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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.
81

Determination of bioactive and potentially toxic compounds in food: raw material analysis and shelf life evaluation

Verardo, Vito <1977> 05 June 2009 (has links)
"Bioactive compounds" are extranutritional constituents that typically occur in small quantities in food. They are being intensively studied to evaluate their effects on health. Bioactive compounds include both water soluble compounds, such as phenolics, and lipidic substances such as n-3 fatty acids, tocopherols and sterols. Phenolic compounds, tocopherols and sterols are present in all plants and have been studied extensively in cereals, nuts and oil. n-3 fatty acids are present in fish and all around the vegetable kingdom. The aim of the present work was the determination of bioactive and potentially toxic compounds in cereal based foods and nuts. The first section of this study was focused on the determination of bioactive compounds in cereals. Because of that the different forms of phytosterols were investigated in hexaploid and tetraploid wheats. Hexaploid cultivars were the best source of esterified sterols (40.7% and 37.3% of total sterols for Triticum aestivum and Triticum spelta, respectively). Significant amounts of free sterols (65.5% and 60.7% of total sterols for Triticum durum and Triticum dicoccon, respectively) were found in the tetraploid cultivars. Then, free and bound phenolic compounds were identified in barley flours. HPLCESI/ MSD analysis in negative and positive ion mode established that barley free flavan-3- ols and proanthocyanidins were four dimers and four trimers having (epi)catechin and/or (epi)gallocatechin (C and/or GC) subunits. Hydroxycinnamic acids and their derivatives were the main bound phenols in barley flours. The results obtained demonstrated that barley flours were rich in phenolic compounds that showed high antioxidant activity. The study also examined the relationships between phenolic compounds and lipid oxidation of bakery. To this purpose, the investigated barley flours were used in the bakery production. The formulated oven products presented an interesting content of phenolic compounds, but they were not able to contain the lipid oxidation. Furthermore, the influence of conventional packaging on lipid oxidation of pasta was evaluated in n-3 enriched spaghetti and egg spaghetti. The results proved that conventional packaging was not appropriated to preserve pasta from lipid oxidation; in fact, pasta that was exposed to light showed a high content of potentially toxic compounds derived from lipid oxidation (such as peroxide, oxidized fatty acids and COPs). In the second section, the content of sterols, phenolic compounds, n-3 fatty acids and tocopherols in walnuts were reported. Rapid analytical techniques were used to analyze the lipid fraction and to characterize phenolic compounds in walnuts. Total lipid chromatogram was used for the simultaneous determination of the profile of sterols and tocopherols. Linoleic and linolenic acids were the most representative n-6 and n-3 essential dietary fatty acids present in these nuts. Walnuts contained substantial amounts of γ- and δ-tocopherol, which explained their antioxidant properties. Sitosterol, Δ5-avenasterol and campesterol were the major free sterols found. Capillary electrophoresis coupled to DAD and microTOF was utilized to determine phenolic content of walnut. A new compound in walnut ((2E,4E)- 8-hydroxy-2,7-dimethyl-2,4-decadiene-1,10-dioic acid 6-O-β-D-glucopiranosyl ester, [M−H]− 403.161m/z) with a structure similar to glansreginins was also identified. Phenolic compounds corresponded to 14–28% of total polar compounds quantified. Aglycone and glycosylated ellagic acid represented the principal components and account for 64–75% of total phenols in walnuts. However, the sum of glansreginins A, B and ((2E,4E)-8-hydroxy- 2,7-dimethyl-2,4-decadiene-1,10-dioic acid 6-O-β-D-glucopiranosyl ester was in the range of 72–86% of total quantified compounds.
82

Application of different instrumental techniques to the selective evaluation of bio-sensible compounds in foodstuff of animal and vegetable origin / Applicazione di diverse tecniche analitiche strumentali alla valutazione selettiva di componenti biosensibili in matrici di di origine animale e vegetale

