|
|
Study of selected vegetable oils from nuts
Lovásová, Kristína ; Kovalčík, Adriána (referee) ; Zemanová, Jana (advisor)
The bachelor´s thesis deals with the characterization of the selected nut oils. The theoretical part concentrates on the topic of vegetable oils, their composition and properties. It also focuses on the nuts, the specification of the selected nut oils and their use in different industries. It includes an overview of analytical methods suitable for assessing the quality of oils. The experimental part compares the results of the oil characterization using the selected methods. Based on the results, the differences between the samples were evaluated. The properties of the oils were determined on the basis of fat characteristics. These were subsequently specified by the determination of fatty acid composition. Fatty acids were determined using gas chromatography with a flame-ionization detector after conversion to methyl esters by acid esterification with boron trifluoride. The determination of volatile compounds was performed through solid-phase microextraction with gas chromatography separation and mass spectrometry detection. According to the fat characteristics, in particular the peroxide value, it was found that both oils were partially oxidatively degraded, even though they were stored in the refrigerator (4 °C). A total of 13 saturated, 7 monounsaturated and 4 polyunsaturated fatty acids were detected. The total content of fatty acids varied, the higher content was detected in the walnut oil. Significant differences occurred in the composition of unsaturated fatty acids; the hazelnut oil had a higher content of monounsaturated oleic acid, the walnut oil had a high content of polyunsaturated linoleic and -linolenic acids. A total of 29 volatile compounds were identified, the number and content of volatile compounds in samples differed. 20 volatile compounds were identified in the walnut oil, and 19 compounds in the hazelnut oil. The higher content was in the hazelnut oil, the quantitatively most important group were aldehydes in both oils.
|
|
|
Volatile profile of Edam type cheese
Balej, Marek ; Kovalčík, Adriána (referee) ; Vítová, Eva (advisor)
This bachelor thesis is focused on specification volatile profile of eidam cheese types, which are natural semi hard cheeses with low heat curd. Subject of theoretical part is basic differentiation of cheeses, description of chemical composition and characteristic of eidam cheese types. After that, issue of their manufacturing process is processed and aroma active substances are described. In the last part of this section, the attention is focussed on specification method of solid phase microextraction connected with gas chromatography with mass spectrometry detection. Experimental part deals with HS-SPME-GC-MS method application on identification of volatile compounds in eidam cheese types. Samples of model cheese were manufactured at Tomas Bata University in Zlín with the use of various added microbial starter cultures and eidam type cheeses with various fat content bought on the market. A total of 64 compounds were identified in samples; of those 18 alcohols, 11 esters, 9 ketones, 7 aldehydes, 5 acids, 3 lactones, 2 terpene hydrocarbons, 2 terpene alcohols, 1 terpene ketone, 1 terpene aldehyde, 4 sulphurous compounds and 1 phenol. The differences were found among model cheese samples and market bought samples in the case of number and type of volatiles.
|
|
|
Aroma profile of processed cheese analogues
Kučerka, Štefan ; Saláková,, Alena (referee) ; Vítová, Eva (advisor)
The aim of this bachelor thesis was to identify and semiquantify volatile (aroma) compounds in samples of processed cheese analogues, produced with full or partial substitution of milk fat with selected vegetable fats/oils (coconut, palm, blended, grapeseed, linseed, apricot kernel, blackcurrant seed). Theoretical part is dealing with characterization of processed cheese analogues, procedure and ingredients used in production. This is followed by a topic of aroma compounds. At the end of theoretical part the method of solid-phase microextraction, gas chromatography and mass spectromectry is described. In the experimental part the model samples of processed cheese analogues were analyzed. They were produced in Tomas Bata University in Zlin. Edam cheese and mentioned fat were used as ingredients. HS-SPME-GS-MS method was chosen to isolate and determinate volatile (aroma) compounds in samples. A total of 152 volatile compounds were identified in samples. Differences in the number and content of the identified compounds were found among samples, aldehydes and acids belonged to the most important groups, sample content speaking.
