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Factors influencing the quality of red wine
Zechmeisterová, Lucie ; Vránová, Dana (referee) ; Omelková, Jiřina (advisor)
In my thesis, I focused on monitoring of microorganisms in the sample of red grape juice and on the interactions between yeasts, bacteria and filamentous fungi. Three different media were applied for the cultivation of microorganisms; firstly for monitoring of total volume of microorganisms, secondly for yeasts and third time for lactic acid bacteria. The indirect method was used for the determination of the amount of viable cells. This method consists in enumerating of visible macroscopic colonies grown up on agar plates. When the cells grew up, the forms of colonies were analyzed visually and the morphology of microorganisms was detected microscopically. The operating time of enzymes in grape juice in the production of red wine was monitored after application of commercial enzymatic preparation. The enzym action in grape juice was observed on the basis of the process of degradation of high – molecular substrate by enzymes through the use of Ubbelohd´s viscometer. The research findings provided a lot of knowledge about the occurance of microflora in the process of production of red wine. The commercial preparations added to grape juice played a significant role.
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Determination of anthocyanins in selected kind of fruit
Forejtarová, Darina ; Vítová, Eva (referee) ; Vespalcová, Milena (advisor)
Contents of this diploma thesis was introduction of method determination of anthocyanin pigments by liquid chromatography. Anthocyanin pigments was determined in various cultivars of elderberry (Sambucus nigra L.) and in selected samples of red wine. In the first part of the theory is described elderberry, its species and chemical composition. Some possibilities of processing and utilization of elderberry in medicine are mentioned here too. The next part of the theory is aimed at chemical agents in wine, characteristics of anthocyanins and their utilization in food processing industry. The methods for determination of anthocyanin pigments with focus on HPLC are also mentioned there. The main objective of the experimental part of this thesis was comparison of content of anthocyanins in various cultivars of elderberry and in selected samples of red wine. In samples of red wine was observed not only cultivars´ influence, but also influence of the crop year on the content of anthocyanin pigments. The separation of the anthocyanin pigments by high-performance liquid chromatography with diode array detection (HPLC/DAD) was performed. The highest content of anthocyanin pigments in elderberry was determined in the cultivar Haschberg. In the case of red wine, the richest source of anthocyanins was the cultivar André 2009 – Rakvice. Higher content of anthocyanins was explicitly proved in young wines rather than in older wines.
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Analysis of VOC Frankovka wines originating in the Modré hory region
Horáková, Lenka ; Machát,, Jiří (referee) ; Diviš, Pavel (advisor)
This diploma thesis deals with the chemical characterization of Frankovka red wines and the possibility of using chemical analysis of wines to distinguish Frankovka wines from VOC Modré hory from other Frankovka wines from the Moravian wine region. The theoretical part describes viticulture in the Czech Republic, the characteristics of the Frankovka variety and the wine classification system in the Czech Republic. The next part describes in detail the association VOC Modré hory, the red wine technology and the use of chemometry for wine authentication. The experimental part deals with the determination of the elemental profile of wines by ICP-MS and ICP-OES methods, analysis of selected phenolic substances by HPLC-MS and analysis of organic acids by IC. Furthermore, the analysis of the aromatic profile of wines was performed using the technique HS-SPME-GC-MS and the total content of phenolic substances in wines was determined by the MAS method. A total of 24 wine samples were analyzed, where 12 samples came from VOC Modré hory and another 12 wines came from other Moravian wine regions. Statistical analysis techniques (Mann-Whitney U-test and PCA) were used to classify wine samples into groups in order to separate wines from VOC Modré hory and other wines from other Moravian regions. The results of this work showed that with the help of chemical analyzes and statistical techniques it was possible to distinguish wines from VOC Modré hory from other wines from the Moravian wine region.
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Biochemical changes accompanying the aging of red wine
Vacková, Tereza ; Hudeček, Jiří (advisor) ; Entlicher, Gustav (referee)
Flavonoids are plant secondary metabolites, which belong to several groups varying in their chemical structure. Anthocyanins and tannins are important flavonoid components of wine that are responsible for its color, taste and other sensory properties. The concentration of anthocyanins in wine is affected by grape variety, processing technology, and climatic conditions. In this Thesis, we studied the changes in color and in related chemical composition, using three non-commercial samples of red wine: Svatovavřinecké (year 2010 and 2012), and home-made wine (prepared without addition of SO2). These changes in color were determined using standard colorimetric method (CIELab) and also a simplified two-parametric spectrophotometric method (tint/color density). The content of anthocyanins was followed using analytical RP-HPLC method. In paralel, simplified oenologic methods for estimation of phenolic compounds were used. Generally the wine samples changed color to darker tint. Chemically, this was caused by polymerisation reactions between anthocyanins and phenolic compounds. This led to the formation of stable pigments characterised by a higher absorption maximum at longetr wavelength, hence a darker tint. Key words: anthocyanins, color, red wine, phenolic compounds, malvidin-3-glucosid, polymeric reactions,...