Gori, Alessandro <1978> 17 April 2009 (has links)
This PhD thesis describes the application of some instrumental analytical techniques suitable to the study of fundamental food products for the human diet, such as: extra virgin olive oil and dairy products. These products, widely spread in the market and with high nutritional values, are increasingly recognized healthy properties although their lipid fraction might contain some unfavorable components to the human health. The research activity has been structured in the following investigations: “Comparison of different techniques for trans fatty acids analysis” “Fatty acids analysis of outcrop milk cream samples, with particular emphasis on the content of Conjugated Linoleic Acid (CLA) and trans Fatty Acids (TFA), by using 100m high-polarity capillary column” “Evaluation of the oxidited fatty acids (OFA) content during the Parmigiano-Reggiano cheese seasoning” “Direct analysis of 4-desmethyl sterols and two dihydroxy triterpenes in saponified vegetal oils (olive oil and others) using liquid chromatography-mass spectrometry” “Quantitation of long chain poly-unsatured fatty acids (LC-PUFA) in base infant formulas by Gas Chromatography, and evaluation of the blending phases accuracy during their preparation” “Fatty acids composition of Parmigiano Reggiano cheese samples, with emphasis on trans isomers (TFA)”
83

Ruolo della Radioimmunoterapia nei Linfomi non Hodgkin

Stefoni, Vittorio <1973> 09 June 2009 (has links)
No description available.
84

L'arbitrato irrituale dopo l'ultima riforma

Arrigoni, Caterina <1980> 29 June 2009 (has links)
No description available.
85

Valutazione dell'evoluzione della componente fenolica di Olea Europaea durante l'intero ciclo di maturazione del frutto

Veneziani, Gianluca <1976> 17 April 2009 (has links)
This PhD thesis is related to the evolution of phenolic composition of olive fruit to demonstrate the relationship between the raw material sources and the compounds responsible for the healthy and sensory properties of virgin olive oil, and to investigate the mechanisms involved in the synthesis and/or in the degradation of the phenolic fraction. On the basis of phenolic compositions of twelve Italian olive cultivars (Bianchella, Canino, Coratina, Dolce di Andria, Dritta, Frantoio, Leccino, Moraiolo, Nocellara del Belice, Nocellara Etnea, Rosciola and Tendellone) analysed, some significative qualitative and quantitative differences were observed. The main results were utilized, during the following analysis of the genetic expressions of olive cultivars, to determine the genes directly involved in the synthesis and the degradation of the phenolic fraction during the different fruit ripening stages. On the basis of the results about the evolution of phenolic compounds of olive drupes a research program aimed to identify the genes involved in the biosynthesis pathways of fruit secoiridoids, was developed by the CNR-Institute of Plant Genetics, Perugia.
86

Sistema per l'estrazione e purificazione di sostanze antiossidanti naturali nelle acque di vegetazione delle olive

Calderoni, Ettore Giacomo <1978> 17 April 2009 (has links)
The olive oil extraction industry is responsible for the production of high quantities of vegetation waters, represented by the constitutive water of the olive fruit and by the water used during the process. This by-product represent an environmental problem in the olive’s cultivation areas because of its high content of organic matter, with high value of BOD5 and COD. For that reason the disposal of the vegetation water is very difficult and needs a previous depollution. The organic matter of vegetation water mainly consists of polysaccharides, sugars, proteins, organic acids, oil and polyphenols. This last compounds are the principal responsible for the pollution problems, due to their antimicrobial activity, but, at the same time they are well known for their antioxidant properties. The most concentrate phenolic compounds in waters and also in virgin olive oils are secoiridoids like oleuropein, demethyloleuropein and ligstroside derivatives (the dialdehydic form of elenolic acid linked to 3,4-DHPEA, or p-HPEA (3,4-DHPEA-EDA or p-HPEA-EDA) and an isomer of the oleuropein aglycon (3,4-DHPEA-EA). The management of the olive oil vegetation water has been extensively investigated and several different valorisation methods have been proposed, such as the direct use as fertilizer or the transformation by physico-chemical or biological treatments. During the last years researchers focused their interest on the recovery of the phenolic fraction from this waste looking for its exploitation as a natural antioxidant source. At the present only few contributes have been aimed to the utilization for a large scale phenols recovery and further investigations are required for the evaluation of feasibility and costs of the proposed processes. The present PhD thesis reports a preliminary description of a new industrial scale process for the recovery of the phenolic fraction from olive oil vegetation water treated with enzymes, by direct membrane filtration (microfiltration/ultrafiltration with a cut-off of 250 KDa, ultrafiltration with a cut-off of 7 KDa/10 KDa and nanofiltration/reverse osmosis), partial purification by the use of a purification system based on SPE analysis and by a liquid-liquid extraction system (LLE) with contemporary reduction of the pollution related problems. The phenolic fractions of all the samples obtained were qualitatively and quantitatively by HPLC analysis. The work efficiency in terms of flows and in terms of phenolic recovery gave good results. The final phenolic recovery is about 60% respect the initial content in the vegetation waters. The final concentrate has shown a high content of phenols that allow to hypothesize a possible use as zootechnic nutritional supplements. The purification of the final concentrate have garanteed an high purity level of the phenolic extract especially in SPE analysis by the use of XAD-16 (73% of the total phenolic content of the concentrate). This purity level could permit a future food industry employment such as food additive, or, thanks to the strong antioxidant activity, it would be also use in pharmaceutical or cosmetic industry. The vegetation water depollutant activity has brought good results, as a matter of fact the final reverse osmosis permeate has a low pollutant rate in terms of COD and BOD5 values (2% of the initial vegetation water), that could determinate a recycling use in the virgin olive oil mechanical extraction system producing a water saving and reducing thus the oil industry disposal costs .
87

