The diploma thesis is focused on the determination of the content of phthalates (PAE) in printed and non-printed plastic packaging materials for meat products. There were analyzed 30 package samples. The sample area was 1 dm2. Concentrations of dibutyl phthalate (DBP) ranged from undetectable values (< 0.1) to 72.6 ug.dm-2 of the sample surface in printed packaging materials. In non-printed wraps it was from undetectable values (< 0.1) to 67.7 ug.dm-2 of the sample surface. Concentrations of di-2-ethylhexyl phthalate (DEHP) ranged from undetectable values (< 0.1) to 98.7 ug.dm-2 of the sample surface in printed packaging materials. In non-printed wraps it was from undetectable values (< 0.1) to 60.3 ug.dm-2 of the sample surface.

This diploma thesis on the topic Monitoring of phthalates content in packaging and their migration from the packaging to the meat products deals with analysis of textile colour-printed packaging intented for packaging of meats products to find out dibutylphthalate (DBP) and di-2-ethylhexylphthalate (DEHP) content and also deals with monitoring migration of these phthalates into model meat products during storage (for twenty-eight days). The values of concentration of DBP and DEHP in packaging reached 24.0 ug.dm-2 and 103.3 ug.dm-2 of the original sample. Sample of meat product was analyzed before packaging and no phthalates were detected. After packaging and storage the highest value of DBP concentration at the end of the storage period was 11,1 mg.kg-1 and concentration of DEHP was 28,2 mg.kg-1 of the original sample. Based on the results from measurements with increasing storage time increased concentrations of these substances in meat products. In accordance with the specific migration limits (for DBP 0,3 mg.kg-1 and for DEHP 1,5 mg.kg-1) mentioned in Commission Regulation (EU) no. 10/2011 on plastic materials and articles intended to come into contact with food have been exceeded in all samples of meat products during storage.

The aim of this diploma thesis was to determine, using gas chromatography, fatty acids in selected animal tissues. Specifically, the muscle, liver, pulmonary and adipose tissues were observed. A total of 32 piglets were divided into two groups with 16 pigs in each group. During 75 days of fattening, each group was given a feed mixture differing in the type of oil added. The experimental group was fed a basic feed mixture with the addition of 2,5 % fish oil, whilst the control group with the addition of 2,5 % palm oil. The animals were fed ad libitum. After slaughter, samples of selected tissues were taken and the process of lyophilisation was carried out. Using extraction method according to Hara, Radin (1978), lipids from lyophilized tissue samples were extracted. Fatty acids present within these lipids were then transformed into more volatile fatty acid methyl esters by the process of derivatization. These were then determined by gas chromatography and the results were statistically evaluated. The effect of fish oil in the feed mixture resulted in the increase of PUFA n-3 (P < 0.01) in all of the tested tissues. The addition of palm oil, on the other hand, had an effect on the content (P < 0.05) of SFA, MUFA in the tested tissues.

The diploma thesis deals with the determination of lipids and fatty acid profile in a barley caryopsis.(Hordeum vulgare). The theoretical part describes the synthesis of fatty acids and their degradation in plant material, secondly, it described the possibilities of lipid extraction and their determination and the possibilities of determination of fatty acids. In the experimental part method of lipid extraction on automated extractor Fex ®IKA and determination of fatty acids by GC-FID were optimized. For analysis of fatty acids two capillary columns SLB-IL 100 and Supelcowax were compared. Twenty varieties of barley from the year 2008 and twenty varieties from the year 2009 were compared based on the content of lipids and the representation of fatty acids in a barley caryopsis. The diploma thesis was realized in the Research Institute of Brewing and Malting, Plc. in Brno.

This diploma thesis deals with the study of non-stationary diffusion of cupric ions in humic gels. The main objective of the work was the optimalization of conditions for using the electrochemical analyzer EcaFlow 150 GLP for the study of diffusion experiments. Next part was focused on reaching of constant concentration profiles of cupric ions in humic gel. Last aim of the study was the bond strength between cupric ions and humic acids. Diffusion was characterized by the values of the diffusion flux and cupric ions concentration profiles in humic gel. The data necessary for calculation were obtained by the electrochemical analyses of the extracts of each slice after diffusion on the EcaFlow 150 GLP. It has been proved that after application of several adjustment is this method suitable for the study of diffusion experiments. By using of different extraction agents was obtained the fractionalization of cupric ions according to the bond strength to humic acids.

The diploma thesis focuses on utilization of diffusion cells in reactivity mapping study on humic acids. In the experimental part, samples 6 humic acids of different origin or chemical modification were studied. All the samples were characterized by basic analytical and physico-chemical methods (elemental analysis, thermogravimetry, determination of acidity, spectrometry). Methylene blue was utilized as a model reactive probe and agarose gel as an inert support medium. An effect of interactions between humic acids and methylene blue on diffusivity of the dye in the hydrogel was determined and discussed.

