The aim of this study was to explore the influence of volatile compounds in dry dog food on its attractiveness for dogs. The assumption was that the attractiveness is mainly affected by volatile compounds presented in the feed. This study brings overall information about dog´s digestive system and its nutritional requirements with the summary of available feeds including the production process and list of the customary ingredients. A survey of the most common volatile compounds including appropriate analytical methods is also part of this study. A feed preference test was performed in experimental part of this study. The preference ratio of two dry dog diets was set to 21:79 % that shows clear preference for one of the feeds. Chemical analysis using gas chromatography-mass spectrometry revealed distinctions in the volatile compounds profile of the tested feeds. 3-tert-butyl-4-hydroxyanisole that is part of synthetic antioxidant BHA was identified to be the main volatile compound that could possibly be responsible for feed preferences observed in this study.

Polycyclic aromatic hydrocarbons (PAHs) are ranked among the organic compounds with long-term permanence pollute the environment. The presence of PAHs react particularly aquatic plants. Duckweed (Lemna minor L.), water plant characterized in that it is exposed to foreign substances significant portion of his body, is a suitable model for the study of plant developmental and metabolic responses to the presence of polycyclic aromatic hydrocarbons. The aim of the thesis was to observe developmental and metabolic responses duckweed on the effect of polycyclic aromatic hydrocarbon fluoranthene. For 21 days were observed in four concentrations of fluoranthene, which accounted for commonly occurring (0.1 and 0.5 mg FLT / l) and slightly increased (1 and 5 mg FLT / L) concentrations of fluoranthene, metabolic and bioenergetic response. We were also observed growth and developmental changes and changes in the content of phytohormones. The study was focused on plant morphology. The results of this work, was evident that the presence of FLT has a significant impact on the appearance and production plants. It was also demonstrated a significant negative impact on the growth parameters. Fluoranthene demonstrated significant effects on the production of plant hormones.

The subject of this thesis was the determination of the profile of volatile aromatic compounds of varietal wines and the subsequent statistical analysis, aiming to find varietal markers of selected varieties – individual substances, their typical contents, mutual correlations. The HS-SPME-GC-MS technique was used to determine the aromatic profile. The main focus of this work was the analysis of the varieties Pálava, Hibernal, Johanniter and Solaris. The data obtained were statistically processed using descriptive and multivariate statistical methods. On the basis of these analyses, models were developed which, from the contents of 14 selected compounds of the aromatic profile, allow the Piwi varieties Hibernal, Johanniter and Solaris to be distinguished from each other and from the Pálava variety and, for the Pálava variety wines, to determine their origin in the Znojmo or Mikulov wine sub-region.

This diploma thesis deals with the determination of aroma volatile compounds in elderberry. The theoretical part describes the botanical characteristics of elderberry, the incidence and the other known species. Further, this work is focused on the chemical composition of elderberry, there are described in detail the content substances and briefly mentioned are medicinal effects of elderberry. Another theoretical part describes the natural processing of this significant plant and technological production of fruit juices. The second half of the theoretical part deals with the method of determining aroma volatile compounds by gas chromatography in combination with SPME technique, which is suitable for identification of aroma substances. In the experimental part of this diploma thesis SPME-GC method was applied to some samples of elderberry and aroma volatile compounds of individual samples of elderberry were determined.

The aim of this diploma thesis was to determine the optimal extraction conditions for obtaining an extract from the plant Plectranthus amboinicus. Plectranthus amboinicus is an aromatic herb of the Lamiaceae family containing a large number of bioactive compounds. Because of this, it has a number of biological effects – antimicrobial, anti-inflammatory, antioxidant, analgesic, etc. To maintain the maximum of sensory and nutritionally valuable components of P. amboinicus, a simple maceration of fresh chopped herb was chosen. Maceration was performed under the following conditions: 40 minutes at 40 ° C, solvent 40% ethanol, weight 20 g of herb per 100 ml of solvent. The extract prepared under these optimal conditions was comprehensively characterized in terms of the content of total polyphenols, their concentration was determined to 0,08 ± 0,02 mgGEA·ml-1, which corresponds to 0,40 ± 0,07 mgGEA·g-1 of the plant. The antioxidant activity of the extract was 241,24 ± 29,24 µgTEAC·ml-1 and the radical scavenging activity of ABTS•+ was determined to be 49,29 ± 5,97 %. The antimicrobial activity was verified by the agar well diffusion method. Two types of bacteria were selected for the determination – gram-positive Bacillus cereus, gram-negative Escherichia coli and yeast Candida glabrata. The results showed that the extracts have the highest antimicrobial activity against B. cereus. There were 64 volatile aromatic compounds identified in the extract, with monoterpenes and sesquiterpenes dominating. The obtained results confirm that P. amboinicus, or its prepared extract, has a good potential for use as a new and non-traditional flavor in various foods and delicacies, which can also increase their nutritional value.

