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Comparison of aroma profile of fruit distillates
Koubek, Miroslav ; Veselá, Mária (referee) ; Vítová, Eva (advisor)
This master thesis deals with the assessment of aroma active compounds in fruit spirits. In the theoretical part the production technology of fruit spirits from raw materials to final product is described. Furthermore, aroma active substances are characterized, and the method for their determination by solid phase microextraction and gas chromatography with mass spectrometry is described. The aim of the experimental part was the identification of volatile substances in different kinds of fruit spirits. Aromatic compounds were identified by the SPME-GC-MS. Domestic fruit spirits obtained from private growers were used as model samples. The differences in the number and type of volatile compounds were found between the samples. Overall 53 volatile compounds were identified. These were composed of 25 esters, 9 alcohols, 5 aldehydes, 4 alkenes, 2 ketones, 1 carboxylic acid and 7 other compounds.
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Influence of aroma compounds on sensory quality of sweets
Motúzová, Eliška ; Zemanová, Jana (referee) ; Vítová, Eva (advisor)
This master´s thesis is focused on determination of aroma active compounds in non-chocolate sweets and their influence on sensory quality/flavour. The theoretical part describes production of non-chocolate sweets, characterizes aroma active compounds including allergenic ones, method for their determination by solid-phase microextraction and gas chromatography with mass detection. For experimental part were used as model samples gummy candies purchrased in regular market. Four flavors were used, specifically yellow (lemon), green (apple), red (strawberry) and orange (orange). The HS-SPME-GC-MS method was used to identify volatile aroma active compounds. To evalutate the sensory quality were used scales, a profile test, and a time course evaluation. Owerall 120 volatille compounds were identified including 8 allergens.
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Changes of aroma active compounds during production of model cheese
Školová, Dominika ; Pořízka, Jaromír (referee) ; Vítová, Eva (advisor)
The aim of the work was identification of aroma active compounds in Moravský bochník cheese type, than discuss their changes during ripening and consider influence of aplication different rates of microbial cultures on number of volatile compounds. SPME-GC-MS was used for identification of volatile compounds. In total, 148 of volatile compounds were identified and 82 of them are considered as aroma active compounds. Three microbial cultures (their combination with predominant thermophilic or mesophilic culture) were used for making samples. The influence of predominant thermophilic/mesophilic culture on number of volatile compounds was not proved. From the point of view of sensory quality, combinations with predominant mesophilic culture proved to be more successful. During ripening, the number of identified compounds was reduced in all the combinations of cultures studied. The optimal time for ripening seems to be three months.
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The content of aroma active compounds in sweets
Paulišová, Sabina ; Hrstka, Miroslav (referee) ; Vítová, Eva (advisor)
This bachelor thesis focuses on identification of aroma active compounds in selected samples of non-chocolate sweets. Based on the results obtained, the aromatic profile of the individual samples is compared. The theoretical part deals with aroma active compounds, legislation and technology of manufacturing non-chocolate sweets. Further experimental technique and the methods used in practical part, namely solid phase microextraction and gas chromatography with mass spectrometry detection are presented. In the experimental part volatile aroma active substances were identified in green colored jelly candy samples available in the common market. For this purpose, the HS-SPME-GC-MS method was used. The individual samples differed in type and number of volatile compounds, depending on the manufacturer. In total 72 different compounds, including 11 aldehydes, 14 alcohols, 27 esters, 1 heterocycle, 8 carboxylic acids, 6 ketones, 4 hydrocarbons and 1 sulfur compound were found.
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Study of Factors Influencing Creation of Volatile Aroma Active Compounds in Natural Materials
Loupancová, Blanka ; Vávrová, Milada (referee) ; Kráčmar, Stanislav (referee) ; Fišera, Miroslav (advisor)
The production of high-quality foods requires the precise control of factors influencing their quality. The aim of this doctoral thesis was to monitor the influence of sterilization heating and storage time and temperature on selected parameters of model food matrix using suitable physical, chemical and sensory methods. Sterilized processed cheese was chosen as the model matrix. Processed cheeses are milk protein concentrates, produced by melting of mixture of natural cheeses, emulsifying salts, water and other dairy and/or non dairy ingredients. Desirable transformation of this mixture to homogenous, smooth, shiny mass with desired textural, structural, rheologic and sensory properties is caused by using high temperature (about 80-100 °C) during melting. Sterilized processed cheese is subjected to additional sterilization heating (above 100 °C) after production, significantly elongating its durability. The processed cheeses (dry matter 40 % w/w, fat in dry matter 45 % w/w) were analyzed in this work, the part of them was sterilized (117 °C 20 min). Cheeses were stored at various temperatures (cold 6 ± 2 °C, laboratory 23 ± 2 °C and elevated 40 ± 2 °C), sterilized cheeses for 2 years, non sterilized for 1 year. During storage, the samples for physical (instrumental measuring of colour and texture), chemical (assessment of fatty acids and aroma compounds) and sensory (paired preference test, ranking test and evaluation using scale) analyses were taken at regular intervals. The influence of sterilization heating and for another the influence of storage conditions on mentioned parameters were investigated. Non sterilized processed cheese kept their very good quality during all the declared durability (4 months), however, then the significant worsening of most sensory properties was observed. In consequence of sterilization heating the changes of cheese colour and texture were observed, confirmed by both sensory and instrumental assessment. The impairment of taste and aroma was also found. These changes are obvious immediately after production and differences were observed during all the durability. In the case of sterilized processed cheese, the significant impairment of single sensory properties was determined, the highest in the case of texture, taste and aroma. The results of instrumental techniques confirm conclusions from sensory evaluation. The measurements of colour and texture vindicate the formation of darker colour (increasing total difference of colour delta E*) and higher hardness (increasing Fmax) of sterilized processed cheeses, continuing during storage. The worsening of taste and aroma is in accordance with lower content of aroma active compounds and selected fatty acids.