The behaviour of humic acids in aqueous solutions is closely connected to the content of acid functional groups and their dissociation abilities. The titration methods are the most often used for the research of acid-base characteristics of humic acids, their results should lead to the determination of the content of functional groups and their pKa. However the determined values depend on many factors including the titration speed. The spectrophotometric determination of dissociation constant was used in this diploma thesis. Reliability of this method was confirmed in bachelor thesis where is mentioned that spectrophotometric determination of pKa corresponds with realistic dissociation behaviour of humic acids in the water much more better than values obtained from titration methods. The principle of newly used spectrophotometry method is the preparation of humic acids solutions in three different media with different pH values. Acid groups of humic acids are practically completely dissociated in intensely basic environment and the measured absorbance is caused by anion of „humate“. On the contrary their dissociation in acid environment is suppressed so much that we measure the absorbance of non-dissociated molecules of humic acids. Deionized water was used like neutral solvent. Water was replaced by acetic buffer in this thesis because of water’s properties which have significant influence on solutions' pH. Buffer was used for diluting or for solubilisation and in these both cases more stable pH values were occurred. The aim of this diploma thesis is investigate UV/VIS spectra of various solutions of humic acids with different values of pH and determinate mean value of pKa of humic acids which could be used like comparison of dissociation behaviours for vary samples. Values of acid dissociation constant were determined from measured dates and compared with values obtained by titration method. The UV/VIS spectra gained in combination with the results of pH measuring and the conductivity next showed the differences in the behaviour of differently prepared samples of humic acids.

The thesis deals with a utilization of hydrogels made of humic acids in both basic and applied research of this valuable natural material. The attention is paid to an interaction between the humic gel and cupric ions as the model heavy metal. The main experimental part focuses on an optimation of simple laboratory diffusion methods which serve as an innovative tool for modeling pollutants’ transport in natural humic environments. Various techniques were used in order to determine a diffusion coefficient of cupric ions in humic gel; the value is closely linked with the studied interaction between solid content of the gel and the diffusing species. Consequently, the diffusivity can be used as a standard parameter for basic reactivity mapping studies concerning humic substances. The final chapter of the thesis deals with a preparation of mixed reversible hydrogels formed by a reaction between humic acids and chitosan. These materials represent a suitable colloidal form for humic acids’ industrial and agricultural applications.

Snow algae as typical extremophiles are good model organisms for study of adaptation for life on the boundary of physiological possibilities. So far, it is not clear, how these microorganisms ensure on the molecular level the optimization of photosynthetic processes in conditions around 0 řC, often with very high light intensity. The aim of this work was to find out light and temperature growth optima of two less studied strains and to assess the composition of fatty acids in selected psychrophilic and psychrotrophic strains from the genera Chloromonas and Chlamydomonas (Chlamydomonadales, Chlorophyta) from culture collections UTEX and CCCryo and collections in Europe including the Czech Republic and Slovakia. Using crossed gradients method, this thesis describes optimal temperature and light conditions of two strains of snow algae isolated from sites in the Krkonoše Mountains that are characterized by different ecological conditions. The strain Chloromonas reticulata Luční originates from alpine zone and according to its growth characteristics, it can be classified as psychrotrophic alga requiring high light. The second tested strain was Chloromonas pichinchae Meandry from forest environment, which is also characterized as psychrotrophic, In contrast to previous strain, it grows in a wide range of...

Type 2 diabetes mellitus represents a metabolic disease reaching epidemic dimensions in the 21st century. Fatty acid-induced apoptosis of pancreatic β-cells significantly contributes to its pathogenesis. Saturated fatty acids (FAs) are strongly cytotoxic for β-cells, whereas unsaturated FAs are well tolerable by β-cells, they are even able to inhibit proapoptotic effects of saturated FAs when co-incubated. According to recent studies, FAs-induced apoptosis in pancreatic β-cells is partly regulated by autophagy, a catabolic process involved in the degradation and recyclation of cell components in lysosomes. The aim of this diploma thesis was to contribute to the clarification of the role of autophagy in FAs-induced apoptosis regulation. We induced apoptosis in human pancreatic β- cell line NES2Y by 1 mM stearic acid (SA) and inhibited it with 0.2 mM oleic acid (OA) co- incubated with SA. We revealed, that the saturated SA used in apoptosis-inducing concentration simultaneously inhibits the autophagic flux in pancreatic NES2Y cell line. When SA is co- incubated with unsaturated OA in concentration sufficient for inhibition of proapoptotic effect of SA, OA is also able to inhibit the block of autophagy induced by the effect of SA. Application of unsaturated OA alone in this concentration did not...