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1
Barošová, Michaela. "Sledování antioxidantů v sušeném ovoci." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2008. http://www.nusl.cz/ntk/nusl-216231.
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Presented diploma work is focused on study of antioxidants in different kinds of dried fruits. Analyses of ascorbate, tocopherols, carotenoids and flavonoids were performed using RP-HPLC with spectrophotometric detection. Analysis of dried fruits showed high level of vitamins and phenolocs mainly in berries. High level of carotenoids was observed in dried apricots and plums. Further, antioxidant activity of dried fruit extracts was tested by ABTS method. High antioxidant activity was found mainly in dried apples, cranberries and blueberries. The biological test with yeast Sascharomyces cerevisiae D7 was used for the analysis of antimutagenic efects of dried fruits. High antimutagenic activity exhibited dried cranberries and blueberries. Most of tested dried fruits with high antimutagenic effect exhibited also high antioxidant activity as well as high content of some antioxidants. No direct correlation was found among these parameters. Last part of this work was focused on study of influence of drying on antioxidant content in two types of apples. Drying at mild controlled conditions exhibited no significant negative effect on active substance content; in some samples their concentration was observed.
2
Tomková, Martina. "Obsah antioxidačních látek ve vybraných druzích ovocných a bylinných čajů." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2008. http://www.nusl.cz/ntk/nusl-216228.
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This diploma project deals with antioxidant and antimutagenic properties of selected herbal and fruit teas commonly used in Czech population. Influence of different tea packaging (bag teas and loose leaf teas) on bioactive compound content was compared. Further, effect of long-term storage in common household conditions was studied. Antioxidant properties of teas were characterized using some group parameters - total antioxidant activity ("Randox Total Antioxidant Status Kit"), total phenolics and total flavonoids - as well as some individual representatives of low molecular weight antioxidants. Higher antixidant content was found in herbal teas than in fruit teas. Comparing bag teas with loose leaf teas higher antioxidant activity was shown in loose leaf teas. Individual antioxidants were analyzed using HPLC method with spectrophotometric detection and verified by on-line LC/MS. IN all tea samples catechins - catechin, epicatechin, epicatechin gallate and other flavonoids - rutin, morin, quercetin, kaempferol, myricetin and luteolin were determined. In most of teas high level of catechin and rutin was detected. The highest level of flavonoids was determined in herbal poured teas. Ascorbic acid content was also determined by HPLC method. Higher vitamine C level was found in most of fruit teas and in rose hip tea. Antimutagenicity of tea extracts was tested by in vitro test using Saccharomyces cerevisiae D7 yeast. High antimutagenic activity showed mainly nettle tea, tutsan tea and most of fruit teas. During long-term storage (1 year, 20°C, darkness) a significant decrease of all analyzed antioxidant parameters was followed. Higher lost of antioxidants was found in fruit teas when compared with the herbal ones.
3
Lichnová, Andrea. "Cereálie - aktivní složky, biologické účinky a vybrané aplikace v potravinářství." Doctoral thesis, Vysoké učení technické v Brně. Fakulta chemická, 2014. http://www.nusl.cz/ntk/nusl-233398.
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The presented doctoral thesis is focused on the study of the biological effects of active compounds found in cereals, on the development of methods of analysis these effects, on the determination of the content of active substances and characterization of the relationship between composition and biological effects of cereals and cereal products. For the analysis several kinds of raw cereal samples (flakes, flour, germ, bran), flavored extruded cereal products and also samples of paddy and husked rice were chosen. To major types of analysed active compounds belong mainly phenolic compounds in the form of glycosides and aglycones, and also saccharides. Group parameters such as total polyphenols, flavonoids and total and reducing saccharides were determined spectrophotometrically, individual phenolics and saccharides were determined by high performance liquid chromatography (HPLC). TEAC, DPPH and CLAMS methods were used to determine the antioxidant activity. Indirect methods of determination of substances with antioxidant effect were used as well. Results of the total antioxidant activity were compared with values of antimutagenic/genotoxic activity obtained by several microbial test systems. Antimutagenic effect was expressed as a percentage of inhibition of effect of standard mutagen and could be considered as a potential preventive effect of cereals to DNA arising primarily by free radicals effect. The highest values of group and individual phenolics, antioxidant and antimutagenic activity were found in germs, bran, in buckwheat products and in coloured and raw rice. In flavoured cereal products addition of chocolate or fruit positively influences content of active phenolic substances as well as sugars, antixidant and antimutagenic activity. In a representative sample of Czech population, questionnairy study was performed to monitor interest in cereals and consumer preferences. The most of consumers consider cereals with chocolate flavour as less healthy than confirmed results of laboratory analyses. In this study some new food products were developed. Several types of model cereal products containing plant (fruit, vegetables) extracts were proposed. Extracts were added to cereals in freeze-dried and encapsulated form. The highest positive effect exhibited addition of local forrest fruit extract. Within preparation of encapsulated extracts several methods of preparing lipid or saccharides particles were also tested. The encapsulation efficiency of the methods and stability and size of particles were analysed. Optimal type of fortified cereal foods could be suggested based on the acquired results. Selected cereals were used as alternative carbon substrates (processed or raw) for the cultivation of microorganisms to produce enriched biomass usable in the feed industry. We can conclude that cereals in raw as well as processed form belong to universal foods and rich sources of biologically active substances. They can be processed by many ways. They can be used for direct consumption, as a part of new products and also undirectly as a substrate for feedstock.
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Křenová, Alena. "Antioxidační aktivita vybraných druhů drobného ovoce." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2015. http://www.nusl.cz/ntk/nusl-217149.
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This diploma´s thesis deals with the determination of total antioxidant activity of red and white gooseberries and red, white and black currants. There are available information about small fruits, an overview of natural and synthetic antioxidants and a summary of the methods to determine the total antioxidant activity in the theoretical part. Frozen fruit samples were provided by Research and Breeding Institute of Pomology Holovousy Ltd. in the project QI111A141 – Research of new technologies in the cultivation of gooseberries and currants with a focus on quality and use of fetuses (Ministry of Agriculture). The total antioxidant activity of red and white gooseberries and currants was measured by spectrophotometric methods using free radicals ABTS•+ and DPPH and was expressed as a Trolox equivalent. The total antioxidant activity of black currants was measured by electron paramagnetic resonance using free radicals ABTS•+ and DPPH and expressed as a TEACABTS and a TEACDPPH. There were measured 8 species of red gooseberries, 6 species of white gooseberries, 12 species of red currants, 6 species of white currants and 8 species of black currants in this thesis. The highest values of total antioxidant activity showed species of red and white gooseberries Alan, Karmen, Pax and Invicta and species of red and white currants Rovada, Orion and Olin. Among black currants, species Ometa and Ruben had the highest values of total antioxidant activity.
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Klepáčková, Kateřina. "Laboratorní ověření účinnosti tradičně využívaných léčivých rostlin Ekvádoru." Master's thesis, Česká zemědělská univerzita v Praze, 2016. http://www.nusl.cz/ntk/nusl-258172.
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Health care in Ecuador varies greatly depending on socioeconomic status, age, sex and place of residence. One third of the population has no regular access to health services and more than two-thirds of the population has no health insurance. Herbal medicine is
the synthesis of therapeutic experience of indigenous physicians which has been evolving
for hundreds of years and its resources are used to prevent and treat various types of diseases. Plants are popular natural remedy due to their efficacy, safety and minimal side effects. However, certain combinations of herbal medicine and drugs can be dangerous. Sciences, which help to examine the context of the traditional use of plants in the timeframe and also contribute to the discovery of their bioactive compounds, are called ethnobotany and ethnopharmacology. This paper investigates ten plants imported from Ecuador, which are traditionally used for healing various types of diseases such as gastrointestinal disorders, influenza, cold, urinary tract infection, skin diseases in the pelvic cavity etc. Efficiency research of herbal medicine has a great significance for future healthcare because
of the expansion of antimicrobial resistance, which is currently becoming a serious health risk for both humans and animals. Antimicrobial and antioxidant activity of plants, which are
in this thesis measured by the broth microdilution method and ORAC method, are important indicators for the analysis of medicinal plants. The only demonstrable positive result
of testing the antimicrobial activity was the discovery of minimum inhibitory concentration
of Espeletia schultzii against Streptococcus pyogenes (MIC=0.256 mg/mL). The highest antioxidant activity was discovered in the plant Croton elegans Kunth (743,64 +- 28,56 microgram of trolox equal to 1 miligram of the extract), for which no records associated to antioxidant activity were found.