|
|
|
Quantitative composition changes of sex pheromone in Anastrepha fraterculus depending on age
Zyková, Kamila ; Kalinová, Blanka (advisor) ; Rezek, Jan (referee)
Males of South American fruit fly Anastrepha fraterculus form leks and release sex pheromone to attract females during the reproductive behavior. The aim of my diploma thesis was to collect samples of volatiles released by variously old males, subsequently to analyze and to determine the changes in the quantitative composition of the sex pheromone depending on age. The volatiles were trapped on adsorbent, eluted with hexane containing internal standard and analyzed by gas chromatography with mass detection. Males release twenty volatiles, including fourteen terpenes: α-pinene, camphene, -pinene, myrcene, Δ3-carene, limonene, (Z)--ocimene, (E)--ocimene, aromadendrene, trans-α-bergamotene, (Z)-β-farnesene, (Z,E)-α-farnesene, germacrene D, (E,E)-α-farnesene; one aldehyde: nonanal; two alcohols: (3Z)-non-3-en-1-ol, (3Z,6Z)-nona-3,6-dien-1-ol and three lactones: suspensolide, anastrephin a epianastrephin. From the list of named compounds there were proved antenal activity of six compounds in previous work, namely trans-α-bergamotene, (Z,E)-α-farnesene, (E,E)-α-farnesene, (3Z)-non-3-en-1-ol, (3Z,6Z)-nona-3,6-dien-1-ol and epianastrephin.
|
|
|
Study of selected vegetable oils from nuts
Lovásová, Kristína ; Kovalčík, Adriána (referee) ; Zemanová, Jana (advisor)
The bachelor´s thesis deals with the characterization of the selected nut oils. The theoretical part concentrates on the topic of vegetable oils, their composition and properties. It also focuses on the nuts, the specification of the selected nut oils and their use in different industries. It includes an overview of analytical methods suitable for assessing the quality of oils. The experimental part compares the results of the oil characterization using the selected methods. Based on the results, the differences between the samples were evaluated. The properties of the oils were determined on the basis of fat characteristics. These were subsequently specified by the determination of fatty acid composition. Fatty acids were determined using gas chromatography with a flame-ionization detector after conversion to methyl esters by acid esterification with boron trifluoride. The determination of volatile compounds was performed through solid-phase microextraction with gas chromatography separation and mass spectrometry detection. According to the fat characteristics, in particular the peroxide value, it was found that both oils were partially oxidatively degraded, even though they were stored in the refrigerator (4 °C). A total of 13 saturated, 7 monounsaturated and 4 polyunsaturated fatty acids were detected. The total content of fatty acids varied, the higher content was detected in the walnut oil. Significant differences occurred in the composition of unsaturated fatty acids; the hazelnut oil had a higher content of monounsaturated oleic acid, the walnut oil had a high content of polyunsaturated linoleic and -linolenic acids. A total of 29 volatile compounds were identified, the number and content of volatile compounds in samples differed. 20 volatile compounds were identified in the walnut oil, and 19 compounds in the hazelnut oil. The higher content was in the hazelnut oil, the quantitatively most important group were aldehydes in both oils.
|
|
|
Aroma profile of processed cheese analogues
Kučerka, Štefan ; Saláková,, Alena (referee) ; Vítová, Eva (advisor)
The aim of this bachelor thesis was to identify and semiquantify volatile (aroma) compounds in samples of processed cheese analogues, produced with full or partial substitution of milk fat with selected vegetable fats/oils (coconut, palm, blended, grapeseed, linseed, apricot kernel, blackcurrant seed). Theoretical part is dealing with characterization of processed cheese analogues, procedure and ingredients used in production. This is followed by a topic of aroma compounds. At the end of theoretical part the method of solid-phase microextraction, gas chromatography and mass spectromectry is described. In the experimental part the model samples of processed cheese analogues were analyzed. They were produced in Tomas Bata University in Zlin. Edam cheese and mentioned fat were used as ingredients. HS-SPME-GS-MS method was chosen to isolate and determinate volatile (aroma) compounds in samples. A total of 152 volatile compounds were identified in samples. Differences in the number and content of the identified compounds were found among samples, aldehydes and acids belonged to the most important groups, sample content speaking.
