čas: 23.4.2021 01:15:45
Obnovit | RAW
Department of Dairy, Fat and Cosmetics
List of available PhD theses
Acid whey and the possibility of its further processing
Acid whey is difficult treatable by-product of quark and some types of yogurt due to high content of salts and lactic acid. Electrodialysis in combination with other membrane and chromatographic processes is potentially applicable technology for valorisation of acid whey. The aim of thesis is to propose and to verify suitable configuration and conditions of acid whey processing. Application of electrodialysis with bipolar membranes is assumed too. Attention will be also focused on utilization of waste streams, from which could be isolated lactic acid or phosphates.
Application of membrane processes for modification of functional properties of whey proteins.
Modeling of rheological properties of dairy products.
Penetration of coumpands into skin depending on their structure
Components of cosmetic products penetrate to the different layers of skin. Depth of their penetration depends on their molecular weight and also on their polarity. Small and lipophilic molecules penetrate in deeper layers of the skin, while large and hydrophilic molecules remain in the surface layers of the skin. The aim of this thesis is determination of penetration depth of substances used in cosmetic products by two different methods – method of skin layer stripping and permeation method of using Franz cells.
Processing of human milk into nutrition products of infants with specific nutritional requirements.
Human milk is considered an ideal source of nutrition for infants. However, in certain cases, it appears that the composition needs to be adjusted for the best development of the infant, especially in the case of preterm infants. This usually involves increasing protein intake, adjusting the ratio of protein and energy, possibly also mineral substances.. Fortification with cow's milk products is possible, but breast milk fortification is better tolerated. Donated milk can be used to advantage for this fortification. The aim of this work is to design of human milk processing into a form suitable for fortification. The procedures used must be as gentle as possible in order to preserve the biologically active substances to the maximum, while ensuring the safety of the products. Human milk components that are not used for fortification, such as fat and oligosaccharides, are also valuable. Another goal of the work is therefore to suggest their use.
Properties of non- starter lactic acid bacteria
A wide consortium of microorganisms is used in the production and maturation of semi-hard and hard cheeses, the most important component of which are lactic acid bacteria (LAB). These are used both as starter and adjunct cultures and enter the process as so-called non-starter lactic acid bacteria (NSLAB), which mainly include facultatively heterofermentative lactobacilli and enterococci. The influence of these bacteria is strain specific and influenced by the technological context and interactions with other microorganisms present in cheese. From the NSLAB group, new strains with significant functional properties can be selected and their potential as adjunct cultures with a positive effect on the ripening of the given types of cheese can be used. On the other hand, they can cause defects in cheese (gas production, production of biogenic amines) or be a reservoir of transferable antibiotic (Atb) resistance genes. Monitoring the transmission of Atb resistance genes in the food chain is one of the current trends in food safety control. This issue is described in more detail in defined cultures of LAB or in probiotic strains, but little data is known about NSLAB resistance. The aim of the PhD thesis will be the isolation and characterization of NSLAB strains from raw milk, cheeses made from raw and pasteurized milk in terms of Atb resistance and other functional (technologically important, protective and probiotic) characteristics. The risk of NSLAB as a potential reservoir of Atb resistance genes will be assessed. Suitable strains of facultatively heterofermentative lactobacilli with comprehensively documented characteristics will be deposited in the Collection of Dairy Microorganisms Laktoflora and verified in experimental productions of semi-hard cheeses.
Systems of antioxidants for lipidic cosmetic formulations
In recent years the situation in cosmetic industry has changed. Synthetic emollients based on non-renewable raw materials and traditional synthetic preservatives and antioxidants are less used, therefore demands on the antioxidant system increase significantly. The aim of thesis is the proposal of antioxidant system for emollients based on renewable raw materials, determination of mutual effect of individual antioxidants and in optimal case the use of antioxidant synergism for lipid protection. Penetration of antioxidants to different skin layers in vitro is going to find out.