Comparative Study on Regional Differences of Lipid Compounds in Camel Milk from Xinjiang, China Using LC-MS/MS-Based Lipidomics

This study revealed regional differences in the lipid profiles of camel milk and identified potential lipid biomarkers for geographical discrimination. By integrating LC-MS/MS-based untargeted lipidomics with LC-MS-based targeted oxidized lipidomics, we systematically analyzed differences in lipids and oxidized lipids in camel milk from Tacheng (TC), Yili (LC), and Altay (AC) regions. A total of 1,286 significantly differential lipids and 71 differential oxidized lipids were identified, demonstrating significant regional variations in camel milk lipid composition, particularly within phospholipids (e.g., PC, PE), sphingolipids (e.g., SM), and glycerolipids (e.g., TG). Furthermore, eight potential lipid biomarkers distinguishing the regions were identified: PC(37:4COOH), PC(18:0/18:3), and DG(19:2/18:1) in AC; PC(16:2/18:3), PE(18:0/22:2CHO), PE(20:0/18:3), and DG(16:0/20:0) in TC; and PS(18:0/22:4) in LC. The study also found significant regional differences in polyunsaturated fatty acids (PUFAs) and their oxidation products (e.g., AA, DHA, EPA, LA), reflecting the profound impact of regional forage composition and environmental conditions on camel milk lipid metabolism. Metabolic pathway analysis indicated significant enrichment in pathways such as glycerophospholipid metabolism, arachidonic acid metabolism, and linoleic acid metabolism, revealing molecular mechanisms underlying camel adaptation to extreme environments (e.g., low temperature and high UV radiation). This research provides crucial molecular evidence for understanding the geographical specificity and environmental adaptability of camel milk lipids.