Empirical and fundamental mechanical tests in the evaluation of dough and bread rheological properties

Balestra, Federica <1979> 05 June 2009 (has links)
Bread dough and particularly wheat dough, due to its viscoelastic behaviour, is probably the most dynamic and complicated rheological system and its characteristics are very important since they highly affect final products’ textural and sensorial properties. The study of dough rheology has been a very challenging task for many researchers since it can provide numerous information about dough formulation, structure and processing. This explains why dough rheology has been a matter of investigation for several decades. In this research rheological assessment of doughs and breads was performed by using empirical and fundamental methods at both small and large deformation, in order to characterize different types of doughs and final products such as bread. In order to study the structural aspects of food products, image analysis techniques was used for the integration of the information coming from empirical and fundamental rheological measurements. Evaluation of dough properties was carried out by texture profile analysis (TPA), dough stickiness (Chen and Hoseney cell) and uniaxial extensibility determination (Kieffer test) by using a Texture Analyser; small deformation rheological measurements, were performed on a controlled stress–strain rheometer; moreover the structure of different doughs was observed by using the image analysis; while bread characteristics were studied by using texture profile analysis (TPA) and image analysis. The objective of this research was to understand if the different rheological measurements were able to characterize and differentiate the different samples analysed. This in order to investigate the effect of different formulation and processing conditions on dough and final product from a structural point of view. For this aim the following different materials were performed and analysed: - frozen dough realized without yeast; - frozen dough and bread made with frozen dough; - doughs obtained by using different fermentation method; - doughs made by Kamut® flour; - dough and bread realized with the addition of ginger powder; - final products coming from different bakeries. The influence of sub-zero storage time on non-fermented and fermented dough viscoelastic performance and on final product (bread) was evaluated by using small deformation and large deformation methods. In general, the longer the sub-zero storage time the lower the positive viscoelastic attributes. The effect of fermentation time and of different type of fermentation (straight-dough method; sponge-and-dough procedure and poolish method) on rheological properties of doughs were investigated using empirical and fundamental analysis and image analysis was used to integrate this information throughout the evaluation of the dough’s structure. The results of fundamental rheological test showed that the incorporation of sourdough (poolish method) provoked changes that were different from those seen in the others type of fermentation. The affirmative action of some ingredients (extra-virgin olive oil and a liposomic lecithin emulsifier) to improve rheological characteristics of Kamut® dough has been confirmed also when subjected to low temperatures (24 hours and 48 hours at 4°C). Small deformation oscillatory measurements and large deformation mechanical tests performed provided useful information on the rheological properties of samples realized by using different amounts of ginger powder, showing that the sample with the highest amount of ginger powder (6%) had worse rheological characteristics compared to the other samples. Moisture content, specific volume, texture and crumb grain characteristics are the major quality attributes of bread products. The different sample analyzed, “Coppia Ferrarese”, “Pane Comune Romagnolo” and “Filone Terra di San Marino”, showed a decrease of crumb moisture and an increase in hardness over the storage time. Parameters such as cohesiveness and springiness, evaluated by TPA that are indicator of quality of fresh bread, decreased during the storage. By using empirical rheological tests we found several differences among the samples, due to the different ingredients used in formulation and the different process adopted to prepare the sample, but since these products are handmade, the differences could be account as a surplus value. In conclusion small deformation (in fundamental units) and large deformation methods showed a significant role in monitoring the influence of different ingredients used in formulation, different processing and storage conditions on dough viscoelastic performance and on final product. Finally the knowledge of formulation, processing and storage conditions together with the evaluation of structural and rheological characteristics is fundamental for the study of complex matrices like bakery products, where numerous variable can influence their final quality (e.g. raw material, bread-making procedure, time and temperature of the fermentation and baking).
88

