## 3 Results and Discussion
### Fatty Acid Profiles and Health Indexes of Groin, Jowl, and Trimming Shoulder Fats
In groin fat, the highest content of palmitic acid (C16:0) was found in the \(sn\)-2 position, 61.67% and 62.14% in the case of fat extracted from the groin of pigs fed liquid and dry feed, respectively (Table 5). The share of this fatty acid in the \(sn\)-2 position in the groin fat of pigs offered liquid feed was 84.04%, and it was higher than in the case of the dry feeding system (82.32%). In the fat extracted from pigs fed liquid feed, the lowest amount of stearic acid (C18:0) was found in the \(sn\)-2 position, and its share in this position reached 10.93%. However, in the fat of dry-fed pigs, the lowest amount of myristic acid (C14:0) was determined in the \(sn\)-2 position, and its share in internal position was similar to that of palmitic acid (C16:0). The share of linoleic acid (C18:2 \(n\)-6) in the \(sn\)-2 position was higher in triacylglycerols of pork fat of pigs fed a liquid diet (19.77%) than in the triacylglycerols of fat of pigs offered dry feed (17.52%). In the case of jowl fat, the dominant acid in the \(sn\)-2 position was palmitic acid (C16:0) (Table 6). In the triacylglycerglycerol molecules of fat of dry-fed pigs, a higher content of palmitic acid was found in the \(sn\)-2 position--59.03%, than in the fat of pigs fed a liquid diet--57.49%. The share of this fatty acid in the \(sn\)-2 position of triacylglycerols in the case of both fats was approximately 88%. Based on the obtained results, it can be stated that palmitic acid (C16:0) was mainly located in the internal position in the triacylglycerglycerol molecule and unsaturated fatty acids (oleic acid and linoleic acid) occupied mainly external positions in triacylglycerglycerol molecules as their share in the \(sn\)-2 position was not high. In the pork fat extracted from trimming shoulder fat (Table 7), as in the case of groin and jowl fats, palmitic acid (C16:0) was most abundant in the \(sn\)-2 position. Its share in internal position reached 84.35% for TSF_L and 82.29% for TSF_D. The share of unsaturated fatty acids in the _sn_-2 position was much lower--in the case of oleic acid, it reached 14.44% for TSF_L and 14.43% for TSF_D. Considering the share of linoleic acid, it can be observed that 21.29% and 19.29% of this fatty acid was esterified in the _sn_-2 position in TSF_L and TSF_D samples, respectively. Taking the above into consideration, it can be concluded that in the studied fats, unsaturated fatty acids were mainly located in the external positions of triacylglycerol molecules. Summarizing the obtained results regarding the distribution of selected fatty acids in the internal (_sn_-2) and external (_sn_-1,3) positions of triacylglycerols of groin, jowl, and trimming shoulder fats and the share of individual fatty acids in the internal (_sn_-2) position, it can be stated that the internal position in the triacylglycerolglycerol structure in the case of studied fats was mainly occupied by saturated fatty acids: myrisistic (14:0) and palmitic (C16:0) acids. These results are in accordance with the literature, as pork fat was reported to contain 80-90% of palmitic acid at the _sn_-2 position [54; 55]. The share of unsaturated oleic and linoleic fatty acids in the _sn_-2 position was not high. This proved that unsaturated fatty acids were mainly located in external positions (_sn_-1,3) in the triacylglycerol molecules of pork fats. Taking into account the structure of triacylglycerols, it can be stated that there was no significant differences in the distribution of fatty acids between internal (_sn_-2) and external (_sn_-1,3) positions in groin, jowl, and trimming shoulder fats of pigs fed dry or liquid diets. Such distribution of fatty acids among positions in triacylglycerols is typical of pork fat [56; 57]. It is worth highlighting that the distribution of fatty acids in the triacylglycerol molecules of fats is very important from a technological and health point of view. It affects the digestion and absorption of fatty acids in the human body.