6
Čaková, Adriana. "Stanovení antimikrobiální a antioxidační aktivity vybraných bylinných extraktů." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2021. http://www.nusl.cz/ntk/nusl-449724.
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Tetradenia spp. is herb naturally growing in Africa and is part of family called Lamiaceae. The herb is used in traditional medicine to cure malaria, angina or as treatment for tropical skin diseases. Maceration was chosen from number of extraction methods, to obtain bioactive compounds from this plant. Optimization was performed with aim to retrieve as much of bioactive compounds as possible. Optimal conditions chosen were: temperature 60 °C, extraction time 40 minutes, solvent 40% ethanol and solid-solvent ratio 1:5. In total 63 aromatic active compounds were found in optimal extract. Terpenes were the most abundant (88,60 %), from them oxygenated monoterpenes (55,65 %) and monoterpenes (29,52 %). Compounds with highest percentage quantity were camphor (51,76 %), cis--ocimene (8,17 %), 3-octyl acetate (7,71 %), trans--ocimene (6,76 %), -terpinene (4,93 %), o-cymene (3,81 %), terpinolene (1,33 %), limonene (1,33 %), camphene (1,19 %) and borneol (1,20 %). Further, total phenolic content was 0,31 ± 0,02 mgGAEml-1, which equals 1,52 ± 0,11 mgGAEg-1 of plant. Antioxidant activity was 417,56 ± 32,84 gTEACml-1 and percentage of radical scavenging activity ABTS•+ was 88,99 ± 7,00 %. Finally antimicrobial activity was determined against bacteria Bacillus cereus, Escherichia coli and yeast Candida glabrata. Against E. coli and C. glabrata there was no inhibition exhibited. Against B. cereus there was seen mild inhibition activity. The results confirm that Tetradenia spp. contain a number of interesting aroma active compounds, which shows antioxidant and antimicrobial activity. The herb has a good potential as natural source of nutritious and sensory active compounds to be used into various foods.
7
Kováčová, Ivana. "Stanovení biologicky aktivních látek ve vybraných přírodních rostlinných extraktech." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2016. http://www.nusl.cz/ntk/nusl-240571.
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This thesis is focused on the study of the effectiveness of active ingredients from natural extracts such as milk thistle and turmeric. The thesis describes the use of modern methods of analysis and identification of active substances located in plants of milk thistle and turmeric. In the experimental part of thesis, which was preceded by a literature search focused on the biological effects of active substances in the chosen natural extracts, the extracts were characterized according to group characteristics (total assessment of polyphenols and flavonoids, assessment of antioxidant activity, and assessment of vitamin C volume and tocopherol). The next part is focused on the study of the encapsulation of natural active substances into the organic particles: liposomes. Silymarin and curcumin were encapsulated as active substances. The idea of a plant with a single active ingredient is usually erroneous. Plants usually contain hundreds of components which cooperate on a given effect. Therefore, the majority of herbalists believe that a simple plant is an active ingredient. However, some plants are known to be containing a particular active phytochemical. For instance, plants such as the milk thistle, turmeric, or a ginkgo are great examples of the plant containing a particular active phytochemical. In these cases, the active compound is disproportionately more effective than the plant itself. Encapsulation efficiency of active ingredients of Silymarin and curcumin was determined by HPLC/PDA. The aim of the analysis was to observe the behavior of elements during the incubation in surrounding of gastric juice model, and the stability while maintaining the particles in model food.
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Bartošová, Jitka. "Stanovení celkové antioxidační aktivity čajových nálevů vybraných druhů čajů." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2009. http://www.nusl.cz/ntk/nusl-216489.
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This thesis deals with the total antioxidant activity (TAA) evaluation of various sorts of tea (green, black, half-fermented, white, mate, rooibos and herbal) depending on the process and time of their treatment. The main emphasis is put on testing a new method of measuring the total antioxidant activity by flow coulometry. The results acquired by this method are compared to the results of the chemiluminescent Trolox equivalent antioxidant capacity (TEAC) method which is a standard for measuring the total antioxidant capacity in various materials and raw materials. The work discusses the reasons for the differences in the values found by both methods.
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Konderla, Patrik. "Studium bioaktivních látek růže šípkové." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2017. http://www.nusl.cz/ntk/nusl-316235.
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Purpose of this thesis was research the content of biologically active substances in herbal rosehip extracts and also determination of antimicrobial and antioxidant activity of these extracts. Teoretical part describes informations about Rosa canina L., detailed specification of biologically active substances, specification of antioxidation and overview of methods determine antioxidant compound and antimicrobial activity. In the practical part was by combination of different solvents, procedures and herbal materials, made 21 extracts of Rosa canina L.. From measuring of these extracts, was made extraction curves and also was determined antimicrobial efficiency against bacterial strains Serratia marcescesns, Bacillus subtilis, Bacillus cereus and Micrococcus luteus. Results shows, that also all extracts has some antimicrobial activity, but only against microorganisms Micrococcus luteus and Bacillus cereus. Also was found that bud extracts contains more bioactive compounds soluble in ethanol, meanwhile rose hip extracts contains more bioactive compounds soluble in water.
10
Hamalová, Veronika. "Stanovení vybraných chemických parametrů plodů šlechtěných odrůd bezu černého." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2014. http://www.nusl.cz/ntk/nusl-217082.
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In this thesis was determinated selected chemical and nutritional parameters in the wild elderberry and 17 cultivated varieties of elderberry. The fruits was provided by the Research and Breeding Institute of Pomology Holovousy Ltd. The theoretical part deals describes elderberry, chemical composition of elderberry, especially biological active substances and its using not only food industry. Closer attention has been focused on effect of saccharides, anthocyanins and methods of their determination, specially determination by HPLC. The experimental part describes the various methods of determination of selected chemical and nutritional parameters. Total dry matter, content of total polyphenolic compounds, monomeric anthocyanin pigment and antioxidant activity was defined in all varieties of elderberry fruits. For some varieties was defined total soluble dry matter, content of organic acids and saccharides by various methods. In the end was compared the values from different methods varieties.
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Valasová, Denisa. "Analýza biologicky aktivních látek v oleji z meruňkových jader." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2017. http://www.nusl.cz/ntk/nusl-316165.
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The Master’s thesis is focused on the analysis of biologically active substances in apricot kernel oil. Apricot oil has recently begun to be widely used in the cosmetics industry, particularly as a part of massage oils or as part of moisturizing creams. The aim of this thesis is to characterize and assess the quality of apricot oil, determination of the content of selected active ingredients, through a series of analytical methods, and subsequent use of this oil in cosmetics and food industry. The thesis is based on the comparison of the quality of pure apricot oil and the oil after the fermentation process. It has been found that apricot kernel oil actually contains large amounts of unsaturated fatty acids. The excellent antioxidant activity of apricot kernels was proven too, especially those after fermentation. In addition to antioxidant activity, the samples contain a relatively large amount of tocopherol after the fermentation. Tocopherol is important for the uptake of free radicals in lipid bilayers, thus slowing down aging, protect the membranes and also prevent from possible cardiovascular and oncological diseases. Furthermore, in the Master’s thesis there were confirmed not only the hydration effects of creams with apricot oil, but also their ability of inhibic transepidermal loss of water from the epidermis. Creams were tested on five probands, aged 23–24, with different skin types. After the application of creams to their skin, these properties greatly improved, the skin has been regenerated and hydrated for 24 hours after the treatment.
