Lipid profile of sheep milk and its impact on taste: a combination study of lipidomics and electronic tongue.

Taste is a defining quality attribute of dairy products, yet its biogenesis remains intricate. It is worth noting that the diverse array of taste precursors within the lipid fraction significantly influences the final sensory profile. Therefore, this study combined lipidomics and electronic tongue to conduct a detailed analysis of the potential relationship between the lipid and taste of sheep milk. The results demonstrated that some bioactive lipids in sheep milk have a high content, such as lysophosphatidylglycerol (LPG), lysophosphatidylinositol (LPI), lysophosphatidylcholine (LPC), short-chain fatty acids (SCFAs), sphingomyelin (SM). Meanwhile, whole sheep milk has less unpleasant taste such as bitterness (sensor value = 1.99 ± 0.28) and bitter aftertaste (sensor value = 0.35 ± 0.02) compared with whole cow milk (sensor values were 3.43 ± 0.02 and 0.44 ± 0.05, respectively) and whole goat milk (sensor values were 3.63 ± 0.28 and 0.76 ± 0.14, respectively). Some potential lipids that may affect the bitterness and astringency aftertaste of sheep milk were also discovered by the Pearson correlation coefficient and linear fitting, including phosphatidylglycerol (12:0_15:0, linear fitting R2 = 0.72), free fatty acid (16:0, linear fitting R2 = 0.51), diacylglycerol (O-19:0_16:0, linear fitting R2 = 0.89), 12-0xochenodeoxycholic acid (linear fitting R2 = 0.73)，Phosphatidylinositol (15:0_21:0, linear fitting R2 = 0.62), etc. This study comprehensively analyzed the lipid profile of sheep milk and preliminarily explored the correlation between lipids and taste, providing a reference for further analyzing the mechanism of taste formation in sheep milk.