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Assessment of fatty acids in selected type of cheese
Těšíková, Karolína ; Sůkalová, Kateřina (referee) ; Vítová, Eva (advisor)
This bachelor’s thesis is focused on identification and quantification of free and bound fatty acids in model cheeses of „Moravský bochník“, made at Tomáš Baťa University in Zlín. Theoretical part is dealing with characteristics of lipids and fatty acids. Furthermore, the classification of cheese types and description of their production and composition are discussed. Finally, the gas chromatography is described as a most commonly used method for assessment of fatty acids. The experimental part focuses on comparing the content of free and bound fatty acids in four model cheeses in relation to the use of different microbial cultures. The method according to the ČSN EN ISO 1735:2005 was employed for extraction of lipids from cheese samples. The present fatty acids were identified and quantified by gas chromatography with flame ionization detector after conversion to methylesters using acid-catalysed esterification with a methanolic solution of boron trifluoride. In total, 32 bound and 20 free fatty acids were identified in cheese samples.
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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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Monitoring of fatty acids content during cheese production
Rajnochová, Veronika ; Mikulíková, Renata (referee) ; Vítová, Eva (advisor)
This master thesis deals with the monitoring of fatty acids during production of natural Edam cheeses, i.e. natural hard cheeses with low heat curd, and of processed cheeses, which were produced from them. The theoretical part briefly characterizes the natural Edam cheese and processed cheese, the main attention is paid to lipids, fatty acids and the possibility of their determination. In the experimental part the content of fatty acids in the model samples of natural and processed cheese produced at Tomas Bata University in Zlín was determined. The method according to ISO 1735 was chosen for extraction of lipids from the samples, the method according to ISO 5509 using methanol solution of potassium hydroxide was chosen for the esterification of fatty acids. The resulting methyl esters were determined by gas chromatography with FID detection.
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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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Changes of fatty acids during production of model cheese
Janoušková, Kateřina ; Babák, Libor (referee) ; Vítová, Eva (advisor)
This thesis deals with the identification and quantification of free and bound fatty acids in model cheese samples of the Moravský bochník type, which were produced at Tomas Bata University in Zlín by a standard technological procedure. In a theoretical part of the thesis, the issues of lipids, fatty acids, as well as the characteristics of high cooked cheeses including Moravský bochník, microbial cultures used in their production, and the possibilities of fatty acids determination are summarized. The ČSN EN ISO 1735:2005 method was chosen for the lipid extraction from cheese samples. Present free and bound fatty acids were identified and quantified by gas chromatography with flame-ionization detection after conversion to methylesters by acid esterification with bortrifluoride as a catalyst. In total 32 fatty acids were identified in cheese samples, the highest amount of caproic, caprylic, capric, lauric, myristic, palmitic, stearic and oleic acids.
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Monitoring of sensory active compounds during cheese production
Ryglová, Hana ; Buňka, František (referee) ; Vítová, Eva (advisor)
This work deals with monitoring of sensory active compounds during production of Edam cheeses, i.e. natural hard cheeses with low heat curd, and of processed cheeses, which were produced from Edam cheeses. Sensory active compounds contribute to overal flavour of cheese. They are volatile compounds, which include alcohols, aldehydes, ketones, fatty acids, esters, lactones, terpenes etc. These compounds were identified and quantified using SPME/GC/FID method in the model samples of Edam cheeses and processed cheeses, produced at Tomas Bata University in Zlin. In total 42 volatile compounds were identified, 6 aldehydes, 7 ketones, 15 alcohols, 6 esters and 8 acids. Differences in number of compounds identified, as well as in the contents of them, were found between samples. Effect of pasteurization on the contents and composition of the identified compounds was the most obvious in the samples of matured cheeses. In the samples of processed cheeses the effect of pasteurization was the most obvious in combination with prolonged heating during melting.
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Business Plan for Establishment of the Small Company
Šimíčková, Anna ; Fischer, Jan (referee) ; Koudelková, Petra (advisor)
This thesis focuses on preparation a business plan of shop with cheese and another delicatessen. The theoretical part defines basic concepts such as enterprise, entrepreneur or business and specifies legal forms of companies in the Czech Republic. Also it defines business plan, their structure and analyzes performed before establishment of a company. The practical part focuses on creating of business plan shop with cheese and another delicatessen.
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The use of solid phase extraction for fractionation of lipids in cheese matrix
Scholzová, Kristýna ; Vespalcová, Milena (referee) ; Vítová, Eva (advisor)
This bachelor thesis deals with Solid Phase Extraction, as a method for isolation of free fatty acids from cheese matrix to be subsequently determined using gas chromatography with FID detection. The theoretical part provides information about milk fat composition and related reactions being a source of flavour compounds, free fatty acids including. The main objective of the theoretical research is to summarize alternatives to determining fatty acids in cheese, focusing on current advancement and use of Solid Phase Extraction for this purpose. The practical part discovers proper technique and conditions for fractionation of lipids by Solid Phase Extraction, using aminopropyl bonded phase columns. Agilent SampliQ Amino columns were utilized to separate lipid mixture and different lipid classes were eluted using suitable organic solvents. Composition and purity of lipid extracts were verified combining thin layer chromatography and gas chromatography. Before being determined by gas chromatography, free fatty acids were converted into methylesters, based on ČSN EN ISO 12966-2. Besides discussing proper experimental conditions, the assesment also comes with solving optimal volumes of sample and eluting solvents to apply. The results of this thesis are considered to be useful base for subsequent experimental optimization and following integration of validated method into process of determining free fatty acids.
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The use of thin layer chromatography for fractionation of lipids in cheese matrix
Pop, Zdeněk ; Vespalcová, Milena (referee) ; Vítová, Eva (advisor)
This bachelors thesis is focused on the use of thin layer chromatography for fractionation of lipids in the cheese matrix. Milk fat, lipids, fatty acids, the possibility of determination of lipid compounds, thin-layer chromatography and gas chromatography are characterized in theoretical part. In the experimental part the conditions for the fractionation of lipids using thin layer chromatography were optimized, selected validation parameters were evaluated, lipid fractions obtained from the solid-phase extraction were verified and fatty acids in lipid fractions in the sample of processed cheese were quantified. The method according to ISO 1735 was chosen for extraction of lipids from the samples. Lipids fractionation was performed on commercially available plates for thin-layer chromatography. The method accrording to ISO 5509 using methanol solution of boron trifluoride as catalyst was chosen for the esterification of fatty acids. The resulting methyl esters were determined by gas chromatography with FID detection.
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The optimization and validation of the GC-MS method for assessment of volatile aroma compounds in cheese
Koubek, Miroslav ; Babák, Libor (referee) ; Vítová, Eva (advisor)
This work deals with the introducing of the method for the determination of volatile aroma active compounds in different types of natural and processed cheeses. The theoretical part describes the basic groups of aroma compounds. Than the methods used for their determination with focusing on solid phase microextraction and gas chromatography coupled with mass spectrometry are described. The experimental part deals with the optimization of the selected method parameters. For extracting volatile substances from the sample matrix the fiber DVB/CAR/PDMS 50/30 m was selected, these compounds were then determined by gas chromatography coupled with mass spectrometry. In the frame of validating proces the repeatability of the method was verified, RSDs of retention times
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