|
|
Characterization of different bran species in terms of ferulic acid content
Nábělek, Jakub ; Štursa, Václav (referee) ; Pořízka, Jaromír (advisor)
This bachelor’s thesis works with an alkaline extraction of a ferulic acid from different kinds of cereal bran. Another researched issue was extraction of nutritionally interesting elements extracted from bran and from hydrolysed waste. Those extracts has possible usage as a mineral fertilizer for plants. In the theoretical part, this thesis deals with problematice of cereals, composition and differences in a cereal grain depending on kinds of cereal and an enviromental conditions. Chemical composition of cereal materials, focused on phenolic acids are also described. Another part deals with theoretical background of methods for the extraction of phenolic acids from bran with description of advantages and disadvantages. Methods for alkaline hydrolysis and extraction of minerals from different kind of bran bran are described in experimental part of this work. Sodium hydroxide (0,5 M) was used for the hydrolysis of bran material. For the determination of the yields of ferulic acid, HPLC method with UV/VIS detection at wave-length 330 nm with usage of mobile phase mixture of methanol and 0,5 % solution of formic acid was used. Acidified deionized water was used for the extraction of nutritionally interesting elements from bran and also from the hydrolyzed material. For the determination of the elemental composition of extracts (Cu, Fe, Zn, Mn, P, Ca, K, Mg), ICP-OES method was used. It was found, that differences in wheat bran species in terms of yields of Ferulic acid are satistically important. The biggest yields of ferulic acid was obtained from the sample of spelt. The smallest yields of this acic was obtained from the sample of oat. Content of micro and macro-elements showed statistical important differences in different kinds of bran and their hydrolyzed waste. Most abundand elemets were obtained from rice bran and from spelts hydrolyzate. The smallest abundand elemens were obtaned from oat bran and hydrolyzate.
|
|
|
Studying the authenticity of coffee of various geographical origins
Flegr, Šimon ; Pořízka, Jaromír (referee) ; Diviš, Pavel (advisor)
This diploma thesis researches coffee authenticity problematice, mainly focusing on the authenticity of geographic origin. In the theoretical part of this work, botanical classification is described as well as production technology and processes. The work also includes chemical composition of coffee, describing the major components and changes during production phases. It describes major production areas of the world, in terms of general description and brief history. Problematics with coffee fraud and its identification are also described. Theoretical part also includes general geological description of 17 studied coffee growing regions. Experimental part is devoted to trace amount analysis of selected elements and volatile compounds. The element analysis was conducted using mass spectrometry or optical emission spectrometry, volatile compounds were determined using gas chromatography combined with mass spectrometry detection. Results were statistically described and analyzed, resulting in several discrimination models based on geographic origin.
|
|
|
Influence of the chicken breeding method on the selected chemical constituents of chicken eggs
Michalec, Adam ; Vespalcová, Milena (referee) ; Pořízka, Jaromír (advisor)
This diploma thesis is focused on the analysis of egg yolks and egg whites from chickens raised with different breeding methods in the Czech Republic using three analytical methods. The Kjeldahl method was used to determine the proteins, the Soxhlet method was used to determine the lipids and ICP-OES was used for elemental analysis. The theoretical part describes the history of chicken breeding, marking and distribution of eggs and composition of eggs based on various aspects. The main point was the separation of egg yolk and egg white and the subsequent description on the chemical and physiological level. Principle of used methods is also described. The experimental part deals with the preparation of samples, calibration samples and process analysis. All the results of analysed substances are summarized, statistically evaluated and compared with the other literature. For this analysis were used eleven different types of eggs from the Czech Republic from six different categories.
