This diploma thesis is focused on the topic The use of polyvinylpolypyrrolidone and possibilities of its regeneration in the beverage industry. The thesis was written in years 2015/2016 at the Department of Post-Harvest Technology of Horticultural Products, Faculty of Horticulture at Mendel University in Brno. The theoretical part deals with the polyphenolics compounds in wine, antioxidant capacity and wine defects related to polyphenols. The last chapter offers multiple methods of removing defects, where the highest priority is given to the clarifier PVPP. The experimental part is aimed at the regeneration of single used PVPP with four different ways and the determination of its efficiency throughout suitable analyses after its reuse in the wine. The resulting data are statistically processed and shown in the graphs.

The aim of this work was to study phenolics and other active compounds in 22 kinds of lager beer and especially to find some differences between Czech beer and beers made in foreign countries. In theoretical part the most useful methods for phenolic and protein analysis are discussed. Further, basic steps of brewery technology are introduced and main beer components with regard to Czech beer specificity are presented. Analysis of total phenolics, total flavonoids, antioxidant activity and most of basic technological characteristics was performed spectrophotometrically. To identification and quantitative analysis of individual phenolics on-line liquid chromatography with photo-diode array (PDA) and mass spectrometry (MS) detection was used. Protein analysis was performed by vertical electrophoresis SDS-PAGE and by Experion microfluidic electrophoresis (BioRad). From the total of 22 samples, 15 Czech beers and 7 beers of foreign marks were enrolled into this study. In these samples levels of brewery characteristics, group antioxidants and individual phenolics were compared. Flask and can beers as well as alcoholic and non-alcoholic beers were compared too. As a model comparative sample the Czech hop of Sládek variety was used. Finally, usefulness of tested parameters to differentiation composition and technology of individual beer samples was evaluated and parameters suitable for Czech beer authenticity analysis were proposed.

Presented diploma thesis is focused on analysis of phenolic compounds in various types of beers. The aim of this work was to find possible differences among several types of beers and also between Czech beers and beers of foreign production. Theoretical part contains detailed description of beer technology, review of important analytical methods for determination of phenolic compounds and total antioxidant activity. The main attention is focused on instrumental technique LC/MS. In the experimental part values of total phenolics and total flavonoids and results of antioxidant status in analyzed beers were determined spectrophotometrically. Basic brewing characteristics were determined by pycnometry. On-line liquid chromatography with photo diode array detection and mass spectrometry detection was used for identification and quantification of individual phenolic compounds. Spectrophotometric analysis of phenolic and flavonoid levels seems to be less specific, that is consistent with findings in accessible literature. It was proved, that iso- bitter compounds exhibit about 65.44 – 90.93 % of the total bitter substances. These components are responsible for the main part of beer bitterness. The HPLC/PDA/ESI-MS was necessary to use for determination of characteristic phenolic compounds in individual types of beer. Within our measurement three columns were tested, the most favourable results were obtained using the column Restek C18. When compared with foreing beers, in Czech beers higher level of majority of phenolic compounds was detected and specific distribution of individual derivatives was found as well.

This master‘s thesis deals with the analysis of 65 different beers, with a focus on finding differences between Czech tap ales, lagers Czech, Czech special beers and foreign beers. Czech beers were compared by the results of analysis among beers bearing the indication "Czech beer" and the group without this indication. The total amount of proteins, polyphenols and carbohydrates was determined using UV-VIS spectrometry. The history of brewing, the nature and types of Czech beers and protected geographical indication "Czech beer" were described. Raw materials for beer production and brewing technology have been listed and described. In the last part of the research, components of beer and the principle of the UV-VIS spectrometry have been specified. Th determination of total protein was performed using Hartree-Lowry method, which is based on two-component reagent. The first component is the biuret agent, the second component is the Folin-Ciocalteau reagent for phenols. Determination of the polyphenols has been carried out by the Folin-Ciocalteau reagent and total carbohydrates were determined spectrophotometrically according to the Analytica EBC using anthron agent. The results were statistically processed and evaluated in the final part.

