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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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Effect of available P and phenolics on mineral N release in acidified spruce forest: connection with lignin-degrading enzymes and bacterial and fungal communities
VANĚK, Daniel
Annotation We conducted over four months a shortterm laboratory incubation experiment to find the best prediction parameters (i.e. initial chemical characteristics) to explain differences in microbial respiration rates and mineral N (DIN) release in different litter in an acidified spruce forest. In addition, we wanted to find the link between the activity of key extracellular ligninolytic enzymes, phenoloxidases (PhOx) and peroxidases (PerOx), microbial respiration and composition of fungal and bacterial communities. Samples of spruce needles (Picea abies) and litter of four dominant understorey vegetation; lady fern (Athyrium alpestre), blueberry (Vaccinium myrtillus), reedgrass (Calamagrostis villosa) and hair grass (Avenella flexuosa), were collected in 2005, 2006 and 2007 from six sites located in watersheds of two glacial lakes (Plešné Lake and Čertovo Lake) in the Bohemian Forest, Czech Republic. Litter samples were incubated at 0 and 10 °C in laboratory controlled conditions for 90 days. Activities of PhOx and PerOx, and C mineralization rate were measured regularly each 14 days. Litter quality characteristics and endophytic microbial community structure, based on 16SrDNA-DGGE fingerprint of bacteria and ITS-DGGE of fungi, were determined at the beginning and end of litter incubation. Our results showed a close correlation of phenolics/POX with DIN release (r ? 0.74, p ? 0.001). Using multivariate analyses, POX seems to play an important role in the change of litter fungal and bacterial community composition. At 0 °C the fungal and bacterial communities of reedgrass and blueberry litter changed in relation to POX and PerOx activity, while at 10 °C the fungal communities after the incubation were additionally affected by the phenolics/NTOT and phenolics/PTOT ratios.
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