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Food Chemistry and Technology
Doctoral Programme,
Faculty of Food and Biochemical Technology
--- Careers--- Programme Details
Ph.D. topics for study year 2025/26Analysis of volatile compounds for assessing the quality and safety of processed foods
AnnotationThe sensory quality of food is closely linked to the content, profile, and changes of sensory-active volatile compounds. This work will focus on the analysis of these compounds in food raw materials, flavourings, and processed foods. The first part will be dedicated to the selection and verification of suitable instrumental methods for the determination of volatile compounds, their precursors, and degradation products. Subsequently, the quality, safety, and origin of specific food matrices will be evaluated. Advanced statistical methods will be used to interpret the analysis results, taking into account the influence of raw materials, recipes, production technology, and storage. The project will be carried out in collaboration with selected food producers and supported by the National Agency for Agricultural Research. Chromatography of technical sugar solutions
AnnotationIn addition to white sugar, the modern sugar factory also produces other products such as bioethanol, biogas, green syrup or molasses, dried beet pulp and fertilizers. It uses a wide range of processes, from extraction, epuration, evaporation and raffination, to subsequent processes such as fermentation, distillation and separation using ion exchangers and molecular sieves. Chromatographic processes are used to soften, decolorize, desugarize or isolate various valuable substances such as betaine. This work will focus on the fractionation of byproducts in the sugar industry using various sorbents and the searching for optimal conditions of chromatographic separation for the recovery of sucrose, betaine, color substances, salts and other valuable components. Refining and concentration of oils high in eicosapentaenoic and docosahexaenoic acid
AnnotationEicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are important polyunsaturated fatty acids (PUFA) of the ω-3 series, which differ in the length of the hydrocarbon chain and the number of double bonds in the all-cis configuration. They are important precursors of eicosanoids (C20), docosanoids (C22) and also elovanoids (C26 – C40). This group of oxylipins affects platelet aggregation (thromboxanes), vasoconstriction and vasodilation (prostaglandins), pro-inflammatory effects (e.g. cysteinyl-LTE4), resolution of inflammation (resolvins, maresins and protectins) and others. The quality of commercial products with a high content of EPA and DHA varies, as they contain different contents of positional and geometric isomers of polyunsaturated fatty acids and also primary and secondary oxidation products of PUFA. The aim of the work will be the technological concentration of PUFA and laboratory or pilot-scale refining of oils with a high content of EPA and DHA. Furthermore, the quality of commercial dietary supplements with high EPA and DHA content will be investigated. Organic synthesis methods will enable the preparation of previously undescribed PUFA derivatives, including their oxidized forms and geometric or positional isomers. Separation and characterization of rye and wheat grain fractions with high content of arabinoxylans and their use in human nutrition
AnnotationArabinoxylans are natural components of some anatomical parts of rye and wheat grains and their concentration is therefore high in some fractions produced during milling. These substances show significant nutritional benefits as fibre components with prebiotic function. In both standard and non-traditional milling processes, fractions containing high concentrations of arabinoxylans can be separated either in the by-products of the surface treatment of the grain prior to milling itself (peeling, debranning) or in the bran particles gradually separated during the actual disintegration process. The aim of this work will be to identify the grain fractions with the highest proportion of arabinoxylans separated by different milling processes. Then, to propose and validate procedures for processing these fractions by hydrothermal treatment or fermentation. As a result of these procedures, sensorial attractive products with high bioavailability and polymeric and oligomeric arabinoxylans should be developed with potential for use as enhancers in the production of cereal-based foods or as nutraceutical ingredients. The effect of the interaction of plant and milk proteins on the properties of hybrid alternatives to dairy products.
AnnotationCurrently, the new trend in food consumption is to move away from animal products. However, plant-based alternatives to dairy products often have unsatisfactory nutritional and sensory properties. Therefore, for many consumers, so-called hybrid foods, which are made up of animal and plant components in an appropriate proportion with the aim of optimising the nutritional and sensory value of the product, may be more acceptable. In the work, the influence of interactions of plant and milk proteins on the technological properties of the mixed raw material, such as the emulsification properties, gel formation, and colloidal stability or texture of the hybrid product, will be monitored. The effect of modern technologies on the quality traits of meat and meat products
AnnotationThe dissertation will focus on the impact of modern physical technologies, such as pulsed electric field (PEF), ultrasound (US), high hydrostatic pressure (HPP), and cold plasma (CP), on the quality of meat and meat products. These innovative methods offer efficient alternatives to conventional processing techniques due to their potential to influence key meat properties, including texture, colour, technological characteristics, and chemical composition. The research will thoroughly examine the effects of selected technologies on the sensory and technological properties of meat, process optimization during drying, and the preservation of sensory and nutritional parameters. Additionally, it will address improvements in microbial and chemical stability, contributing to extended shelf life and safety of meat and meat products. The study's findings will provide new approaches to meat processing and the production of meat products, combining high quality with efficient and sustainable manufacturing practices. The application of these novel technologies presents a promising opportunity, offering alternative methods for the meat industry that can deliver a competitive edge in the development of new and innovative products. Exploring the structural diversity of selected natural polysaccharides
AnnotationThe dissertation thesis will focus on the isolation and characterization of polysaccharide fractions and pure polysaccharides and possibly other biologically active metabolites from natural sources using appropriate spectroscopic (FTIR, Raman, NMR), chromatographic (GC/FID, GC/MS, GPC/SEC, HPLC/ELSD) and other separation methods (e.g. IEC). For pure polysaccharide fractions, biological activities (e.g. anti-inflammatory, immunomodulatory, prebiotic, etc.) will be tested in collaboration with the Department of Biochemistry and Microbiology, University of Chemistry and Technology, Prague. Bioavailability testing of selected polysaccharide fractions will be an integral part of the dissertation. |
Updated: 25.3.2022 16:21, Author: Jan Kříž