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Aroma active compounds of selected types of herbs
Škutová, Pavla ; Hrstka, Miroslav (referee) ; Vítová, Eva (advisor)
This diploma thesis deals with the identification of aroma active compounds in medicinal herbs. The group consists of 5 types of herbs: lemon balm (Melissa officinalis), pot marigold (Calendula officinalis), clary sage (Salvia sclarea), milk thistle (Silybum marianum), goat’s rue (Galega officinalis). These plants are known for their positive effects in folk medicine. The SPME-GC-MS method was chosen to characterize the fragrances. During the identification of volatile compounds, emphasis was put on suspected fragrance allergens listed in EC Regulation 1223/2009 in Annex III. Overall 106 compounds were identified together with 8 allergens in lemon balm, pot marigold contained 104 compounds with 7 allergens included, 82 compounds including 5 allergens in clary sage, 73 compounds were identified in milk thistle including 6 allergens and 110 compounds with 9 allergens included in goat’s rue.
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Assessment of aroma active compounds in selected type of cheese
Dostálková, Andrea ; Sýkora, Michal (referee) ; Vítová, Eva (advisor)
This bachelor thesis deals with the aroma active compounds of Emmental and Moravský bochník types of cheeses, i.e. natural hard cheese with high heat curd. In the theoretical part these cheeses are characterized, their chemical composition is described as well as individual steps of their manufacturing process. After that a literature search focused on aroma active substances is made and the following methods are described: solid phase microextraction for their isolation and gas chromatography with mass spectrometry for detection. In the experimental part the selected SPME-GC-MS method is used to identify volatile aroma active compounds in cheeses with high heat curd bought on the market and samples of model cheeses manufactured at Tomas Bata University in Zlín with the use of various ratios of added dairy cultures. The differences among samples were found in the number and types of volatile compounds. A total of 129 compounds were identified in samples; of those 35 alcohols, 9 aldehydes, 24 ketones, 16 carboxylic acids, 23 esters, 1 ether, 16 hydrocarbons, 2 sulphurous and 3 nitrogenous compounds.
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Aroma active compounds in fruit distillates
Kocinger, Oskar ; Veselá, Mária (referee) ; Vítová, Eva (advisor)
This work deals with the identification of substances responsible for the taste and aroma of fruit spirits. Solid phase microextraction method coupled with gas chromatography and mass spectrometry (SPME-GC-MS) was used for extracting and identifying volatile substances present in a total of six samples of fruit spirits, namely 3 samples for plum distillate and 3 samples for apricot distillate. The results of the individual analyzes were compared and the most frequently occurring substances were identified. These compounds are most likely responsible for the typical aroma of fruit spirits of this kind.
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Assessment of aroma active compounds in selected type of cheese
Páral, Marek ; Mahdalová, Martina (referee) ; Vítová, Eva (advisor)
This bachelor thesis deals with the determination of aroma active compounds in white mold cheeses, i.e. soft, mold cheeses maturing from the surface. In the theoretical part, cheeses are generally characterized, their chemical composition, properties and process of production are described. After that It´s focused on aroma active compounds. The metabolism of their formation in cheese and their determination by means of solid phase microextraction and gas chromatography with mass detection are described. In the experimental part of the bachelor thesis, the SPME-GC-MS method was used for identification and semiquantitative determination of aroma active compounds in three samples of white mold cheeses made in the Czech Republic purchased in a market. Comparison of cheeses showed differences in the number and types of determined compounds as well as in total contents. A total of 66 volatile compounds were identified in samples; of those 1 aldehyde, 17 alcohols, 19 esters, 9 carboxylic acids, 15 ketones, 1 sulphur compound ¨ and 3 hydrocarbons.
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Aroma active compounds of selected types of medical herbs
Pecinová, Ester ; Diviš, Pavel (referee) ; Vítová, Eva (advisor)
This thesis deals with aroma active compounds of selected types of medicinal herbs, specifically lavender (Lavandula officinalis), peppermint (Mentha piperita), sage (Salvia officinalis), St. John’s wort (Hypericum perforatum) and hyssop (Hyssopus officinalis). In the theoretical part the single herbs were characterized including botanical description, chemical composition, medicinal properties, adverse effects and the practical use; aroma active compounds present in herbs are also emphasized. Based on the literature search, gas chromatography coupled with mass spectrometry as currently the most frequently used method, was chosen for the assessment of aroma compounds. Solid Phase Microextraction was used for isolation of volatile compounds from dried herbs. Within experimental part of the work selected parameters of the SPME-GC-MS method were optimized, aroma compounds in samples of herbs were identified, and twenty four suspected fragrance allergens due to the Regulation (EC) N° 1223/2009 were also identified and quantified. Overall 69 compounds were indetified together with 2 allergens in lavender, 59 compounds including 5 allergens in peppermint, sage contained 49 compounds with 4 allergens included, 41 compounds were identified in St. John’s wort including 4 allergens and finally 64 compounds with 4 allergens included in hyssop.
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