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The electrochemical study of the degradation of the natural dyes from historical objects
Ramešová, Šárka ; Schwarzová, Karolina (advisor) ; Navrátil, Tomáš (referee)
The oxidation of quercetin (3,3',4',5,7-pentahydroxyflavone) and luteolin (3',4',5,7-tetrahydroxyflavone) has been studied. These intensively coloured polyphenolic compounds belong to a large group of naturally occuring flavonoid compounds. They were used with advantage as colourants in old tapestries. The study concerns the analysis of degradation processes of the original dyes. Degradation products formed during the ageing process can be used as fingerprints for the determination of the original colours. The degradation processes of flavonoid compounds were studied by electrochemical methods, absorption spectrometry and separation methods in aqueous media. The oxidation mechanism involves electron transfer coupled with chemical reaction and is influenced by the acidobasic properties of quercetin. The dissociation constants pK1 and pK2 of quercetin and pK1 and pK2 of luteolin were determined by combining of independent methods: acid-base titration and UV-Vis spectroscopy. The stability of both compounds significantly depends on the presence of the oxygen. The distribution of the oxidation products of quercetin in aqueous media within the exposure to oxygen was monitored by LC-MS/MS and LC- DAD analysis.
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Studium vlivu požití kávy na antioxidační stav organismu
Prucková, Zdeňka
The theoretical part deals with the characterization of coffee, its production, chemical composition of grain and coffee swallowed impact on the health of an organism. It also deals with antioxidants, their division and their effects on the human body. There is described glutathione, one of the most important antioxidant in the blood. The practical part is engaged in an experiment consisting of the capillary blood collection and subsequent determination of thiol groups Ellman method, determine the total content of reduced glutathione by high performance liquid chromatography with electrochemical detection and determination of total protein content in blood by the Bradford method,. All results are shown in graphs. Contents of glutathion and thiol groups with regular consumption of coffee increased, protein content did not change. In the last part of the experiment, sensoric analysis of the test sample of instant coffee was carried out. Coffee was rated as average, because the overall impression was rated an average of 52.7 points.
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Studium vlivu požití zeleného čaje na antioxidační stav organismu
Papanová, Veronika
This bachelors thesis Study of green tea ingestion on antioxidant status of the organism is divided into two parts theoretical and practical. The theoretical part deals with materials for the production of green tea and its production, chemical composition, health effect and the impact on the human organism during use. The practical part is about experiment with capillary blood samples using Ellmans method, Bradford assay and High performance liquid chromatography with electrochemical detection. The practical part also including the sensory questionnaire. The results show that green tea is able to increase the substances with antioxidant effect in blood. Values of Ellmans method and HPLC ED analysis are comparable and thiol groups and reduced glutathione growth is observed. According the result of the Bradford assay it seems that green tea has no effect on the protein content in blood. The overall impression of the sensory analysis is satisfactory 73,8 points.
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Význam selénu vo výžive kôz
Bieleschová, Ela
The theoretical part of the master's thesis contains knowledge about nutrition of goat, anatomy of the digestive tract, free radicals, selenium and ingredients of goat's milk based on available literature resources. The objective of the practical part was to experimentally determine the impact of the the addition of selenium to feeding ration for organic raised goats on qualitative and quantitative parameters of goat's milk and selenium content in goat's milk. The experiment was held on an organic farm in Prostejov area in June and July 2016, it lasted 30 days. Goat breeds raised on the farm were White Shorthaired and Anglo-Nubian. There were 12 goats studied in the experiment, divided into a treatment group (n = 6) and a control group (n = 6). Milk samples from each goat were collected at the beginning and end of the experiment The samples were analyzed in a laboratory for analysis of milk in Brno - Turany, selenium was analyzed at the Department of Chemistry and Biochemistry MENDELU. The results were evaluated and compared. The results of the experiment shows that the addition of selenium had an impact on its concentration in goat's milk but it had no effect on milk components (fat, protein, lactose, urea, somatic cell count) and milk yield.
