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Využití suchého ledu v technologii vín révy vinné
Horníčková, Iva
Bachelor theses deals with application of dry ice in technology of grapevine wines. In the theoretical part phenolic substances are described, next the meaning of pre-fermentation maceration, factors affectiong maceration and the last part is focused on dry ice, its composition and production and purchase possibilities. The purpose of the theses is to find out the effect of cold maceration on resultant wines. Two red and two pink wines were produced, while one of them was made by cold maceration and the other one without cooling during maceration. In the case of cold variants, basic analytical parameter were measured during pre-fermentation maceration and sensory evaluation was performed for young wines. The results show that the Frankovka variety is cold maceration suitable for both, the rose and red variation of wines.
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Izučenije vybrannych fenolnych veščestv, obladajuščich antioksidantnoj aktivnostju, v jagodach i vine novych mežvidovych sortov vinograda v uslovijach Juga Moravii, Češskoj respubliki
Khafizova, Asiya Askhadovna
Nowadays the study of phenolic compounds and their content in food is of great interest due to their versatile capabilities, and above all their beneficial influence on human health. According to numerous research works phenolic compounds are able to decrease the level of cardiovascular diseases, and they have bactericidal, fungistatic, antioxidant and vitamin properties. Most authors agree that vineyard site, as a combination of soil-climatic conditions, and rootstocks have a significant influence on accumulation and distribution of phenolic compounds. That is why the influence of different vineyard site and rootstocks on content of various phenolic compounds and spectrophotometric indexes of must and wine of new interspecific grape varieties was studied. The results of our research allowed us to choose the best rootstock and vineyard site for each variety. The comparison with control varieties showed that the influence of the year on content of individual phenolic compounds is more prominent than the influence of studied factors (vineyard sites and rootstocks). The knowledge in that area could help to select and recommend certain vineyard sites and rootstocks for those varieties. The choice will be based both on the quality of must and wine and on the potentially positive influence on human health. The correlation of the antioxidant properties with the principal polyphenols showed that individual compounds are weakly associated with all antioxidant parameters, suggesting that the expression of antioxidant activity is rather a consequence of synergism between various phenolics, and it is not simply attributed to specific constituents. On the other hand a strong positive correlation of AAR in grape juice and catechin content was established, these data indicate that catechin is likely to play a major role in antioxidant activity of grapes.
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Chemical composition of wine produced from PIWI cultivars
Michálková, Kateřina ; Vítová, Eva (referee) ; Pořízka, Jaromír (advisor)
This diploma thesis deasl with the chemical charakterization of wine from selected PIWI varieties. The theoretical part describes the general origin and reason for breeding PIWI varieties, a closer characterization of selected three PIWI varieties, Johaniter, Hibernal and Solaris. The next part is devoted to the description of analytical methods that were used to determine the chemical characteristics. The experimental part is developed to the determination of chemical characteristics, namely general characteristics such as alcohol, total phenols, phenolic substances, volatile substances and elemental composition. The results show that are differences between wines from selected PIWI varieties in therms of chemical composition. The most represented organic acid was in the range of 735,1-1286,2mg/l malic acid. This was followed by acetic in the range of 100-400mg/l. The antioxidant activity was determined in the range of 0,2988-0,9683 mmol/l of Trollox and content of total phenols 273,5-390,3mg/l. Of the phenolic substances, gallic acid was the most represented, ranging from 6,9-13,9mg/l. As another, abundant phenolic substances, catechin in the range of 1,6-6,0mg/l was detected. Of the determined elements, phosphorus in the range of 165,4-450,5mg/l was the most represented. Representatives of ethyl ester, ethyl acetate, decanoic acid ethyl acetate and hexanoic acid ethyl ester, were detected as the most abundant volatiles. From the measured data it was evident that wines from PIWI varieties different from standard varieties, especially in the profile of aromatic substances.
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The in vitro effects of selected fenolic substances on isolated rat vessels
Rajtmajerová, Iveta ; Pourová, Jana (advisor) ; Hrdina, Radomír (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Iveta Rajtmajerová Supervisor: PharmDr. Jana Pourová, Ph.D. Title of diploma thesis: The in vitro effects of selected fenolic substances on isolated rat vessels Silymarin flavonolignans are endowed with various aspects. Recently their hepatoprotective effect has been discussed widely as well as their positive influence on the cardiovascular system. This diploma thesis is concerned with the vasodilatory effects of silybin-A, silybin-B, silybin-A + B and isosilybin-A on rat aorta. The aim of this study was to test the vasodilatory effect of selected substances. The dependence of aortic relaxation on the increasing concentration of tested substances was measured. Isolated Wistar breed rat aorta was used. DRC curves were created and EC50 values were assessed from the obtained values of vessel tension. The results were evaluated subsequently. The vasodilator potential of silybin-A and isosilybin-A is comparable; hence the position of the substituents may be irrelevant in having any impact on relaxation of the vessels. Different vasodilatory effects of silybin-A and silybin-B have been observed thus, the relaxation could be stereoselective. The testing of the equimolar mixture of silybin-A and...