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Ferdová, Jitka. "Změny aktivit enzymů v ovoci v průběhu dlouhodobého uchovávání." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2010. http://www.nusl.cz/ntk/nusl-216605.
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This study is focused on study of changes of enzyme and low-molecular weight antioxidants in different fruits during long-term storage. In theoretical part individual low-molecular weight antioxidants and enzymes are described. The main causes of fruit decay and some possibilities of fruit preservation and storage are summarized. As biological material some common fruits were chosen - green and red apples, peaches, plums and white grapes. The fruits were stored in laboratory, cellar, in refrigerator and in freezer. In freezing experiments some ways of fruit preparation and processing were tested and their influence on fruit antioxidant status was compared. Shortened storage experiment was applied on blueberries, cranberries, raspberries and strawberries too. In fruits some group parameters – total antioxidant status, dry mass content, ascorbate level, total flavonoids and total phenolics were analyzed spectrophotometrically. Individual flavonoids and phenolics were determined by RP-HPLC/UV-VIS and on-line LC/PDA/ESI-MS. Antioxidant enzyme activities (superoxide dismutase SOD, catalase CAT, polyphenol oxidase PPO and lipoxygenase LOX) were measured by spectrophotometry. The surface microscopy and cultivation of moulds from fruit surface were performed too. Influence of storage conditions on biological activities is dependent on fruit sort. Freezing is the most suitable procedure for long-term storage without significant changes of active substance content. Long-term storage in controlled temperature conditions and/or atmosphere is usable for fruits with longer storage period. In these fruits stabile levels of antioxidant enzymes are stored for relatively long time. Some of enzymes act synergistically. Enzyme activities differed according to storage phase; at the beginning mainly high SOD and LOX activities were observed. CAT and PPO are probably activated as defence systems in rippened and/or damaged fruits. Levels of total as well as individual low molecular weight antioxidants varied during storage in all sorts, generally, increased course with longer storage period can be observed.
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Kalábová, Jana. "Studium antimikrobiálního účinku vybraných druhů koření." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2013. http://www.nusl.cz/ntk/nusl-216977.
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The antimicrobial effects of cinnamon, clove and ginger (grand and fresh) extracts against Bacillus subtilis, Aspergillus niger and Pichia fermentans were studied in this thesis. Selected spices were extracted in three solvents (ethanol, water and ethyl acetate) and inhibition effect on tested microorganisms was studied using two methods disc diffusion and broth dilution methods. The antioxidant activity and total polyphenolic compounds from spices were also determined. The results showed that cinnamon and clove extracts in ethyl acetate and ethanol were a promising antimicrobial substances for all tested microorganisms. Combination of cinnamon and clove especially ethyl acetate extracts showed an aditive effect. However, in the case of broth dilution method, fresh ginger inhibited bacterial growth under optimal growth conditions of Bacillus subtilis (35 °C, pH 7, 250 rpm). Minimum inhibitory concentration (MIC) values for all susceptible microorganisms was determined 8,3 mg/ml. The highest amounts of polyphenolic substances were found in cinnamon and clove ethanol extract and this result was in correlation with antioxidant activity.
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Boberová, Jana. "Optimalizace technologie výroby echinaceových kapek." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2020. http://www.nusl.cz/ntk/nusl-433148.
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This diploma thesis deals with the production of herbal drops from Echinacea and the determination of the content of selected active substances. In the theoretical part, the taxonomic classification of echinacea, its botanical characteristics and growing conditions are mentioned. The history of cultivation and uses of this plant are also mentioned. An important chapter of the theoretical part is the chemical composition of the plant and differences in composition between individual cultivars of Echinacea. Methods for obtaining active substances and their determination are also mentioned. The last chapter is devoted to the technology of production of echinacea drops. In the experimental part, the extraction was optimized for dried flowers and roots of E. purpurea. The following extraction system was determined for the flowers: 40% ethanol, time 6 hours, weight to solvent ratio 1:10 and room temperature. For the roots, 20% ethanol and a time of 24 hours, a ratio of 1:10 and room temperature were evaluated as the best conditions. Furthermore, the best extracts were prepared, in which the content of total phenolic substances was set at 0.799-0.839 mg/ml, then the antioxidant activity was determined in the range from 116 to 242 µg T/ml, and finally the analysis of aromatic substances was performed by HS-SPME-GC-MS. Two commercial samples were also tested to compare the prepared extracts.
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Pelikánová, Blanka. "Stanovení vybraných chemických parametrů v plodech nových odrůd rybízů." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2014. http://www.nusl.cz/ntk/nusl-217090.
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Presented diploma thesis is dedicated to the determination of selected chemical parameters of fruits of new currant varieties. The theoretical part is focused on the characteristics of currant, the biologically active substances of its fruits and also the utilization of current in the food industry. Further part of the theory deals with the main chemical parameters which were examined: polyphenols, anthocyanins, ascorbic acid and antioxidant activity. In the practical part there were determined selected chemical parameters in six white, twelve red and thirteen black varieties of currant. Anthocyanins and polyphenols have been determined spectrophotometrically. The content of ascorbic acid in selected varieties of currant was determined by HPLC. As a technique for the determinationof the antioxidant activity was selected the method of free radical DPPH.
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Vysoká, Marie. "Vývoj energetických nápojů nového typu s obsahem přírodních aktivních složek." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2017. http://www.nusl.cz/ntk/nusl-316171.
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The aim of this thesis is the development and preparation of a new energy drink. The theoretical part of the thesis focuses on the comparison of the drinks available in market, the presentation of the main active ingredients and the proposal of enriching the new energy drink. It also describes the possibility of using an encapsulation and the method used to determine specific compound in energy drink or encapsulated particles. In the experimental part of the work, at the beginning, the main content of energy drinks were characterized, for instance caffeine, sugar, polyphenol and vitamin C. Subsequently the energy drink based on selected types of loose teas that were enriched with the encapsulated extract of acai, acerola, maca, goji and ginseng was designed. All extracts contained large amounts of polyphenols and antioxidants. In addition, acerola extracts contained very high amounts of vitamin C. Two types of particles, alginate particles and liposomes were prepared for encapsulation. For all particles, encapsulation efficiency, size, stability, and antioxidant activity were determined. Long-term stability was then monitored within three months. The particles were also exposed to artificial gastric, pancreatic and bile juice. All tested particles showed very good encapsulation efficiency. In terms of long-term storage stability in an aqueous environment. Particularly liposome particles, which also showed high stability by zeta potential measurement, were suitable. On the contrary, in case of alginate particles, when stored in an aqueous medium, the release of active substances occurred. Finally, an energy drink was created and subjected to sensory analysis. The best energy drink was based on black or green tea with alginate particles acai, goji and ginseng.
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Kapiton, Ulyana. "Srovnání vlastností aroniových pomazánek různého původu, složení a různé technologie výroby." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2019. http://www.nusl.cz/ntk/nusl-401850.
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This diploma thesis deals with comparison of the properties of chokeberry spreads of different origins, composition and different production technologies. The theoretical part contains a brief description of the chokeberry – Aronia melanocarpa, an overview of the most important substances contained in the chokeberry and examples of the use of aronia, not only in the food industry. Furthermore, the legislative requirements for the production of spreads and the production technology itself are described. In this thesis is also described a new patented technology of spread production using HTD technology. Another part of the theoretical part is a literature review of the determination of anthocyanins in chokeberry by HPLC method. The experimental part describes the laboratory procedures used for determination of dry matter, carbohydrates by HPLC with ELSD detector, anthocyanin dyes, total phenolic compounds and antioxidant activity. Another part of the work was a questionnaire survey and sensory analysis of selected chokeberry spreads. The panel members prefered the Lowicz chokeberry spread, for which was determined 29,39% dry matter, 15,15 mg.g-1 anthocyanins, 9,20 mg.g-1 total phenolic compounds, 158,42 mg.g-1 fructose and 151,26 mg.g-1 glucose and the antioxidant activity was determined to be 5,94 mg.g-1.