Nuovi approcci terapeutici nel trattamento dei linfomi non hodgkin di derivazione dai linfociti T periferici

Musuraca, Gerardo <1976> 09 June 2009 (has links)
No description available.
89

Leucemia Mieloide Cronica: outcome a lungo termine dei pazienti con risposta ottimale ad Imatinib. Risultati del GIMEMA CML WP

Palandri, Francesca <1977> 19 April 2010 (has links)
No description available.
90

Effetti clinici e biologici della terapia epigenetica nelle sindromi mielodisplastiche a basso rischio

Filì, Carla <1975> 19 April 2010 (has links)
Background: Nucleoside 5-Azacitidine (5-Aza) in high risk MDS patients (pts) at a dose of 75mg/mq/day subcutaneously for 7 days, every 28 days, induces high hematologic response rates (hematologic improvement (HI) 50-60%, complete remission (CR) 10-30%) and prolongation of survival (at 2 years 50,8%). Aim: The role of 5-Aza in low-risk MDS patients is not well defined but its use in the earlier phases of disease could be more effective and useful to control the expansion of MDS clone and disease progression. In our phase II, prospective, multicentric trial a low-dose schedule of 5-Aza (75 mg/mq daily for 5 consecutive days every 28 days) was given to low-risk MDS pts in order to evaluate its efficacy and tolerability and to identify biological markers to predict the response. Methods: From September 2008 to February 2010, 34 patients were enrolled into the study. Fifteen patients had refractory anemia (RA), 5 patients refractory anemia with ringed sideroblasts (RARS), 7 patients refractory cytopenia with multilineage dysplasia (RCMD) and 7 patients refractory anemia with excess blasts-1 (RAEB-1). All patients failed previously EPO therapy and were in chronic red blood cell (RBC) supportive care with a median transfusions requirement of 4 units/monthly. The response treatment criteria was according to IWG 2006. Results: At present time 31 out of 34 pts are evaluable: 12/31 pts (39%) completed the treatment plan (8 courses), 7/31 pts (22%) performed the first 4 courses, 8/31 (26%) made 1 to 3 courses and 4/31 (13%) died during the treatment period. Out of 12 pts who completed the 8 courses of therapy 10 (83%) obtained an HI, 2/12 (17%) maintained a stable disease. Out of 10 pts who obtained HI, 4 pts (40%) achieved a CR. Generally the drug was very well tolerated. The most commonly reported hematologic toxicities were neutropenia (55%) and thrombocytopenia (19%) but they were transitory and usually no delay of treatment was necessary. 2/4 pts died early after the 1th cycle for septic shock and gastrointestinal hemorrage respectively whereas 2/4 pts died in a condition of stable disease after the 4th cycle for pneumonia and respiratory distress. Samples for biologic studies have been collected from the pts before starting the therapy and at the end of 4th and 8th course. Preliminary data on the lipid signalling pathways suggested a direct correlation between PI-PLC-β1 gene expression and 5-Aza responsiveness. Conclusion: Interim analysis of our study based on the small number of cases who completed the treatment program, shows that 83% of pts obtain an HI and 40% obtain a CR. 4 patients died during the treatment and even if the causes were reported as no related to the therapy it has been considered that caution has to be reserved in given 5-Aza in these pts who are elderly and frail. Preliminary data of PI-PLC-β1 gene expression suggest that this and probably other biological markers could help us to know a priori who are the patients who have more chances to respond.

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