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Vplyv fortifikácie v rôznych štádiách macerácie/fermentácie na antioxidačné vlastnosti vín
Holovic, Michal
Diploma thesis dealt with studying and evaluating the impact of fortification in different stages of maceration/fermentation on antioxidant properties of wine. The literary part of the work was clearly described chapters on various production methods and types of fortified wines, different classes of phenolic substances present in wine and study of antioxidant activity of wine and methods of assessment. In the practical part, were selected three blue grape variety from which it was successively produced 9 samples fortified wines. Time fortification took place in three different stages of maceration. The first was the fortification to the must before the start of fermentation, a second fortification during the fermentation of sugar - fermentation to about 7 % by volume alcohol, and the third fortification after fermentation in young dry wine. Fortification was carried out by adding the calculated amount of spirit in the volume of wine or must, at the same level of spirituosity all the resulting wine samples. After some time joining the distillate was carried out basic analysis of wine samples and determination of the profile of phenolic compounds. Spectrophotometric method was further assessed total content of phenolic compounds, flavanols, anthocyanins and antioxidant activity, which was determined by two different methods. Basic analysis and spectrophotometric measurements were performed in triplicate and the results were averaged. Samples of fortified wines were finally sensory evaluated participation of 12 tasters, and all the results summarized in tables and graphs, statistically evaluated and described in drawing conclusions for practical use.
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Vliv macerace na antiradikálovou aktivitu moštů révy vinné
Strýček, Jan
The work deals with the effect of maceration on the content representation of selected phenolic compounds, which have a positive impact on human health and the antiradical activity of musts. Influencing factor in this study is a temperature at which the must was macerated. It made one variety with different temperature maceration (Sauvignon) and the second variety, which was performed at only one temperature of maceration. Literary section contains a description of the progression of grape, its biochemical composition, description and distribution of phenolic substances, a description of free radicals and antioxidants. Phenolic compounds are divided into two groups - a flavonoids and nonflavonoids. These substances passes during maceration to the must. They affect the color, taste of the must and wine and also have a positive impact on human health The experiment was conducted in 2013 (September, October). The grapes were macerated 0, 2, 4, 8, 12, 24 and 48 hours, after manual gathering and initial processing. The samples were measured by optical density at different wavelengths, we measured also antiradical activity. Results were analyzed and it was found that a significant influence on the contents of the measured substances and quantities has temperature maceration.
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Role kyslíku při výrobě červených vín
Stašová, Veronika
The bachelor thesis deals with the importance of oxygen at red wine production. The first chapter is focused on the importance of oxygen, its physically-chemical pro-perties and its importance in the field of viticulture. The second chapter describes ele-mentary compounds originated from grapes. The third chapter concentrates on possible occurrence of various types of oxidation and their influence on final organoleptic pro-perties of wine. The following part of the bachelor thesis describes modern technological procedures used at wine production. The final part is oriented on positive and negative effects of oxygen on wine during the aging process in different types of tanks and classification of wooden barrels.
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Porovnání fenolických profilů ovocných a révových vín
Michlovský, Ondřej
This thesis deals with phenols in fruit wines and grape wines. In the literary part, there are description of phenols, select kinds of fruit, technological methods of wine production, diseases and defects of wines, types and kinds of wines and their marketing. In practical part, there were made fourteen kinds of wines, then these wines were laboratory and sensory evaluated.
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Porovnání analytických a senzorických vlastností vín zrajících v různých skladovacích nádobách
Prátová, Zuzana
The aim of this thesis was to compare the analytical and sensory attributes of wines aged in different storage containers for a certain period of aging . The theoretical section describes wine storage containers from history to the present, their advantages and disadvantages. There are more details of barrique barrels , their processing and burning . The following section discusses the selection of appropriate containers for alcoholic fermentation. There is an important process of biological degradation of acid before red wine maturing, which is described in the next chapter. A large part of the chapter is devoted to wine aging . There are some effects in terms of oxygen, depending on maturation, pH for red wine colours, pH of the acid. An important chapter is the aging of wines in barrique barrels , followed by a change of phenolic compounds, dependence of oak and volatile compounds on physico -chemical characteristics of wines. In subsequent chapters there is explained the concept of wine aging , there are cataracts, diseases and defects of wines that may occur during aging . In the experimental part I used two red wines and one white wine . Wines were divided into inert containers and various barrels of different manufacturers and volumes. Red wines were produced in the same technology manner and the aging conditions (temperature , humidity) were the same as well. The aim was to evaluate the analytical and sensory values of wines for the time of one year . The attempt for white wine was aimed for the time of three months. The main intention was to monitor changes in the content of phenolic compounds : polyphenols, anthocyanins , polyphenols amount of gallic acid, hydroxycinnamic acids and flavonoids. Differences for each wine were observed depending on the container size and the ripening time. The senzory evaluation was an important parameter. Wines matured in barrels showed aromatic complexity and tannin structure with finesse .
