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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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Microbiology of wine
Valicová, Markéta ; Navrátilová, Jana (referee) ; Omelková, Jiřina (advisor)
The aim of this work was the investigation of the amount and the composition of microflora during the winemaking of red wine. The study was performed in 3 factories in Velké Pavlovice region, where each of them utilized its own technological approach. According to this, during the period of preliminary fermentation, 3 different technological procedures were used, which differed in application of commercial yeasts and enzymes, and sulphur dioxide. They differed also in the temperature during the period of alcoholic fermentation and the application of commercial bacteria during the period of malolactic fermentation. From the experimental results follows that the application of different technological approaches leads to the differences in the number of both yeast and bacteria viable cells and the total number of microorganism cells in the period of preliminary, alcoholic and malolactic fermentation.
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The monitoring of the lactic acid bacteria in the Moravian wines
Valicová, Markéta ; Španová, Alena (referee) ; Omelková, Jiřina (advisor)
The aim of this Master Degree Thesis was to monitor the total number of lactic acid bacteria occurring in grape must during wine production. The study was performed on the red wine grape variety Cabernet Moravia from organic vineyard and on the white wine grape variety Sauvignon from both organic and integrated vineyards. The isolation of pure cultures of lactic acid bacteria from mixed cultures and subsequently their identification by genus and species-specific PCR was also subject of the thesis. The experimental results show that the number of viable cells of lactic acid bacteria is influenced not only by the wine grape variety, whether it is a variety of red or white wine grape, but also by the way of wine growing. The method of wine growing also had an impact on the species representation of lactic acid bacteria in each variety.
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Stanovení biogenních aminů ve víně
Novotná, Michaela
This thesis focuses on the determination of the amount of individual biogenic amines in eight samples of wines coming from four European countries – Czech Republic, Spain, Austria a Hungary. There was chosen one white and one red wine variety from each country. All of wine samples was dry – content less than 9 g sugar per liter. Varieties were: Grüner veltliner (one sample from Austria and second sample from Hungary), Chardonnay (one sample from Czech Republic and second sample from Spain), Zweigeltrebe (from Austria), Cabernet Moravia (from Czech Republic), Blauer Portugieser (from Hungary) and Tempranillo barrique (from Spain). The amount of biogenic amines was determined by ion-exchange liquid chromatography with UV/VIS detection. The bigges amount of biogenic amines was detectected in Zweigeltrebe. The lowest in Chardonnay (Czech Republic). Putrescine was detected in all samples, by contrast histamin was mostly under the detection limit.
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The monitoring of the lactic acid bacteria in the Moravian wines
Valicová, Markéta ; Španová, Alena (referee) ; Omelková, Jiřina (advisor)
The aim of this Master Degree Thesis was to monitor the total number of lactic acid bacteria occurring in grape must during wine production. The study was performed on the red wine grape variety Cabernet Moravia from organic vineyard and on the white wine grape variety Sauvignon from both organic and integrated vineyards. The isolation of pure cultures of lactic acid bacteria from mixed cultures and subsequently their identification by genus and species-specific PCR was also subject of the thesis. The experimental results show that the number of viable cells of lactic acid bacteria is influenced not only by the wine grape variety, whether it is a variety of red or white wine grape, but also by the way of wine growing. The method of wine growing also had an impact on the species representation of lactic acid bacteria in each variety.
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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.
|
|
|
Microbiology of wine
Valicová, Markéta ; Navrátilová, Jana (referee) ; Omelková, Jiřina (advisor)
The aim of this work was the investigation of the amount and the composition of microflora during the winemaking of red wine. The study was performed in 3 factories in Velké Pavlovice region, where each of them utilized its own technological approach. According to this, during the period of preliminary fermentation, 3 different technological procedures were used, which differed in application of commercial yeasts and enzymes, and sulphur dioxide. They differed also in the temperature during the period of alcoholic fermentation and the application of commercial bacteria during the period of malolactic fermentation. From the experimental results follows that the application of different technological approaches leads to the differences in the number of both yeast and bacteria viable cells and the total number of microorganism cells in the period of preliminary, alcoholic and malolactic fermentation.
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