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Development of mass spectrometric methods for structural analysis of fatty acids and estolides
Cudlman, Lukáš ; Cvačka, Josef (advisor) ; Kozlík, Petr (referee) ; Lísa, Miroslav (referee)
(EN) This doctoral thesis summarizes the use of modern mass spectrometric methods for the structural identification of fatty acids and triacylglycerol estolides (TG-EST) and their subsequent characterization in the lipidome of vernix caseosa, i.e., the biofilm covering the skin of the human fetus during the last trimester of in-utero development. Vernix caseosa has mainly antimicrobial properties and the ability to heal wounds and burns. The first part of the doctoral thesis focuses on the diversity of fatty acids in the lipidome of vernix caseosa. These acids form the structural subunits of complex lipids, such as the abundant triacylglycerols and wax esters. By studying fatty acids and their structural features, this thesis has provided valuable insights into the structural variability of the vernix caseosa lipidome. Without a full understanding of the structure of these key subunits, it would be impossible to complete the analysis of this lipidome in the future. In this thesis, fatty acids using high-performance liquid chromatography (HPLC) and modern mass spectrometry methods, namely ultraviolet photodissociation (UVPD) and ozone-induced dissociation (OzID), were characterized. The coupling of HPLC and mass spectrometry (HPLC-MS) provided unambiguous information on the positions and geometry of...
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Comparison of microbial metabolic production from waste and powder whey
Elefantová, Petra ; Vítová, Eva (referee) ; Babák, Libor (advisor)
The master’s thesis discusses the comparison of microbial metabolic production from waste and powder whey. Whey is obtained as a by-product of cheese production. Lactose (preferably whey) using lactic acid bacteria (eg. Lactobacillus) under suitable temperature conditions is converted to lactic acid. Effect of temperature, effect of salts and effect of yeast extract on lactic acid production by L. casei were investigated. HPLC metod was determined lactid acid. In the practical part were used bacteria of the genus Lactobacillus. It was found that for dried and waste whey is the optimal temperature of 35 °C. At this temperature is the greatest gain of lactic acid. The highest concentration of lactic acid was obtained by using 20 g of yeast extract for dried whey and for waste whey were used 24 g of yeast extract. When monitoring the effect of salt concentration on the production of lactic acid, it was found that using only MnSO4·H2O gain most of lactic acid.
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Content of rutin in selected elderberry cultivars
Píšťková, Magdalena ; Hrstka, Miroslav (referee) ; Vespalcová, Milena (advisor)
The aim of this diploma thesis was to determine the rutin content in springs and leaves of 19 elderberry species (Sambucus nigra L.) with use of liquid chromatography. Furthermore the rutin content was determined in its significant sources – rue and buckwheat. The observed values were compared in order to answer the question whether it is useful to use the elderberry spring and leaves as a new source of rutin. Theoretical part of the thesis describes elderberry in general, its chemical composition and its usage in medicine. Following part concentrates on important substances contained in elderberry – flavonoids. Also principles of extraction techniques and HPLC are discussed. In practice the rutin was gained from plant matrix with use of pressurized hot water extraction (PHWE) which was performed in three five minutes long cycles. Conditions during the PHWE were set up to 80 °C and 150 bars. Obtained extract was purified with use of SPE columns and analyzed by HPLC with DAD detector (wave length – 360 nm). HPLC was performed with SUPELCOSILTMLC-8DB column. The mobile phase was composed of MeOH, H2O, and HCOOH in ration of 36:61,5:2,5. The set up flow of mobile phase was 1 ml/min. In the leaves the highest rutin content was determined in Pregarten – 26,34 ± 0,50 mg/g. On the other hand the lowest rutin content in leaves was determined in Körsör – 3,74 ± 0,13 mg/g. In springs the obtained results were as follow. The highest content was determined in Samyl – 4,87 ± 0,01 mg/g and the lowest content was determined in Heidegg 13 springs – 0,56 ± 0,01 mg/g. Also the HPLC detection limit – 6,3 . 10-5 mg/ml and quantitation limit – 2,1 . 10-4 mg/ml were determined for rutin.
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Analysis of selected biologically active substances in cereal products
Skutek, Miroslav ; Kočí, Radka (referee) ; Márová, Ivana (advisor)
Presented diploma thesis was focused on study of biologically active compounds, especially some sugars in cereal products. In experimental part the total of 29 different cereal materials, food industry waste products and natural complex matrixes (microbial polysaccharide, honey, beer) were used. As a part of this work optimization of analytical methods suitable for analysis of simple sugars, oligo- and polysaccharides was done. In cereal samples reduced and neutral sugars were analyzed spectrophotometrically and individual sugars were detected by chromatography. For HPLC/RI analysis optimal mobile phase composition and chromatography conditions were proposed. For mono- a oligosaccharides C18-NH2 sorbent, mixture acetonitril:water 75:25 as mobile phase and flow 1 ml/min were verified as suitable separation parameters. Thin layer chromatography of mono- and oligosaccharides was optimized too. Introduced chromatography and spectrophotometry methods were then applied to analysis of cereal samples. As a model sugar natural microbial polysaccharide pullulan was used to analytical method testing. In cereal products and food matrixes total neutral and reduced sugars as well as products of their acid and enzyme hydrolysis were measured. Detailed analysis of some glycoside composition was tested too. As the most usable method for both qualitative and quantitative analysis of cereal sugars HPLC/RI method was found. To detailed identification of malto-oligosacharides tandem LC/MS/MS technique using derivatization by 1-phenyl-3-methyl-5-pyrazolon was tested too.
