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Miniaturizované techniky pro analýzu průmyslových kvasinek / Miniaturized techniques for analysis of industrial yeastsObalil, Jiří January 2008 (has links)
Carotenoids are natural pigments that have antioxidation and antimutagenic abilities. They are produced with the help of new technological methods. For example, carotenoid yeast Rhodotorula glutinis produces -carotene with the yield of up to 6 – 10 mg/g of the dry substance. The method of the mass spectrometry with the nanoelectrospray in the positive mode was optimized for the determination of -carotene, lycopene and astaxanthin in this project. Ionizing voltage of 4 kV and the sample flow rate of 15 – 80 nl/min through the spray silica fused capillary with the internal diameter of 25 µm were found to be the optimum parameters of the analysis. A mixture of chloroform with the addition of ammonia was used as a spray solvent for both standard and cellular samples. During the process of ionization by nanoelectrospray, -carotene and lycopene form cation radical [M] • + with the molecular mass to charge ratio (m/z) of 536, while asthaxanthin forms the protonated molecule [M + H]+ with the m/z of 597. The partial lysis of individual Rhodotorula glutinis cells was demonstrated under microscope in the organic solvents tetrahydrofuran and dimethylsulfoxide. Chloroform, acetone, acetonitrille, methanol and isopropanol did not affect the cells after a 15 min treatment.
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Sledování kvalitativního a kvantitativního zastoupení vitaminů v masozeleninových přesnídávkách určených pro dětskou vyživuSolčány, Veronika January 2016 (has links)
This thesis deals with the qualitative and quantitative representation of vitamins in the meat-vegetables based infant food. The work is divided into the theoretical and the experimental part. The theoretical part describes a child nutrition and the vitamins. In the chapters, dealing with vitamins, is a description of particular vitamins, their biological functions in the body, the recommended daily dose and their stability during food processing. These chapters concern fat-soluble vitamins (vitamin A, D, E and K) and water-soluble vitamins (B-group vitamins and vitamin C) as well. The work deals with nutrition of infants, toddlers and young children under age of 10 years too. For the each age group there is given the daily recommended dose of vitamins. Experimental part deals with the quantification of vitamins (retinol, ascorbic acid, A-tocopherol and B-carotene) by the HPLC analysis in the samples of the meat-vegetables based infant food. The influence of storage time and conditions (exposure to daylight vs storage in the dark) was measured on concetration of the examined vitamins in the samples. The results were statistically analyzed using software Statistica 12 (Wilcoxon signed-rank test, linear regression, p<0,05) and showed, that all monitored vitamins degrades during storage. The concetration of vitamins in the product is also influenced by the storage conditions (the faster degradation of vitamins occurred in samples exposed to daylight).
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Environmentální faktory ovlivňující tělesnou vůni člověka / The Environmental Effects on Human Body OdourDneboská, Tereza January 2012 (has links)
The main source of the human body odour is an axillary region. Human body odour is individually specific and results from genetic and environmental factors. Human body odour is an important sexual attractant for potential partners. It is influenced by environmental factors, such as an emotional state and health. Important environmental factors influencing human body odour are also eating habits. However, we know very little about how particular dietary components shape our body odour. Only the effect of red meat and garlic consumption have been tested. Here we tested the effect of caffeine (from usual source and guarana) and beta- carotene. In our three experiments we used a balanced within-subject experimental design. Volunteers donated twice their body odour: once after ingestion of the tested substance, second time in the control situation. Samples were then assessed for their attractiveness and intensity by group of women. Results showed that caffeine consumption may influence negatively attractiveness and intensity of human body odour. Guarana and beta-carotene did not show any significant results. These results partially confirmed that dietary factors influence the quality of the human body odour. This field should be further studied as a part of the environmental factors influencing human...
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Stanovení beta-karotenu v ječmeni metodou HPLC / Determination of beta-carotene in barleycorn by HPLCPuč, Vojtěch January 2008 (has links)
This diploma thesis deals with the natural antioxidants present in cereals, especially in barley (Hordeum vulgare). A close attention is paid to the study of carotenoids determination was conducted. In the experimental part, the method of beta-carotene determination was optimized using high-performance liquid chromatography, diode array detector and mass detector (HPLC/DAD/APCI-MS). The method was used for the beta-carotene and lutein determination in the samples of barleycorn, malt and green barley. This method involves the sample saponification, extraction by diethylether, followed by separation on ODS Hypersil 250x4,6 mm, 5m column, using MTBE/MeOH (20:80) as mobile phase and spectrophotometric detection (450 nm). Quantitative analysis was implemented in the HPLC/DAD system. The MS detector was used for identification of analytes. A number of still unpublished data about the content of beta-carotene and lutein in several varieties of malting barley, malt and green barley are stated in this thesis. The highest content of beta-carotene was found in the green barley sample of variety Malz, harvested in first grow phase (8,49 mg/kg of the dry matter). The content of beta-carotene in barleycorn is relatively low (0,07-0,14 mg/kg of the dry matter). The content of beta-carotene is several times higher in the malt produced from barleycorn (0,24-0,56 mg/kg of the dry matter). The diploma thesis was implemented in the Research Institute of Brewing and Malting, Plc. in Brno.
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Analýza biologicky významných látek / Analysis of biological significant substancesMaděránková, Denisa January 2008 (has links)
Selected methods of Raman spectroscopy, like surface-enhanced Raman spectroscopy and single molecule Raman spectroscopy, are described in this diploma work. The basis of two methods for numerical modelling of optical properties of micro- and nanoparticles are prefaced. The methods are Discrete Dipole Approximation and Finite Difference Time Domain. Micro- and nanoparticles are used in surface enhanced Raman spectroscopy and other nanospectroscopic methods. Further, the main instrumentation needed for Raman spectroscopy is described. The first part of experimental section of this work is numerical modelling of photonic nanojet that occures behind dielectric microparticles. This phenomenon leads to a new technique of confocal microscopy with Raman spectra measuring. The second experimental section contains results of Raman spectra measurement with beta-carotene and surface-enhanced Raman spectra of beta-carotene in silver-sol solution.
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Vliv stresových faktorů na tvorbu karotenoidů v izolovaných kmenech půdních řas / Effect of stress factors on carotenoid production in isolated soil algae strainsOčadlíková, Terezie January 2021 (has links)
Microscopic green algae produce a number of beneficial substances. The commercially used ones include mainly pigments, especially secondary carotenoids. While primary carotenoids are part of the photosynthetic apparatus, secondary carotenoids are produced only under certain specific conditions (e.g. high exposure to light, nitrogen deficiency). Secondary carotenoids have antioxidant properties that protect the cell from adverse effects. The strains currently in commercial use and the strains that are tested for potential use come almost exclusively from algal collections, so this thesis focuses on strains isolated from nature. Two strains of aeroterrestrial green unicellular algae, which showed potential of producing carotenoids, were found and isolated. These strains were identified as Tetracystis pulchra (clade Dunaliellinia) and Tetracystis sp., a strain related to Tetracystis tetraspora SAG 98.80, belonging to the clade Stephanosphaerinia. The culture conditions for T. pulchra were subsequently optimized and then the culture was subjected to a series of experiments, examining the effect of stress factors on carotenoid formation and accumulation. Specifically, the effect of nitrogen starvation, light intensity, temperature and UVA radiation was tested. It has been shown that especially the light...
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