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Vejrostová, Petra. "Studium směsných přírodních antimikrobiálních preparátů a možnosti jejich stabilizace." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2016. http://www.nusl.cz/ntk/nusl-240734.
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Present diploma thesis is focused on natural antimicrobial substances. The aim of the experimental part of thesis was testing of antimicrobial activity of selected natural substances in free and encapsulated forms, preparation of particles and monitoring of their long-term stability. Various teas extracts (aqueous, ethanoic and DMSO) and aqueous herbs extracts were used as plant antimicrobial substances. Liposomes and chitosan particles with encapsulated aqueous teas extracts were prepared by ultrasonication. Encapsulation efficiency, size, stability and antioxidant activity for all particles were specified. Consequently, within a two months period, long-term stability for these particles was monitored. Spectrophotometric method for determining total polyphenols was used for evaluating encapsulation efficiency as well as for monitoring of long-term stability. The DLS method was used for determination of size and stability of particles. Antioxidation activity was monitored by using spectrophotometric method using ABTS. For testing antimicrobial activity of various types of teas, herbs extracts and their mixtures and combianitons with lysozyme and antibiotics, broth dilution methods were used while using both Gram positive and Gram negative bacterial test strains. Antimicrobial activity of prepared particles was also monitored, the antimicrobial activity was especially significant with the chitosan particles. Suitable combinations of natural substances whatever with antimicrobial or antioxidation effect either in free or encapsulated form could be used for applications for example in cosmetics industry, food processing or in medicine.
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Macuchová, Simona. "Studium aktivity enzymových a nízkomolekulárních antioxidačních systémů." Doctoral thesis, Vysoké učení technické v Brně. Fakulta chemická, 2010. http://www.nusl.cz/ntk/nusl-233305.
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Oxidative processes play important role in cell physiology and pathology as well. Balance of these processes is supplied by cooperating antioxidative systems; function of antioxidant defense systems depens on high levels of antioxidants in organism. Presented work is focused on developement and optimization of methods for analysis of important enzyme and non-enzyme antioxidants as well as total antioxidant capacity of selected types of biological material. Extractions and analyses of vitamin E, carotenoids, superoxide dismutase, catalase, peroxidase and lipoxygenase in barley and malt were optimized. RP-HPLC and HPLC/ESI-MS were used for analysis of vitamin E, phenolic and carotenoid content, spectrophotometry was used for enzymes activity analysis. A new methods for catalase and lipoxygenase activities were developed and compared with direct UV methods. Superoxide dismutase activity was determined by commercial diagnostic kit. A colorimetric method was used for peroxidase activity determination. Some kinetic parameters of enzymes were provided too. Optimized methods were used in the analyses of antioxidants in plant material - in barley and malt - in sets of samples of 6 varieties cultivated in four different locations for two years. Content of individual antioxidants differed depending on the variety, but usually were not found significant differences in the levels, depending on growing location. Perhaps climatic conditions have the greatest influence on levels of low molecular weight and enzymatic antioxidants at the specific location; oxidation processes are influenced both the quantity of moisture, both by sunlight, which induces oxidative processes in cultivated plants. The activity of antioxidants in barley caryopses is rapidly increasing during the malting process; an elevated temperature and moistness first induces activation the enzyme systems including antioxidant. In caryopsis is metabolic activity increased during which we can expect an increased production of radicals; for this purpose can antioxidant systems be activated that protect cells from damage by oxidative stress. In the second part of work optimized methods were applied in two clinical trials focused on study of the influence of exogenous antioxidants intake on metabolic and antioxidant status in human organism. In the first clinical study influence of food supplement containing polyunsaturated fatty acids and vitamin E on metabolism of hyperlipidaemics was evaluated. After 3-month supplemenation a lipid profile was improved and serum antioxidant levels increased. The second experiment was focused on enzyme and non-enzyme antioxidant levels in healthy subjects after temporarily intake of specific foods rich in antioxidants. After two-month intake plasma phenolic substances were slightly increased. Total antioxidant capacity and activities of enzyme antioxidants were not affected. Results of both clinical exeriments showed that supplying of antioxidants in natural form or in the form of food supplements does not markedly affect metabolism of healthy subjects, while in patients with chronic diseases antioxidant supplementation can positively influence metabolic status. Results of this work showed that optimized methods are suitable for analyses of antioxidant status parameters and also for monitoring of exogenous antioxidant intake.
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Burdějová, Lenka. "Komplexní analýza léčivých rostlin a jejich potenciál při využití v potravinářském průmyslu." Doctoral thesis, Vysoké učení technické v Brně. Fakulta chemická, 2018. http://www.nusl.cz/ntk/nusl-382420.
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Presented thesis deals with the complex characterization of extracts from medical plants using spectroscopic and chromatographic techniques, with emphasis on the influence of solvent, post-harvest treatment of the sample, location and year of production on selected parameters. Part of the work is devoted to application of selected extracts from medical plants in suitable form into beverages. The thesis is divided into two parts. At the first part of the work combination of electron paramagnetic resonance, ultraviolet visible spectroscopy, liquid chromatography and inductively coupled plasma optical emission spectrometry was applied for characterization of aqueous, ethanol and dimethylsulfoxide extracts from 10 selected medical plants, which were collected from two different locations during two years (2015, 2016) and post-harvestly treated by two ways (freezing, drying). In total, 39 parameters were determinated: namely total phenolic compounds content, total flavonoids content, 14 specific phenolic compounds, colour characteristics in the CIE L*a*b* system (L *, a*, b *, C*, h°, BI), radical-quenching activity using the cation radical of the 2,2'-azino-bis- (3-ethylbenzothiazoline-6-sulfonic acid), antioxidant/pro-oxidant activity using the spin trapping technique in the presence of 5,5-dimethyl-1-pyrrolin-N-oxide (DMPO)/potassium peroxodisulphate and content of 15 minerals (Al, As, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, P, Pb, Zn). The results confirmed that the studied parameters of medical plants are influenced by the extraction system, post-harvest treatment of samples, year of production, origin of samples (locality) and species composition. It has been shown that the type of extraction solvent significantly affects the composition of the extracts. On the basis of these analyzes, for food application – the isolation of the main functional components (phenolic compounds, flavonoids) –50% ethanol, post harvest treatment by drying and samples of Mentha piperita, Melissa officinalis, Hypericum perforatum and Salvia officinalis were selected. The second part of the thesis was focused on the application of selected extracts of medical plants to beverages (syrups). The above mentioned plants, 25% ethanol instead of 50% ethanol (due to the limitation of the ethanol content in final raw material), were selected for the application. At first, extraction of medical plants was optimized. Suitable ratio of material and solvent (1:10), extraction time (8 h) and herb absorbency (50–62 %) were determined. The prepared extract after filtration was applied to the syrup concentrate in different ratios to produce one-species syrups and further sensorially tested to select the suitable recipe, the best flavour and basis for the production of two-species syrups. The mint syrup was the most tasty and generally the most acceptable one-species syrup, and sage syrup was selected as the basis for two-species syrups. Further, the most appropriate recipes of the two-species syrups were chosen, the most sensorially acceptable one was selected and further tested if it would be appropriate to colour them. Preferentially, it has been found that it is not necessary to colour two-species syrups. On the basis of the sensory analysis, it has been found that peppermint and sage-peppermint syrups were the most tasty and acceptable syrups, which could be, after further testing, produced industrially to enrich the food market.
