čas: 23.4.2021 00:06:58
Obnovit | RAW
Department of Carbohydrates and Cereals
List of available PhD theses
Biologically active wound dressings based on natural and modified polysaccharides
This dissertation is focused on the preparation of bioactive wound dressings based on de novo isolated and/or chemically modified polysaccharides. These polysaccharide materials will be enriched with selected biologically active compounds. The wound dressings experiments will be planned in order to obtain the most comprehensive information of their physicochemical, thermal and mechanical properties and biological activities, which will be tested in collaboration with will be tested in cooperation with the Department of Biochemistry and Microbiology at University of Chemistry and Technology Prague.
Characterization of natural raw materials and products by vibrational spectroscopic methods
Vibration spectroscopic methods in combination with multivariate analysis will be used to characterize sets of model samples of raw materials of various origins, foodstuff, their chemical components (polysaccharides) or other products. The aim of the work will be to develop a procedure for sorting and evaluating the composition and quality of food raw materials and products using these methods including preparative approaches and sample preparations. The conclusions of vibrational spectroscopy will be substantiated and compared with the results obtained by common analytical methods.
Chemical and biochemical transformation of sucrose for production of other sugars and sugar alcohols
Sucrose is a very good raw material for chemical and biochemical reactions. The sugar industry produces it in large quantities in a crystalline form of high purity, its production is stable and traditional, long-term storage and thus becomes a relatively cheap and well-defined reactant or substrate for further transformations. The work will be focused on the search for catalysed chemical, enzymatic or biological transformations of sucrose to common (glucose, fructose) or rare saccharides (psicose, tagatose, allosa, altrose, etc.) and sugar alcohols (mannitol, xylitol, erythritol, etc.). Various inorganic catalysts, enzyme groups, and microorganism strains will be used for the transformation to achieve high yield and concentration in the reaction mixture. The product will be isolated by membrane and chromatographic techniques and by crystallization.
Control of membrane filtration process with backwash
Tangential flow membrane filtration is used as a separation method in all kind of industries. This is a process in which the membrane forms a selective barrier and the inlet is continuously fed along the membrane. Unlike conventional filtration, there is no formation of filtration cake and filtration can take place for a long time; pressure is most often the driving force. The whole system is then composed of membrane modules, pressure gradient pumps and control valves to ensure the desired direction of the filtered medium. The work is focused on the filtration of food products with the aim to isolate, separate or thicken the selected component from the feed mixture, using the measured data to build a filtration model and use it in the design and implementation of a higher management system. The measurement will be carried out on the existing double-pump filtration unit TIA with ceramic membrane modules and backwash unit. The station is also equipped with pressure, temperature, flow and primary pressure control via flap valves via the Siemens S1200 programmable logic controller.
Development of gluten-free sourdoughs and optimization of their physicochemical and nutritional parameters
Recently, there has been an increase in the population's interest in gluten-free products of all kinds, especially bread and other bakery products. Gluten-free products are required not only by groups of people suffering from celiac disease or other forms of gluten intolerance, but also by many other takers who are not diagnosed with intolerance. At the same time, there is a growing interest in bakery products containing various types of vital sourdoughs. The aim of this work will be testing and optimization of technological procedures used in the preparation of sourdoughs from gluten-free cereals and pseudocereals (sorghum, rice and buckwheat). In particular, procedures for activation of fermentation processes from available commercial starter cultures and also spontaneously started based on natural flour microflora will be examined. Furthermore intrinsic fermentation conditions (temperature, time, consistence). The procedures will be optimized on the basis of selected physicochemical characteristics of the resulting sourdoughs (especially pH and titratable acidity, content and mutual ratios of organic acids, profiles of volatile compounds), selected nutritional characteristics and further on the sensory properties of the sourdoughs and experimental bakery products prepared using them.
Effect of thermal processes on fiber composition and nutritional value of biscuits
Fiber content is one of the important qualities of cereals. The presence of dietary fiber in the diet stimulates intestinal peristalsis, reduces the absorption of lipids, cholesterol and sugars. Technological food processing influences the content, bioavailability, nutritional quality and physicochemical properties of the dietary fiber. On the contrary, the addition of dietary fiber influences the technology and consequently the sensory quality of the food product. The role of dietary fiber is to contribute to a general microstructure of fiber-enriched foods. The thesis will focus on evaluation of influence of thermal processes used in the secondary processing of cereals on dietary fiber, and the bioactive substances accompanying fiber in the outer layers of grains. The theoretical part will devote to the definition, methods of determining and the health effects of dietary fiber and a description of technological operations, mainly thermal processes used in the production of biscuits and breakfast cereal products, which will be devoted to the experimental part of the work. Besides the traditional materials used in bakery technology also new specially milled flours and flours from unconventional sources as barley or buckwheat will test.
Microalgae polysaccharides: isolation, structure and biological activities
The microalgae cultivation creates biomass, which is a potential source of biologically active compounds such as structural polysaccharides, proteins, polyphenols, carotenoids, etc. This dissertation will be focused on isolation and structural characterization of polysaccharides and biologically active metabolites of microalgae by spectroscopic, chromatographic and separation methods. Antioxidant, antitumor, immunomodulatory activities of selected compounds will be tested in cooperation with the Department of Biochemistry and Microbiology at University of Chemistry and Technology Prague.
Physico-chemical properties and biological activities of chocolate and confectionery with a fortified formulation
The effect of value-added materials on the physico-chemical properties and biological activity will be monitored on model samples of chocolate and selected confectionery. Wood-decay mushrooms and medicinal herbs or their extracts will be used to fortify chocolate and selected confectionery. The aim of the work will be to verify, in particular, the extent to which the technological behavior of fortified materials changes using rheology, differential scanning calorimetry and X-ray diffraction. At the same time, the biological activities of fortified products will be monitored using adequate approaches.
Polysaccharides of wood decay mushrooms: isolation, structure and biological activities
The wood decay fungi are potential sources of biologically active compounds such as secondary metabolites: proteins, structural polysaccharides, terpenoids, polyphenols, etc. This dissertation will be focused on isolation and structural characterization of biologically active metabolites by spectroscopic, chromatographic and separation methods. Antioxidant, antitumor, immunomodulatory activities of selected compounds will be tested in cooperation with the Department of Biochemistry and Microbiology at University of Chemistry and Technology Prague.
Process modeling of sugarhouse with bioethanol and biogas production
The operation of the modern sugar factory is based on the production of white sugar and of other products such as bioethanol, biogas, green syrup or molasses, dried beet pulp and fertilizers. It is a combination of classical sugar production starting with extraction, epuration, evaporation and refinery, as well as related processes such as fermentation, distillation or separation using ion exchangers and molecular sieves. All these processes are interconnected into a global process unit aimed at minimizing the consumption of energy, fuels and solvents. The work will be focused on creating a modular process diagram describing the entire sugar production with related processes. The aim is to create a static or dynamic model based on mass and energy balances using existing software environment (AspenTech, Sugars, Matlab) or own developed computing environment.
Starch nanoparticles – preparation and uses
Starch-based nanoparticles, which are extensively investigated nowadays, may be used as fillers and reinforcing agents in polymer composites, carriers for drug delivery, barrier coating materials, and stabilizers in oil-in-water emulsions. The addition of starch nanocrystals from different botanical origin to biodegradable films of waxy starch has improved barrier and mechanical properties of the resulting materials. The thesis is focused on the preparation of starch nanoparticles and their potential applications.