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Processing techniques for red wines and their potential health benefits have intensively been investigated, however, information relevant to the grape and wine industry in Texas is less frequently available. The overall objective of this work was to investigate the reduction of 3-alkyl-2-methoxypyrazines that can affect the quality of Texas wines and to study the health benefits of Texas wines. The methods used include SPME-GC-MS and molecular bioassays. The first objective was to demonstrate the anti-inflammatory potential effect of red wine polyphenols from Black Spanish wine (Vitis aestivalis hybrid) in colonic human fibroblast cells. Results show that an extract prepared from Black Spanish wine decreased gene expression and activation of NF-kB transcription factor and target proinflammatory cytokines and cell adhesion molecules. Induction of microRNA-126 (miR- 126) by wine extract was found to be one of the underlying molecular mechanism by which wine extract decreased vascular cell adhesion molecule (VCAM-1) and inflammation in colon cells. These mechanisms may be relevant to the prevention of iv inflammatory bowel disease (IBD) that may increase the risk for colon cancer. The second objective was to investigate the role of the green june beetle (GJB ) as exogenous source of MPs other than the multicolored Asian Lady beetle (Harmonia axyridis). Over the last decade, the green june beetle has been suspected to be a source of MPs based on intermittent reports from Texas growers of an atypical aroma and flavor reminiscent of crushed green June beetles (GJB). Specifically the North region of Texas seems affected. Results demonstrated GJB as source of 3-isopropyl-2- methoxypyrazine, where one GJB could elevate MPs above sensory perceptible levels in 4.3 gallons of wine. The incorporation of GJB to the winemaking process may contribute negatively to the sensory properties of Texas wines and therefore should be strictly controlled. The third objective was to explore the potential effect of micro-oxygenation treatment and accelerated aging techniques relevant for the state of Texas in the reduction of 3-Isobutyl-2-methoxypyrazine (IBMP), and 3-isopropyl-2-methoxypyrazine (IPMP) levels as determined by SPME-GC-MS. Results show that MPs were not affected by MOX or oak interaction. Although the data suggest that MOX and oak exposure do not directly affect MPs concentration. The fourth research objective was to explore the potential effect of three commercial available yeast strains, BM45, K1, and D80, on MPs levels in Black Spanish wines. Black Spanish wines were fermented with MB45 strain resulted in the highest amount of MPs. Conversely K1 and D80 yeast strains reduced IBMP levels in comparison with the control. An increase in IBMP was not expected. However it has been demonstrated that amino acids valine and leucine are MPs precursors. If Vitis v aestivalis hybrid grapes contained a similar methyltransferase enzyme found in Vitis vinifera grapes and S. cerevisiae contained similar IPMP biosynthesis pathway found in Pseudomonas perolens BM45 may have led to the increased IBMP observed in the fermentation. In addition we evaluated MPs levels of wines fermented over 20 days with a chemical defined grape juice medium containing a concentration of yeast available nitrogen of 200 mg N/L. Data suggest that wines fermented with BM45 and D80 yeast strains reduced IBMP but K1 yeast did not show any effect in comparison with the control. In addition MPs were evaluated in the yeast mannoproteins fraction. Results show the presence of IBMP in low concentration below the method detection limit. This data demonstrate for the first time that yeast mannoproteins binds IBMP. to evidence for interactions between mannoproteins secreted by the D80 yeast strain and IBMP. This work will provide valuable information regarding the potential health benefits of Vitis aestivalis hybrid grapes and reduction of MPs and thus improving the quality of Texas wines

The aroma compounds suitable for food flavouring are mainly of plant origin. It is necessary to take into account the possible allergic effects of some of them. The theoretic part of this thesis is focused on aroma compounds and their biological effects. It also describes methods useful for their isolation and analysis with a nearer intent on the methods used in this thesis - solid phase microextraction and gas chromatography. The aim of the experimental part was to establish, optimise and validate the method for determination of allergic aroma compounds chosen and subsequently to enable its using in wide spectrum of food and other products.

The aim of the diploma thesis was the aroma active compounds assessment and sensory profile determination of various types of sea buckthorn (Hippopha rhamnoides L.). The theoretical part provides the detailed description of this plant, comprising the occurence, taxonomy, chemical composition and use. Experimental part summarizes the data obtained: identification and quantification of aroma compounds using the SPME – GC –FID and GC-MS method and evaluation of complete sensory profile. Various cultivars of sea buckthorn harvested in 2009-2012 were analysed. In total 23 various types of sea buckthorn were measured, 23 alcohols, 10 aldehydes, 11 esters, 14 ketones and 5 acids were found.

