|
|
Porovnání komerčně dostupných maceračních enzymů při výrobě bílých vín
Maleňáková, Daniela
This bachelor thesis deals with the influence of macerating enzymes in the white wine production. The use of enzymes, description of pectins and their change during the production of wine, and various types of maceration are described in detail in the literature review. The main aim of this work was to map macerating enzymes commercially obtainable in the Czech Republic and select representative sample for experimental part. Pomace from crushed grapes was divided into 9 batches, treated with enzymes and macerated for 24 hours. The pomace was pressed and stripped subsequently. The yield values, basic parameters and the polyphenolic profile of the must were evaluated for all samples. An evaluation of the enzymes parameters was performed based on these measurements. The results of measurements revealed that the best results were achieved by the Lallzyme Cuvee Blanc enzyme from LALLEMAND company.
|
|
|
Využití třapin v technologii vín révy vinné
Helmová, Tereza
The bachelor thesis on The use of grape vines in the technology of wine grape vines in the first part deals with the literary summary on the given topic, namely the composition of grapes, the principle of maceration and Frankovka as a variety. Further, the bachelor thesis develops in the experimental part, which consists in the maceration of certain parts of the stems. The Frankovka variety is used for the experiment. The results of the experiment consist of sensory evaluation and chemical analysis.
|
|
|
Aronia as a raw material for cosmetic production
Palkovská, Kateřina ; Sýkora, Michal (referee) ; Zemanová, Jana (advisor)
This bachelor thesis deals with extraction of polyphenols from fruits and leaves of aronia and consequent use of obtained extract in cosmetic production. In the theoretical part are information about the origin of the aronia, the botanical characteristics of Aronia Melanocarpa and about its utilization. Furthermore, the chemical composition of the plant material of the aronia is described, which is also common for fruits. At the end of the theoretical part are described extraction and separation techniques, methods of determination of total polyphenolic compounds and brief characteristics of the material safety data sheet. The experimental part describes the optimization of the prepared extract so that the extract contains as many polyphenolic compounds as possible. 50% ethanol at room temperature was shown to be optimal for leaf and fruit extraction, and the maceration time was found to have a significant effect on the polyphenolic compounds obtained. For the obtained optimized macerate, some chemical and physical properties such as pH, density, refractive index were determined for the purpose of producing a material safety data sheet and product specification. At the end of the experimental part were prepared cosmetic products with the addition of macerate from crushed aronia fruits.
|
|
| |
|
|
Vliv různých technik studené macerace na obsahové látky vína
Blasch, Jiří
This bachelor thesis deals with the composition of wine, describes cold maceration and its effect on extraction of substances from white and blue grape varieties. The thesis describes technology for grapes cooling and its use in viticulture. The effort was put on summarization of current knowledge of maceration methods which were further used in experiment with Riesling variety. Different methods of pre-fermentation maceration (in terms of contained substances and sensory feeling) were compared.
|
|
|
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.
|
|
|
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.
|
|
|
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.
|
|
|
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.
|
|
|
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.
|
guest ::
