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Preparation and characterization of packaging films based on beta-keratin
Měšťánková, Zuzana ; Mikulíková, Renata (referee) ; Kovalčík, Adriána (advisor)
This diploma thesis deals with keratin isolation from poultry feather waste and preparation of keratin-polymers composite films utilizing isolated keratin. The main goal was to isolate keratin from poultry feathers by hydrolysis and compare yield of diverse hydrolysis types. The most efficient was hydrolysis using 0.5% sodium hydroxide with yield 480 g of keratin per 1 kg of chicken feathers. Structure, morphology and thermal properties of isolated keratin was analyzed. Comparison with protein molecular weight standard it was revealed that hydrolysis cleaved keratin to macromolecules smaller than 15 kDa. Scan electron microscopy showed that size of lyophilized keratin particles was in the order tens of µm and had an irregular shape. Further, composite films based on isolated -keratin and other polymers were prepared. Thermal analysis showed, the addition of keratin significantly reduced the thermal stability of composite films. Analyses revealed that Polyvinyl alcohol composite films reached the best mechanical properties. For example, an addition of 0.25 g of keratin per 1 g of polyvinyl alcohol increased the tensile elongation by up to 68.9%. Moreover, the film based on chitosan and keratin had antibacterial properties. The results demonstrate that it is able to efficiently isolate keratin from poultry feather waste by alkaline hydrolysis and isolated keratin can be utilized to prepare potentially applicable keratin-polymers composite films.
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Pretreatment of polysaccharide waste materials to maximize of hydrolysis products
Myslivcová, Pavla ; Trachtová, Štěpánka (referee) ; Babák, Libor (advisor)
This thesis deals with study of the polysacharidic waste material pretreatment in order to maximize the hydrolysis products. It has been chosen a pastry as a waste material, specifically rolls and bread. Pastry was pretreated by milling and 15% w/v suspension of pastry in the water was prepared. Then several types of hydrolysis were performed with suspensions. Products of hydrolysis were characterized by spectrophotometric method of Somogyi-Nelson and efficiency of hydrolysis was compared. Three acids (H2SO4, HNO3, HCl) and two alkalis (NaOH, KOH) in three various concentration were used for the chemical hydrolysis. Microwave and ultrasound were chosen for the physical hydrolysis.
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Extraction of arabinoxylans from wheat bran
Koblasová, Dana ; Kouřilová, Xenie (referee) ; Diviš, Pavel (advisor)
This diploma thesis is focused on the use of wheat bran as a raw material for extraction of arabinoxylans. Wheat bran is a waste product of mill processing of wheat into flour and is mainly used as a livestock feed. However, the amount of bran produced significantly exceeds its consumption as feed, which opens up space for research into their further use. Polysaccharides such as cellulose, hemicelluloses and lignin are mainly present in the bran. The most common type of hemicelluloses are arabinoxylans, which form the main structural component of wheat bran. Alkaline extraction disrupts hydrogen and covalent bonds and releases polysaccharides of various molar weights from the crosslinked cell wall structure. Hydrolysis is required to obtain arabinose and xylose. Trifluoroacetic acid was chosen for the hydrolysis. The acid breaks down glycosidic bonds of the poly- and oligosaccharides to give the corresponding monosaccharides. The experiments made during this thesis have shown that the yield of multi stage extraction is twice as high as the yield of single stage extraction. Hydrolysis of the solid fractions after alkaline extraction revealed that a relatively large amount of arabinoxylans and other carbohydrates still remain bound in the complex matrix of the bran cell wall. Thus, alkaline extraction alone may not be the best option for obtaining arabinoxylans on a larger scale, or process optimization must be considered. Extraction with the addition of hydrogen peroxide appears to be effective for large-scale extraction processes.
