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Solubility control of biodegradable starch-based packaging
Krobot, Štěpán ; Ondreáš, František (referee) ; Lepcio, Petr (advisor)
This bachelor thesis deals with the preparation and testing of biodegradable films based on starch. The aim of the thesis is laboratory preparation of foils based on various types of starch, glycerol, polyvinylalcohol and with the addition of plasticizer – citric acid. Four different types of starch and two types of polyvinyl alcohol were used. In the first series of samples, the ratio of added glycerol to starch content was varied. Samples in the second series were prepared in the same ratios, but with different PVA. A citric acid solution was added into the last series of samples. The second aim of the thesis, after pressing the films, was to determine their solubility and stability in aqueous media depending on the ratio between added glycerol to starch content, the type of polyvinylalcohol used, and the addition of citric acid to the mixture. It has been found that citric acid appears to affect the chemical structure of the films and thus their solubility in aqueous media as well as their mechanical properties. Fourier-transform infrared spectroscopy (FTIR) was used to study the structure of the films and to elucidate its effect on solubility.
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Plants polysaccharides and their importance in food production
Klanicová, Barbora ; Illková, Kateřina (referee) ; Omelková, Jiřina (advisor)
Some findings about plant polysaccharides, their characteristics and structures, modifications, changes, their biosynthases, isolationes and primarily their importance in food-stuff industry are the subject matter of this review. Because of their modifications and because of the significant role they play in food-processing industry it is focused on starch and cellulose. For better understanding of whole meaning it was necessary to attend to the theme from the initiation – mainly the cell structure and then syntheses, especially photosynthesis, ways that are monosaccharides and polysaccharides generated.
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Processing optimalization of biodegradable starch based packaging and its characterization for adaptation on production technology
Krahulová, Veronika ; Ondreáš, František (referee) ; Lepcio, Petr (advisor)
This diploma thesis focuses on the problematics of preparation of biodegradable starch based packaging. The aim of the thesis is to optimize the preparation and verify the characteristics for further adaptation and production technologies. The films consisted of starch, PVA and glycerol. Four types of starches, three types of PVA and different ratios of glycerol were tested. Films were prepared by casting with glycerol as a plasticizer, instead of distilled water, to reduce the energy cost of the preparation. The mechanical properties of the films were tested as well. The experimentally determined values of elongation at break and tensile strength of the wheat starch films were compared with a semiempirical model. Results revealed that the preparation of thermoplasticization of starch with glycerol leads to a considerable increase in elongation at break but at the same time to a marked decrease in tensile strength compared to the preparation from solution. The rheological properties of the prepared films were also investigated. Infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were used to study the structure of the films.
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Stanovení želatinizace škrobu zrna ječmene pomocí přístroje Rapid Visco Analyzer
Cetkovský, Tomáš
The gelatinisation temperature is one of the important parameters in the evaluation of barley quality. During gelatinisation, the viscosity of the mixture of starchy substance and solvent is being changed by temperature. The aim of this study was to measure the viscosity in the process of starch gelatinization of barley grain using Rapid Visco Analyzer (RVA). A total of 36 barley varieties were evaluated by RVA. Barley samples were analysed in the RVA, and 13minute and 15minute measurement methods were used to evaluate starch gelatinisation. The results were statistically evaluated and compared. The results of the measurements showed the validity of both methods, confirming their applicability in the malting and brewing industry. The maximum expanded measurement uncertainty for the parameters studied ranged from 1 to 16%. The parameters studied were 61.8–84.8% influenced by method and 2.6–30.6% influenced by variety, according to the analysis of variance and variance component estimation of RVA parameters. Gelatinization temperature was 84,8 % influenced by method and only 2.6% by variety. The gelatinisation temperature of the varieties was different depending on the type of method used. The RVA13 values averaged at 87.3 °C and in average were always 5.8 °C higher than those measured by RVA15. The average gelatinisation temperature measured by RVA13 was 81.5 °C.
