###### Abstract
The fatty acid profile has an impact on the nutritional quality of milk and dairy products. In order to assess the nutritional value of a diet and determine whether it has a positive effect on consumer health, the proportions of individual fatty acids are broadly examined, including desirable fatty acids (DFA), hypocholesterolemomic/hypercholesterolemomic index (H/H), atherogenicity index (AI) and thrombogenicity index (TI), and (n \(-\) 6)/(n \(-\) 3) ratio. The contents of all the previously mentioned milk constituents, such as fatty acids and minerals, may differ from their contents in dairy products. Research results indicate that these differences may be due to various factors used in the technological process, such as heat treatment, homogenization or pasteurization, standardization [26; 27; 28; 29; 30], fermentation, starter culture type, fermentation time, and storage time and conditions [31; 32; 33; 34; 35; 36]. High nutritional value of yogurts and other fermented milk drinks is highly influenced by the quality of milk and the production process used, as well as the possible increase in their bioavailability due to the fermentation process. Yogurt is one of the best-known foods containing probiotics [37; 38]. It is defined as a coagulated milk product that results from lactic acid fermentation in milk by _Lactobacillus bulgaricus_ and _Streptococcus thermophilus_[39]. The lactic acid bacteria (LAB) used in the yogurt production are microorganisms that are involved in the traditional fermentation process. Other lactic acid bacteria (LAB) species are now frequently used to impart unique characteristics to the final product. Thus, a carefully selected mixture of LAB species is used to complement each other and to achieve a remarkable efficiency in acid production. In order to ensure good conditions for effective milk fermentation and to obtain the right quality of yogurt, you can use special mixtures of starter cultures available on the market. These mixtures contain several strains of lactic acid bacteria with acid-forming, protective, and organoleptic properties, which ensure the proper process of milk fermentation. As research indicates that certain strains of the genus _Bifidobacterium_ are capable of converting CLA isomers (_cis_-9, _trans_-11 C18:2 and _trans_-10, _cis_-12 C18:2) from the linoleic acid (LA) present in milk, there is an increase of new probiotic strains available on the market [40; 41; 42; 43; 44; 45]. _Bifidobacterium_ have many beneficial properties, including production of lactic and acetic acids, which results in a positive lowering of the pH in the human digestive tract [40; 42]. Research on the ability of probiotic _Bifidobacterium_ to biosynthesize CLA may afford new possibilities for improving the functional propertiesof food through the microbiologically-promoted increase in the amount of health-promoting components [40; 45]. Therefore, this study aimed to analyze the composition of fatty acids, with particular emphasis on the content of _cis9 trans_11 C18:2 (CLA) acid, the content of minerals, and lipid quality indices in raw milk, pasteurized milk, and in yogurts produced with selected starter cultures enriched with _Bifidobacterium bifidum_.