čas: 23.4.2021 02:06:39
Obnovit | RAW
Department of Food Preservation
List of available PhD theses
Analysis of volatile profiles for assessing the quality and safety of processed foods
Gas chromatography with mass spectrometric detection in various configurations (one-dimensional, chiral, multidimensional, with olfactometry) will be used to analyse volatile profiles of various raw materials and processed foods. The aim of the thesis will be the evaluation of quality, detection of microbial contamination and identification of causes of sensory defects. The results of targeted and non-targeted analyses obtained by GC / MS will be correlated with the outputs of other laboratory methods (chromatographic, microbiological and sensory analysis). Advanced statistical methods will be used to interpret the results of analyses, considering the influence of raw materials, recipe, production and storage conditions. The project will be supported by National Agency for Agricultural Research and will be in cooperation with selected food producers.
Assessing of minor plant raw materials quality
Minor plant raw materials are often neglected, due to low production volume, and sufficient attention is not paid to their quality. The aim of this work is to assess the quality of selected minor raw materials of plant origin. The work will be also focused on development of new analytical methods for evaluating the quality of studied materials.
Food safety - contamination from food contact materials
The study will be focussed on identification a quantification of selected contaminants in food contact materials and on quantification of the level of their migration into food. The work will include the development of suitable analytical procedure for contaminant determination and safety assessment related to present contaminants.
Innovation of foods based on lactic acid fermented vegetables and fruits
Lactic acid fermented foods are known for centuries. Thanks to its long sustainability, increased nutritional value, required sensory properties and also unpretentious and cheap preparation have become very popular worldwide. This work is focused on the preparation of lactic acid fermented vegetable and fruit products and on the possibilities to enlarge the range of these products. Specifically, a fermentability of individual types of vegetables or fruits, including its mixtures, will be determined with respect to sensory properties of the final products. The effect of addition of probiotic and starter cultures will be estimated according to selected qualitative properties of the products. During fermentation processes characteristic changes will be monitored through the chemical, microbiological and sensory parameters.
Methods of effective assurance of health microbiological safety, technological harmlessness and the quality of non-alcoholic beverages
In the food industry, acetic acid bacteria belonging to the Acetobacteraceae family are both health and technologically undesirable bacteria that often contaminate non-alcoholic flavoured and unflavoured beverages on different bases. For contaminated drinks, the decrease in quality is due to the occurrence of serious sensory defects. As regards to human resources, the species Acetobacter cibinongensis, Asaia bogorensis, Asaia lannensis, Gluconobacter frauterii have the status of opportunistic pathogens causing serious nosocomial infections in immunocompromised persons. The doctoral thesis is focused on the detection, characterization and identification of acetic acid bacteria isolated from non-alcoholic beverages and the production environment using modern and classical microbiological methods. The aim of the work is to contribute to refinement of laboratory control of non-alcoholic beverages during elimination of undesirable bacteria affecting its health microbiological safety, quality and durability.
Optimizing the production of fermented foods
The project will focus on the development and optimization of the production of fermented foods (meat, fruit and vegetable products). The basic factors affecting the quality and safety of fermented products are: starter cultures, quality of used raw materials, microbial contamination of raw materials, recipe, technological processes, fermentation conditions, packaging and distribution conditions. As part of the project, new recipes will be developed and the production of processes will be optimized, including selection and dosing of suitable starter cultures, packaging and distribution of fermented meat, fruit and vegetable products. Within the project, individual technological processes will be optimised, both in a pilot plant environment and at individual food manufacturers.
The authenticity of honey and other bee products
Honey is widespread and the most important bee product. Due to the high price, its quality and authenticity are commonly violated. Frequently, it is the manufacturer's deliberate adulteration (addition of other ingredients to honey) or misleading indication of botanical or geographical origin. The project will be focused on verifying the authenticity of honey on its physicochemical parameters and chemometrics. The botanical origin of honey (floral, honeydew, unifloral) and its geographical origin will be also assessed based on these parameters. The evaluation of beeswax, which can be relatively easily adulterated with paraffins, stearic acid or palmitic acid, will be the second part of the project. This phenomenon can have a negative impact on the health of bee colonies and the chemical composition of honey. Experimental work will be done in cooperation with selected testing laboratories and will implement common and recent methods of food analysis (chromatography and isotopic methods, mass spectrometry, melissopalynology).
The effect of modern technologies on the quality traits of meat and meat products
The red meat industry has been identified the variability in eating quality as a significant disadvantage to consumer demand. A more consistent eating quality can be a key differentiation and demand driver for specific meat products in the market. Consumer expectations of product performance and reliability, particularly tenderness and colour, will continue to rise. Quality based differentiation can provide significant benefits to consumer satisfaction and capture unrealised value for the Czech industry. The utilisation of novel technologies is a promising area to deliver alternative methods to the industry and provide a competitive advantage in the area of value-addition. The development of novel tenderisation methods can boost the profitability of the meat industry. With this respect, the effect of pulsed electric fields (PEF), high pressure processing (HPP), shockwave (SW), ohmic heating (OH) technology on meat and meat products quality traits will be investigated.
The effect of thermal pasteurization and thermal sterilization on the microbial stability of canned products
Technological processes using the effects of thermal pasteurization and thermal sterilisation applied in the canning industry are not always sufficient, in particular, for elimination of some health and technological undesirable thermo-resistant microorganisms. Their resistance to high temperatures can be characterized as 'D' and 'z' values. In the past these inactivation parameters were detected in the foods model systems based on liquid cultivation media, but not in real solid foods, as it would be more appropriate. The doctoral thesis is focused on the determination of the heat characteristics ('D' and 'z' values) for selected microorganisms isolated from pasteurized or sterilized industrially produced canned products. Another area of interest is sublethal injury of microorganisms during thermal processes with subsequent reparation (or even resuscitation) ability of partly injured cells in the environments rich in proteins, magnesium and manganese ions, using modern and classical detection methods. The aim of the work is to submit an innovative complex of theoretical knowledge and experimental results for evaluation of microbial stability of heat-treated canned products during the protection of its health microbiological safety, technological harmlessness and standard quality.