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Burdějová, Lenka. "Charakterizace plodů aronie (Aronia melanocarpa) a muchovníku (Amelanchier alnifolia)." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2014. http://www.nusl.cz/ntk/nusl-217029.
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Diploma thesis deals with the characterization of chokeberry (Aronia melanocarpa) and saskatoon berry (Amelanchier alnifolia) fruits. The theoretical part focuses on the botanical classification, chemical composition, curative effects and the use of chokeberry and saskatoon berry in the food industry. Further, the attention is also devoted to a review of methods for the determination of important antioxidants, specialized on the determination of polyphenols, anthocyanins, ascorbic acid and total antioxidant activity. The experimental part of the work deals with the determination of selected parameters in different varieties of chokeberry and serviceberry, harvested in 2012 and 2013 using spectroscopic and chromatographic techniques with an emphasis on effect of solvent (50% ethanol, destilled water, DMSO). Specifically total content of polyphenols and anthocyanins, color characteristics using the CIE L*a*b* system and the ability of the sample to reduce the iron are determined using the UV-VIS-NIR spectroscopy. Further ascorbic acid concentration in individual extracts is quantified by High performance liquid chromatography coupled with a diode array detector and the total antioxidant activity is characterized by electron paramagnetic resonance involving •DPPH and ABTS•+ assays.
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Jančíková, Simona. "Charakterizace jedlých obalů pro potenciální použití při balení potravin." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2019. http://www.nusl.cz/ntk/nusl-401908.
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In the last years, the edible packaging has been gaining popularity due to the potential usage as the packaging for food instead of synthetic materials. The edible packaging can positively affect the packaged food by the active properties or due to its intelligent properties can monitor the changes in food. In theory, the legislation about the packaging of food and edible packaging was described. The substances for edible films preparation and additives, which can improve the properties of the edible films, were described too. In this part, the undesirable microorganisms occur in food and the chapters about active and intelligent properties of the edible films were summarized. The main aim of the thesis was the practical preparation of edible packaging/films made from furcellaran, gelatin hydrolysate with the addition of water dried or fresh rosemary extracts in concentrations 5 %, 10 %, and 20 %. In the experimental part, the physical analysis was done – textural parameters such as tensile strength and elongation at break, water content, and thickness. In the chemical analysis the total polyphenols content, determination of polyphenols by HPLC, antioxidant activity, optical properties and antimicrobial activity of the prepared edible films were done. There were found out, that the total polyphenols content and antioxidant activity were the highest in the 20%DR (TPC: 6,79 ± 0,06 mg gallic acid/g; DPPH: 87,84 ± 0,07 %). Also, the 20%DR and 20%FR changed color in different pH (3 and 12). The antimicrobial activity was negative. The thesis showed that the addition of natural extracts to edible films can increase the polyphenols content and they can also work as the UV protector.
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Fajtl, Zdeněk. "Study of qualitative parameters of fruit juices and possibilities of their modification via technological modifications." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2015. http://www.nusl.cz/ntk/nusl-217155.
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Ovocné šťávy jsou celosvětově nejoblíbenějšími nealkoholickými nápoji. Kromě vitamínů a minerálů jsou také bohatým zdrojem polyfenolů, které jsou považovány za látky přispívající k celkové antioxidační aktivitě. Zvyšující se požadavky konzumentů na kvalitu a bezpečnost potravin nutí výrobce k zvyšování výrobních a kvalitativních standardů potravin. Nedávné inovace ve výrobě ovocných šťáv vedly k modifikacím výrobních podmínek, které zahrnují změny ve složení šťávy (např. přídavek ovocné dužiny nebo malých ovocných kousků), vylepšování vlastností obalových materiálů a modifikace produkční atmosféry. Cílem diplomové práce bylo pomocí metod EPR a UV-VIS spektroskopie posoudit vliv různých výrobních postupů na vybrané kvalitativní znaky (antioxidační aktivita, změna barvy a koncentrace vybraných fytochemikálií) pomerančových šťáv s dužinou a ananasových šťáv, a charakterizovat jejich změny v průběhu dlouhodobého skladování. Získané výsledky byly zpracovány metodami multivariační statistické analýzy s cílem posoudit vliv původu suroviny, roku produkce a použitých výrobních podmínek na sledované parametry a celkovou kvalitu ovocných džusů. Výsledky jasně prokázaly, že pasterizace ovlivňuje kvalitu výrobku; ačkoli byla použita „šetrná“ pasterizace, byl u těchto vzorků pozorován mírný pokles prakticky všech monitorovaných parametrů v porovnání s čerstvými – nepasterizovanými šťávami. Avšak pokud jde o po-pasterizační změny, byl prokázán významný vliv produkční atmosféry na monitorované kvalitativní parametry šťáv, prokazující, že náhrada kyslíku inertními plyny může výrazně prodloužit trvanlivost šťáv. Kinetické studie změn sledovaných parametrů na době skladování ukazují, že ve většině případů dochází k postupnému zhoršování všech monitorovaných parametrů, a to bez ohledu na technologii zpracování šťávy. Ve vzorcích vyrobených použitím modifikované atmosféry bylo, v závislosti na typu inertního plynu, pozorováno zpomalení poklesu jednotlivých kvalitativních parametrů šťáv jako výsledek aplikace inertní atmosféry. Tento trend byl zřejmý především pro delší skladovací období, zatímco na začátku skladování (6 - 7 týdnů po výrobě dané šťávy) byly pozorované trendy nejednoznačné. Lze proto předpokládat že tento „ochranný“ efekt inertní atmosféry je ovlivňován fyzikálně-chemickými vlastnostmi jednotlivých plynů, zejména jejich rozpustností v kapalném médiu. Výsledky také prokázaly že vlastnosti šťáv jsou ,bez ohledu na druh ovoce, výrazně ovlivňovány také sezónními vlivy a původem surové šťávy. Z výsledků statistické analýzy vyplývá, že rok výroby je silným diskriminačním faktorem. Na základě všech monitorovaných charakteristik, bylo dosaženo absolutní diskriminace vzorků pomocí kanonické diskriminační analýzy. Pokud jde o původ surovin, byla dosažena pouze částečná diferenciace, i když s poměrně vysokým klasifikačním skóre. Pokud jde o technologii výroby, byla dosažena pouze částečná diferenciace vzorků podle typu použitého inertního plynu. Získané poznatky pomohou výrobcům ovocných šťáv s optimalizací výrobních podmínek s cílem získat výrobek s maximem prospěšných vlastností, které by si udržel po celou dobu expirace, jejíž délka může být také optimalizovány na základě prezentovaných výsledků.
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Javorská, Kateřina. "Stanovení vybraných chemických parametrů plodů moderních odrůd angreštů." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2014. http://www.nusl.cz/ntk/nusl-217081.
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Diploma thesis deals with determination of individual chemical parameters contained in modern varietes of gooseberries (Grossularia uva-crispa). The theoretical part is focused on the botanical characteristics of the plant, a description of selected varietes, chemical composition and food utilization fruits. The second half of the theoretical part is devoted to the characterization of selected nutritional parameters and methods for determination of total anthocyanins, phenolic compounds, vitamin C and antioxidant activity. Total of 17 varietes of gooseberries, which come from growers Vondráček and the Research and Breeding Institute of Pomology Holovousy Ltd. were analyzed in the experimental part. pH differential method was used to determination total monomeric anthocyanins. Total content of polyphenols were determined by using the Folin-Ciocalteu reagent. Next was determined content of vitamin C in all varieties by HPLC and was evaluated the total antioxidant aktivity using radical DPPH. In conclusion, individual varieties of gooseberries were compared by the contents of the determined chemical parameters.
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Michálková, Kateřina. "Chemická charakterizace vín z vybraných PIWI odrůd." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2020. http://www.nusl.cz/ntk/nusl-413558.
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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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Holasová, Petra. "PSE extrakce rostlinného materiálu pro potravinářské účely." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2009. http://www.nusl.cz/ntk/nusl-216538.
