National Repository of Grey Literature 123 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Biologicky významné látky v bylinných čajích u čeledi hvězdnicovité
Stejskalová, Lenka
The importance of herbs and herbal teas is a frequently researched topic due to the content of biologically active substances. Plant material is a source of a large number of diverse components, which are proven to have a beneficial effect on the human organism. These substances are able to help in the prevention and possibly treatment of some human diseases. To fully understand the function of individual plants, it is necessary to know the content of individual groups of biologically active substances. The first part of this master's thesis named Biologically Important Substances in Herbal Teas of the Family Asteraceae escribes and defines herbal teas and organic farming. It also describes the Asteraceae family and focuses more specifically on selected species within this family, including marigold (Calendula officinalis), chamomile (Matricaria chamomilla L.), coltsfoot (Tussilago farfara L.) and coneflower (Echinacea purpurea). The consumption of herbal teas is currently high and still growing, therefore it is necessary to know the composition of the used plants. Representatives were chosen for their popularity and abundant use in the preparation of herbal teas. For each representative, there is a short botanical description and description of the contained substances. In the next chapter of the theoretical part, phenolic substances, their determination and effect on human health are presented. The group of flavonoids, which is a subgroup of phenolic substances, is described in more detail. The last section of the theoretical part explains the concepts of antioxidants, free radicals and methods of determining antioxidant activity. These groups were selected for measurement because they are substances showing effect on human health. In the practical part of this work, the total content of polyphenols, the total content of flavonoids and the total antioxidant capacity are determined in selected species. All these groups are determined spectrophotometrically. The essence of this work was to find out whether the content of these compounds in the same in samples from different productions. For each representative, one sample originating from organic farming (known as “BIO“) and one sample originating from conventional agriculture are examined. These two samples were statistically compared.
Posouzení trvanlivosti vybraných druhů dřev pro obchodovatelný výrobek
Sion, Matěj
In this thesis, the problem of the resistance of terrace boards to biological degradation. The following woods were chosen for the experiment: 1) Garapa (Apuleia leiocarpa Vog.) → is a representative of tropical woods and at the same time a species required by customers. 2) Mulberry (Morus) → a possible alternative in future years. 3) Acetylated European alder wood (Alnus glutinosa) → a possible alternative, when this method of modification appears to be very effective. The selected woods were tested according to the ČSN EN 350 standard for resistance to the wood decay fungi of white rot (Trametes versicolor) and brown rot (Gloeophyllum trabeu) and Coniophora puteana). The second part of this thesis was the determination of the total content of extractive substances (ES), phenolic substances (FS), carbohydrates (C), and pH values of aqueous leachate selected wood species. All samples were tested and compared with each other. The wood of the mulberry tree was evaluated and as to how these properties change along the radius of the trunk. The selected woods have been found to be suitable for decking. Weight losses (white and brown rot) were in negative values, so the fungi were not able to attack the wood and it was classified in durability class 1 "very durable". From the point of view of chemical composition, it was found that the most chemical substances are contained in the wood of the mulberry tree, garapa, and the least acetylated alder. In the case of the mulberry tree, it was also found that the amount of chemical substances varies depending on the position along the stem radius. The high resistance of garapa and mulberry to wood-rotting fungi is mainly caused by the content of chemical substances. The resistance of acetylated alder was due to the acetylation process.
Physiological, structural, and biochemical leaf traits of selected Poaceae species involved in oxidative stress protection and acclimation to different light conditions
Hunt, Lena Macrie ; Albrechtová, Jana (advisor) ; Lux, Alexander (referee) ; Šantrůček, Jiří (referee)
This thesis examines physiological, structural, and biochemical leaf traits in grasses (Poaceae family) and how they contribute to oxidative stress protection. Light is a major factor contributing both to oxidative stress in plants and the induction of protective mechanisms at the leaf level. The agriculturally important species barley (Hordeum vulgare) was used to investigate responses to varying irradiance and atmospheric CO2 levels. Barley was further used as a model organism to study the influence of different spectral qualities on oxidative protective mechanisms, particularly phenolic compound induction. This thesis also examines the protective leaf functional traits of wild grass species (Nardus stricta, Calamagrostis villosa, Molinia caerulea, and Deschampsia cespitosa) in a high-irradiance arctic-alpine tundra grassland. Phenolic compounds are important protective secondary metabolites in plants that protect against oxidative stress from high irradiance. This thesis evaluates phenolic compounds and their contributions to plant stress tolerance and introduces a novel method of quantifying the histochemical detection of phenolics in leaf cross-sections. Key results indicate that light quantity and quality play major influential roles in the accumulation of phenolic compounds. High irradiance...
