed lupin was 0.51. The NHI was significantly (r ≥ 0.95 **) related to CHI.
27

Phosphorus benefits of white lupin, field pea and faba bean to wheat production in Western Australian soils

Nuruzzaman, Mohammad January 2005 (has links)
[Truncated abstract] Soils of Western Australian cropping regions are very low in phosphorous. White lupin, chickpea, and faba bean are being increasingly used in rotations with wheat on these soils. Yield of wheat after a legume crop is frequently higher than its yield after wheat. It has been reported that in addition to nitrogen, legumes can also contribute to improve the availability of phosphorous for the subsequent crops. This PhD research project aimed at optimising the economic returns of wheat-legume rotations through more efficient use of P fertiliser in the legume phase as well as enhanced availability of soil P in the subsequent wheat phase
28

Einfluss der Entkeimung von Lupinensaatgut und Lupinenproteinisolaten auf ausgewählte ernährungsphysiologische, sensorische und technofunktionelle Eigenschaften

Melde, Denise 09 October 2017 (has links) (PDF)
Nach den Ergebnissen der zweiten Nationalen Verzehrsstudie sind in Deutschland bereits 66 % der Männer und 51 % der Frauen übergewichtig (BMI > 25) oder adipös (BMI > 30) [BMELV, 2008]. Bisher auf dem Markt befindliche „Light-Lebensmittel“ mit Fettaustausch- bzw. Fettersatzstoffen weisen jedoch häufig sensorische Mängel auf. Im Kooperationsprojekt „Pflanzliche Fettaustauschstoffe aus sphärischen Proteinmizellen“ (Universität Leipzig: Institut für Lebensmittelhygiene; Freising: Fraunhofer IVV) wurde ein Lupinenproteinisolat entwickelt, welches micellare Strukturen mit hydrophober Oberfläche ausbilden kann und sich aufgrund seiner fettähnlichen Eigenschaften als neuer proteinbasierter Fettaustauschstoff in Lebensmitteln eignet. Aufgrund der geringen mikrobiologischen Stabilität und einer hohen Belastung mit sporenbildenden Bakterien, z. T. Bacillus cereus, waren jedoch Maßnahmen zur Entkeimung der Rohstoffe sowie des Proteinisolats notwendig. Die Arbeit stellt diese Maßnahmen und deren Einfluss auf die mikrobiologische Beschaffenheit sowie sensorische, technofunktionelle und ausgewählte ernährungsphysiologische Eigenschaften dar. In der vorliegenden Arbeit wurde eine physikalische Methode der Saatgutentkeimung etabliert (130 °C/60 min), welche die mikrobielle Stabilisierung des lupinenproteinbasierten Fettaustauschstoffes sicherstellte, wobei die sensorische Qualität (Geschmack, Cremigkeit, Farbe) nur minimal, die ernährungsphysiologische (in-vitro-Verdaubarkeit, Maillard-Produkte, Polyphenolgehalt) jedoch nicht beeinflusst wurde. Starke Veränderungen der technofunktionellen Eigenschaften (z. B. Gelbildung, Wasserbindung, Emulgierbarkeit, Schaumbildung etc.) konnten sowohl im positiven als auch im negativen Sinne nicht beschrieben werden. Lichtmikroskopische Aufnahmen und Untersuchungen der Proteine mittels SDS-PAGE und DSC bestätigten eine nur geringfügige Beeinflussung der micellaren Struktur und Proteinzusammensetzung. Die Anwendung als Fettaustauschstoff in Lebensmitteln würde somit nicht beeinträchtigt. Der Einfluss der Saatgutbehandlung auf das Protein war wesentlich geringer als eine direkte thermische Behandlung des Proteinisolats. Im Hinblick auf den Gesamtprozess sollte eine Pasteurisierung der feuchten Proteinisolate im nichtproteinschädigenden Temperaturbereich (75 °C/5 min) dennoch durchgeführt werden, um während des Prozesses eingetragene Mikroorganismen zu inaktivieren.
29

Einfluss der Entkeimung von Lupinensaatgut und Lupinenproteinisolaten auf ausgewählte ernährungsphysiologische, sensorische und technofunktionelle Eigenschaften

