## 3 Results and Discussion
### Fatty Acid Composition  
GC-MS was used as a reliable method for the analysis of the fatty acid composition and the content of polyunsaturated, monounsaturated, and saturated fatty acids in the fat extracted from the cream samples fermented with _B. animalis_ subsp. _lactis_ Bb-12 and enriched with essential oils from the lemon peel, clove bud, and juniper berry. The fatty acid profile of the studied fat samples was determined after 21 days of storage at 6 \({}^{\circ}\)C and is presented in Table S1. The GC-MS analysis revealed the presence of 20 fatty acids. Saturated fatty acids were the dominant group in all the tested fat samples. In our work, their content ranged from 67.36% (fat extracted from cream not subjected to fermentation) to 68.32% (stored sour cream without essential oils). The most abundant saturated fatty acids were myristic acid (C14:0), palmitic acid (C16:0), and stearic acid (C18:0). The content of myristic acid (C14:0) was the greatest in fermented cream, containing 50% clove bud essential oils amounting to 11.84%, while in the remaining fat samples, it ranged between 11.58% and 11.78%. No statistically significant differences were noted in the content of this acid between the sour cream and stored sour cream samples. Moreover, the content of palmitic acid was slightly higher in samples fermented with _Bifidobacterium_ compared to the nonfermented cream samples, except in the case of those samples enriched with lemon peel, clove bud, or juniper berry essential oils at their highest concentrations (100%). Similar observations were made regarding the content of stearic acid (C18:0) in the analyzed fat samples. Short-chain fatty acids (C4:0-C10:0) accounted for 6% of saturated fatty acids. Along with butyric (C4:0), caproic (C6:0), and caprylic acid (C8:0), capric acid (C10:0) was also found and its content was comparable in the analyzed fat samples, with the greatest amount noted in the fat extracted from sour cream samples enriched with 100% lemon peel and juniper berry essential oils and with 50% and 100% clove bud essential oils. The presence of C6:0, C8:0, and C10:0 fatty acids in ruminant milk may cause a specific aroma in milk and may exert beneficial effects on human health by inhibiting bacterial and viral growth, as well as by dissolving cholesterol deposits [66]. Compared to saturated fatty acids, the content of monounsaturated fatty acids in the analyzed samples ranged from 28.24% to 29.07%. Among these acids, oleic acid (C18:1 \(n\)-9) was the most abundant and its share in the total composition of fatty acids was, on average, 21.85%. In the fat samples extracted from sour cream enriched with three essential oils at the level of 100%, compared to the fat samples from sour cream not containing essential oils, a slightly lower oleic acid content was found in the cream sample not treated with _B. animalis_ subsp. _lactis_ Bb-12 and in the sample enriched with essential oils, both after storage for 21 days and immediately after fermentation. The highest content of oleic acid was noted in the sour cream samples containing juniper berry and clove bud essential oils that were added to the fermented cream at concentrations of 12.5% and 25%, and the oleic acid content in these samples exceeded 22%. The other monounsaturated acids found were myristoleic (C14:1), palmitoleic (C16:1), gadoleic (C20:1), C18:111, and C18:112 acids, in minor amounts. Similarly, the content of polyunsaturated fatty acids in the fat separated from sour cream samples accounted for 3.22-3.58% of the total fatty acid composition. The highest total content of polyunsaturated fatty acids was found in the fat separated from nonfermented cream (3.58%) and the lowest was found in the sour cream samples enriched with juniper berry essential oils that were stored for 21 days. Among the polyunsaturated fatty acids, linoleic acid (C18:2 \(n\)-6) was dominant in all tested fat samples, with an average amount of 1.59%.