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Thesis on the topic Antioxidant in herbal teas is divided into two parts. The first part theortical is concerned with the description and division of antioxidants. There are mentioned some synthetic antioxidants, some major intracellular antioxidant and natural antioxidant, which are represented by polyphenolic compounds as the main components of herbal teas. Furthmore, there is described the determination of biologically active compounds by extraction techniques to chromatographic methods. In the theoretical part are also described individual samples of herbs used for analysis. The second part is concerned with the practical determination of polyphenolic acids in selected samples of herbal teas. Two extraction techniques were chosen for separation of polyphenolics acids. The first was Soxhlet extraction accelerated and the second was exctraction shaker. For the determination of polyphenolic acids was used high performance liquid chromatography (HPLC) coupled with a diode array detector (DAD) and with mass detector type triple quadrupole. The measured results show that in most samples of herbs were the most represented chlorogenic acid and caffeic acid.

This thesis examines the influence of yeasts on the final stage of wine, consists of theoretical and practical parts. The theoretical part deals with the yeast themselves, their description, nutrition, the most important yeast for wine fermentation methods and influences that affect the fermentation process. The second part is devoted to work for bridges for optimal fermentation, there must be engaged in expanding and methods of sludge. The next section is devoted to chemical reactions during fermentation, wine composition and in the last part describes the training and maturation of wine. In the practical part is devoted to the production of wine from Pinot Blanc and his subsequent analytical analysis, determination of individual elements such as alcohol, glucose, fructose, glycerol and total acidity. In the last phase is devoted to the evaluation of individual analysis and discussion.

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The aim of the study was monitoring of two of phthalic acid esters in agricultural soils in the Czech Republic for free years: dibutyl phthalate (DBP) and di 2 ethylhexyl phthalate (DEHP). The monitoring of the phthalate content took place in twelve regions of the Czech Republic. Soil sampling was carried out using the zig-zag pattern from topsoil and subsoil. The soil samples were taken from the following cultures: arable land, permanent grassland and hop gardens. Concentration levels were established by means of high performance liquid chromatography with UV detection. Samples were extracted using sonication and mixture of acetone-hexane (1:1). The established concentrations of the esters of phthalic acid were as follows: for dibutyl phthalate from 0,02 to 1,78 mg.kg-1 dry weight; for di 2 ethyhexyl phthalate from 0,06 to 2,22 mg.kg-1 dry weight; total concentration of both phthalates then ranged from 0,24 to 2,83 mg.kg-1 dry weight. When comparing the concentration levels established in the present study with the values set by the Ministry of Environment of the Czech Republic and stated in its Guideline stemming from the RSL (Regional Screening Levels) published by the United States' Environmental Protection Agency (USEPA), none of these values were exceeded in this study.

The thesis focuses on beer components with health benefits and methods of determination of these substances. The theoretical part is divided into 5 chapters in which the brewing process is described including the necessary raw materials, the issue of biologically active substances and the methods of their determination are here also outlined. In the last part there are also briefly mentioned volatile substances found in beer. The aim of the experimental part was to determine organic acids, phenolic compounds and 5-MTA in the chosen samples of Czech and German lagers. For the analysis, 5 samples from each country were used. To the analysis was also used beer brewed in the premises of Mendel University in Brno. In this beer were determined the changes in the content of selected substances in 6 stages of the brewing process and in the final product. Beer is a complex matrix, requiring a solid phase extraction (SPE) treatment prior to HPLC analysis.