Melde, Denise 30 June 2017 (has links)
Nach den Ergebnissen der zweiten Nationalen Verzehrsstudie sind in Deutschland bereits 66 % der Männer und 51 % der Frauen übergewichtig (BMI > 25) oder adipös (BMI > 30) [BMELV, 2008]. Bisher auf dem Markt befindliche „Light-Lebensmittel“ mit Fettaustausch- bzw. Fettersatzstoffen weisen jedoch häufig sensorische Mängel auf. Im Kooperationsprojekt „Pflanzliche Fettaustauschstoffe aus sphärischen Proteinmizellen“ (Universität Leipzig: Institut für Lebensmittelhygiene; Freising: Fraunhofer IVV) wurde ein Lupinenproteinisolat entwickelt, welches micellare Strukturen mit hydrophober Oberfläche ausbilden kann und sich aufgrund seiner fettähnlichen Eigenschaften als neuer proteinbasierter Fettaustauschstoff in Lebensmitteln eignet. Aufgrund der geringen mikrobiologischen Stabilität und einer hohen Belastung mit sporenbildenden Bakterien, z. T. Bacillus cereus, waren jedoch Maßnahmen zur Entkeimung der Rohstoffe sowie des Proteinisolats notwendig. Die Arbeit stellt diese Maßnahmen und deren Einfluss auf die mikrobiologische Beschaffenheit sowie sensorische, technofunktionelle und ausgewählte ernährungsphysiologische Eigenschaften dar. In der vorliegenden Arbeit wurde eine physikalische Methode der Saatgutentkeimung etabliert (130 °C/60 min), welche die mikrobielle Stabilisierung des lupinenproteinbasierten Fettaustauschstoffes sicherstellte, wobei die sensorische Qualität (Geschmack, Cremigkeit, Farbe) nur minimal, die ernährungsphysiologische (in-vitro-Verdaubarkeit, Maillard-Produkte, Polyphenolgehalt) jedoch nicht beeinflusst wurde. Starke Veränderungen der technofunktionellen Eigenschaften (z. B. Gelbildung, Wasserbindung, Emulgierbarkeit, Schaumbildung etc.) konnten sowohl im positiven als auch im negativen Sinne nicht beschrieben werden. Lichtmikroskopische Aufnahmen und Untersuchungen der Proteine mittels SDS-PAGE und DSC bestätigten eine nur geringfügige Beeinflussung der micellaren Struktur und Proteinzusammensetzung. Die Anwendung als Fettaustauschstoff in Lebensmitteln würde somit nicht beeinträchtigt. Der Einfluss der Saatgutbehandlung auf das Protein war wesentlich geringer als eine direkte thermische Behandlung des Proteinisolats. Im Hinblick auf den Gesamtprozess sollte eine Pasteurisierung der feuchten Proteinisolate im nichtproteinschädigenden Temperaturbereich (75 °C/5 min) dennoch durchgeführt werden, um während des Prozesses eingetragene Mikroorganismen zu inaktivieren.:1 Einleitung und Zielstellung 1 2 Stand des Wissens 4 2.1 Die Lupine 4 2.1.1 Anbau und Verbreitung 4 2.1.2 Einsatz von Lupinenprodukten und -proteinen in der Humanernährung 5 2.1.3 Inhaltsstoffe und deren Verteilung 5 2.1.4 Lupinenproteine 10 2.1.4.1 Einteilung und Struktur der Lupinenproteine 10 2.1.4.2 Lupinenproteine und Allergenität 12 2.1.5 Eigenschaften der verschiedenen Lupinenproteinfraktionen 13 2.1.5.1 Ernährungsphysiologische Eigenschaften 13 2.1.5.2 Funktionelle Eigenschaften 15 2.1.5.3 Modifikation der Proteinstruktur 15 2.1.5.4 Herstellung verschiedener Lupinenproteinpräparate 16 2.1.5.5 Micellare Proteine 17 2.2 Möglichkeiten der Fettreduktion in Lebensmitteln 18 2.2.1 Fettaustauschstoffe 18 2.2.1.1 Fettaustauschstoffe