Department of Dairy, Fat and Cosmetics

Granting Departments:	Department of Dairy, Fat and Cosmetics
Study Programme/Specialization:	Food Chemistry and Technology ( in English language )
Supervisor:	doc. Ing. Šárka Horáčková, CSc.

Annotation

In the production and cheese ripening, a wide consortium of microorganisms is used, the most important of which are lactic acid bacteria (LAB). These are used both as starter and adjunct cultures and, on the other hand, they 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 depended on technological process 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 functional (technologically important, protective and probiotic) characteristics, Atb resistance and other. The risk of NSLAB as a potential reservoir of Atb resistance genes will be assessed. Suitable strains of LAB with documented properties will be deposited in the Czech Collection of Dairy Microorganisms Laktoflora and their activity will be verified in experimental cheese productions.

Granting Departments:	Department of Dairy, Fat and Cosmetics
Study Programme/Specialization:	Food Chemistry and Technology ( in English language )
Supervisor:	doc. Ing. Jiří Štětina, CSc.

Annotation

Currently, 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 findings will be used to design a technology for a hybrid cheese alternative.