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Vliv zinkových nanokomplexů na zdravotní stav organismu modelových zvířat
Jeník, David
Zinc is widely used as an alternative to antibiotic in piglets. Recent studies demonstrated the antibacterial effect of zinc nanoparticles. It is believed that zinc nanoparticles will exhibit better antibiotic effects than previously used medication zinc. There is a need to define ZnNPs effect on the organism. This thesis compares the influence of administration of zinc oxide nanoparticles and zinc standard forms at the dose of 2000 mg/Zn/kg diet in rat organism. The antioxidant status of rats and toxicity of zinc and zinc nanoparticles were monitored. The level of accumulated zinc for blood was on average 12 mg / kg ± 6 mg / kg, for liver 74 mg / kg ± 50 mg / kg, for kidneys 37 mg / kg ± 30 mg / kg for both nanoparticles and normal zinc . ZnNPs and zinc oxide did not extremely influence antioxidant status of samples of blood, liver and kidney. A significant effect was observed with GSH levels. Histological study of liver and duodenum showed slight tissue damage after administration of both zinc and nanoparticles. Zinc nanoparticles demonstrated beneficial effects as well as standard form.
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Monitoring kyseliny askorbové v ovocných nápojích
Chytilová, Barbora
The thesis deals with monitoring of ascorbic acid and other substances in selected fruit drinks. The theoretical part begins with a summary of knowledge about the occurrence and importance of ascorbic acid and their physiological effects. Furthermore, the content of vitamin C in individual fruits is compared. The following part deals with the division of soft drinks and raw materials, used for the production of soft fruit drinks. Part of the thesis is focused on the technology of fruit juice production obtained by direct pressing of fruit material and technology of fruit drinks production from fruit concentrates. The practical part is focused on determination of vitamin C concentration as well as vitamins of group B (B1, B2, B3, B5, B6) and organic acids (citramic acid, citric acid, malic acid, pyruvic acid and succinic acid) in samples of direct fruit juices and juice from concentrate. Mass spectrometer-coupled high-performance liquid chromatography (HPLC-MS) was used to detect vitamin C and other substances.
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Funkční potraviny z pohledu biologicky aktivních látek
Holasová, Denisa
The bachelor thesis describes functional foods and biologically active compounds with positive effects on human health. The introduction of the thesis is focused on definition, characteristics and classification of functional foods. The main part of the text is dedicated to biologically active substances that vary in the chemical structure, origin and physiological functions in our body. The final part of the bachelor thesis demonstrates protective effect of functional foods against lifestyle diseases such as cancer, cardiovascular disease, diabetes mellitus and gastrointestinal diseases. The long-time consumption of functional foods brings a lot of health benefits to the human organism.
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Konverze biologicky aktivních látek při přípravě zelených a černých čajů
Procházková, Anna
This graduation theses deals with the cultivation, processing, preparation of tea and the chemical composition of tea leaves in the theoretical part. Furthermore deals with the synthesis of biologically active substances in plant materials and their conversion from the preparation of tea to the transformation in the human organism after its consumption. It also briefly summarizes and defines the issues of free radicals and antioxidants as part of their functioning in the human body, and then attempts to objectively summarize their main pharmacological effects. The practical part, focused on the determination of phenolic substances and the total antioxidant capacity of selected green and black teas, is supplemented by their sensory analysis.
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Bylinné čaje a jejich antioxidanty
Ilčíková, Ladislava
In its first part, this Bachelor thesis named Herbal Teas and Their Antioxidants defines the term free radical and oxidative stress. Firstly, it discusses antioxidants which are presented in vegetal materials. It divides them into categories pursuant to their origin and their structure, and to other significant antioxidants and it researches their medicinal properties in relation to various groups of diseases, Secondly, it explains the consequences of excessive intake of antioxidants. The second part of this work deals with the preparation of herbal teas and their proper use. t characterizes twenty widely known and lesser-known herbs, which are most often being used to prepare herbal tea and it talks about their effect on human health. Free radicalm oxidative stress, antioxidants, herbal teas, vegetla antioxidants, herbs
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Isolation of active compounds from algae and their application in cosmetic products
Nováková, Laura ; Byrtusová, Dana (referee) ; Skoumalová, Petra (advisor)
The bachelor thesis is dedicated to the study of active substances and antioxidant effects of cultivated microalgae. We compared the results with a commercial alga that is freely available. In the theoretical part we focused on description of algal metabolites in cosmetics and a brief description of the methods used in their testing. In the experimental part there were analyzed three types of extracts (aqueous, alcohol and oil) from 4 species of algae. It is mainly the content of polyphenols, flavonoids and antioxidant activity that is determined. According to the results, the highest content of active substances was found in oil extracts. All extracts were encapsulated into liposomes. The average size of the nanoparticles was in range of 200 nm to 300 nm. The particles were stable enough also for long-term stability. The largest decrease was observed in the oil extract of the cultivated algae Chlorella vulgaris. The cytotoxicity of oil extracts was realized by MTT test on human cell cultures HaCaT. Finally, we concluded that the prepared liposomal particles could be used for anti-aging cosmetics.
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