Untargeted metabolomics allows to discriminate raw camel milk, heated camel milk, and camel milk powder

The metabolomic profiles of raw camel milk (RCM), heated camel milk (HCM) and camel milk powder (CMP) were analysed by ultra-high-performance liquid chromatography coupled with quadrupole time of flight mass spectrometer (UHPLC-Q-TOF/MS). One hundred and nineteen significantly changed metabolites with variable importance for the projection (VIP) > 1 (t-test p < 0.05) from the positive mode were selected and identified in RCM, HCM and CMP. These metabolites included saccharides, glycosylamines, adenosines, and phospholipid. Among the saccharides, the content of d-lactose was the highest and slightly increased after thermal treatment. Dipeptides, including His–Pro and Lys–Trp, were significantly increased in HCM and CMP. As for glycosylamines, the content of N-acetylneuraminic acid was the highest. The amounts of larixinic acid increased dramatically in HCM and CMP (p < 0.001), which may improve the flavour of camel milk.