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Detoxification of coffee sediments by oxidation processes
Maňáková, Helena ; Pořízka, Jaromír (referee) ; Diviš, Pavel (advisor)
This bachelor thesis deals with the detoxification of used coffee grounds by the oxidation processes. The theoretical section describes the characterization of coffee beans and used coffee grounds. Furthermore, this section describes the valorisation of coffee grounds, especially its application as a fertilizer. The final part of the theoretical section focuses on the characterization of phenolic compounds, which are responsible for toxic properties of used coffee grounds, and analytical methods are described, which include UV–VIS spectrophotometry and high–performance liquid chromatography. The aim of the experimental part is the sample preparation, the application of the effective detoxification process and the analysis of the detoxificated used coffee grounds, focusing on the content of phenolic compounds. At the end of the experimental part, data processing is described. Three types of coffee grounds were used for determination of phenolic compounds: raw, defatted and the third type was defatted and simultaneously hydrolysed. High amounts of phenolic acids were identified in every sample, especially the gallic, ferulic, chlorogenic and caffeic acid. After an oxidizing agent was applied, positive detoxification of every sample of used coffee grounds was confirmed. For the most effective and most economical oxidation, a 1% oxidizing agent was chosen, which after a 10–minute oxidization efficiently reduced the content of the phenolic compound.
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Basic chemical characteristics of cranberry juice
Cao, Ha Thuy ; Hrstka, Miroslav (referee) ; Vespalcová, Milena (advisor)
This bachelor thesis is about lingonberries and cranberries. It is mainly about berries which were used for chemical analysis. The berries are from the Research and Breeding Institute of Pomology Holovousy Ltd. and they have delivered six cultivars of lingonberries and three cultivars of cranberries. There is a research of general information about classification, botanical description, important chemical substances such as vitamins, natural colorants and products made in the industry. Furthermore there is descriprion of chemical methods for basic analysis. The next part of bachelor thesis is about how all these methods were applied to berry juice. What instruments and chemicals were used. First assessment was profit of juice which was about 50,00–60,00 %, but lingonberry Runo bilawskie has at least 31,49 % and cranberries have less profit too. Total solids were determined in the range of 11,40 % (Pilgrim) to 18,50 % (Runo bielawskie) and solitable solids are in range of 10,00 % (Pilgrim) to 16,08 % (Korál). Lingonberry contains more reducing sugars (8,81–12,92 %) than cranberry (7,90–9,03 %). Titratable acids are about 32,04–49,60 mmol.l-1 for lingonberry and about 55,40–60,67 mmol.l-1 for cranberry. The measurements show that pH of both berries are about 3. The most phenolic substances are found in range of 2187,11–3476,75 mg.l-1. Berries content anthocyans colorants in range of 54,91-65,29 mg.l-1 and the most in cranberry. All results are shown in charts and in the end there is a discussion and conclusion about methods and results.
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Possibility of further use of elderberry marc
Sedláčková, Lucie ; Pořízka, Jaromír (referee) ; Vespalcová, Milena (advisor)
This Diploma thesis talks about the production of concentrates and lyophilisate from the extract of elderberry moldlings (elderberry, Sambuvus nigra L.) and by determination by chosen chemical characteristics of these products. The theoretical part includes the botanical characteristics of the plant species Sambucus nigra L. Next is the part that is dedicated to biologicaly active substances found in elderberry and it‘s possible usage in the food industry. Next is the part where the extraction, purification and indentification of anthocyanic dyes are described. In the next part is the analyrical method HPLC described, including the description of instrumentation. The last part talks about the description of the used methods: methods for the concentration of the extract, UV-VIS spectrophotometry, determination of phenolic compounds, determination of dry matter, determination of active acidity and the overall titrating acidity. The experimental part contained the optimalization of the process of producing the extract from elderberry moldings. The extract obtained was then concentrated for preservation and characterization purposes based on selected chemical properties. The total content of anthocyanin dyes was chosen as a quality parameter. The most suitable process for the preparation of the extract was chosen to be the ratio of moldings and solvent 1:2, 4 (m/V). The most suitable solvent was chosen to be a mixture of water and ethanol in a ratio of 1:1 (V/V). According to the needs of the submitter, an extract with the use of water as the extraction agent is also provided. The prepared extract was then concentrated on a vacuum evaporator or lyophilized for storage purposes. The dye degradation while using the evaporator was the lowest in a 40 ° C water bath. The final products were characterized by the determination of soluble solids, pH, titration acidity, total phenolic compounds and total anthocyanin dyes. The anthocyanin pigments contained identified by liquid chromatography are: cyanidine-3-sambubioside, cyanidine-3-glucoside, cyanidine-3-sambubioside-5-glucoside, and cyanidine-3,5-diglucoside The total content of anthocyanins in the concentrate was determined to be equivalent to cyanidine-3-glucoside at 2.8 gl-1 and in the lyophilisate 2.5 gl-1.