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.

This diploma thesis deals with the optimization of jelly candies production, application of herbal extract to produced candies, and subsequent characterization of produced samples in terms of volatile (aromatic) substances, total phenolic substances, antioxidant aktivity, and sensory quality. Optimization parameters – the amount of gelatin and the addition of citric acid, were selected based on the sensory analysis. Additions of 7,5 % gelatin and 2 % acid were proven to be optimal. The sources for the production of herbal extracts were the plants Aronia melanocarpa and Echinacea purpurea, which are known for their high content of bioactive substances. The further sensory analysis determined the optimal amount of extract added to jelly candies samples – in the case of chokeberry it was 4 % and in the case of echinacea it was 1 % of the extract. In the sample with chokeberry extract of optimal composition, ie 7,5 % gelatin, 2 % citric acid, and 4 % extract, 46 volatile substances were determined, of which nonanal (12,17 %) and thymol (8,70 %) were the most represented, the total polyphenol content was 472.88 ± 8.02 gGAEg-1 of the sample and the antioxidant activity was determined to be 828.99 ± 17.74 gTEACg-1 of the sample. The sample with echinacea extract of optimal composition, ie 7,5 % gelatin, 2 % citric acid and, 1 % extract, contained 56 volatile substances, the most represented being nonanal (12,08 %), thymol (6,19 %), and decanal (5,52 %). The total polyphenols in this sample were determined to be 291.09 ± 10.17 gGAEg-1 of the sample and its antioxidant activity was determined to be 850.91 ± 30.29 gTEACg-1 of the sample. Samples with the addition of chokeberry extract, which gave the confectionery a fruity, slightly sour taste and a pink to dark purple color, were considered more pleasant/acceptable; samples with echinacea had an herbal aroma and taste and orange color.

This master thesis deals with preparation of extracts from fruits of aronia, optimization of conditions for extraction and subsequent characteristics of the obtained optimal extract. In the theoretical part information about the botanical characteristics of Aronia melanocarpa and about its utilization are mentioned. Furthermore, the chemical composition of aronia fruits is described and the main biologically active substances contained in the plant are described. At the end of the theoretical part extraction and separation techniques, determination methods of antioxidant, antimicrobial activity and determination of aromatic active compounds are described. The experimental part describes the optimization of maceration so that the macerate contains as much polyphenolic substances as possible, as well as aromatic active substances. 40% ethanol, at a temperature of 60 ° C, with a weight solvent ratio of 1: 5, for 40 minutes proved to be optimal for the maceration of aronia fruits. The total polyphenol content of the optimal extract was determined to be 5237.2 ± 40.7 mgGAEkg-1 and the antioxidant activity by TEAC to be 512.5 ± 5.04 gml-1. 24 aromatic active compounds were identified in the extract, with the largest percentage being monoterpenes and aldehydes. Furthermore, it was found that the extract did not show antimicrobial activity against the microorganisms used (Bacillus cereus, Escherichia coli and Candida glabrata). The obtained results confirm that aronia extracts are an important source of many biologically active compounds and can be used in food as a natural source of nutritionally and sensory valuable substances.

This diploma thesis deals with the determination of aroma compounds in selected species of less known fruits (sea buckthorn, cornelian cherry, rowanberry, medlar, japanese quince and chokeberry). The theoretical part is focused on the description of these plants, their chemical composition, possibility of utilization and processing. Aroma compounds were identified and quantified in experimental parts. The aroma compounds were extracted by solid-phase microextraction and analysed by gas chromatography. A total of 45 compounds were identified. This compounds included 17 alcohols, 9 ketons, 8 aldehydes, 6 acids and 5 esters. Concurrently, the sensory evaluation of these fruits was carried out. The profile test and evaluation using graphical scales were used for evaluation of pleasantness and intensity of taste and odour.

The aim of this diploma thesis was to determine the aroma active compounds in different varieties of black elderberry (Sambucus nigra L.) and in elder juices that were mixed in different proportions with grape juice. The sensory analysis of these juices was subsequently performed with focusing on their tastiness. The theoretical part deals with the description of the black elderberry, its occurrence, composition and use at home and in industrial processing, as well as a description of aroma active compounds, which have been previously identified in elder by various authors. In the experimental part aroma active substances were identified and quantified in seven selected varieties of elder. Solid Phase Microextraction method was used for their isolation and subsequent analysis was performed by gas chromatography. 39 aroma active compounds were identified totally in fruits of the black elderberry, of which 15 alcohols, 11 aldehydes, 7 ketones, 5 esters and 1 acid. 45 aroma active compounds were identified totally in elderberry juices, of which 19 alcohols, 8 aldehydes, 5 ketones, 7 esters and 6 acids. The sensory analysis of elder juices was performed using ranking test and evaluation using the scales.