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Aroma profile of selected types of fruit juices
Baštová, Daniela ; Zemanová, Jana (referee) ; Vítová, Eva (advisor)
This diploma thesis is focused on determination the aroma profile of selected species of fruit juices (apple, grape, carrot, orange, blackcurrant and elderberry juice). The theoretical part deals with the composition and properties of selected species of fruits and their juices, then deals with juice‘s technological process and selected methods for the determination of aroma active compounds. The experimental part describes the instrumental and sensory analysis. The six pure fruit juices and five mixed fruit juices were used for instrumental evaluation. The aroma active compounds were extracted by SPME and subsequently identified and quantified by gas chromatography. The sensory evaluation was performed by ranking test and evaluation using hedonic scale.
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Assessment of aroma active compounds in elderberries
Kolibačová, Silvie ; Ürgeová,, Eva (referee) ; Vítová, Eva (advisor)
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.
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Assessment of chosen aromatic compounds in foods
Ascherová, Adriana ; Buňka, František (referee) ; Vítová, Eva (advisor)
This diploma thesis is focused on aromatic substances occurring in food. The theoretical part describes their characteristics, the use of fragrances of plant origin for flavoring of food and points to their possible negative effects on the human organism. Twenty six potentially allergenic fragrances are thus identified in European legislation and an overview of their physical properties, occurrence and use is also processed in this work.The aim of the experimental part was to develop and validate a method for assessment of fragrances using headspace solid phase microextraction combined with gas chromatography (HS-SPME-GC-FID). The following parameters have been validated : repeatability, linearity, limits of detection (LOD) and limits of quantification (LOQ). The HS-SPME-GC-FID method was finally applied to selected samples of foods commonly available on the market.
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Assessment of aroma active compounds in chosen fruit types
Frechová, Vendula ; Vespalcová, Milena (referee) ; Vítová, Eva (advisor)
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.
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Assessment of chosen aromatic compounds in cosmetics
Novotná, Petra ; Souralová Popelková, Miriam (referee) ; Vítová, Eva (advisor)
This master thesis deals with the assessment of selected fragrant substances in cosmetic products. At the beginning the occurrence, methods of acquiring and application of these substances is described. They are essential components primarily in cosmetic products, however they can cause an allergic reaction in sensitive individuals. The theoretical part of this thesis also describes the cause and the progress of these undesirable effects. There are several hundreds, up to thousands fragrant substances used in the perfume industry, from which 26 was designated by the European regulations as potential allergenic fragrant substances and their content is regulated. Legislative standards as well as the overview of the methods used to determine these fragrances are given here. The experimental part is focused on the development and validation of the separation methods for determining of the selected and potentially allergenic fragrant substances. The method used was a solid phase microextraction using Carboxen/Polydimethylsiloxane fiber combined with a gas chromatography coupled to a flame ionization detector (SPME-GC-FID). Amylcinnamyl alcohol, benzyl alcohol, cinnamyl alcohol, coumarin, lyral, ?-isomethyl ionone were among the determined allergenic substance. Consequently, this method was also applied on 10 selected cosmetic products specimens, in which the linalool and geraniol were identified as the most common allergenic substances.
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Assessment of aroma active compounds in elderberries
Bazgerová, Petra ; Ürgeová,, Eva (referee) ; Vítová, Eva (advisor)
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.
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Assessment of chosen aromatic compounds in foods
Škopová, Jitka ; Buňka, František (referee) ; Vítová, Eva (advisor)
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.
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Assessment of aromatic compounds of plant origin in foods
Jelínková, Monika ; Hrstka, Miroslav (referee) ; Vítová, Eva (advisor)
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.
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Aromatic substances of wine
Stávková, Markéta ; Vespalcová, Milena (referee) ; Ruibar, Jiří (advisor)
This bacherols thesis consists of two parts, of theoretical part and practical part. The theoretical part delimits wine-producing regions in Czech republic, explains growing of grapevine. The thesis is concerned with the soil classification, amount of mineral element and decribes the quality and aroma of a wine. It´s briefly concerned with bouquet of wine during wine production. Deals with chemical changes in must during fermentation using yeast. The practical part is concerned with soil analysis of vineyard Rajhradské Klášterní. The goal of this experimental part was to finding out amout of mineral elements in samples and their comparison between the four vineyard. Aromatics are analyzed by gas chromatography and sensory analysis.
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Monitoring of allergenic aroma compounds in foods
Plevová, Petra ; Sůkalová, Kateřina (referee) ; Vítová, Eva (advisor)
This thesis deals with the identification and quantification of aromatic potentially allergenic substances which normally occurs in food, but their amount is not legislatively controlled. These aroma compounds have many positive and negative effects on human body, although they are not main types of allergens, several studies have highlighted their potentially allergenic character. For monitoring of the content of these substances non-chocolate confectionery were chosen as model samples. Theoretical part summarizes the production technology of non-chocolate confectionery from raw materials to final processing. It also deals with the characterization of 26 potentially allergenic aroma substances and their occurrence in nature and also in food or cosmetic products. In the experimental part potentially allergenic aroma compounds occurring in samples of jelly confectionery were identified and quantified using the SPME–GC–FID method.
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