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Application of Separation Techniques Connected with Mass Spectrometry for the Analysis of Environmentally Important Compounds
Mácová, Daniela ; Čelechovská, Olga (referee) ; Márová, Ivana (referee) ; Demnerová, Kateřina (referee) ; Čáslavský, Josef (advisor)
The identification of the hydrolysis and photodegradation products of flexible polyurethane foams (PUFs) with addition of biooriginated and biodegradable additive was the first topic of this dissertation work. Separation of polyurethane foam hydrolysis degradation products, designed for ecotoxicological tests, was managed by high-performance liquid chromatography coupled with mass spectrometry (HPLC/MS). The degradations product structure was elucidated by tandem mass spectrometry (MSn). PUF photodegradation products were obtained by exposure of materials by irradiation at 254 nm. Semi-volatile degradation products were isolated from the exposed polyurethane by n-hexane extraction; volatile compounds were collected by solid phase microextraction (SPME). Gas chromatography with mass spectrometry (GC/MS) and complete orthogonal tandem gas chromatography with mass spectrometry (GCxGC/TOF MS) was used for separation and identification of photodegradation products. The influence of the bio-filler on the character of degradation products and the possible effect of PUF degradation products on the environment was discussed at the end of this section. The determination of isoprostanes – markers of oxidative stress in tissues of beadlet anemone (Actinia equina) was the subject of the second topic. F2-isoprostanes were synthesized from the arachidonic acid. With thereby prepared isoprostanes the method of determination by liquid chromatography with tandem mass spectrometry (HPLC/MS/MS) was developed and optimized. The isoprostane isolation process from the Actinia equina tissues was optimized with solid phase extraction (SPE). The resulting methodology was used to quantify isoprostanes in tissues of anemones, which were exposed to both moderate and high temperature changes. The temperature changes were used to initiate the oxidative stress in organisms. In addition, concentration levels of unknown compounds were also monitored. These unknown compounds were extracted from tissues together with F2-isoprostanes and their identity is discussed in this dissertation work too. The possibility of using isoprostane levels in the Anthozoa tissues for the oxidative stress monitoring is discussed in the conclusion of this work.
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Isolation of pure aminoacids from wheat bran
Sloupová, Klára ; Diviš, Pavel (referee) ; Pořízka, Jaromír (advisor)
Wheat bran is a promising material containing a wide range of useful components, including proteins. In addition, it is produced in significant volumes. Currently, wheat bran is used for the production of energy by combustion and for feed purposes. Gradually, new methods of valorization of this material are being sought. One of the possibilities of using wheat bran is the isolation of proteins, hydrolysis, and separation of selected amino acids. This diploma thesis deals with this issue, it is focused on the recovery of arginine and leucine from a protein isolate. Proteins were extracted from wheat bran by changing the pH. Thanks to the subsequent lyophilization a protein isolate was gained. Prior to hydrolysis of the resulting isolate, a stability test of arginine and leucine amino acid standards was first performed, to which various hydrolysis methods were applied. Acid hydrolysis using a mineralizer, which was applied to the protein isolate, was proved to be the most effective. This was followed by the derivatization of the hydrolysates with OPA and analysis of the resulting hydrolysates by high-performance liquid chromatography with UV-VIS detection. Then, suitable adsorption and desorption conditions were optimized. It was found that the time dependence does not affect the amount of adsorbed material on the sorbent. Therefore, an application time of 15 minutes was chosen. While optimizing the amount of used standard, it was found that the optimal weight was 0.25 g of sorbent. The selected conditions were applied to the protein hydrolyzate. Two fractions were obtained by the separation of selected amino acids due to the change in the pH of the citrate buffer. After the application of this procedure, 0.26 g of arginine and 0.82 g of leucine were obtained from one kilogram after evaporation. From evaporation two, 1.01 g of arginine and 0.25 g of leucine were obtained after evaporation.
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A bioconversion study of cellulosic waste to ethanol using yeasts systems
Čalová, Iveta ; Vítová, Eva (referee) ; Babák, Libor (advisor)
This diploma thesis deals with the optimization of the production of ethanol from waste paper using yeast. There were used 4 kinds of paper as a substrate - office paper, non-recycled workbook, recycled workbook and newspaper. All papers were pretreated with the following procedures: grinding, microwaves + NaOH, microwave + H2SO4 and microwave + H2SO4 + NaOH. The glucose concentration was determined in enzymatic hydrolysis by HPLC. Saccharomyces cerevisiae were chosen for ethanol production. The production of ethanol was carried out with all the pretreated papers in simultaneous saccharification and fermentation. During hydrolysis, the pretreated papers have reached the highest results in the combination with microwave + H2SO4 + NaOH. Non-recycled workbook was the only exception, where the highest concentration of glucose has been obtained by the pretreatment of microwaves + H2SO4. Following results have been acquired: office paper 24,69 gdm-3, non-recycled workbook 22,47 gdm-3, recycled workbook 16,94 gdm-3 and newspapers 15,36 gdm-3. SSF was carried out again with all the papers and their pretreatments. The highest concentration of ethanol has been achieved in microwave pretreatment + H2SO4 + NaOH. The highest overall concentration has been gained from the office paper, amounted to 16,98 gdm-3. The maximum concentration of ethanol for non-recycled workbook has been 15,25 gdm-3, for recycled workbook 12,2 gdm-3 and for newspapers 12,59 gdm-3.