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.

Echinacea purpurea is a rich source of biologically active compounds, which are attributed to several therapeutic effects. This thesis is focused on the optimization of the extraction process, considered these substances. Maceration was chosen as a type of extraction, due to its simplicity. The Optimal conditions were solid-solvent ratio 1: 5, 40% ethanol, 60 °C, 60 minutes. An extract from the dried flowers of Echinacea purpurea was prepared by this optimized process. The content of total phenolic compounds was set on 365.18 ± 3.51 [mg_GAEl^(-1)] and the antioxidant activity was 507.50 ± 6.89 [mg_TEACl^(-1)]. The percentage of radical scavenging activity ABTS•+ was 95.45 ± 1.30. The antimicrobial activity of the extract was tested against 3 microorganisms – Escherichia coli, Bacillus cereus and Candida glabrata. There was not detected inhibitory effect on the growth of microorganisms. In a total, 39 volatile compounds were identified, and the biggest group were represented sesquiterpenes (70.9%). The obtained results confirm that Echinacea extract has antioxidant activity and contains several interesting aromatic substances, In the future, it can be used as a natural resource of nutritionally and sensory valuable compounds, e.g., into various foods and delicacies.

This diploma thesis deals with the comparison of aroma compounds in goat and cow milk. The content of aroma active substances in samples of goat and cow milk, which were analyzed by HS-SPME-GC-MS method, is monitored. In the theoretical part, milk is characterized, its formation in the dairy mammary gland is described, its composition including an overview of aromatic active substances, physical and chemical as well as its sensory properties, milk defects and differences between cow's and goat's milk are described. Further, gas chromatography in combination with solid phase microextraction technique in tandem with mass spectrometry is described. In the experimental part, 13 samples of goat and 8 samples of cow milk were subjected to HS-SPME-GC-MS analysis. Samples were analyzed fresh and after heat treatment. Altogether, 78 volatile substances were identified in the samples. Ketones were the most numerous, aldehydes, alcohols and carboxylic acids were the most abundant chemical groups. There were differences between samples in number as well as in content of the identified compounds, 64 in goat milk and 48 in the cow milk.

Plectranthus amboinicus is a herb that was found to have a lot of bioactive compounds, most of them are polyfenolic compounds. Extraction is neccesary to obtain bioactive compounds and to use them subsequently in food or cosmetic industry. Three methods of extraxtion – maceraction, PHWE and PFE, were used in this study. The best yield of extracted polyfenols was observed by maceration. Maceration was, in the next step, optimized using mathematical statistical method of planned experiment (DOE). The optimal conditions found for extraction were: temperature 60 °C, solvent 40% ethanol, time 90 minutes, solid-solvent ratio 1:10. Total phenolic compunds content in this extract was 0,18 ± 0,05 mgGAE·ml-1, which means 1,83 ± 0,53 mgGAE·g-1 of plant. The antioxidant activity was 148,69 ± 26,92 gTEACml-1. Percentage of radical scavenging activity ABTS•+ was 30,03 ± 5,44 %. Further, 27 of volatile aroma compounds were identified in optimal extract, the most important were: -selinene (16,67 %), trans--bergamotene (14,22 %), caryophyllene (14,11 %), 3-carene (8,22 %), -copaene (7,55 %), -terpinene (6,28 %), humulene (5,87 %), cadina-1(10)-4-diene (5,19 %).

The thesis deals with the issue of potentially allergenic aroma compounds in food. Aroma compounds suitable for food flavouring are mainly of plant origin. These aroma compounds and their mixtures have a lot of positive and negative effects on human organism. Although the aroma compounds are not among main groups of allergens, several studies indicate a potential risk of allergenic effects of some aroma compounds. The theoretic part of this thesis focuses on aroma compounds of plant origin and gives an overview of 26 the most important fragrance allergens according to the European cosmetic legislation. The aim of the experimental part was to verify the selectivity and appropriateness of the currently used methodology of headspace solid-phase microextraction and gas chromatography-flame ionization detection (HS-SPME-GC-FID) for determination of selected allergenic aromatic active compounds. Secondly, it is to use a proven method for a wide spectrum of real food products.

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.