auf Proteinbasis (Mikropartikulierte Proteine) 18 2.2.1.2 Fettaustauschstoffe auf Kohlenhydratbasis 19 2.2.1.3 Quellstoffe 19 2.2.2 Fettersatzstoffe 19 2.2.2.1 Spezielle Triglyceride 20 2.2.2.2 Kohlenhydratpolyester 20 2.2.2.3 Retrofette 20 2.3 Herstellung des lupinenproteinbasierten Fettaustauschstoffes 20 2.4 Saatgutbehandlung 21 2.4.1 Methoden der Lebensmittelkonservierung 22 2.5 Proteinfunktionalität 25 2.5.1 Definition und Zusammenhang zu Proteinen 25 2.5.2 Ausgewählte funktionelle Eigenschaften 26 2.5.2.1 Wasserbindevermögen 26 2.5.2.2 Ölbindevermögen 26 2.5.2.3 Löslichkeit 27 2.5.2.4 Emulgiervermögen 27 2.5.2.5 Schaumbildungsvermögen 28 2.5.2.6 Gelbildungsvermögen 29 2.5.2.7 Oberflächenhydrophobität 30 2.5.2.8 Bedeutung für die Lebensmittelentwicklung 30 3 Material und Methoden 32 3.1 Material 32 3.1.1 Saatgut 32 3.1.2 Geräte, Chemikalien, Verbrauchsmaterial, Software 32 3.1.3 Pufferlösungen 39 3.1.4 Herstellung Bradford-Reagenz, 5-fach 39 3.1.5 Auswahl der Vergleichssubstanzen 39 3.2 Methoden 40 3.2.1 Herstellung der Proteinisolate 40 3.2.2 Mikrobiologische Analysen 41 3.2.3 Bestimmung der Trockenmasse 41 3.2.4 Bestimmung des Proteingehalts 42 3.2.5 Thermische Behandlungsmethoden im Prozess 42 3.2.5.1 UHT-Erhitzung des Extraktes 42 3.2.5.2 Pasteurisierung des Isolats 44 3.2.6 Saatgutentkeimung 44 3.2.6.1 UVC-Bestrahlung 44 3.2.6.2 Trockene Erhitzung 45 3.2.6.3 Autoklavieren 46 3.2.7 Sensorische Untersuchungen 46 3.2.8 Proteinfunktionalität 47 3.2.8.1 Ölbindevermögen 47 3.2.8.2 Wasserbindevermögen 47 3.2.8.3 Gelbildungsvermögen 47 3.2.8.4 Emulgiereigenschaften 47 3.2.8.5 Schaumbildungsvermögen 48 3.2.8.6 Proteinlöslichkeit 48 3.2.8.7 Oberflächenhydrophobität 49 3.2.9 Ernährungsphysiologische Eigenschaften 50 3.2.9.1 in-vitro-Verdaubarkeit 50 3.2.9.2 Maillard-Produkte 50 3.2.9.3 Nachweis reduzierender Zucker .50 3.2.9.4 Nachweis von Glykoproteinen 50 3.2.9.5 Polyphenolgehalt der Lupinenflocken und Proteinisolate 51 3.2.10 Proteincharakterisierung 51 3.2.10.1 Lichtmikroskopie 51 3.2.10.2 Dynamische Differenzkalorimetrie 51 3.2.10.3 Natriumdodecylsulfat-Polyacrylamidgelelektrophorese 52 4 Ergebnisse und Diskussion 54 4.1 Thermische Behandlungsmethoden im Prozess 54 4.1.1 UHT-Erhitzung des Extraktes: Einfluss auf Mikrobiologie und Proteinausbeute 54 4.1.2 Pasteurisierungsversuche: Einfluss auf Mikrobiologie und Proteinqualität 55 4.2 Saatgutentkeimung - Mikrobiologie und Proteinausbeute 56 4.2.1 Versuchsreihe I 56 4.2.2 Versuchsreihe II 61 4.3 Sensorische Untersuchungen 63 4.3.1 Verkostungen 64 4.3.2 Farbmessung der Proteinisolate und Flocken 65 4.4 Proteinfunktionalität 69 4.4.1 Wasser- und Ölbindevermögen 69 4.4.2 Gelbildungsvermögen 72 4.4.3 Emulgiereigenschaften 74 4.4.4 Schaumbildungsvermögen 78 4.4.5 Proteinlöslichkeit 81 4.4.6 Oberflächenhydrophobität 83 4.5 Ernährungsphysiologische Eigenschaften 86 4.5.1 Maillard-Produkte 86 4.5.2 Nachweis reduzierender Zucker 87 4.5.3 Nachweis von Glykoproteinen 87 4.5.4 Verdaubarkeit 88 4.5.5 Polyphenolgehalte 89 4.6 Proteincharakterisierung 91 4.6.1 Lichtmikroskopie 91 4.6.2 Dynamische Differenzkalorimetrie 95 4.6.3 Natriumdodecylsulfat-Polyacrylamidgelelektrophorese 98 5 Zusammenfassung 105 Anhang 109
30

