Use of some microbial oils in foods and cosmetics

This bachelor thesis focuses on preparation of microbial oils from oleaginous yeasts and the subsequent characterization of their properties and biological effects on organisms. The thesis is divided into two main parts, theoretical and experimental part. The theoretical part provides an overview of information about microbial oils and the possibilities of their current or future applications in food and cosmetic industry. It also describes other lipophilic metabolites synthesized by carotenogenic yeasts and briefly characterizes the carotenogenic yeast strains as well as analytical methods used in the experimental part. Experimental part was focused on the process of optimization of the extraction of lipophilic active compounds from yeast biomass. The best option proved to be the combination of three solvents such as dimethyl sulfoxide, hexane, and ethanol. Using this approach, the extracts were prepared from Rhodotorula kratochvilovae, Rhodotorula mucilaginosa, Rhodosporidium toruloides, Cystofilobasidium macerans and Sporobolomyces pararoseus biomass. All of the prepared extracts were characterised based on the content of lipophilic metabolites by UV-VIS spectrophotometry and by analysis on HPLC/PDA and GC/FID. Furthermore, the antioxidant activity, SPF, antimicrobial effect, and short-term stability of these extracts were determined. The best temperature to preserve these extracts proved to be 7 °C. Three extracts with the highest SPF values were chosen and added to the prepared cosmetic emulsion which was characterized and the sensory analysis was carried out. The MTT cytotoxicity assay on human HaCaT keratinocytes was realized for the three extracts that were added to the prepared cosmetic product as well as for their combination