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Flavonoids were identified and quantified in samples of dry leaves of plant Stevia rebaudiana Bertoni. Content of flavonols (kaempherol, quercetin, myricetin, rutin) and flavons (apigenin, luteolin) were compared in three samples (standard leaves of Stevia rebaudiana Bertoni, Stevia rebaudiana Bertoni origin from Ukraine and from Czech republic), that were extracted by three extraction methods (PSE, ultrasonic extraction, Soxhlet extraction) with two polar solvents, methanol and ethanol, in combination with non-polar hexane. Extracts were analyzed by HPLC with detection UV-VIS. Antioxidant activity and total content of flavonoids in extracts were measured by spectrometry. Stable free radical DPPH. was used for determination of scavenging effect in extracts. PSE was the most effective extraction method with this conditions – 120 °C, dynamic mode and with methanol like solvent.
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Matějková, Markéta. "Sledování změn vybraných druhů lokálního ovoce v průběhu mražení." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2011. http://www.nusl.cz/ntk/nusl-216759.
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This diploma thesis was focused on study of low-molecular antioxidants present in various kinds of fruits, namely berries. In theoretical part detailed characterization of antioxidants studied in presented work and their biological effects are introduced. Further, principals of processing and storage of specified species of fruits are discussed. Changes observed during storage of specific fruits are described too. In practical part changes in content of selected antioxidants in berries were followed. As studied material strawberries, raspberries, blueberries, red and black currants were used. All kind of these fruits was stored in fridge for six months using several different kind of processing. Berries were stored as whole fruits, whole osmotically processed fruits by sucrose, raw pulp and sweetened pulp. At first, starting values of selected antioxidant parameters were measured in fresh fruits (ascorbate, total antioxidant activity, total phenolics, catechins and individual flavonoids). After freezing the same parameters were measured regularly in two month periods. As the most suitable method of fruit processing, with regard to antioxidant content, storage of the whole fruits or pulp can be recommended. Content of ascorbate decreased in all forms and species of the processed fruits during all the time of storage. Oppositely, the content of other studied antioxidants exhibited fluctuations or increasing trend. Sensory analysis was proved for the whole fruits and also for whole sweetened fruits.
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Tobolková, Blanka. "Moderní postupy hodnocení kvalitativních parametrů potravin." Doctoral thesis, Vysoké učení technické v Brně. Fakulta chemická, 2014. http://www.nusl.cz/ntk/nusl-233382.
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Antioxidant properties and some other characteristics of selected organic and conventional products (wine, spelt flours) were evaluated in view of their potential utilization as markers suitable for food unambiguous differentiation according to the affiliation to production system. Beside these, study of fruit juices stability during storage in dependence on different technological procedures of juice processing was performed. In both cases, combination of dominantly EPR and UV/VIS spectroscopy but also other methods (e.g., HPLC, AAS, electrophoresis) was applied to evaluate the stability and antioxidant properties of selected samples. Statistical methods, especially methods of multivariate statistics were used to assess the influence of production and technological-processing operations on antioxidant status of foods and their selected characteristics. Qualitative analysis of Slovak and foreign organic and conventional wines proved that their antioxidant properties are influenced by production system, vintage and variety. On the basis of statistical analysis, descriptors of AAE, kTEMPOL and %RS were selected as the most powerful markers for Slovak organic and conventional wines discrimination. The discrimination of white and red organic and conventional wines possessed 100% and 95.2% correctness, respectively. High correctness of differentiation of Slovak and foreign wines was also achieved. Monitored descriptors of antioxidant activity of spelt flours varied in dependence on season, origin, variety, production system and depend also on way of spelt treatment, although this effect is not so significant. It was also confirmed that the type of extraction agent substantially affects the composition of extracts including polyphenols and flavonoids concentration, affecting thus also their antioxidant activity. Mixture of 50% ethanol/water was selected as the most promising extraction system. Although the results of individual spectroscopic assays revealed high variability and often ambiguous trends, the differences found were sufficient for successful differentiation of both wines and spelt flour samples according to the selected criteria by multivariate statistical processing of the data. Influence of changes in technological procedures of fruit juice processing (nitrogen atmosphere application, utilization of caps with oxygen scavengers) on radical-scavenging properties of 100% pineapples juices with pieces of pineapple and 100% orange juices with pulp was assessed as well. Results obtained proved that antioxidant activity of juices varied in dependence on storage conditions (temperature, storage time, light exposure) and depends also on origin, variety and quality of fruit used. However, the application of nitrogen atmosphere and active packaging materials is not sufficient enough to eliminate the oxidation reactions in juices, but changes in antioxidant activity are better predictable. It can be concluded that EPR spectroscopy could be effectively applied for wines and spelt flours differentiation according to the way of production and to assess the stability of food products, either alone or in combination of UV/VIS spectroscopy and the other methods, utilizing multivariate statistics for processing of experimental data.
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Vacková, Hana. "Studium biologických účinků technického konopí a jeho frakcí." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2017. http://www.nusl.cz/ntk/nusl-316189.
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Cannabis is the only plant which contains cannabinoids and thanks to these compounds it has enormous potential. This thesis deals with the analysis of technical hemp. Effects of cannabinoids and methods used for cannabis analysis are discussed in the theoretical part. The experimental part includes spectrophotometric characterization of cannabis, it´s antimicrobial effects and thin layer chromatography analysis. Three sorts of Cannabis sativa L. were analyzed, namely Finola, Fedora and Kompolti. Firstly, the content of polyphenols, flavonoids and antioxidant activity in prepared tinctures were determined. Moreover, antimicrobial test were performed using disk test and turbidity determination. Gram-positive and Gram-negative bacteria and yeast organism were tested. It was found that cannabis tinctures possess good antimicrobial effects. Some of them are comparable with synthetic antibiotics. Finally, thin layer chromatography enabled visualization of cannabinoids in prepared tinctures.
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Lošková, Tereza. "Extrakce anthokyanových barviv z bezinkových výlisků." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2018. http://www.nusl.cz/ntk/nusl-376808.
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This Diploma thesis deals with the production of the concentrate from the Elderberry marc extract (Sambucus nigra L.). The basic chemical characteristics in this concentrate were determined. The theoretical part of the thesis deal with the botanic characteristic of the Elderberry and its berries. The characteristic of the phenolic compounds, mainly anhocyanins was summarized. The use of the anthocyanin pigments in the food industry, the possibilities of their extraction and the concentrate production was discussed. Thereafter the methods of the anthocyanin content and the phenolic content determination were described. In the experimental part of study, the production of the anthocyanin rich extract from Elderberry marc was optimized. The extraction of the marc by the 1:1 ethanol/water (V/V) solvent with the ratio marc/solvent 1:2 (w/V) showed the most convenient. The production of the concentrate followed. During the concentration on the rotary evaporator the pigment degradation was investigated. The degradation decreased with the decrease of the temperature. The final concentrate was prepared from the extract on the rotary evaporator by 45 °C for 15 minutes. This product had the 7times lower volume compared to the initial extract. In the final concentrate come of the chemical characteristic were determined. By liquid chromatography (HPLC) the major pigments cyanidin-3-sambubiosid and cyanidin-3-glucosid were determined. Their total content was determined to 34,9 gl-1. The total anthocyanin content was determined by pH differential method to 7,1 gl-1 (expressed as cyanidin-3-glucoside equivalent). The total phenolic content was determined to 27,1 gl-1 (expressed as gallic acid equivalent) by Folin-Ciocalteu method. By electron paramagnetic resonance the increase in antioxidant activity with the increase in concentration was found. Up to 42 aromatic compounds was determined in Elderberry marc, its extract and the final concentrate.
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Vrchovská, Vendula. "Antioxidační aktivita nízkomolekulárních fenolických látek." Doctoral thesis, 2007. http://www.nusl.cz/ntk/nusl-271008.