Effects of long- and short-term crop management on soil biological properties and nitrogen dynamics

Stark, Christine H. January 2005 (has links)
To date, there has been little research into the role of microbial community structure in the functioning of the soil ecosystem and on the links between microbial biomass size, microbial activity and key soil processes that drive nutrient availability. The maintenance of structural and functional diversity of the soil microbial community is essential to ensure the sustainability of agricultural production systems. Soils of the same type with similar fertility that had been under long-term organic and conventional crop management in Canterbury, New Zealand, were selected to investigate relationships between microbial community composition, function and potential environmental impacts. The effects of different fertilisation strategies on soil biology and nitrogen (N) dynamics were investigated under field (farm site comparison), semi-controlled (lysimeter study) and controlled (incubation experiments) conditions by determining soil microbial biomass carbon (C) and N, enzyme activities (dehydrogenase, arginine deaminase, fluorescein diacetate hydrolysis), microbial community structure (denaturing gradient gel electrophoresis following PCR amplification of 16S and 18S rDNA fragments using selected primer sets) and N dynamics (mineralisation and leaching). The farm site comparison revealed distinct differences between the soils in microbial community structure, microbial biomass C (conventional>organic) and arginine deaminase activity (organic>conventional). In the lysimeter study, the soils were subjected to the same crop rotation (barley (Hordeum vulgare L.), maize (Zea mais L.), rape (Brassica napus L. ssp. oleifera (Moench)) plus a lupin green manure (Lupinus angustifolius L.) and two fertiliser regimes (following common organic and conventional practice). Soil biological properties, microbial community structure and mineral N leaching losses were determined over 2½ years. Differences in mineral leaching losses were not significant between treatments (total organic management: 24.2 kg N ha⁻¹; conventional management: 28.6 kg N ha⁻¹). Crop rotation and plant type had a larger influence on the microbial biomass, activity and community structure than fertilisation. Initial differences between soils decreased over time for most biological soil properties, while they persisted for the enzyme activities (e.g. dehydrogenase activity: 4.0 and 2.9 µg g⁻¹ h⁻¹ for organic and conventional management history, respectively). A lack of consistent positive links between enzyme activities and microbial biomass size indicated that similarly sized and structured microbial communities can express varying rates of activity. In two successive incubation experiments, the soils were amended with different rates of a lupin green manure (4 or 8t dry matter ha⁻¹), and different forms of N at 100 kg ha⁻¹ (urea and lupin) and incubated for 3 months. Samples were taken periodically, and in addition to soil biological properties and community structure, gross N mineralisation was determined. The form of N had a strong effect on microbial soil properties. Organic amendment resulted in a 2 to 5-fold increase in microbial biomass and enzyme activities, while microbial community structure was influenced by the addition or lack of C or N substrate. Correlation analyses suggested treatment-related differences in nutrient availability, microbial structural diversity (species richness or evenness) and physiological properties of the microbial community. The findings of this thesis showed that using green manures and crop rotations improved soil biology in both production systems, that no relationships existed between microbial structure, enzyme activities and N mineralisation, and that enzyme activities and microbial community structure are more closely associated with inherent soil and environmental factors, which makes them less useful as early indicators of changes in soil quality.

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