The master´s thesis is focused on the study of biologically active compounds of fennel. The theoretical part describes basic characteristics of fennel and its chemical composition, further specifies plant´s biological active substances and antioxidants, also describes extraction techniques for obtaining these bioactive compounds, methods of their determination and verification of antimicrobial effect. In the experimental part were spectrophotometrically determined contents of polyphenols and flavonoids in the prepared extracts of fennel tea, whole and crush spice. On the basis of extraction curves, antioxidant activity and potential antimicrobial activity against the selected microorganisms Bacillus subtilis, Bacillus cereus, Serratia marcescens a Micrococcus luteus was determined in the samples with the highest values of the given bioactive substances. Among the all monitored extracts, the inhibitory effect was showed only by an aqueous extract of the fennel tea against the bacterial strain of Micrococcus luteus.

The diploma thesis deals with the preparation of extract and concentrate of anthocyanin dyes from aronia moldings (Aronia melanocarpa). It also determines chemical properties important for human´s health, which are important also for further possible use of extract/concentrate as natural red food coloring. A series of extractions of dried and powdered aronia moldings was carried out in the experimental part of the thesis, aiming for the optimization the conditions of the extraction. Extracts were characterized by content of total anthocyans, content of total fenolic substances and total antioxidant activity. The best laboratory conditions for extraction were determined as follows: amount of moldings 12,5 g, composition of extraction agent ethanol:water 1:1, volume of extraction mixture 60 ml and time of the extraction 11 hours. Prepared extracts were concentrated on vacuum evaporator. It has been found that the temperature of the water bath in the vacuum evaporator can not exceed 40 °C. At higher temperatures there is significant degradation of anthocyanins. Furthemore, the content of individual anthocyanic dyes in extract and concentrate, from aronia moldings, was quantified by HPLC. The major anthocyanin, cyanidine-3-galactoside, was contained in the concentrate at 923,6 ± 8,5 mg·l-1, the other specified anthocyanin, minor cyanidine-3-glucoside, was present at a concentration of 53,5 ± 0,3 mg·l-1.

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.

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.

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.

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.

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.

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.

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.

Orientador: Giuseppina Pace Pereira Lima / Resumo: As plantas alimentícias negligenciadas como a Pereskia grandifolia Hawer e Talinum paniculatum (Jacq.) Gaertn são definidas por possuírem uma ou mais partes, ou produtos, que podem ser utilizados na alimentação. Entretanto, o consumo destas espécies não é comum e tão pouco são divulgadas informações sobre o preparo e a importância nutricional. O cozimento, além de facilitar a palatabilidade dos vegetais, pode aumentar a biodisponibilidade dos compostos bioativos. Essas hortaliças são consumidas, geralmente, após o processamento térmico, que diminuem os fatores antinutricionais presentes quando in natura. Desta forma, o objetivo deste estudo foi avaliar o efeito do cozimento em fervura, vapor e micro-ondas em diferentes tempos, com relação ao conteúdo de poli(fenois) e carotenoides, bem como a atividade antioxidante total em P. grandifolia e T. paniculatum. Os resultados contribuíram para a caracterização de compostos fenólicos e carotenoides em folhas de P. grandifolia e T. paniculatum, os quais possuem uma série de benefícios para a saúde humana. Estes compostos variam conforme a espécie analisada e o processamento térmico empregado, podendo aumentar o valor nutricional e funcional do alimento, sendo essas espécies importantes fontes de compostos bioativos, que podem auxiliar o organismo humano a combater os radicais livres. / Abstract: Neglected food plants such as a Pereskia grandifolia Hawer and Talinum paniculatum (Jacq.) Gaertn are defined by contain one or more parts, or products, that can be used in feeding. However, the consumption of these species is not common and there is few information about the culinary preparation and nutritional importance. Besides, cooking, can to facilitated the palatability of the vegetables, may increase the bioavailability of the bioactive compounds. These vegetables are usually consumed after thermal processing because there is a decrease in antinutritional factors. Thus, the objective of this study was to evaluate the effect of boiling, microwave and steam cooking at different times, about the content of polyphenols and carotenoids, as well as a total antioxidant activity in P. grandifolia and T. paniculatum. The results contributed to the characterization of phenolic compounds and carotenoids in P. grandifolia and T. paniculatum leaves, which have a series of benefits for human health. These compounds vary according to the species analyzed and the thermal processing employed, and may increase the nutritional and functional value of the food. These species are an important sources of these bioactive compounds, which can help the human organism fight against the free radicals. / Mestre