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Study of the chemical processes during kombucha technology
Chludilová, Markéta ; Obruča, Stanislav (referee) ; Pořízka, Jaromír (advisor)
The kombucha drink is referred to as leavened tea with added sponge called a scobie. In this way, a low-alcohol beverage is obtained, which gains considerable popularity, especially due to the alleged beneficial properties for human health. The microbial composition of this beverage is very rich, consisting of bacteria and yeasts living in a beneficial symbiosis [11]. The microbial composition of the drink and its beneficial effects on human health are very closely related. This work deals with the analysis of the chemical composition of the commodity beverage, especially with regard to the content of major components such as organic acids, carbohydrates and ethanol. These analytes are among the most common and most profoundly found substances in the carbohydrate beverage and are very closely related to the microbial composition of the scoby itself [3]. Combo beverage samples were supplied by RebornFood, one of which is the commercial production of this drink on the Czech market. At the same time, this company bases itself on purely natural fermentation of beverages, and therefore it is not particularly involved in the production process. The results of this diploma work point to the effect of the scoby used and the associated occurrence of analytes in the beverage, as well as the production process associated with the formation of analytes, which is described in several articles. It is expected that this work will provide information both on the production conditions and on the chemical properties of the beverage related to the condition of the scoby, which will be used further, both for RebornFood and the material used to solve the technical problems of this beverage production.
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Determination of athenticity of plant foods by molecular techniques
Plášková, Anna ; Mikulíková, Renata (referee) ; Němcová, Andrea (advisor)
The aim of presented diploma thesis was to determination of authenticity of fruit baby foods for early infant feeding using molecular methods. In the experimental part, isolation kit was used for isolation of plant DNA from fruits (strawberry, apricot, raspberry, apple) and from six commercial fruit products for children. Isolated DNA was characterized and verified using PCR methods with primers specific for plant rDNA (ITS2). Specific primer pairs were designed to amplify DNA for the detection of one fruit species. Primer specificity was assessed with four fruit species. A mixture of fruit puree from the two fruits was used to determine the sensitivity of the multiplex PCR assay. Six commercial fruit products were evaluated to verify the applicability of the multiplex PCR assay. The methodology of molecular detection of fruit DNA by qPCR and multiplex qPCR (duplex) includes approaches, which enable to detect two fruits (strawberry-raspberry, apricot-apple) in one reaction and thus reduces time and money requirements.
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Validation of HPLC method for determination of organic acids in beverages
Hanychová, Silvie ; Divišová, Radka (referee) ; Diviš, Pavel (advisor)
This diploma thesis focuses on validation of RP–HPLC method for determination of organic acids in fruit juices. The aim of this thesis was to determine suitability of the method for verification of the fruit juices authenticity based on analysis of organic acids. The theoretical part describes chemical composition of fruit and fruit juices and focuses on organic acids. It provides description of various methods of organic acids analysis with more detailed description of High Performance Liquid Chromatography and its validation. The experimental part focuses on optimalization and validation of the method. Samples of malic, citric, succinic and ascorbic acid were analysed. The optimalized method was validated and following performance parameters were determined: repeatability, linearity, limit of detection (LOD) limit of quantitation (LOQ). RP–HPLC method was applied to real samples of 100% fruit juices (apple, orange and grapefruit) and the authenticity parameters were verified.
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Analysis of selected nutritional parameters in the new varieties of gooseberries
Nováková, Jana ; Vítová, Eva (referee) ; Vespalcová, Milena (advisor)
Diploma thesis deals with the new varieties of gooseberries. The theoretical part characterizes gooseberry from a biological point of view, what is the content of healthful nutrients and states food technology aspects. Furthermore, the theoretical part deals with the main parameters examined nutrition: vitamin C, anthokyanům and antioxidant activity. In the experimental part was measured both weight solids content and soluble solids. Vitamin C was measured by HPLC, anthocyanins using a pH differential method and for antioxidant activity determination was selected method by Kanedy known also as DPPH.
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Determination of organic acids in beer
Štáblová, Taťána ; Divišová, Radka (referee) ; Diviš, Pavel (advisor)
The topic of this bachelor’s thesis is determination of organic acids in Czech beers with protected geographical indication. There are described the main components for beer production and the production of malt and beer itself in the theoretical part. Part of this work is dedicated to analytical methods used in determination of organic acids. High–performance liquid chromatography and ion chromatography were used to determine the content of organic acids. The experimental part deals with sample preparation, calibration solutions and procedure of analysis. The obtained results of analyzed substances are summarized, discussed, and compared with results of analyses of foreign papers. Differences in content of organic acids in lager and draught beers were determined. Five lager beers and five draught beers were used for the analysis.
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