|
|
|
Possibility of utilization of solid waste from spent coffee grounds rafination for agricultural purposes
Slavíková, Zuzana ; Vespalcová, Milena (referee) ; Pořízka, Jaromír (advisor)
The main focus of this diploma thesis is the utilization of spent coffee ground (SCG) and its biorefinery products in agriculture primarly as a prospective organic fertilizer. The study verifies an influence of the addition of native SCG as well as its acid hydrolysed, defatted and oxidized forms to experimental clay soil on chemical and physical properties (ph, conductivity and mineral content). Growing experiments were realized by using Lactuca sativa to detect positive or negative effects on growth. Samples of basic soil and soil with the addition of commercial NPK fertilizer served as a reference to measuring data. Measurements showed that addition of SCG and products of its biorefinery to the soil caused a decrease of pH and an increase of conductivity of soil samples. Significant increase of extractable calcium, magnesium, manganese and moderate increase of potassium content was detected. 2 % addition of SCG to soil had no impact on plants growth. The number and visual appearance of lettuces were comparable with plants in basic soil. No seed on acid hydrolysed samples germinated, which was caused by an increase of conductivity and sulphate content in these samples. In defatted and oxidized samples the early germination and the highest number of lettuces was observed. The low content of phosphorus in all soil samples had a great impact on growth rate and visual appearance of cultivated lettuces. In comparison with soil with NPK addition, lettuces in samples with SCG and its form had a pink-grey colour and lower growth.
|
|
|
Application of analytical techniques and chemometry for authentification of wine
Pořízka, Jaromír ; Karovičová, Jolana (referee) ; Jarošová, Alžběta (referee) ; Diviš, Pavel (advisor)
This PhD. thesis is focused on application of different analytical techniques for determination of elemental composition of Moravian wine combined with analysis of selected polyphenol compounds. Two spectrometric techniques were used for elemental analysis of wine – Mass spectrometry and Optical emission spectrometry with inductively coupled plasma (ICP-MS and ICP-OES). Analysis of organic constituents of wine was evaluated by High performance liquid chromatograph with diode array detector (HPLC-DAD). Data from analysis of wine were used for construction of mathematical models for determining geographical origin of wine and for determining type of varietal wine. Data handling was performed by usage of multivariate statistical methods (cluster analysis, principal component analysis and canonical discriminant analysis). For the discrimination of wine by the geographical origin, two separate models for white and red wine were constructed. Effectiveness of discrimination of Moravian wine (with knowledge about origin) into 4 wine regions was 100 % successful for white wine and 96,43 % for red wine samples. Those models were used for cross validation test of unknown samples with result 95 % successfully classified samples of white wine and 82,15% of red wine. Besides that, mathematical model for discrimination and classification of varietal wine was made. Müller Thurgau, Riesling and Gruner Veltliner were discriminated by the usage of 8 elemental parameters. Discrimination success rate of known samples was evaluated by canonical discriminant analysis with 95,83% of correctly classified known samples and 70,83% of correctly classified unknown varietal wine (cross validation test). In addition to these part of research, impact of different grape production systems on elemental composition of wine and Vitis Vinifera was studied. The core of the study was to find the connections between the type of agriculture and chemical properties of wine and Vitis Vinifera. Two agriculture systems were assessed – Organic agriculture and Integrated pest management. . Results of this study showed that quantity and manner of pesticide application is very important factor affecting the final elemental composition of the grapevine and wine, especially the content of copper, zinc and manganese. That knowledge can be used in the future for creation of classification model of wine according to grape production system. For comparison of radical scavenging activity, electron paramagnetic resonance spectroscopy (EPR) with DPPH method was used. In the case of this study, the influence of vine growing under different farming systems on the total antioxidant activity of wine was found to be insignificant.
|
|
| |
|
|
Production and characterization of biochar from mixed plant waste
Bureš, Vojtěch ; Nábělek, Jakub (referee) ; Pořízka, Jaromír (advisor)
This work focused on biochar production from mixed vegetable waste in the context of home gardens and small farms. The aim of the work was to produce different types of biochar from common mixed garden waste material and then to characterize it according to the European Biochar Certificate (EBC) classification, as well as to develop a methodology for household biochar production, according to current knowledge. Four of the five biochar samples produced met all the criteria for the EBC-Feed category and are therefore suitable for any form of use, including animal feed production. The last sample did not meet the EBC parameters for usable biochar due to above-limit levels of polycyclic aromatic hydrocarbons (PAHs), but according to current studies and the new European Union limit values for fertilisers and amendments, the detected PAHs concentrations do not prevent its application to agricultural land. Therefore, based on the findings of this work, it is possible to recommend domestic production of biochar and its application to agricultural soils for long-term improvement of soil quality.