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Vermicomposting of wine production waste
Clark, Oskar William ; Innemanová, Petra (advisor) ; Grasserová, Alena (referee)
Vermicomposting is a method of biological waste management, with the potential for valuable returns in the form of biofertilisers and savings of time and effort. These qualities make vermicomposting ideal for the processing of winery waste materials. Vermicomposting has advantages over traditional composting in terms of the speed of transformation of the input materiál, but also in terms of producing a safe fertiliser. Waste materials from the wine industry, which primarily include grape marc and winery wastewater, have several properties that can contribute to phytotoxic effects in soil. This thesis provides an overview of the management of waste materials from the wine industry, the differences between white and red wine production, and the suitability of vermicomposting for application in small- and large-scale winery waste management. The experimental part of this thesis examines the time requirement of vermicomposting to transform grape marc into a material that does not possess properties that inhibit plant growth. Experimental measurements of the relationship between vermicompost age and germination inhibition show that vermicomposting increases the pH of the substrate and stabilizes it over time. The experiment also showed that vermicompost has a statistically significant stimulatory...
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Analysis of VOC Frankovka wines originating in the Modré hory region
Horáková, Lenka ; Machát,, Jiří (referee) ; Diviš, Pavel (advisor)
This diploma thesis deals with the chemical characterization of Frankovka red wines and the possibility of using chemical analysis of wines to distinguish Frankovka wines from VOC Modré hory from other Frankovka wines from the Moravian wine region. The theoretical part describes viticulture in the Czech Republic, the characteristics of the Frankovka variety and the wine classification system in the Czech Republic. The next part describes in detail the association VOC Modré hory, the red wine technology and the use of chemometry for wine authentication. The experimental part deals with the determination of the elemental profile of wines by ICP-MS and ICP-OES methods, analysis of selected phenolic substances by HPLC-MS and analysis of organic acids by IC. Furthermore, the analysis of the aromatic profile of wines was performed using the technique HS-SPME-GC-MS and the total content of phenolic substances in wines was determined by the MAS method. A total of 24 wine samples were analyzed, where 12 samples came from VOC Modré hory and another 12 wines came from other Moravian wine regions. Statistical analysis techniques (Mann-Whitney U-test and PCA) were used to classify wine samples into groups in order to separate wines from VOC Modré hory and other wines from other Moravian regions. The results of this work showed that with the help of chemical analyzes and statistical techniques it was possible to distinguish wines from VOC Modré hory from other wines from the Moravian wine region.
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Biochemistry of polyphenols effects in the treatment of vascular disease
Kondrashov, Alexey ; Štípek, Stanislav (advisor) ; Pecháňová, Olga (referee) ; Matouš-Malbohan, Ivan (referee)
This Ph.D. thesis deals with the deep analysis of polyphenols effects toward vascular disorders. This work provides a number of experimental results of studying both the effects of natural bioactive compounds in red wines and potatoes, and their application to the experiments which includes experimental animal models with spontaneous hypertension. Methods and equipment used in experimental studies allowed us to make several new statements regarding the universal nature of the relationships between the antioxidant capacity and the polyphenolic content in examined foodstuffs. Besides this it is also recognized that food is a source of minerals which also contribute to the total antioxidant capacity and therefore may have influence the endogenous antioxidant enzyme system by providing the essential cofactors. Experimentally we have found that the concentrations of magnesium known for its therapeutic action in wine and red wine extract are comparable to the mineral waters recommended for the treatment and prevention of cardiovascular and metabolic diseases. Moreover, synergistic interactions between selected minerals have been found. The key issue of bioavailability of polyphenols for supporting the idea of the beneficial effects of diet rich in fruits and vegetables toward vascular disease prevention...
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Bariková vína
Pavelicová, Kristýna
The thesis entitled Barrique wine deals in the teoretical part with technology of production of red wine from grape harvesting after wine training. This is followed by the ri-pening of wine in barrique special barrels whose chemical wood composition is described the same as its influence on the wine quality. Furthermore the thesis describes the chemical composition of wine and biologically active substances in barrique wines. The last chapter of the theoretical part deals with methods in the analysis of polyphenolic compounds. In the practical part the work focuses on the identification of polyphenolic compounds in barrique wines. This happens in seven samples of wines and on the monitoring of changes in the content of substances during extraction of oak chips in ethanol. For detection High performance liquid chromatography in tandem with a mass spectrometry was used.
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Možnosti vinifikace hroznů odrůdy Frankovka pro VOC Modré Hory
Hloušek, Petr
In the thesis entitled The possibilities of vinification of grapes of the variety Frankovka for VOC Blue Mountains, the primary objective was to evaluate the influence of autochthonous yeast on the commercial by fermentation in an automatic vinifier, an open and closed vessel. Next, find out by ripening the wines in a wooden barrel and an impervious container whether it suits more maturation with increased or minimal amount of oxygen. The result of this work was then the sensory analysis of the wine was quantified into a 100 point table according to the OIV as well as the aromatic profile and profile of the structure and strength of the wines, which were then processed into the graphs. Experimental samples were analyzed by individual parameters - anthocyanins, total polyphenols, antioxidant capacity and color parameters.
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Studium flavonoidů v červených vínech
Kandourova, Alexandra
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.
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