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Determination of nutritional values and antioxidant capacity of different edible roots
Ciffrová, Karolína ; Bendová, Agáta (referee) ; Němcová, Andrea (advisor)
This bachelor thesis deals with selected edible roots, their nutritional composition, antioxidant capacity and use in healthy eating. Eight selected edible roots were analyzed: type A, B and C potatoes, red potatoes, sweet potatoes, and purple potatoes were selected as representatives of potatoes. Jerusalem artichoke and cassava represent the other two root crops. The theoretical section of the thesis describes the basic characteristics of root crops, as well as the description and composition of the nutritional substances they contain, i.e. proteins, carbohydrates, fats, vitamins and antioxidant properties. The general characteristics of the methods used for analysis are also described here. The experimental part is based on specific analyses, procedures, results, chemicals and laboratory equipment used to determine the basic nutritional values and antioxidant capacity of these selected root vegetables. First, the total dry matter content was established to be about 23 % in the selected root crops. Higher dry matter content was determined for the cassava at 35 %. Crude protein content determined by the Kjeldahl method ranges from 6.5-9.9 %. The gravimetrically determined fiber in the given root crops was in the range of 0.27–0.91 %. The starch content is significantly higher in the cassava (46 %) than in other root crops. The inulin content was determined in sweet potatoes and Jerusalem artichokes instead of starch content; this value is significant for the Jerusalem artichoke (258.58 g/kg). Fat content in grams per 100 grams of dry matter was determined by Soxhlet extraction. Significant fat content was determined for sweet potatoes (12.6 g/100 g). From the extracted fats, the fatty acid profile was determined for individual root vegetables, such as the content of saturated (SFA), monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA). Total and reducing carbohydrates, determined by the spectrophotometric method, were measured separately in the peel and pulp of the root crops. Antioxidant capacity was determined using antioxidant activity values, polyphenol and flavonoid concentrations. Of the vitamins, vitamin C was determined, vitamin E only in type B, C and purple potatoes. For sweet potatoes, beta-carotene was determined to be 540.56 g/g. The measured and calculated results are plotted in graphs. Finally, there is a discussion of the conclusions of the individual methods.
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The importance of variety in yield of table potatoes (\kur{Solanum tuberosum} L.)
ŠPLÍCHAL, Jonáš
In the theoretical part of the bachelor thesis, attention was paid to the description of the tuber potato, morphological characteristics of the potato, and the division of varieties according to the length of the growing season and according to the cooking type. In the following chapters, the growing principles and conditions of potato pro-duction, the content substances in potato tubers and the possibilities of their influ-ence by cultivation technology and breeding were defined. Equally important is the chapter devoted to the varietal variation of production and content parameters of potato tubers since the practical part of the bachelor thesis was devoted to this to-pic. For this purpose, a small-plot experiment was set up at the Lukavec site (620 m above sea level) with potato varieties Adéla, Antonia, and Rosara, and the yield parameters (total yield, proportion of tubers over 35 mm) and selected content cha-racteristics (starch and dry matter content) were monitored. The Rosara variety had the highest starch and dry matter content.
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Response of potatoes to split application of nitrogen and plant auxiliaries
MICHALÍČEK, David
The aim of the diploma thesis wasto evaluate the yield of tubers and the share of starch in tubers in potato varieties with different growing seasons and to point out or refute the need for nitrogen during cultivation. Next, to focus on the effect of nitrogen fertilization on dry matter and starch content. It was a small plot experiment, which was based on the Valečov experimental station. Two varieties were selected for the experiment, the early and the semi-early ones. The first variant is a plant not fertilized with nitrogen. The other variant was fertilized before planting. In another variant, a split application of nitrogen was performed, and in the fourth variant, an auxiliary plant preparation was applied, supporting stolon growth and root formation. The experiment further records treatment and conditions during the growing season. Individual differences between the varieties were also recorded during the experiment. For variants 2 and 3, the effect of fertilization on the yield of potato tubers in both varieties was demonstrated. The yield also increased significantly in the variant with the use of an auxiliary preparation. The semi-early variety Antonia reacted best to the auxiliary herbal preparation and the early variety Colomba achieved the highest yield in the variant with foliar application of urea. Antonia recorded a yield of 58.4 t/ha for the control variant, 64.3 t/ha for the second variant and 66.9 t/ha for the third fertilizer before planting. The variant with an auxiliary product then recorded a yield of 68.53 t/ha, which was a higher yield compared to the control variant by 10.1 t/ha. For the very early Colomba variety, the yields for the variant without fertilization were 66.14 t/ha, variant No. 2 then 83.18 t/ha, the variant with fertilization before planting recorded a yield of 79.26 t/ha and the variant with auxiliary product 78.85 t/ha. The differences between the fertilized variants during the growing season were 4.23 t/ha for the Antonia variety in favor of the auxiliary plant preparation. For the Colomba variety, the difference was 4.33 t/ha in favor of the urea variant. At the same time, the size ratio of the tubers also changed. In the case of the Antonia variety, there was a decrease in starch content in the fertilized variants, but in the case of the Colomba variety, the decrease was not confirmed in all variants.
