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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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Vliv malolaktické fermentace na aromatický profil červeného vína
Veselý, Radek
This master's thesis is specifically concerned with the influence of malolactic fermentation on the aromatic profile of red wine. The literary (theoretical) part defines the malolactic fermentation and describes the volatile substances formed during malolactic fermentation. The practical part results from an experiment of various kinds of malolactic fermentation, where there are used two different strains of lactic acid bacteria. The experiment was carried out on three different varieties of wines which were sensorically and analytically evaluated.
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Možnosti technologických postupů při výrobě vína a jejich optimalizace
Kostihová, Lucie
The bachelor thesis is focused on technological processes for wine production. It is dedicated to modern methods of wine making process from grapes and also to tradi-tional production mainly applied by small winemakers. The first chapter describes the history of the cultivation and production of wine in the world and in our country from ancient times to the present. The second chapter investigates the individual stages of wine production. It describes the composition of grape and grape harvesting, their proc-essing from stamping, through adjustment of must, spontaneous alcoholic fermentation or fermentation with the aid of pure cultures of wine yeasts. In the thesis is mentioned malolactic fermentation which is increasingly used in the wine production. It is realized with the help of lactic acid bacteria such as Oenococccus oeni. Also the thesis intro-duces with stabilisation of wine and its bottling. The third part deals with the yeasts used in the wine industry. It is focused on various strains of wild yeasts but also pure yeast cultures used in modern wine production.
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Vplyv spontánnej a riadnejs technológie na obsah biogénnych amínov v bielych vínach
Blšáková, Lucia
The diploma thesis deals with the influence of spontaneous and controlled technology on the creation of biogenic amines. In the literary part, it deals with the properties, origin and their occurrence. It further describes the various factors and microorganisms that influence their creation. Consequently, it focuses on the effect of biogenic amines on health and factors that may increase their toxicity in the microorganism. At the end of the literature search, describe focuses on the creation of biogenic amines in wine, their content in world wines and focuses on oenological factors affecting their content. The experimental part describes the Chardonnay experiment procedure in detail. It was divided into four variants. Two of them were technologically processed in the barrel, the other two in a glass container. Subsequently, both versions in the barrel and in the glass were divided into a production process processed by spontaneous and controlled technology. Samples were sampled during the experiment and then analyzed analytically by HPLC for the formation of biogenic amines. The resulting wines were sensory evaluated. All results were statistically processed and compared with studies dealing with similar issues.
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Vliv doby inokulace na průběh malolaktické fermentace
Hasil, Radim
Malolactic fermentation effects on wine by acidity reducing and improving of microbial stability and aromatic characteristics of wine. Malolactic fermentation can be performed before alcoholic fermentation, during and at the end of alcoholic fermentation and after. It always depends on the situation and type of wine. This diploma thesis dealt in literary part with malolactic fermentation, malolactic fermentation bacteria and its types, timing of the lactic acid bacteria inoculation and with processes and influences affecting on the course of malolactic fermentation with consequent effects on characteristics of wine. The practical part was based on different ways of malolactic fermentation implementing, on inoculation of lactic acid bacteria, which are positive and negative to citric acid, together with yeast at the start of alcoholic fermentation, at the end with using of residual heat, and after alcohol fermentation in wine. This part monitored value changes in ongoing malolactic fermentation and finally compared sensory evaluation of resulting products.
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Sledování sloučenin vázajících oxid siřičitý ve víně
Herzán, Jakub
The diploma thesis deals with observation of development of compounds that are able to bind sulfur dioxide. These are carbonyl compounds that are mostly product of yeast and bacteria metabolism. Theoretical part deals with sulfur dioxide, its characteristics and forms that are present in wine and it also deals with compounds that bind the sulfur dioxide. The diploma thesis also analyzes technology of production of wine by Sur-lie method and malolactic fermentation that enable reduction of SO2 in wine to the minimum value. The subject of research was to produce six types of wine from the same raw material with graduaded total dosage of sulfur dioxide. The experiment took six months during which was accomplished grapes processing, fermentation, three-month wine aging in stainless steel tanks, wine preparation for bottling, bottling and one-month aging in bottles. Throughout the whole experiment periodical samplings, evaluation of volume of carbonyl compounds and evaluation of individual forms of sulfur dioxide were realized. Basic analytical parametres of wines were determined and the wine was sensory evaluated.
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Vliv malolaktické fermentace na aromatický profil červeného vína
Veselý, Radek
This master's thesis is specifically concerned with the influence of malolactic fermentation on the aromatic profile of red wine. The literary (theoretical) part defines the malolactic fermentation and describes the volatile substances formed during malolactic fermentation. The practical part results from an experiment of various kinds of malolactic fermentation, where there are used two different strains of lactic acid bacteria. The experiment was carried out on three different varieties of wines which were sensorically and analytically evaluated.
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Vliv malolaktické fermentace na analytické a senzorické parametry bílých vín
Němec, Tomáš
This thesis deals with the influence of malolactic fermentation on analytical and sensory characteristics of white wines. Literary section addicts oneself to population growth lactic acid bacteria and factors affecting their development in wine, the metabolism of lactic acid bacteria and their products and how these products influence organoleptic properties of white wines. The practical part deals on the experiment of the inoculation of two different species of lactic acid bacteria in wines at different stages of vinification and on the analytical and sensory evaluation of produced wine.
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Sledování průběhu malolaktické fermentace
Štětkářová, Lucie
Malolactic fermentation (MLF), or malolactic fermentation is a process which converts Malic acid to lactic acid. Made with lactic fermentation bacteria. There are different kinds of lactic acid bacteria -- positive (Oenococcus oeni) and negative (Lactobacillus, Pediococcus). Malolactic fermentation on wine by reducing acidity, improves the stability of microbial and sensory properties of wine. Malolactic fermentation we can perform before the alcoholic fermentation, during alcoholic fermentation and alcoholic fermentation. It always depends on the situation and the type of wine. The aim of the practical part of the thesis was to track the progress of malolactic fermentation in white, pink and red wine. Malolactic fermentation was observed for two strains of bacteria -- commercial tribe and citrátnegative tribe.
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