This diploma thesis is deal with influence of maceration period on the amount of yeast assimilable nitrogen that it is in wine must. In literary part I generally described role of nitrogen in vine and yeast assimilable nitrogen. In experimental part were choosen two varieties, "Tramín" and "Rulandské bílé". The grapes of these varieties were macerated for 48 hours after stemming and milling. Both of these varieties were made in two different ways, the first was uncooled and the second was cooled to 5 degrees. Sampling was carried out after 0, 2, 4, 12, 24 and 48 hours of maceration and volume of yeast assimilable nitrogen and other parameters were measured in the samples. These results were evaulated statistically and influence of maceration period on the amount of yeast assimilable nitrogen and other volumetric substances in must of grape vine were researched.

The aim of this diploma thesis was to study the literature related to terpene compounds in aromatic varieties of wine and to describe muscat and tramin variety. The study used varieties 'Irsai Oliver', 'Moravian Muscat' and 'Red traminer'. For these varieties in a given year, was determined content of free and bound terpene compounds in berries and wine. There was different time of must maceration for given varieties, namely 5, 12, 24 hours and control without maceration of pomace. The experimental part of the thesis dealt with assessment of the terpene compounds and sensory evaluation. The aim was to find out which terpene compounds are characteristic for different wine varieties and what is the most suitable length of maceration for the particular wine variety.

This thesis deals with the problem of usage of stems while vinification while the results are bouth analytic and sensoric as well.

The thesis deals with kryotechnology and wine production using kryotechnology and monitoring molar substances of wines produced by kryotechnology in comparison to classical production. The first part introduces the maceration of grapes for white wines and methods of maceration, then the factors that influence the maceration, the next section deals with the fabric composition of berries and eventually meet with kryotechnology and its methods. In the experimental part is a brief description of all the three varieties of which the experiment was performed. This is followed by a description of the conduct and methods of production well and finally this section is being set of analytical and sensory methods to be performed. In the results, we will learn what conclusions and opinions we have come here and see clearly expressed the results in graphs where it is clearly shown how the wine itself developed from primary production.

This Diploma thesis deals with kryomaceration and wine production using kryotechnology. The thesis examines the differences between molar composition of wines produced by classic method and wines produced by kryomaceration technology using very low temperatures of maceration. The first part of my thesis introduces molar composition of grapes and kryomaceration saying which ways are possible to use. In the experimental part are firstly described all three varieties of wines, which were used for the experiment. The second part tells about continuance and methods used for production of wines. There is prepared an aggregate of analytic and senzorical methods, which were used for production of wines in the end of this part. The last part of my thesis is about results. These results shows conclusions and opinions on given topic. The results are displayed in graphs which are decribed a clearly shows the progress of the wine behaviour from the beggining to their final figure.

The submitted thesis was focused on the study of redhead wines. In the experiment, wines of the redhead type were made using the technology of mixing of must and mixing of mash. For both variants, wines with different proportions of white and blue varieties were created. It was a variant of 75 % of the white variety to 25 % of the blue variety, 50 % of the two varieties and the third variant was 25 % of the white variety to 75 % of the blue variety. Pinot Blanc variety was used for the experiment for a white varieties and the Zweigeltrebe variety was used for the experiment for blue varieties. It also produced classic white and red wine from the varieties. Sensory analysis was performed on wines. Basic analytical parameters (alcohol, titratable acids, reducing sugars, pH and glycerol), antiradical activity and phenolic compounds (anthocyanins, flavanols, flavonols, hydroxycinnamic acids) were also measured. The results show the fundamental impact of maceration of the solids of the berries on the resulting wines, followed by the influence of the variety used. Wines produced by maceration of mashes contained higher values of phenolic substances than wines produced by fermentation of musts.

This Diploma thesis contains information about cryomaceration and using of dry ice in wine technology. Base on that we could compare differences in basic wine parameters or amount of fenolic and sensoric contrasts in mature wines. In theoretical part of this thesis are describe principles of cold maceration or cryomaceration, but main focus was on maceration method with dry ice. In next part we oriented on calculating total costs and usefulness of dry ice. Final part is all about maceration and squeezing of blue grapes. In the beginning of experimental part is described variety Frankovka in general, which was used to this experiments. In following article is explained how the experiment was handled, what practices were used for it and why I chose analytic and sensoric method for this experiment. In Final part are presented graphs, results, conclusions we made in this experiment.

This diploma thesis deals with study of flavonoids in red wine. This dissertation is divided into two parts: theoretical and practical. Theoretical part is define phenolic compounds, pays attention to flavonoids as important polyphenols which influence quality of red wines. The particular subchapters pay attention to maceration, respectively cryomaceration. The aim of the experimental part of this diploma thesis was to compare wines from Pinot noir. The wines were produced by two ways of maceration: fermentative maceration and cryomaceration at 4, 5°C for 3, 7, 14 days. At the same time, the effect of post-fermentation maceration was monitored in these two ways too. For wines was investigated the content of phenolic compounds, anthocyanins, flavanols content of catechin, epicatechin and antioxidative activity. Fermentative maceration positively influenced the content of total phenolic substances and post-fermentation maceration increased the catechin and epicatechin concentration. For red wines, cryomaceration appears to be a desirable step in production.

This diploma thesis discusses the specifics of qvevri wine-making method, that represents very ancient footprint of wine technology. There are described and compared traditional wine-making methods with those which are used dominantly in wine-producing countries. The thesis deals with the chemical composition of wines vinified by different technologies. The knowlage gained from literary sources is compared eith the results of the experimental part.

The literary part of the thesis brings the insight into the issue of free radicals and their impact on the health of the organism. It deals with the specific abilities and the role of antioxidants in the protection against the negative impact of radicals. It also pays attention to flavonoids as major polyphenols in red wines which significantly influence the antioxidative activity, and thus the health benefits of wine. The practical part shows, using the spectrophotometric DPPH and FRAP methods, the comparison of antiradical activity and reducing power in selected samples of red wines made by different technologies of maceration. The results show the direct relationship between the maceration method and the measured values of the antioxidative potential of the red wines. The discussion and the final part of the thesis suggest new questions and possible directions for further research.