## 3 Results and Discussion  
### Fatty Acid Composition and Lipid Quality Indices  
Data presented in Table 1 shows the total content of fatty acid groups and the values of lipid quality indices in the analyzed samples. The fatty acid composition of milk fat is very complex as it includes over 400 different fatty acids (FAs) of various chain lengths and degrees of unsaturation. The fat of cow's milk contains about 70% of SFAs, 25% of MUFAs, and 2-5% PUFAs ([PERSON] _et al._, 2016; [PERSON] _et al._, 2016). The short-chain fatty acids (SCFA) (from C4:0 to C10:0 carbon atoms) account for approximately 10% of the total SFAs. Saturated fatty acids (SFAs) were found in the highest amount in the fats extracted from the analyzed milk samples. Pasteurized milk was found to contain the highest content of these acids. Fat from raw milk and yogurts was characterized by a significantly (\(p<0.05\)) lower SFA content (Table 1). The fat from pasteurized milk had a significantly (\(p<0.05\)) higher content of short-chain fatty acids (SCFAs) and odd-chain fatty acids (OCFAs). The content of branched fatty acids (BCFAs) in the fat of the analyzed milk and yogurts was at a similar level. Analyzed pasteurized milk and yogurts produced using FD-DVS YC-X16 Yo-Flex with BB-12 had a significantly (\(p<0.05\)) higher MUFA content than raw milk and yogurts produced using FD-DVS YC-180 Yo-Flex with BB-12. The highest content of PUFAs (20.19 mg/g fat) was determined in the fat from pasteurized milk. Raw milk and fat from yogurts produced had significantly lower (\(p<0.05\)) contents of PUFAs (Table 1). The fatty acid profile of dairy products, apart from the quality of the raw material, may be influenced by the conditions used in the technological process, such as heat treatment, homogenization, fermentation, and storage. However, the studies addressing these issues have produced inconsistent findings. According to [PERSON] et al. (2016), milk after pasteurization was characterized by a higher content of SCFAs and PUFAs and lower content of MUFAs. In turn, [PERSON] et al. (2016) presented a study in which an increase in short-chain fatty acids (SCFA) and medium-chain fatty acids (MCFA) as well as a decrease in long-chain fatty acids (LCFA) after pasteurization and cooking, was observed, due to high milk temperature, while the study by [PERSON] et al. (2016) demonstrated a decline in SCFAs. From the nutritional point of view, it is particularly important to determine the content of (n \(-\) 6) PUFA and (n \(-\) 3) PUFA fatty acids because their proper supply is essential for human health ([PERSON] _et al._, 2016). The conducted research showed a significantly higher (\(p<0.05\)) content of (n \(-\) 3) and (n \(-\) 6) PUFAs in fat obtained from pasteurized milk (Table 1) than in fat from raw milk and yogurts. Analyzed milk and yogurts had the (n \(-\) 6)/(n \(-\) 3) ratio at a similar level. Excessive amounts of (n \(-\) 6) PUFAs and a high (n \(-\) 6)/(n \(-\) 3) ratio present in a diet are said to promote the pathogenesis of many diseases, whereas diets with an increased level of (n \(-\) 3) PUFAs and a lower (n \(-\) 6)/(n \(-\) 3) ratio exert suppressive effects ([PERSON] _et al._, 2016; [PERSON] _et al._, 2016). The research by [PERSON] et al. (2016) showed that yogurts and pasteurized milk had significantly lower contents of (n \(-\) 6) acids than raw milk, and the content of (n \(-\) 3) acids was significantly lower in yogurts than in raw and pasteurized milk. The research presented by these authors indicated that yogurts were characterized by a significantly higher (n \(-\) 6)/(n \(-\) 3) ratio than raw and pasteurized milk. The optimal (n \(-\) 6)/(n \(-\) 3) ratio should be 2:1 to 3:1; however, the risk of many chronic diseases can be reduced by diets with a lower (n \(-\) 6)/(n \(-\) 3) ratio, which makes it more desirable [59]. The values of DFAs (desirable hypocholesterolemomic fatty acids) and OFA (hypercholesterolem fatty acids) were different in the analyzed milk and produced yogurts (Table 1).