|
|
|
Volatile profile of Edam type cheese
Balej, Marek ; Kovalčík, Adriána (referee) ; Vítová, Eva (advisor)
This bachelor thesis is focused on specification volatile profile of eidam cheese types, which are natural semi hard cheeses with low heat curd. Subject of theoretical part is basic differentiation of cheeses, description of chemical composition and characteristic of eidam cheese types. After that, issue of their manufacturing process is processed and aroma active substances are described. In the last part of this section, the attention is focussed on specification method of solid phase microextraction connected with gas chromatography with mass spectrometry detection. Experimental part deals with HS-SPME-GC-MS method application on identification of volatile compounds in eidam cheese types. Samples of model cheese were manufactured at Tomas Bata University in Zlín with the use of various added microbial starter cultures and eidam type cheeses with various fat content bought on the market. A total of 64 compounds were identified in samples; of those 18 alcohols, 11 esters, 9 ketones, 7 aldehydes, 5 acids, 3 lactones, 2 terpene hydrocarbons, 2 terpene alcohols, 1 terpene ketone, 1 terpene aldehyde, 4 sulphurous compounds and 1 phenol. The differences were found among model cheese samples and market bought samples in the case of number and type of volatiles.
|
|
|
Quantitative composition changes of sex pheromone in Anastrepha fraterculus depending on age
Zyková, Kamila ; Kalinová, Blanka (advisor) ; Rezek, Jan (referee)
Males of South American fruit fly Anastrepha fraterculus form leks and release sex pheromone to attract females during the reproductive behavior. The aim of my diploma thesis was to collect samples of volatiles released by variously old males, subsequently to analyze and to determine the changes in the quantitative composition of the sex pheromone depending on age. The volatiles were trapped on adsorbent, eluted with hexane containing internal standard and analyzed by gas chromatography with mass detection. Males release twenty volatiles, including fourteen terpenes: α-pinene, camphene, -pinene, myrcene, Δ3-carene, limonene, (Z)--ocimene, (E)--ocimene, aromadendrene, trans-α-bergamotene, (Z)-β-farnesene, (Z,E)-α-farnesene, germacrene D, (E,E)-α-farnesene; one aldehyde: nonanal; two alcohols: (3Z)-non-3-en-1-ol, (3Z,6Z)-nona-3,6-dien-1-ol and three lactones: suspensolide, anastrephin a epianastrephin. From the list of named compounds there were proved antenal activity of six compounds in previous work, namely trans-α-bergamotene, (Z,E)-α-farnesene, (E,E)-α-farnesene, (3Z)-non-3-en-1-ol, (3Z,6Z)-nona-3,6-dien-1-ol and epianastrephin.
|
|
|
Supercritical Fractionation of Volatiles and Non-volatiles from Different Plant Sources
Topiař, Martin
The focus of this work was on using the SFE combined with different fractionation techniques (additional separator, sorption on silica gel in one step with the extraction) in a range of pressures and temperatures (9–30 MPa, 40–50 °C) to enhance volatiles in extracts from the leaves of eucalyptus. Its essential oil is widely used in cough pills or toothpastes and in addition, several studies proved insecticidal and repellent activity of eucalyptus extract.1,2 The efficiency of SFE in terms of extract composition and yield was compared with hydrodistillation. The composition of volatiles in the isolates was determined using GC-MS and GC-FID.
Fulltext: content.csg -  PDF
Plný tet: SKMBT_C22015061709330 - PDF
|
guest ::