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Brlicová, Radka. "Antioxidační aktivita extraktu Epimedium sp." Master's thesis, 2009. http://www.nusl.cz/ntk/nusl-279140.
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The goal of thesis was to demonstrate the antioxidant activity of the genus Epimedium extract and collect information the main content substances and biological activity species of the genus Epimedium as well. Epimedii herba (Yinyanghuo, Horny Goat Weed or Barrenwort) is one of the best known and most frequently used plants in Chinese medicine for its tonic, anti-reumatic and aphrodisiacal effects. The main content substances are flavonoids, alkaloids, lignans and terpenic compounds. Flavonoids, ikariin, epimedin A, epimedin B, epimedin C and ikaritin, have diverse effects such as antioxidant, estrogenic, osteogenic, antidepressant-like, antianginal and anticancerogenic. To demonstrate the antioxidant activities of methanolic extract and dry aqueous extract from herba Epimedium x rubrum, I used two methods, the method of measuring antioxidant activity against the stable radical DPPH (diphenylhydrazyl) and method of measuring antioxidant activity against superoxide. From measurement I observed that the dry aqueous extract from herba has a higher antioxidant activity against DPPH than the methanolic extract. I measured an antioxidant activity against superoxid radical of the dry aqueous extract of drug and solutions of routine, trolox and ascorbic acid. From measurements I observed that the dry...
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Vachová, Simona. "Flavonoidy a antioxidační aktivita červených vín." Master's thesis, 2014. http://www.nusl.cz/ntk/nusl-190195.
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The literary part of the thesis brings the insight into the issue of free radicals and their impact on the health of the organism. It deals with the specific abilities and the role of antioxidants in the protection against the negative impact of radicals. It also pays attention to flavonoids as major polyphenols in red wines which significantly influence the antioxidative activity, and thus the health benefits of wine. The practical part shows, using the spectrophotometric DPPH and FRAP methods, the comparison of antiradical activity and reducing power in selected samples of red wines made by different technologies of maceration. The results show the direct relationship between the maceration method and the measured values of the antioxidative potential of the red wines. The discussion and the final part of the thesis suggest new questions and possible directions for further research.
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Skálová, Miluše. "Antioxidační aktivita fenolických látek v Betulae folium." Master's thesis, 2007. http://www.nusl.cz/ntk/nusl-281153.
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ANTIOXIDANT ACTIVITY OF FENOLIC SUBSTANCES IN BETULAE FOLIUM Miluše Skálová Univerzita Karlova v Praze, Farmaceutická fakulta, Katedra farmakognozie, Heyrovského 1203, 500 05, Hradec Králové Abstract The aim of this study was to investigate antioxidant activity of exctracts of the drug Betulae folium and of buds and leaves of birch collected during the onthogenesis. Also it was appionted content of flavonoids by the method HPLC (High Performance Liquid Chromatography) and it was observed changes during the onthogenesis. The maximal content of caffeic acid in buds was similar like in leaves. The presence of chlorogenic acid was registreted in leaves which were collected in june. High content of the hyperoside was in buds before they have got blossom. and in the young leaves. The next lower maximum was in young leaves, which were collected at the end of may. This value was compareable with the content in dry leaves and also in drug of Betulae folium, which was bought in the pharmacy. The presence of kvercitrin was reminded in buds before blossoming, the similar value was in young leaves, afterthat came a huge decrease of this value. The significant content-increase of kvercitrin was reminded in dried leaves. There are significant differences between the fresh and the dried leaves of the same collection....
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Nehybová, Monika. "Antioxidační aktivita plodů různých kultivarů Sambucus nigra L." Master's thesis, 2014. http://www.nusl.cz/ntk/nusl-340542.
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8. Abstract The fruit of the European elder, Sambucus nigra L., is used in therapy as a drug Sambuci fructus for its diaphoretic, diuretic and laxative effects. Cultivars of European elder are being studied for the use in the food industry and pharmacy. The fruit contains especially large amount of anthocyanins and flavonoids that are known for their antioxidant activity. The aim of this work is to measure the antioxidant activity of the drug Sambuci fructus and of the fruit of the European elder cultivars Samdal, Mammut, Sambo, Sambu, Sampo, Bohatka, Haschberg, Weihenstephan, Allesö, and Samyl. An extract containing anthocyanins was obtained from fruit by a process based on extraction of frozen material with acidified water at high temperature, followed by separation with polymer non-ionogenic polystyrene-divinylbenzene sorbent. The content of anthocyanins in the extracts was determined spectrophotometrically using a modified pH-differential method. The absorbance was measured along the range of 350 - 600 nm. The content of the anthocyanins was quantified in units of mg of cyanidin 3-glucoside in 1 ml of extract. The content ranged from 0.33 - 2.76 mg cyanidin 3-glucoside/ml of extract. The highest content was in the extract from the fruit of the cultivar Samdal and the lowest was of the cultivar Mammut....
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Kabourková, Eliška. "Vliv zkrmování bylin na antioxidační aktivitu jater." Master's thesis, 2013. http://www.nusl.cz/ntk/nusl-169518.
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Zavadil, Stanislav. "Neurotropní a antioxidační aktivita vybraných druhů jednoděložných alkaloidních rostlin." Master's thesis, 2011. http://www.nusl.cz/ntk/nusl-312265.
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Zavadil S.: Neurotropic and antioxidative activity in vitro of monocotyledonous alkaloidal plants. Diploma thesis, Charles University in Prague, Faculty of Pharmacy in Hradec Králové, Department of Pharmaceutical Botany and Ecology, Hradec Králové 2011, 74 p. The aim of the diploma thesis was to process screening of total and alkaloidal extracts from four selected plants of the Amaryllidaceae family (Hymenocallis sp., Chlidanthus fragrans, Nerine bowdenii, Zephyranthes grandiflora) and test their anticholinesterase activities to human blood acetylcholinesterase (HuAChE) and to human plasma butyrylcholinesterase (HuBuChE). For the purpose of preliminary determination of substances that could be responsible for the biological activity of these extracts, GC/MS analysis of alkaloidal extracts was carried out. All of these plants were analyzed by GC/MS for the first time. During the processing of GC/MS data we identified alkaloids, which weren't in these plants previously described. The alkaloidal extract of Chlidanthus fragrans showed the strongest inhibition of HuAChE (IC50 = 20.1 ± 2.9 µM) and the alkaloidal extract from Nerine bowdenii was the most potent inhibitor of HuBuChE (IC50 = 4.8 ± 1.1 µM). All alkaloidal extracts didn't show an interesting antioxidant activity. The alkaloid belladine was...
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Bednaříková, Veronika. "Srovnání antioxidační aktivity u nealkoholických nápojů." Master's thesis, 2013. http://www.nusl.cz/ntk/nusl-167755.
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Přibylová, Marie. "Antiproliferativní, antioxidační a protizánětlivá aktivita chinonů, terpenoidů a jejich derivátů." Doctoral thesis, 2013. http://www.nusl.cz/ntk/nusl-322586.
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Plant compounds play an important role in human medicine. They are a source of new drugs or serve as an inspiration for drugs' development. This thesis presents a study about syntheses of derivatives and biological activities of two groups of natural products, quinones and terpenoids. Terpenoids are plant secondary metabolites which are known for their antimicrobial, anti-inflammatory and anti-tumoral activities. We have focused on two representatives, paclitaxel and carvacrol. GnRH-paclitaxel anti-tumor conjugates potentially suitable for targeted delivery to cancer cells were prepared. Their antiproliferative activities in vitro were evaluated on MCF-7 cancer cell line and cytotoxicity in rat hepatocytes. Carvacrol and its derivative were tested for its possible anti- inflammatory effect, which was assessed in vitro as their potential to inhibit prostaglandin E2 biosynthesis via cyclooxygenase pathway. Quinones, other targets of the thesis, are well-known for biological activities similar to terpenoids. Thymoquinone, juglone and their derivatives were tested in vitro as inhibitors of cyclooxygenases and 5-lipoxygenase. Derivatives of juglone were prepared to help us to suggest structure-activity relationship of this compound. Thymoquinone and its derivatives were evaluated for their antioxidant capacity...
