Mechanistic Studies on the Effects of Solvent Fractionation on the Fatty Acid Distribution of Altay Sheep Tail Fat and Blood Lipids in Mice

This study investigated the physicochemical properties and fatty acid composition of Altay sheep tail fat and its fractionated products and conducted animal experiments simulating the dietary fat intake pattern of urban residents in China to evaluate their effects on blood lipid metabolism in mice. The results showed that the low-melting-point fraction (liquid at 2 ℃) exhibited the highest unsaturated fatty acid content (52.03%), while the high-melting-point fraction (solid at 32 ℃) had the highest saturated fatty acid content (54.21%). The animal experiments indicated that mice gavaged with the liquid fat showed the lowest obesity level, whereas the rapeseed oil group had the highest body mass index (BMI). Each fraction showed no significant difference in degree of obesity compared with the control group. There were no significant differences between any of the experimental groups in organ coefficients. The blood lipid profile analysis showed that the 2 ℃ liquid fat group had the highest high-density lipoprotein cholesterol (HDL-C) level (2.78 mmol/L). The 32 ℃ solid fat group showed the highest triglyceride (TG) concentration. The lowest level of low-density lipoprotein cholesterol (LDL-C) was found in the rapeseed oil group, which showed no significant difference compared with the liquid fat group (P > 0.05). Furthermore, there was no intergroup difference in total cholesterol (TC) concentrations (P > 0.05). Overall, the liquid fat fraction had significant advantages in both nutritional and health aspects. This study provides valuable insights for the development of Altay sheep tail fat as a functional edible lipid source.