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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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Development of probiotic dietary supplement
Krahulcová, Aneta ; Vítová, Eva (referee) ; Vránová, Dana (advisor)
The thesis deals with a theme of probiotic mikroorganisms which are aplicated as a dietary supplement. Health benefit on the host have been known for a long time, however, there might be some negative effects affecting a consumer. In connection with this observation defining requirements and evaluating of safety of probiotics in food was necessary. The new probiotic dietary supplement can not be expanded on the market without these processes. Every strain must be tested separately on each property. The ability of rezistance against conditions inside human gastrointestinal tract belongs to the most basic tests. The aim of the practical part is testing this ability of rezistance in vitro by simulated conditions. The model of gastrointestinal juices was designed according to the Czechoslovak codex. The form contributes to the higher rezistance of probiotics within implementing to the host. Also a dosage form of probiotics was involved to a in vitro testing.
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The content of lactic acid bacteria in several types of probiotic foods
Páterová, Alena ; Vránová, Dana (referee) ; Vítová, Eva (advisor)
Probiotics are defined as live microorganisms that have, if ingested, a positive impact on human and animals health. The best known probiotics are the lactic acid bacteria, among them most commonly used are lactobacilli and bifidobacteria. For therapy the minimum daily consumption of at least 100 g of milk product with a minimum 1000000 of probiotic bacteria in 1 g or 1 ml is considered. In this work, several products that have declared on the label probiotic cultures have been selected. All products were analyzed for the number of lactic acid bacteria. Two media - MRS agar and skim milk agar Modified were used for cultivation. Cultivation proceeded at 37 °C for 48 hours under aerobic and anaerobic conditions. Amount of live bacteria, which must be present in the product, indicates Ministry of Agriculture No. 77/2003 Coll.. Quantitative representation of lactic acid bacteria in all selected products comply with the requirements of legislation.
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Microbial characterization of yoghurts and probiotic foods.
Kocourková, Hana ; Burdychová, Radka (referee) ; Španová, Alena (advisor)
Zvýšená konzumace fermentovaných mléčných výrobků v posledních letech vede k zavádění nových výrobků na trh. Funkční a probiotické produkty jsou v dnešní době také hojně rozšířeny. Cílem diplomové práce bylo posoudit mikrobiální kvalitu komerčních jogurtů a nefarmakologických probiotických výrobků. Bylo zkoumáno 24 vzorků jogurtů a 8 vzorků probiotických mléčných výrobků. Pozornornost byla zaměřena zvláště na kvantifikaci mikroorganismů v jednotlivých výrobcích a na sledování viability buněk. Většina mléčných produktů obsahovala počty odpovídající minimální požadované hodnotě 1x107cfu/ml. Nicméně byly objeveny produkty, které neobsahovaly živé bakterie nebo obsahovaly jen jejich menší množství. To platí zejména pro běžné jogurty. Probiotické mléčné výrobky v zásadě obsahovaly větší množství bakterií než jogurty, protože je u nich navíc požadováno 1x106cfu/ml minimálního množství specifických bakterií jiných než jogurtových startovacích kultur. Isoláty z fermentovaných mléčných výrobků byly identifikovány jako Streptococcus thermophilus and Lactobacillus spp. Isoláty byly poté rozlišeny na jednotlivé kmeny pomocí RAPD použitím tří různých primerů. Byla zjištěna velká různorodost mezi kmeny rodu Lactobacillus spp. používaných různými podniky.
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Food products with probiotics
Zemanová, Tereza ; Valicová, Markéta (referee) ; Trachtová, Štěpánka (advisor)
Fermented dairy products containing probiotic microorganisms which are distinguished by favorable effects on the intestinal microflora, are in present time consumed in large quantities. Products range in which microorganisms are contained in recent years expanded greatly. On the market are currently available not only milk, but also meat or vegetable products of this type. The aim of work was to get acquainted with probiotic microorganisms, a description of their use in food industry, and whether they have for us “Homo sapiens sapiens,, favorable or unfavorable effects. In the practical part of work was showed the presence of probiotic bacteria in fermented dairy product using the polymerase chain reaction methods.
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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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Probiotic foods
Páterová, Alena ; Navrátilová, Jana (referee) ; Vítová, Eva (advisor)
This bachelor thesis summarizes the knowledge about problematic of probiotics and their positive effects on human health. Probiotics are live microorganisms, which, at application in appropriate quantity as component of food, have health benefit in humans and animals. Probiotics are already an important component of treatment in gastroenterology, in hepatology, at treatment of urogenital system, at prevention and therapy of cancer and mycoses. The best known probiotics are lactic acid bacteria, of which most often used are Lactobacillus and Bifidobacterium genera. Lactic acid bacteria because of their unique metabolic characteristics are involved in many fermentation processes of milk, meat and vegetables. We can say, that advances in probiotic bacteria research are beneficial for both the consumers and the producers.
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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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Malolaktická fermentace a možnosti načasování inokulace mléčnými bakteriemi
Hasil, Radim
This thesis deals with the malolactic fermentation and the accuracy of timing of lactic acid bacteria inoculation. The literary part deals with the bacteria malolactic fermentation, its controlled form, description of lactic acid bacteria and their time of inoculation into wine and advantages and disadvantages of this operation. The practical part is based on the methods of malolactic fermentation and inoculation of lactic acid bacteria after alcoholic fermentation in to wine and sensory evaluation of resulting products.
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