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Optimization of the production of yogurt with increased protein content from wheat bran
Adamczyková, Michaela ; Vítová, Eva (referee) ; Pořízka, Jaromír (advisor)
This thesis deals with the use of wheat bran in the form of protein isolate as an additive in the food industry, optimalization of the formula of fortified yoghurts and the encapsulation of plant proteins, used as a method to mask the negative sensory properties of products with the addition of these proteins. The theoretical part deals with the characterization of fermented milk products, wheat bran as a source of protein and the possibilities of masking the negative sensory properties of protein isolates. The produced yoghurts were sensory evaluated and their nutritional and technological properties were analyzed in the experimental part. By sensory analysis of yoghurts made from different types of milk, full-fat UHT milk was determined to be the best for the production of fortified yoghurts. Yoghurts prepared from this milk were fortified with wheat bran protein isolate. The products thus had an increased nutritional value, but their sensory values deteriorated. The yoghurts had a gritty feel, which was subsequently mitigated by grinding the protein isolate to finer parts. The formula for the production of fortified yoghurts was optimized by the addition of alternative protein, which had a positive effect especially for yoghurts with a 10% protein content. Yoghurts with protein isolate were evaluated with a negative score for the bitter taste parameter. Encapsulation of proteins significantly reduced the intensity of the bitter taste. Synergy of all prepared samples was determined by filtration. Yoghurt from full-fat UHT milk showed a syneresis of 31.76 ml per 100 g of yoghurt. The addition of protein led to a change in the synergy of this yoghurt. From the rheological analysis, it was determined that 10% yoghurt with encapsulated particles had a higher value of dynamic viscosity and yield stress. Sensory analysis data were evaluated using principal component analysis.
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Use of wheat bran for fertilizer production
Maňáková, Helena ; Štursa,, Václav (referee) ; Diviš, Pavel (advisor)
This diploma thesis deals with the production of fertilizer from wheat bran and spent coffee grounds, which are produced in large quantities in the food industry. The efficiency of the removal of caffeine and phenolic substances from coffee grounds using the oxidation reason and the possibility of recycling the usable oxidizing effect were tested. We managed to oxidize almost all phenolic substances and a significant amount of caffeine from coffee grounds, even through the recycled oxidizing effect. Fertilizer in the form of pellets was subsequently formed from coffee grounds and bran. During pelleting, the optimal degree of wetting of the material was studied to achieve optimal yield of pellets and sufficiently strong pellets. Different ratios of substrates for pelletization were also studied and the quality of produced pellets was assessed. The content of macro and microelements in the prepared pellets was determined. Pellets have been shown to be a good source of elements important for plant growth.
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Biotechnological production of polyhydroxyalkanoates on wheat bran
Guziurová, Pavlína ; Pernicová, Iva (referee) ; Obruča, Stanislav (advisor)
The bachelor thesis deals with the biotechnological production of polyhydroxyalkanoates (PHA) from lignocellulosic waste – wheat bran. The aim was to determine whether the hydrolysate from wheat bran subjected to different types of pretreatment could be used as a substrate for the production of PHA using selected bacterial strains. The selected strains were Halomonas organivorans, Halomonas halophila and two strains of Schlegelella thermodepolymerans. Halophilic strains were proved as the best producers and were subsequently used for cultivations. The hydrolysates after neutral pretreatment were utilized by the bacteria most efficiently, due to the lowest content of microbial inhibitors (phenolic substances) where the bacteria produced the most PHA. The highest value of produced PHA was determined on the hydrolysate after neutral pretreatment by using the strain Halomonas organivorans, namely 2,82 g/l. The hydrolysate was also used for the production of lactic acid bacterial strains of Lactobacillus. The highest achieved concentration of produced lactic acid was 16,73 g/l by the Lactobacillus casei strain.
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Measurement of viscosity of suspensions during wheat bran processing
Koukal, Jan ; Slavíková, Zuzana (referee) ; Pořízka, Jaromír (advisor)
This bachelor thesis deals with the assessment of the viscosity evolution of wheat bran suspension during alkaline hydrolysis. Wheat bran is a widely produced low-cost by-product of the milling industry. Due to its composition, bran is a suitable substrate for biorefining and involvement in the circular economy. However, during processing, viscosity development occurs, which greatly affects the energy requirements for processing. The temporal evolution of viscosity during alkaline hydrolysis was determined using a rotational rheometer at constant shear rate. Viscosity was assessed as a function of NaOH concentration, temperature and bran ration. Furthermore, the evolution of viscosity was measured during alkaline extraction of proteins. The highest viscosity was measured in a 0.2 M NaOH system at 30 °C with a bran to hydroxide ratio of 1:10. Its value was 0.991 ± 0.010 Pa.s. Based on the theoretical part and the data obtained from rheological measurements, the design of a stirred reactor for wheat bran processing on an industrial scale was carried out. It is a vertical cylindrical vessel with a total volume of 10 m3. The vessel is equipped with three Chemineer HE-3 hydrofoil impellers mounted on a vertical shaft. The power input of the agitator was calculated at 2.8 kW and compared to a conventional 4-blade, 45-degree pitched blade turbine, the chosen design was four times more efficient.
