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Application of Mass Spectrometry for the Determination of Oxidative Stress Markers and Mycotoxins
Čumová, Martina ; Večeřa, Zbyněk (referee) ; Hajšlová, Jana (referee) ; Vávrová, Milada (referee) ; Čáslavský, Josef (advisor)
The first topic presented in the dissertation thesis is determination of isoprostanes as markers of oxidative stress and other compounds affected by presence of oxidative stress. Isoprostanes iPF2-III, iPF2-VI, iPF2-VI, astaxanthin and polyunsaturated fatty acids (PUFA), especially arachidonic acid (AA) were monitored in Atlantic salmon eggs (Salmo salar). Methods for the determination of these compounds have been developed and optimized using chromatographic separation coupled to conventional or mass spectrometric detection. Freshly laid eggs, eyed embryos and non-viable eggs were used to test a general hypothesis that egg viability can be affected by susceptibility to oxidative stress, either through the specific fatty acid concentration and/or the antioxidant capacity of the eggs. Levels of isoprostanes and arachidonic acid (AA) were significantly higher in non-viable eggs than in control (eyed embryos) as well as relative abundance of PUFA. While no difference of isoprostanes was found between freshly laid and control those from the Atlantic stock except iPF2-VI which was observed under the LOQ in the control. Higher levels of PUFA and AA in comparison with the control were observed in the freshly laid eggs. However, the only statistically significant difference was observed in the amount of astaxanthin. Different levels of PUFA and astaxanthin may be related to their biochemical consumption during the development of eggs. This work evaluated potential effect on the viability of eggs Salmo salar due to the presence of oxidative stress. The monitoring of mycotoxins in food and feed was the subject of the second topic. Mycotoxins are secondary metabolites produced by fungi. They are ubiquitous undesirable natural contaminants that are toxic for humans and animals. Today are known more than 500 mycotoxins. However, only few of them are regulated by the European Union. The European Food Safety Authority (EFSA) was asked by the European Commission to provide a scientific opinion on other mycotoxins for which statutory limits could be developed. In this study is proposed simultaneous screening allowing fast, reliable and sensitive approach, identification and quantification of 17 mycotoxins in food and feed sample. The method includes both mycotoxins regulated by the EU and selected mycotoxins required by the EFSA (aflatoxins, deoxynivalenol, nivalenol, zearalenone, fumonisin, ochratoxin A, T-2 toxin, HT-2 toxin, enniatins and beauvericin). Analytes are isolated by the modified QuEChERS method. For separation and target mycotoxins detection, ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC –MS/MS) was employed. The method also allows determination of ergot alkaloids (ergocornine, ergosine, ergocryptine, ergocristine and their respective epimers). The developed method was used either for monitoring mycotoxins and ergot alkaloids in feed and raw materials and barley and malt prepared from it.
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Determination of selected perfluoroalkyl compounds in complex matrices
Ondreášová, Klára ; Vávrová, Milada (referee) ; Mgr. Petra Kosubová, Ph.D (advisor)
Diploma work focuses on the determination of selected representatives of perfluoroalkyl substances in complex matrices, particularly, in sewage sludge and feed. In case of sewage sludge, samples were extracted into methanol and three extractions techniques were compared: accelerated Soxhlet, pressurized liquid extraction and Powley method. Powley method showed sufficient efficiency, the lowest matrix effect and minimal background. Perfluorooctane sulfonate was present in all tested samples of sewage sludge (0.74–38.02 ng.g-1). Other detected compounds were perfluorodecanoic acid and perfluorooctanoic acid. Three extraction techniques were tested on feed samples (QuEChERS, fast methanol extraction and Powley method into acetonitrile). Powley method provided the cleanest extracts and showed simultaneously the highest recovery of native perfluoroalkyl substances and the lowest matrix effects. Perfluorooctane sulfonate and perfluorooctanoic acid were rarely present in samples of complete and supplemental feeds, while other perfluoroalkyl substances were found at levels below limit of quantification or they were not detected at all. Perfluorooctane sulfonate (0.100–2.768 ng.g-1), perfluoroundecanoic acid and perfluorotridecanoic acid were determined in all fish meal samples.
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Development and production of a food optimized for exotic birds
SOVOVÁ, Marie
My bachelor's thesis is focused on the development and production of seed and grain feeding mixture for exotic birds which are kept in captivity as pets. Commercially produced mixtures and newly made ones are compared in this thesis. The analysis was conducted for two groups of exotic birds, for sixty individuals of the Estrildid Finches family, and forty individuals of parrots. The result of it is that four new sorts of feeding mixtures were made with economic savings. All the nutritional parameters remained preserved.
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Nutritive value determination of granular feed mixtures for dogs
ZNOJ NOVOTNÁ, Barbora
The aim of this thesis was evaluate the nutritive value of complete granulated dry food for adult dogs in normal activity. 17 dry feeds were choosen with regard to quality classes - 7 superpremium, 5 premium and 5 economy. Content of moisture, crude protein, crude fat, crude fibre, crude ash were determined in laboratory and NFE (nitrogen-free extracts - carbohydrates) and metabolizable energy were determined by calculations. The results of the analysis were compared with figures stated on the packaging of the feed. Quality classes were compared with each other. It was found that 12 from 17 feeds exceeded the tolerance limites for declarated nutrients. Not all of the feeds on the market is suitable for the dogs and an appellation superpremium isn't guarantee of good quality.
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Influence of selected factors on reproduction of fish \kur{Betta splendens}
HOMOLKA, Václav
The Siamese fighting fish (Betta splendens; order Perciformes, family Osphronemidae) is a fish occurring in the area of south east Asia. Above branchial organ (so-called labyrinth) allowes it to breath an air oxygen. It is a territorial sort of fish, males are brawling to each other. In a breeding fish take alive or frozen food and also artificial feed. The fish is bubblenest, spawns are put into a foam nest, built by a male, that takes care about the posterity for some time. The task of the work was to verify the influence of chosen feeds sorts and concentration of humic substances in water for a success in reproduction of Betta splendens fish. The experiment was performed in an aquarium room at institute of biological disciplines AF USB. The experimental work started on 12. 12. 2011 and was finished on 25. 2. 2013. Tested fish were by particular couples put into tanks, at which there were breeding afterwards. It was evaluated the frequency of spawns and the number of embryos. From the result of the work there is obvious that the feeding by a beef heart was preferable for fish´s fertility in a monitored time area about approximatelly 75% in comparison to feeding by a chicken breasts muscles. The presence, or more precisely the concentration of humic substances obviously did not affected the fertility. All fish´s groups embodied higher grade of fertility at the beginning of the monitored time area (probably higher fertility at younger - more vital fish). Siamese fighting fish is very demanded fish at aquarists, this is why is very important to evaluate certain parameters of breeding and rearing of these fish.
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