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Antioxidační účinky vybraného sortimentu léčivých, aromatických a kořeninových rostlin se zaměřením na dřeviny
Kolísková, Barbora
The literary section of this bachelor's thesis is aggregately dealing about substances with antioxidant effects which are located in medicinal trees and shrubs. The literary section also describes selected medicinal trees and shrubs. The practical experiment was based on assessment substances with antioxidant effects which are in selected medicinal trees and shrubs. It was analysed 16 species of fruit of medicinal trees and shrubs. Total antioxidat capacity, total phenolic content and total flavonoid content were determined The highest value of total antioxidant capacity was measured in Mespilus germanica 'Holandská'. The highest values of total phenolic content and total flavonoid content were determined in Rosa pommifera 'Karpatská'.
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Stanovení biologicky aktivních substancí v rostlinném materiálu
Dobeš, Jiří
This thesis is focused on the determination of antioxidants and antioxidant activity. In the first work DMPD method was optimized to determine the antioxidant activity of antioxidants standards and the reaction was monitored depending on the time, temperature and concentration. In the second work automated determination of antioxidant activity of phenolic compounds standards rutin, quercitrine and standards of phenolic acids gallic acid and ferulic acid was tested using five different methods used in the determination of antioxidant activity using an automated pipetting machines and spectrophotometer. In the third work phenolic profile and total antioxidant capacity (TAC) was determined in apricot cultivars with methods high frequency liquid chromatography with tandem electrochemical and UV spectrometric detection and these two methods were compared. In the fourth work electrochemical methods used for the determination of phenolic compounds were described. In the fifth work oxidative stress induced by silver ions in the Staphylococcus aureus bacterial culture was investigated using spectrophotometric and electrochemical methods.
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Content of selected phenolic compounds in spice plants.
BERANOVÁ, Zuzana
This work concerns the amount of certain phenols in some of the representatives of families Alliaceae, Lamiaceae and Apiaceae. Phenols in plants are widely represented and highly concentrated. Flavonoids are one of the smallest, yet quite significant classes of phenols. Ingestion of food containing flavonoids can prevent certain diseases such as Arteriosclerosis. cardiovascular and tumor diseases. This work focuses, for their special biological effects, on five flavonoids: Kaempferol, Quercetin, Myricetin, Apigenin and Luteolin. For determining the content of phenols a method of High-performance liquid chromatography (HPLC) was used. Three representative of the family Alliaceae, two representatives of the family Lamiaceae and three representatives of the family Apiaceae were analysed. Only edible parts of the plants were used for the analysis and the amount of phenols was compared in certain plants planted in beddings to the plants planted in greenhouses. At first, the qualitative representantion of phenols was ascertained by the HPLC method. The result is chromatographic profiles, which were then used in calculating the amount of particular phenols. Then the total amounts of kaempferol, quercetin, myricetin, apigenin and luteolin were found out thanks to HPLC method. The biggest amount of total kaempferol was determined in petroselium hortense planted in beddings (588 mg/kg of fresh sample) and in a greenhouse (340 mg/kg of fresh sample). The biggest amount of quercetin was determined in red onion planted in a greenhouse (773 mg/kg of fresh sample) and in ocimum basilicum planted in beddings (535 mg/kg of fresh sample). The biggest amount of apigenin was determined in petroselium hortense planted in a greenhouse (1790 mg/kg of fresh sample) and in petroselium chrispum planted in beddings (3690 mg/kg of fresh sample).
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Optimization of conditions and procedures for plant extraction.
SMUTNÍKOVÁ, Kateřina
The thesis deals with the content of selected phenolic compounds in some species of the genus Amaranthus, in black elderberry (Sambucus nigra L.) and buckwheat (Fagopyrum esculentum M.). Phenolic compounds are a group of natural compounds exclusively vegetable character. Flavonoids represent only one group of phenolic compounds. Flavonoids show many positive biological effects, in particular act as antioxidants. Natural flavonoids may cause to prevent from coronary- heard diseases and other diseases associated with older age. In recent years the increased attention is paid to flavonoid investigation due to its biological effects. For the determination of phenolic substances there were used two independent analytical methods. There are the high-performance liquid chromatography (HPLC) and micellar electrokinetic capillary chromatography (MECC). The MECC method was used for determination rutin and free quercetin. The highest content of rutin was found in leaves of buckwheat (76,400 mg/kg of dry weight) and the lowest content of rutin was determined in buckwheat hulls. The highest content of rutin was observed in teas from buckwheat leaves and inflorescence. This amount of rutin corresponds with rutin content in more than two pills of Ascorutin (the most favourite flavonoid medicament in the Czech Republic) The HPLC method was used for quantitative determination of phenolic acids. The content of free quercetin was monitored in all samples. No free quercetin was found both in plant material and in samples of teas. The ethanolic extract from the elderberry inflorescence didn´t contain any free quercetin. Free quercetin wasn?t found in any further samples of teas, which were prepared by described methods.
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