Regional variations of lipids in camel milk from Xinjiang, China: a UHPLC-MS/MS-based lipidomics study

Camel milk is widely recognized in Xinjiang for its rich nutritional profile and potential health-promoting properties. Here, we integrated lipidomics and oxylipidomics to deconstruct lipid heterogeneity in camel milk from grazing Bactrian camels across three ecologically distinct regions of Xinjiang, China (Yumin, TC; Huocheng, LC; Fuhai, AC). Critically, our sampling strategy encompassed three ecologically distinct counties, spanning over 400 km-a spatial scale sufficient to capture Xinjiang's biogeographic gradients. We identified 1,286 significantly differential lipids and 71 oxidized lipids, particularly in phospholipids, sphingolipids, and glycerolipids. Eight exploratory candidate lipids were identified for geographical discrimination: PC(37:4COOH), PC(18:0/18:3), DG(19:2/18:1) (AC); PC(16:2/18:3), PE(18:0/22:2CHO), PE(20:0/18:3), DG(16:0/20:0) (TC); PS(18:0/22:4) (LC). Significant differences in polyunsaturated fatty acids (arachidonic acid, docosahexaenoic acid, eicosapentaenoic acid, linoleic acid) and their oxidation products were observed, reflecting regional forage and environmental impacts. Overall, these findings provide a preliminary basis for understanding region-specific lipid variation in camel milk and a descriptive framework for future validation studies on geographical traceability.