|
|
|
Monitoring of inorganic contaminants in moravian white wines
Šebek, Richard ; Slavíková, Zuzana (referee) ; Pořízka, Jaromír (advisor)
This bachelor thesis is focused on monitoring of selected inorganic contaminants, especially metallic elements and macro elements, in Moravian white wines. The aim of this thesis is to compare the element composition of wines according to the geographical origin, different production system and vine varieties. Two spectrometric techniques were used for elemental analysis of wine samples: Inductively coupled plasma with mass spectrometer and inductively coupled plasma with optical spectrometer (ICP–MS and ICP–OES). Evaluation of the results was carried out using statistical method of variance analysis (ANOVA). Vanadium, copper, lead and magnesium were evaluated as statistically significant in at least one Moravian sub-region. No statistically significant results were found in other comparisons.
|
|
|
Study of protein isolates digestibility
Čulíková, Andrea ; Juglová, Zuzana (referee) ; Pořízka, Jaromír (advisor)
Proteins are the structural components of all tissues of the human body. They are biopolymers that consist of amino acids. According to their origin, proteins are divided into plant and animal proteins. In the bachelor thesis, the properties of proteins isolated from wheat bran and commercial protein isolates from different plant and animal sources are discussed. Among the plant proteins, soy, almond, sunflower, chia and rice proteins were studied. Of the animal proteins, beef and whey proteins, among the most popular on the market, were studied. Specifically, the bachelor thesis deals with protein isolates, their composition, extraction methods by which protein isolates can be obtained from sources and subsequently their digestibility. The digestibility of protein isolates is one of the nutritional parameters that determines how well our body can utilize a given protein. In the experiments part, methods for the determination of protein content and digestibility in protein isolate samples were described. The Kjeldahl method was used to determine the protein content of the samples, and the results were then compared with the protein content indicated on the packaging. The enzymatic digestion process was simulated, the residue was subsequently lyophilized, and the digestibility of the protein isolate samples was studied gravimetrically. The results showed that whey protein was the best source of protein with respect to digestibility, with a PDCAAS value of 96.8% and a PDCAAS value of 0.94.
|
|
|
Bioflavouring of low alcoholic beer by dry hopping
Dušánek, Václav ; Mikulíková, Renata (referee) ; Pořízka, Jaromír (advisor)
This bachelor thesis deals with the influence of cold hopping of low-alcohol beers on analytical properties and sensory profile of beer. The effect of cold hopping was observed using the varieties Kazbek, Jazz, Mimosa and Uran. In the experimental part, the production process of low-alcohol beer using immobilized yeast is described. After the main fermentation, the low-alcohol beer was kegged into five cuvettes and after 20 days cold-hopped at a dose of 3 g/l with individual varieties. The effect of cold hopping with individual varieties on the organoleptic properties of the beer was observed. Bitterness was determined, with cold-hopped beers showing an increase between 17-24 % in bitterness. Furthermore, the ethanol content was determined by high-performance liquid chromatography at 2,14 % vol. A significant increase in all volatiles, in particular -myrcene and linalool, was found in the cold-hopped beers by gas chromatography with mass spectrometry. The sensory analysis showed that the cold hopping had a positive effect on the overall impression and masked the taste defects of the reference low-alcohol beer. The best hop evaluated for the use of the cold hopping method was the Kazbek variety. The Jazz and Mimosa varieties were also perceived relatively positively by the evaluators. On the other hand, the Uran variety achieved a worse overall impression than the reference beer.
|
guest ::
