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The Methods for the Detection of Antioxidant Substances
TURKOVÁ, Kateřina
Antioxidants and free radicals are widely discussed in the clinical and nutritional literature. Various reactive oxygen species (ROS) may be produced from normal biochemical, essential metabolic processes or from external sources as exposure to a variety of agents presented in the environment. Lipids, proteins, carbohydrates and DNA are all capable of reacting with ROS and can be implicated in etiology of various human disorders. The antioxidant system protects the organism from the effects of free radicals by scavenging them and thus preventing structural damage of cells. Measuring the individual components of the antioxidant system has provided important information about the defences against free radical effect. During the last decade, many analytical methods have been developed to determine the antioxidant activity of natural compounds and their mixtures in vitro. Some procedures involve the methods based on the generation of various radical species and their elimination by treatment with potential antioxidant compounds. The tests used for the evalution of total antioxidant activity are: Trolox equivalent antioxidant capacity-TEAC, diphenylpicrylhydrazil - DPPH, oxygen radical absorbance capacity-ORAC and the methods testing the ability to prevent lipid peroxidation. The other group includes the procedures that are based on measurement of redox properties of compouds (ferric reducing antioxidant potential assay-FRAP, cyclic voltammetry, HPLC).
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Sources and methods of saturation of the organism with antioxidants
NOVOTNÁ, Nikola
The aim of the thesis is to characterize sources of antioxidants and inquire the depth of knowledge about antioxidants among students of secondary school. The theoretical part of the thesis describes and divides important antioxidants for human health. The main sources of antioxidants in human diet are there divided, described and compared as well. The practical part of the thesis includes the inquiry which evaluates the theoretical interest in antioxidants and dietary intake of antioxidant supplements among 17-19 years-old secondary school students. The results are analyzed and graphically displayed. Research shows that more than a half of the respondents know the term antioxidants and consume these substances in the diet. However, it is important to increase knowledge of antioxidants already among young people and ensure the intake of these essential substances from a varied diet.
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Factors influencing changes to the content of antioxidants in the body.
MERLEOVÁ, Gabriela
This thesis deals with the relationship between antioxidants and free radicals, their interactions and effects on the human body. Characteristics, properties and occurrence of some antioxidants such as carotenoids, flavonoids, ascorbic acid, selenium, melatonin, quercetin, etc., may explain some of the mechanisms of their effects on human health, particularly in the area of lifestyle diseases such as cardiovascular disease, cancer and obesity. Fruits and vegetables are important sources of dietary antioxidants and therefore are regularly added to the diet part of the antioxidant defense of the organism, although the content of antioxidants in these foods may be changed by external influences. Information used in this study were obtained from the scientific and professional publications and periodicals found in domestic and international databases of scientific and specialist literature.
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Antioxidants in Food and Their Function in the Process of Defence Against the Free Radicals Effects
MOUDRÁ, Táňa
The thesis deals with antioxidants in food and their function in the process of defence against the effects of free radicals. At first, antioxidants are defined and their clasification is described in the theoretical part. Then this part deals with antioxidants in food, their effects on people´s health and antioxidants recommended daily doses. Possitive and negative effects of free radicals on people´s health and their relation to antioxidants are mentioned next. In the practical part, I concentrate on the survey focused on the investigation of the population awareness of antioxidants and their effects on health. One hundred and sixty respondents took part in the survey. They were devided into two groups; working people and pensioners. The questionnaire contained twelve questions which investigated the population awareness of the topic. The data collection took place in January 2013 and it was evaluated in February 2013. The collected data were evaluated according to basic statistical methods. The ascertained answers were put into unified tables and then they were compared. Especially, the general awareness was investigated and then the effect of education on the knoledge of the topic was considered.
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Antioxidants in food and possibilities of nutrition application
DUBNOVÁ, Martina
The bachelor thesis concerns with the occurrence of antioxidants in foods, the possibilities of their applications in nutrition and population awareness on the topic antioxidants. The theoretical part describes the types of antioxidants, effects on human health and occurrence in foods and their recommended daily dosage. Further characterize free radicals and their negative effects on the organism. The practical part contains the research of the knowledge about antioxidants in the population in the form of a questionnaire. The results are analyzed and charted. The antioxidants are known by 82% of respondents. For the question ?What the antioxidants are used for? answered 54% of respondents correctly. In which foods the antioxidants are is known by 58% of respondents. The greatest awareness of antioxidants is in the group of workers, as well as students and in the group of retired respondents is the awareness of antioxidants slightest. Research shows that awareness of antioxidants which play a major role today in the prevention and treatment of lifestyle diseases and shows that more than half of respondent?s answers were inadequate.
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EPR study of beer samples and brewing materials
Stopka, Pavel
Hydroxyl (OH.), nitroxide (NO.)and stable organic free radicals were identified and determined in samples of beer. The maximum of their concentration is 5-10 min. after the opening of bottle. The influence of UV irradiation and hydrogen peroxide is de
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