Abstract: The metabolites and lipids in donkey milk from Xinjiang and Shandong were studied by non-targeted metabolomics and lipidomics. The results showed that there were significant differences in metabolites and lipids between the two groups of samples. With variable importance in the projection (VIP) > 1, P < 0.05 and fold change (FC) ≥ 2 or < 0.5 as the threshold, 12 and 34 differential metabolites were selected in the positive and negative ion modes, respectively, including some important compounds such as morphiceptin, madlongiside C, valyl-hydroxyproline. Further analysis revealed that these compounds could be related to proteolysis and microbial metabolism. With VIP ≥ 3.0, P < 0.001 and FC ≥ 2 or < 0.5 as the threshold, 50 and 36 differential lipids were selected in negative and positive ion modes, respectively. The differential lipids and metabolites found in this study can be used as potential markers for geographic origin identification, while will provide a theoretical basis for intensive processing of donkey milk.

Key words: donkey milk; non-targeted; metabolomics; lipidomics