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Study of the effect of fertilizer containing wheat bran on lettuce growth
Smrčková, Kamila ; Pořízka, Jaromír (referee) ; Diviš, Pavel (advisor)
The aim of the work was to perform growth experiments on a laboratory scale with soil, which was enriched with 2,5 vol. % of wheat bran/coffee grounds/biochar and to study soil and growth characteristics on Lactuca sativa L. The coffee grounds were added raw or modified by oxidation/extraction. Phytotoxic properties of coffee grounds were confirmed by germination tests, although there was an effort to reduce the content of phenolic substances by oxidation /extraction. Soil additives caused an increase in content of organic matter, water capacity, pH and conductivity of all mixtures compared to the control soil. Elemental analysis of soils before cultivation did not show any positive effect on the content of mineral elements compared to the control soil. On the other hand, higher mineral (P, Mg, Ca, K, Mn, Fe, Cu and Al) content compared to soil was recorded cultivation experiments. Chlorophyll a was the most abundant in cultivated plants and reached the lowest concentration in plants grown in a mixture with EXKS. Salads differed in mineral content, too. Salads with the highest content of phosphorus were growed on the mixture BU+OT+PŮDA. On the contrary, content of potassium is salads was negatively affected by mixture with EXKS. Microelements (Fe, Zn, Al, Cu, Cr and Mn) were most affected in the salad by the addition of raw coffee grounds and OXKS2.
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Activation of biochar from wheat bran
Sauchanka, Katsiaryna ; Kalina, Michal (referee) ; Pořízka, Jaromír (advisor)
This graduation work is devoted to the issue of biochar production from wheat bran and ways of its surface activation. The theoretical part summarizes information about biochar, its physico-chemical properties, production methods and surface modification options. It also contains description of EBC certificate, that sets requirements for biochar which is placed on the market. The practical part of the work focuses on activating of the biochar surface and comparing the results with the available literature and European biochar certificate.
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Fortification of bakery products with protein isolate from wheat bran
Bidmonová, Karolína ; Vítová, Eva (referee) ; Pořízka, Jaromír (advisor)
Proteins, as the major structural component of all cells and tissues, along with fats and carbohydrates, are a key macronutrient in human nutrition. An insufficient protein intake in the diet can lead to health problems and increasing protein malnutrition. Food fortification plays an important role in eliminating this protein deficiency. Wheat products, as a widely consumed food, seem to be a suitable commodity for protein fortification. Wheat bran was selected as a suitable source of protein due to its availability, protein content and relative simply method of a protein isolation. In the experimental part, the protein was extracted from wheat bran and used to prepare the mixtures. The mixture contained T530 flour and the 5%, 10% and 15% addition of the wheat bran protein isolate. From these mixtures, doughs were prepared and were subjected to chemical and rheological analysis. Finally, wheat baguettes with the addition of wheat bran protein isolate were made. The texture and taste properties of the baked products were verified by sensory analysis. The mixtures of flour and whey protein and a sample of unriched flour were also analysed to compare the results. Applied tests have shown that the addition of protein influences not only nutritional and chemical but also rheological properties. The addition of wheat bran protein isolate had a negative impact on the taste properties of the baguette Higher addition of BPI caused the increase of the bitterness of products. Taste optimization could be a topic for future study.
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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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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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Preparation and characterization of protein concentrates from wheat bran
Hubačová, Klára ; Diviš, Pavel (referee) ; Pořízka, Jaromír (advisor)
The diploma thesis deals with usage of wheat bran as a source of high-quality proteins. Every year mill industry produces large amounts of by-products. These by-products are constituted by wheat bran. There is a big effort to use these type of materials within a circular economy. Wheat bran contains about 14–18 % proteins which appears to be a good component for valorisation. It is possible to extract proteins from bran according to their behaviour in the range of pH. Proteins are soluble in alkaline pH and can be precipitated around their isoelectric point. The final treatment of precipitated proteins is lyophilisation. The next step is characterisation of the product. There are a few parameters to analyse: purity of the isolate, amino acid profile, composition of minerals, water contain etc. Interest in nutrition is on the rise not only by professional sportsman. This isolated product could serve as a potential protein supplement.
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