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Benešová, Nina. "Neurotropní a antioxidační aktivita vybraných druhů jednoděložných alkaloidních rostlin. II." Master's thesis, 2012. http://www.nusl.cz/ntk/nusl-307083.
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Benešová N.: Neurotropic and antioxidative activity in vitro of monocotyledonous alkaloidal plants II. Diploma thesis, Charles University in Prague, Faculty of Pharmacy in Hradec Králové, Departement of Pharmaceutical Botany and Ecology, Hradec Králové 2012, 72 p. The aim of this diploma thesis was to analyse alkaloidal extracts of six selected plants from Amaryllidaceae family (Nerine filifolia, Nerine undulata, Nerine filamentosa, Scadoxus multiflorus, Sprekelia formosissima, Sternbergia lutea) and test their biological activity to human cholinesterases (HuAChE, HuBuChE) using Ellman's method and antioxidative activity measured by DPPH test. Thanks to GC/MS analysis was identified a huge range of alkaloids of Amaryllidaceae family that belongs to various structural types. Some of them have not been determined yet due to unavailability of their spectras in commercial libraries and literature. The best inhibitory activity against human blood acetylcholinesterase was described in alkaloidal extracts of Nerine undulata (IC50 14,30 ± 1,20 µg/ml) and Nerine filifolia (IC50 18,54 ± 0,79 µg/ml) and against human plasma butyrylcholinesterase in extracts of Sternbergia lutea (IC50 3,07 ± 0,05 µM) and Nerine filamentosa (IC50 13,00 ± 0,71 µg/ml). Antioxidative activity of alkaloidal extracts from the bulbs...
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Hrstka, Václav. "Neurotropní a antioxidační aktivita vybraných druhů jednoděložných alkaloidních rostlin. IV." Master's thesis, 2013. http://www.nusl.cz/ntk/nusl-324156.
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Hrstka V.: Neurotropic and antioxidative aktivity of some selected species of monocotyledonous alkaloidal plants in vitro IV, Diploma thesis, Charles University in Prague, Faculty of Pharmacy in Hradec Králové, Department of Pharmaceutical Botany and Ecology, Hradec Králové 2013, 69 p. The objective of this thesis was to prepare ethanolic and alcaloidal extracts from six Daffodil's species of Amaryllidaceae family. In addition, measuring of inhibitory activity to human cholinesterases (HuAChE and HuBuChE) was included. According to results of particular extracts, identification of alcaloidal spectrum of each extract was performed using GC/MS analysis in order to evaluate inhibitory activities that had been measured. All plants described within the work were scrutinized by complete GC/MS analysis for the first time. A pure alkaloid homolycorine was isolated from the species Narcissus Sir Winston Churchilli. Its structure was identified according to its NMR spectrum and MS study. Inhibitory activity to HuAChE and HuBuChE of this alkaloid in pure form was also tested. The strongest inhibitory activity against HuAChE was detected in extract from Narcissus Flower Record with value IC50 = 5,6 ± 2,1 µg/ml. The most significant activity to both esterases had extract from Narcissus poeticus var. recurvus...
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Kantor, Eduard. "Neurotropní a antioxidační aktivita vybraných druhů jednoděložných alkaloidních rostlin. III." Master's thesis, 2013. http://www.nusl.cz/ntk/nusl-324184.
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Kantor E.: Neurotropic and antioxidative activity of some selected species of monocotyledonous alkaloidal plants. Diploma thesis, Charles University in Prague, Faculty of Pharmacy in Hradec Králové, Department of Pharmaceutical Botany and Ecology, Hradec Králové 2013, 64 S. The aim of the diploma thesis was to process screening of total ethanolic and alkaloidal extracts from 15 selected monocotyledonous plants (Fritillaria meleagris, Fritillaria assyriaca, Fritillaria imperialis var. lutea, Fritillaria thunbergii, Fritillaria davisii, Fritillaria acmopetalla, Eucomis bicolor, Eucomis autumnalis, Eucomis comosa, Bulbocodium vernum, Brodiaea californica, Bessera elegans, Ornithogalum thyrsoides, Bellevallia romana, Gloriosa rotschildiana) and test their anticholinesterase activities to human blood acetylcholinesterase (HuAChE) and to human plasma butyrylcholinesterase (HuBuChE) and also test their antioxidant activity. The alkaloidal extract of Fritillaria imperialis var. lutea showed the strongest inhibition activity of HuAChE and HuBuChE (IC50, HuAChE = 41,54 ± 1,58 µM; IC50, HuBuChE = 5,12 ± 0,37 µM). The ethanolic extract of Fritillaria thunbergii was the most potent inhibitor of HuAChE (IC50, HuAChE = 135,0 ± 5,1 µM; IC50, HuBuChE = 79,56 µM) and the extract of Fritillaria imperialis var. lutea...
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Breiterová, Kateřina. "Neurotropní a antioxidační aktivita vybraných druhů jednoděložných alkaloidních rostlin. VIII." Master's thesis, 2015. http://www.nusl.cz/ntk/nusl-332832.
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Author: Kateřina Breiterová Title: Neurotropic and antioxidative activity of some selected species of monocotyledonous alkaloidal plants in vitro. VIII. Diploma thesis Charles Univerzity in Prague, Faculty of Pharmacy in Hradec Králové, Department of Pharmaceutical Botany and Ecology 2015, 101 p. More than 50 % cases of dementia are nowadays caused byAlzheimer's disease (AD). AD is a progressive neurodegenerative disease and it causes gradual memory loss, disorientation and behavioral disorders which affect patient's social and occupational life. AD is characteristic by loss of neurons in some regions of brain - for example hippocampus and cortex. Ethiopathogenesis of this disease is not completely known - that is why the treatment is still just symptomatic. Formation of β-amyloid deposits in brain tissue plays an important role - it is a protein which creates extracellular plagues around neurites and causes their degeneration and death. Intracellular tangles are made up of the changed τ-protein. These tangles also cause death of the neuronal cell. The degeneration of neurons is supported by reactive oxygen radicals too. The another problem is a glutamatergic system disorder. This set of excitatory amino acids is important for correct long-term memory formation. Patients with AD suffer from...
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Poláková, Kristína. "Stanovení fenolových látek a antioxidační aktivity u různých druhů káv." Master's thesis, 2012. http://www.nusl.cz/ntk/nusl-150797.
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Šobrová, Pavlína. "Biochemický profil efektu deoxyvalenolu podávaného v podobě přirozeně zaplísněné pšenice na potkany." Master's thesis, 2010. http://www.nusl.cz/ntk/nusl-88089.
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Tomíšková, Jana. "Vliv pořadí laktace na metabolismus selenu u dojnic." Master's thesis, 2012. http://www.nusl.cz/ntk/nusl-166799.
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Seďová, Zuzana. "Hodnocení kvality u produktů z jahod." Master's thesis, 2013. http://www.nusl.cz/ntk/nusl-167825.
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Caletková, Jarmila. "Stanovení fenolových látek a antioxidační aktivity v bobulích různých odrůd hroznů." Master's thesis, 2010. http://www.nusl.cz/ntk/nusl-87393.
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Vnuková, Kristina. "Stanovení fenolových látek a antioxidační aktivity u různých druhů chleba, pečiva a jiných obilných výrobků." Master's thesis, 2010. http://www.nusl.cz/ntk/nusl-88225.
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Štiasna, Klára. "Hodnocení rodu Origanum L. z hlediska obsahu silice a antioxidantů." Master's thesis, 2013. http://www.nusl.cz/ntk/nusl-169902.
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