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Coordination of growth and cell cycle progression in green algae
IVANOV, Ivan
Within the past century microalgae have gained importance both as model organisms in cell cycle research and as a biotechnological platform for the production of a variety of economically important compounds. This thesis examines the coordination of growth and cell cycle progression in green algae and attempts to explore the biotechnological relevance of some of the findings. Furthermore, the applicability of confocal Raman microscopy for both quantitative and qualitative analysis of storage biomolecules during the course of the cell cycle of Desmodesmus quadricauda is also investigated. Temperature and light shift experiments showed that there is no direct correlation between growth and cell cycle progression in D. quadricauda. Further analysis revealed that supraoptimal temperature has a profound effect on the cell cycle of Chlamydomonas reinhardtii causing a block in cell division, increase of cell size and over accumulation of starch. Starch production through supraoptimal temperature was successfully demonstrated in pilot scale experiments, however it was estimated that light availability within the culture poses a major limiting factor. Confocal Raman microscopy was successfully applied for the quantitative and qualitative analysis of storage biomolecules including starch, lipids, polyphosphates and guanine.
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Utilization of waste banana peels for packaging materials
Vachta, Jonáš ; Mikulíková, Renata (referee) ; Kovalčík, Adriána (advisor)
This bachelor thesis deals with isolation of cellulose from waste banana peels and it’s use as a filler in composite films. The aim of this work was to prepare a bioplastic capable of being an eco-friendly alternative to conventional polymers with a potential for application in the packaging industry. The cellulose was isolated from banana peels using a method combination of alkalic and acidic hydrolysis and bleaching by sodium chlorite. The samples after isolation were characterised by Fourier transform infrared spectroscopy (FT-IR) and their average particle size was determined by microscope observation. Subsequently, composite films were prepared using agar and starch matrix, glycerol as plasticizer and isolated cellulose as filler in various concentrations to assess the effect of added cellulose on the properties of the resulting bioplastics. Characterization of the prepared bioplastics included FT-IR measurement, surface examination by a scanning electron microscope (SEM) and the determination of mechanical properties by measuring tensile strength, elongation at break and Young’s modulus. It was found that the addition of cellulose from banana peels has a positive effect on the mechanical properties of all prepared agar- or strach-based composites, with the exception of elongation at break in agar films, where there was a slight decrease compared to the reference films.
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Preparation of polysaccharidic binders used in artworks
Švajcrová, Lenka ; Hrdličková Kučková, Štěpánka (advisor) ; Čapek Adamec, Martin (referee)
The main aim of this bachelor thesis was to prepare polysaccharide binders from the chosen kinds of starch (gained from potatoes, corn, wheat, rice and kuzu), Arabic gum and to pigment them. The created samples of the polysaccharide binders were then prepared for further investigation using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) and Fourier transform infrared spectroscopy (FT-IR). This work is also focused on the history of the production of starch, its origin, contained substances and growing of the specific plants, from which the starch is obtained from. Furthermore, there is also described the technology process of paintings and other polychromatic arts creation. The technical character of paintings is actually determined by the binders, thus apart from the polysaccharide binders there are also described oil, protein and oil-resin binders. Key words: polysaccharidic binders, starch, Arabic gum, artworks
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