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Active substances in cereal products for baby food
Hurtová, Jana ; Pařilová, Kateřina (referee) ; Márová, Ivana (advisor)
Present bachelor thesis is focused on the study of antioxidant substances in cereal products for baby food. The theoretical part is aimed at describing the anatomical structure and chemical composition of cereal grain, characterization of antioxidants with the focus on natural antioxidants, the technology and nutritional parameters of cereal products. The experimental part deals with the content of phenolic compounds, flavonoids, and the total and reducing sugars in the total of 12 kinds of cereal products with different flavour – 5 types of oak pap, 3 types of fiber pap and 4 corn paps. The work includes the analysis of ascorbic acid by titration method and the analysis of tocopherol, carotenoids and catechins by high performance liquid chromatography as well. The highest content of total phenolics and flavonoids was found in corn pap with raspberries and also in cereal pap with chocolate. High levels of vitamins E and C were found predominantly in flavoured fiber pap.
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Changes of the content of some active substances in aplle and pear fruits during storage
Matějková, Markéta ; Halienová, Andrea (referee) ; Márová, Ivana (advisor)
In presented bachelor thesis low molecular substances antioxidants found in plant food were described. Antioxidants from apples and pears were studied in detail, particularly their changes during storage in different conditions. Fruit species were described more closely in this study. The theoretical part is focused on ripening and storage of the fruits. The most common diseases of apples and pears are introduced too. In the practical part changes of some antioxidant levels in apples Idared (red-yellow) and Golden Delicious (green-yellow) were analyzed. Apples were stored for 2 months in three various storage conditions – at standard ambient temperature in the lab, in cellar and in refrigerator. In regular intervals samples were taken and levels of low molecular antioxidants (vitamin C, total phenolics, total flavonoids) and total antioxidant activity in apple fruits were analysed and compared. A surface microflora of the apples was analysed during the whole storage time. The most suitable storage conditions exhibited cellar (9 °C, 38,4 %). Phenolic changes in apples were substantially lower than flavonoid changes, while ascorbate content decreased dramatically with the storage time. Antioxidant activity was related mainly to ascorbate levels, influence of flavonoid changes was observed too. Antioxidant parameters were analyzed also in pear fruits, whose were stored only for very short time.
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Analysis of biologically active substances in some cereal products
Valentová, Radka ; Starečková, Terezie (referee) ; Márová, Ivana (advisor)
Presented bachelor thesis is focused on study of biologically active substances in cereal products. In theoretical part over view of cereal active substances, predominantly phenolic compounds were introduced. In practical part 15 kinds of cereal products were analyzed. In these materials some group parameters - total phenolics, total flavonoids and total antioxidant activity were measured by spectrophotometry. RP-HPLC/UV-VIS method was performed for analysis of selected individual flavonids. The highest content of phenolic compounds was measured in cereals containing fruits (raspberries, blueberries, tropical and red fruit), cacao, crusty fruits (hazel nuts, sunflower seeds) and buckwheat. All cereal products contain catechine, epicatechine, catechin gallate, epicatechin gallate, chlorogenic and ferulic acid. As a part of bachelor thesis simple sensory analysis was performed and consumer questionnaires were evaluated.
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L-ascorbyl-6-palmitate and its utilization in dietary and cosmetic supplements.
Palíková, Petra ; Zemanová, Jana (referee) ; Vránová, Dana (advisor)
Bachelor‘s thesis deals with the effection of antioxidants in foods and cosmetics supplements. Some antioxidants as vitamin A and beta-carotene, vitamin E and tocopherols and vitamin C as L-ascorbic acid and her derivate L-ascorbate-6-palmitate are described here. This derivate can by used as an accessory material in cosmetics and foods preparations, especially in the preparations that contain oil or fats, because as a lipophilic compound keeps them from getting rancid.
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Possibilities for utilization of selected vegetable oils in foodstuffs.