This paper is dedicated to gathering information about utilization of Vitis vinifera L. extracts, mainly grape seed extract (GSE), production of GSE in two variants (aqueous or methanol GSE) and description of its characteristics. Extract was rich in polyphenols (13462 mg/l GAE), measured by Folin-Ciocaltel method. Also 3615 mg/l GAE of flavonols was present in GSE. Antioxidant activity measured by DPPH method was high, 7978 mg/l GAE. Disc diffusion method was used for antimicrobial activity analysis. GSE's effect was tested on five common microorganisms. Results of the experiment show that GSE strongly inhibits growth of Bacillus cereus, Candida tropicalis and Enterococcus faecalis. However, it was not effective against Escherichia coli and Pseudomonas aeruginosa.

The work was devoted to the technology of flavored beers and consisted of two parts. In the first one, we dealt with their basic division, commonly used raw materials, the description of individual technological steps and the difference between the production of ordinary and flavored beers. They have also been divided based on their origin and assigned to the typical geographical areas in which they are produced. In the second - experimental part - nine micro samples were created and by help of FermentoFlash destillation, and spectrophotometer the basic parameters were determined. Such as the original extract, weight, volume, alcohol and color of wort. Also, the total polyphenol content and antioxidant capacity were determined using DPPH and FRAP methods. A sensory evaluation was made in order to detect sensory differences depending on the phase in which the fruit was added. The results were subjected to statistical research and reviewed and compared the results published by other authors.

This thesis is introducing us theme of the metabolic profile of biologically important compounds in honey. This thesis is devided into two parts. The first part (the literature review) is introducing characteristic of honey, history of a use for medical purposes, honey content, content of biologically active compounds and their positive effects on human health. There are also described methods of determination polyfenolic compounds in honey. The second part of this thesis (practical part) deals with determination of polyfenols in 11 kinds of honey using the high pressure liquid chromatography mass spectrometry (HPLC-MS). Extraction was carried out by using liquid-liguid extraction using ethylacetate and diethylether as a solvent and solid phase extraction using water as a solvent. These methods were then statistically compared.

This paper was written to provide the literature review on the topic of horticultural production in Namibia or in neighboring countries, with a focus on vegetable species. To suggest a prospective representative vegetable species from the study area, which could have production potential in the Czech Republic. Four chosen cultivars (Metro, Nakare, Bira and Shidimba) from the Cowpea (Vigna uinguiculata L Walp) species were experimentally tested in conditions of the Czech Republic. They were grown naturally extensively with no fertilizers, herbicides or pesticides used. They're morphological parameters were then recorded and laboratory analyzed using ANOVA and three valuables [flavonoids, total antioxidants capacity (TAC) and polyphenols] were determined using different methods with the spectrophotometry.

Data shows that if the year is similar to year 2013, as regards to the increased content of titratable acid, there can be a longer maceration pulp, which may serve as the future harmoniousness wine. Appropriate sufficient time of maceration for any decrease in titratable acidity corresponds to the period of maceration form 4 to 12 hours. Regarding the tartaric acid and malic acid, the time of maceration appears to be approximately 8 hours. From this time forth there may be rises in values of malic acid,which can cause microbiological instability. If we wanted to get the largest share of the health-promoting substances of this year, the must had to be macerated at least 48 hours.

This thesis was created in years 2013/2015 at the Institute of Post-Harvest Technologies of Horticulture of the Mendel University in Brno. The thesis deals with the nutritional composition of grapevine juices with the emphasis on phenolic constituents, about the methods of determination of the antioxidant activity and the technology of production of fruit juices and the legislative requirements on their quality. In the practical part, the variety of grapevine juices with the addition of spruce chips or their extracts was suggested and sensorial parameters, all of the polyphenols and the antioxidant activity was determined.