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Vliv různých technik studené macerace na obsahové látky vína
Bíza, Petr
This bachelor thesis deals with the influence of various types of cold maceration technique on substances contained in wine. The thesis is divided into two parts: theoretical and practical. The theoretical part is about dfinitions of terms which simplify an orientation in this area, a composition of must and cold maceration techniques. The practical part contains a description of a wine grape variety, which has been chosen for the experiment, a technology of wine making, sensory evaluation and analytical analysis.
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Vliv macerace rmutu pří výrobě rosé vín
Vrbová, Libuše
This thesis deals with the influence of maceration of the mash in rosé winemaking. The literary section describe the phenolic compounds contained in grapes, the possibility of producing rosé wines and factors affecting the course of maceration. The aim of the work was to determine what type of maceration is the most suitable for the production of rosé wines. For the observed samples were examined maceration time and the influence of sulfur dioxide. He evaluated the sensory profile of wines colourists range using the CIE L * a * b * and the content of phenolic compounds. The experiment was conducted at the blue grape variety 'Pinot Noir'. Of ground grapes were created two variants. Mash without addition of SO2 and mash with the addition of sulfur dioxide. For each variant was produced six rosé wines with different length of maceration of the mash. Desired time maceration were 0, 5, 10, 15, 20 and 25 hours. Found mash conducted in non-inert conditions at 13 ° C. The results implies that the best time maceration for the production of rosé wines from varieties 'Pinot Noir' is 15 hours with the use of sulfur dioxide.
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Developement and optimalization of methods for extraction of selected compounds from Hypericum perforatum
Chytil, Dalibor ; Štursa, Václav (referee) ; Pořízka, Jaromír (advisor)
Bachelor's thesis deals with the optimization of processes for extraction of phenolic compounds from St. John´s Wort (Hypericum perforatum). The theoretical part of the work focuses on characterization of this herb, its botanical classification, traditional use, chemical composition and curative effects. Increased attention is further devoted to a theory of preparation of samples for extraction of phenolic compounds and suitable techniques for extraction and characterization of phenolic compounds from extracts of St. John´s Wort. The experimental part of the thesis deals with application of theoretical knowledge. When optimizing the emphasis was on influence of solvent (water acified to pH 4, pH 5, pH 6), influence of extraction technique (ultrasound extraction, subcritical water extraction, maceration) and influence of extraction period (10, 20, 30 min). Extracts were subjected to determination of selected parameters (total phenolic content, total flavonoid content, antioxidant activity) in leaves of St John´s Wort harvested in June 2016 using UV-VIS spectroscopy. The used extraction techniques are significantly different from each other.
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Vliv doby macerace na množství asimilovatelného dusíku u moštů révy vinné
Škrobák, Stanislav
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.
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Kryomacerace v technologii bílých vín
Stejskal, Ondřej
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.
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Vliv macerace na antiradikálovou aktivitu moštů révy vinné
Strýček, Jan
The work deals with the effect of maceration on the content representation of selected phenolic compounds, which have a positive impact on human health and the antiradical activity of musts. Influencing factor in this study is a temperature at which the must was macerated. It made one variety with different temperature maceration (Sauvignon) and the second variety, which was performed at only one temperature of maceration. Literary section contains a description of the progression of grape, its biochemical composition, description and distribution of phenolic substances, a description of free radicals and antioxidants. Phenolic compounds are divided into two groups - a flavonoids and nonflavonoids. These substances passes during maceration to the must. They affect the color, taste of the must and wine and also have a positive impact on human health The experiment was conducted in 2013 (September, October). The grapes were macerated 0, 2, 4, 8, 12, 24 and 48 hours, after manual gathering and initial processing. The samples were measured by optical density at different wavelengths, we measured also antiradical activity. Results were analyzed and it was found that a significant influence on the contents of the measured substances and quantities has temperature maceration.
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Technologické možnosti pří výrobě rosé vín
Vrbová, Libuše
The thesis deals with the technological possibilities in the production of rosé wines. In the first two chapters, discusses the history and current production of rose wines in the Czech Republic and abroad. The third chapter deals with the appropriate varieties of grapes. Further work is focused on the production itself rosé wines. The technology is described from the harvest of grapes in the vineyard to the subsequent storage of the product. The last chapters are devoted to the phenolic substances contained in the production of rosé wines and claret. Today, rosé wines have an important position on the Czech market. Absolute majority of winemakers produce rose wines in the way of short maceration of blue grapes, eventually without maceration.
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Studium terpenických látek v aromatických odrůdách révy vinné
Teturová, Denisa
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.
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Flavonoidy a antioxidační aktivita červených vín
Vachová, Simona
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.
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