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Basic chemical properties of fruits of selected cherry varieties
Chmil, Vojtěch ; Vítová, Eva (referee) ; Diviš, Pavel (advisor)
Diploma thesis is focused on chemical characteristics of nine selected sweet cherry varieties in nine parameters. Total and soluble solids were analyzed with these results 13.07–16.58 % for total and 14.67–19.50 °Brix for soluble solids, ash content 0,31–0,39 %, titratable acidity 5.44–9.91 g of malic acid per 1 kg of fresh cherries and formol number 14.45–23.73 ml of 0.1 M NaOH per 100 g of cherries. Then there were analyzed crude proteins content calculated from total nitrogen content determined by Kjeldahl method with results 0.41–0.68 % of crude proteins. Molecular absorption UV/VIS spectrophotometry was used for determination of total phenolic substances 0.30–0.89 g of gallic acid per 1 kg of cherries and total content of anthocyanins 128–848 mg of cyanidine-3-glucoside in 1 kg of cherries. Saccharides were determined by high performance liquid chromatography (HPLC) with ELSD detector. Content of glucose was 45.45–59.49 g/kg and fructose 46.88–60.01 g/kg. All results are compiled using tables and graphs and discussed. Experimental part of the thesis also describes principles and procedures of every analysis, so it can be reproduced. In theoretical part there is described botanical characteristic of cherry tree (Prunus avium L.), active substances contained in its fruits and their use in food industry. At the end of the theoretical part there is described instrumentation of high-performance liquid chromatography.
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The in vitro effects of selected fenolic substances on isolated rat vessels
Rajtmajerová, Iveta ; Pourová, Jana (advisor) ; Hrdina, Radomír (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Iveta Rajtmajerová Supervisor: PharmDr. Jana Pourová, Ph.D. Title of diploma thesis: The in vitro effects of selected fenolic substances on isolated rat vessels Silymarin flavonolignans are endowed with various aspects. Recently their hepatoprotective effect has been discussed widely as well as their positive influence on the cardiovascular system. This diploma thesis is concerned with the vasodilatory effects of silybin-A, silybin-B, silybin-A + B and isosilybin-A on rat aorta. The aim of this study was to test the vasodilatory effect of selected substances. The dependence of aortic relaxation on the increasing concentration of tested substances was measured. Isolated Wistar breed rat aorta was used. DRC curves were created and EC50 values were assessed from the obtained values of vessel tension. The results were evaluated subsequently. The vasodilator potential of silybin-A and isosilybin-A is comparable; hence the position of the substituents may be irrelevant in having any impact on relaxation of the vessels. Different vasodilatory effects of silybin-A and silybin-B have been observed thus, the relaxation could be stereoselective. The testing of the equimolar mixture of silybin-A and...
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Phenolic substances in algae
Ráček, Jan ; Pichrtová, Martina (advisor) ; Pilátová, Jana (referee)
Phenolic substances are considered to be a group of secondary metabolites, known primarily from land plants (Embryophyta). Their function is to absorb harmful ultraviolet radiation, to protect plants from grazing and to attract pollinators and seed spreaders. However, these compounds have also been reported in some phylogenetically unrelated algal groups, the most important of which are brown algae (Phaeophyceae), siphonous green algae from the Dasycladaceae family and conjugating algae (Zygnematophyceae). The aim of this work is to summarize the current knowledge about phenolic compounds of these groups with an emphasis on their significance for the biology of the species. The first part describes phenolic compounds in general and also outlines the way they are biosynthesized. The next chapters then deal with the three algae groups. The most explored ones in this area are brown algae, which contain a unique type of tannins called phlorotannins in their thallus. This is followed by green siphonous algae from the family Dasycladaceae, which synthesize sulphated coumarins and then conjugating algae in which gallic acid-based phenolic compounds have been found. The common feature of these substances is, as with land plants, the ability to absorb radiation from the ultraviolet part of the spectrum and...
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