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UTILIZATION OF FOOD PROCESSING WASTE FOR LACTIC ACID AND ETHANOL PRODUCTION
Hudečková, Helena ; Kráčmar, Stanislav (referee) ; Buňka, František (referee) ; Márová, Ivana (advisor)
The doctoral thesis is focused on the microbial production of lactic acid and ethanol using food processing waste as substrate. Coffee processing waste (spent coffee grounds), wine production waste (grape pomace) and orange processing waste (orange peel) were chosen as substrates for experiments. The theoretical part is dedicated to summarizing current knowledge about waste from food production and possibilities of its processing. It also deals with selected metabolites (lactic acid, ethanol) to which these wastes can be used. Part of the experiments was focused on the characterization and optimization of hydrolysis to maximize the amount of fermentable saccharides. Different combinations of chemical, physical and enzymatic hydrolysis of selected substrates have been tested. Subsequently, a suitable strain for lactic acid and ethanol production was searched for. In the case of lactic acid production, 7 bacterial strains were selected (Lactobacillus casei CCM 4798, Bacillus coagulans CCM 2013, Bacillus coagulans CCM 2658, Lactobacillus rhamnosus CCM 1825T, Lactobacillus delbruckii subsp. bulgaricus CCM 7190, Lactobacillus plantarum CCM 7039T, Streptococcus thermophilus CCM 4757). These strains were first cultivated on the synthetic media containing different kind of saccharides. Afterward, the cultivation on the waste biomass hydrolysates were tested. In the case of ethanol production, 2 yeast strains kmeny (S. cerevisiae CNCTC 6646 a S. cerevisiae CNCTC 6651) were cultivated on hydrolysates of individual waste substrates. Subsequently, the experiments focused on the production of lactic acid and ethanol on hydrolysates of waste biomass in bioreactor were done. The last part of this doctoral thesis deals with the microaerobic pretreatment of lignocellulosic biomass to increase the production of organic acids during the acetogenic phase of anaerobic digestion.
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Optimization of bioethanol production by Zymomonas mobilis
Andrlová, Kateřina ; Vítová, Eva (referee) ; Babák, Libor (advisor)
Diploma thesis deals with use of Zymomonas mobilis for the production of bioethanol from waste paper. There were used three kinds of substrate (cardboard, drawing and office paper) to optimize of bioethanol production. Individual papers were subjected to the same pre treatment, namely a milling, a combination of microwave irradiation and NaOH, a combination of microwave irradiation and H2SO4 and combination microwave irradiation, H2SO4 and NaOH. The substrates were decomposed by enzymatic hydrolysis after pre treatment to evaluate the best pre-treatment. Simultaneous saccharification and fermentation was carried out for each substrate (with two of the best pre-treatment). The samples were taken during the hydrolysis and the simultaneous saccharification and fermentation, and were determined by HPLC. Growth curves of Zymomonas mobilis were constructed, as the most appropriate for SSF was chosen temperature of 40 ° C in which the exponential phase took place at the time of 6 15 hours. During hydrolysis was monitored glucose concentration in the solution. The maximum concentration of glucose was in the cardboard (microwaves + H2SO4 + NaOH) 16.46 gdm-3, a drawing (microwaves + H2SO4 + NaOH) 31.78 gdm-3, and office paper (microwaves + H2SO4) 25.04 gdm-3. The concentration of ethanol for SSF was highest in the same cases as in the hydrolysis. The cardboard was the maximum concentration of bio ethanol 9.5 gdm-3, for the drawing 16.1 gdm-3 and for the office paper 12.13 gdm-3.
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