Krátká, Milena ; Vránová, Dana (referee) ; Zemanová, Jana (advisor)
The aim of this work was to find out and compare the composition of the chosen vegetable oils with regards to both the chemical composition and the pharmacological effects as the supplementary nutrition. All the oils selected contain large amount of the essential fatty acids, which has the positive effect on human health. Evening Primrose oil, borage oil and black currant seeds oil contain the large amount of the gama-linolenoic acid (GLA), which has the positive influence on the curing of the diabetes, menstrual syndrome, cancer, cardiovascular diseases, viral infections and skin disorders. Flax and hemp oil are excellent sources of the essential fatty acids in optimal ratio and are rich in other important substances, like phytoestrogenes and phytosterols. The lipids containing the high amount of the unsaturated fatty acids are predisposed to the oxidation during the storage. The oxidized essential fatty acids have the antimetabolic effect, which is working against the positive effect of original essential fatty acid. It is thus important and recommended to accompany the consumption of the polyunsaturated fatty acids (PUFA) with the antioxidants. In this work the effects of the antioxidants were also taken into account. From the oils selected the highest amount of the antioxidants can be found in Sea buckthorn oil, which contains the antioxidants like vitamin E, carotenoids etc. This work was also aimed at the literature review of the stabilization of the unsaturated fatty acids, technological production processes, reactions taking place in oils during their storage and the analytical methods used for the characterization of the oils.
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Influence of storage conditions on content of biologically active substances in apple fruits.
Ferdová, Jitka ; Čarnecká, Martina (referee) ; Márová, Ivana (advisor)
This study deals with antioxidants in diet and their effects on human organism. Further, it summarizes the agents affect the quality of apples in the course of long-term storage and it outlines the possibility of defence against them. In the experimental part methods of determination of antioxidant enzymes superoxid dismutase (SOD), catalase and polyphenol oxidace (PPO) in apples were introduced. The enzymes were measured in apples tissues in liquid nitrogen after 158 days in normal or modified atmosphere. In Apple the quantitative and qualitative analysis of proteins was realized. Further, some low molecular antioxidants (total phenolics, total flavonoids and vitamin C) as well as total antioxidant status were measured in frozen raw juice. This values were compared with values from apples analyzed immediately after the harvesting. Artificial inoculation with fungi was made in the last part and the fruitfulness was observed.
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Patatin proteins relative abundance in correlation to antioxidative activity of tubers of cultivated and wild potato species
MEJZLÍK, Petr
The aim of the thesis was to determine the content of pure tuber proteins, patatin relative abundance in total tuber protein, and subsequently its antioxidant potential. The theoretical part dealt with general potato characteristics, potato tuber chemical composition and description of analyzed cultivated and wild potato species. In the practical part results of laboratory analysis were presented. It was determined statistically significant genotype variability of antioxidant activity for potato tuber protein as well as for potato tuber dry matter here ranging from 0.221 (Solanum berthaultii 07S0300031) to 0.0066 mg of ascorbic acid/g dry matter (Solanum tuberosum cultivar Kuras). Any direct relationship between potato tuber protein content or patatin relative abundance and antioxidant activity was found. The findings are compared with the literature.
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Effect of oxidative stress on antioxidant systems, telomere length and telomerase activity in \kur{Locusta migratoria}
VRBOVÁ, Kristýna
Oxidative stress is caused by an imbalance between oxidants and antioxidants. Oxidative stress generated by reactive oxygen species (ROS) or reactive nitrogen species (RNS) occurs when protection of antioxidants fails or when an amount of ROS is too high. Telomeres, regions of repetitive nucleotide sequences at the end of chromosomes, are especially sensitive to oxidative stress because they contain a lot of guanine which is often oxidised. Antioxidants play an important role in protection against oxidative stress. In this thesis I analysed the effect of oxidative stress caused by paraquat on activity of antioxidant enzymes (catalase and superoxide dismutase) and telomere length in Locusta migratoria. I also studied differences in telomere length between locusts of various development stages and telomerase activity in locusts and other Orthoptera.
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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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Electrochemical Study of Rhamnazin
Ramešová, Šárka ; Sokolová, Romana ; Degano, I.
The natural flavonoid compound rhamanzin (3,5,4’-trihydroxy-7,3’-dimethoxyflavone) is important bioactive compound with antioxidative, anti-allergic, and anti-inflammatory properties. The cyclic voltammetry is used for the electrochemistry behavior of rhamnazin. The determination of oxidation pathways is supported by the identification of degradation products using separation technique.
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