Development of fortified gluten-free cereals for specific nutrition
Dohnalová, Radka ; Fialová, Lenka (referee) ; Márová, Ivana (advisor)
The bachelor thesis was focused on the development of enriched gluten-free cereals for special nutrition. The fortified cereal product included processed microbial biomass, either as a freeze-dried powder or as an extract, for which the phenolic content, antioxidant content and protein content were determined. The theoretical part includes findings from professional literature on gluten-free cereals, pseudocereals and their chemical composition. Subsequently, a review on microalgae and yeasts was prepared including a list of their metabolites. The literature search focused on green microalgae and carotenogenic yeasts. In the experimental part, the characterization of the selected pseudocereals and optimization of the prepared extracts of the selected microalgae and carotenogenic yeast were firstly carried out. The selected pseudocereals were amaranth, buckwheat and quinoa. The green microalgae strain Chlamydomonas reinhardtii and the carotenogenic yeast strain Cystofilobasidium macerans were selected for enrichment of the pseudocereals. Carbohydrates, proteins, fatty acids, -glucans, gluten, vitamins, phenolic substances, flavonoids and antioxidants were determined in the pseudocereals. Total fatty acids, lipophilic substances, phenolic substances and total antioxidant activity were detected in the microbial biomass. Finally, mixed cereal products were prepared from pseudocereal flour, microbial biomass and microbial extract. The cytotoxicity of the selected extracts was determined by MTT assay. It was found that the addition of algal biomass alone or algal extract to cereal flours resulted in a significant increase in protein. The yeast ethanol extract increased the phenolic and antioxidant content of the cereal products.
Possibilities of using spices in the production of ham salami
Vershinina, Alina ; Szotkowski, Martin (referee) ; Mikulíková, Renata (advisor)
This bachelor's thesis focuses on the possibilities of using different spices, specifically cumin, nutmeg, allspice and marjoram, in the production of ham cuts. The aim of the work is to investigate the effect of these spices on the taste, aroma and other sensory properties of the ham cut and to assess their contribution to improving the overall quality of the product. The methodology includes the collection of samples of ham cut with various additions of spices, the performance of sensory analysis and chemical analysis for the identification and quantification of phenolic substances present in individual spices. Subsequently, the results will be evaluated and their significance for the production of ham cuts will be discussed. The results of this work could contribute to a better understanding of the use of spices in the production of meat products and provide data for the optimization of recipes and processes in the food industry.
Obsahové látky jedlých květů a jejich antioxidační aktivita
Tvrzníková, Eliška
This diploma thesis deals with phytochemicals with antioxidant effect in edible flowers. In the literary section are described edible flowers, antioxidants and substances harmful to human health. In the selected assortment is described the morphology of the flower, the origin, the distribution, the occurrence, the demands, the use and the multiplication according to whether they are species growing in the wild or cultivated species are described. In the practical part, flowers were harvested from March to May 2017 and their content was determined - vitamin C, flavonoids, phenols, saponins, antioxidants. This thesis confirmed that phenolic substances are primarily responsible for the antioxidant capacity. The highest antioxidant capacity along with phenolic substances was in the flowers of Bergenia ciliata.
Hodnocení fenolické zralosti hroznů v podmínkách jižní Moravy
Dvoracký, Milan
The importance of monitoring the quality parameters (sugar content, titratable acid pH) in determining the optimum ripeness of blue grape varieties can be considered a method which provides only limited and inadequate information. To determine the required quality should be evaluated ripening grapes intended for the production of high quality red wines in addition to sensory methods and analytical methods which are able to define the change of phenolic compounds in berries and accordingly influence the determination of the harvest. The values of phenolic compounds vary significantly depending on the site and variety. My thesis tracks changes and development of phenolic compounds in berries, their relationship to quality and sensory parameters. It deals with the sensory evaluation method ripe berry grape seeds and also world-renowned analytical method "Glories", evaluating the level of phenolic compounds on selected varieties and habitats in South Moravia.
Základní parametry moštů révy vinné
Výmola, Tomáš
In this bachelor´s work was after studying the collected domestic and foreign sources analysed consisted of the basic parameters of the must of the vine, wine production and subsequently to frequent diseases and defects of the wine where we can meet. To the overall quality of the wine occurs in the vineyard, during the processing of the grapes, fementation of the mas hor even in the achal wine during his training or after the subsequent filling into bottles.
Antioxidative parameters of fruit model product.
KRATOCHVÍLOVÁ, Lenka
The content of the main components (anthocyanins, quercetin, chlorogenic acid, L-ascorbic acid, rutin, total polyphenols) was determined in the syrup of elderberries (Sambucus nigra L.) by spectrophotometry or high-performanceliquid chromatography. Furthermore, the antioxidant activity of this syrup was determined using three methods: ABTS, FRAP, and DPPH. The measurement results were statistically processed and compared using correlation analysis, specifically using the Pearson correlation coefficient. It was found that the prepared product contains 2160 mg/kg anthocyanins, 201 mg/kg rutin, 26 mg/kg chlorogenic acid and 679 mg/l polyphenols. No free quercetin was found. The content of L-ascorbic acid in the original elderberries was relatively low and therefore for study purposes, the syrup was enriched with this substance in the amount of 0.5% (w/w) to study the connection of its content with other substances. It is clear from the statistical processing that the concentration of chlorogenic acid correlates with the antioxidant activity measured by the FRAP method and the concentration of polyphenols to the antioxidant activity measured by the DPPH method.

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