Characterization and difference of lipids and metabolites from Jianhe White Xiang and Large White pork by high-performance liquid chromatography–tandem mass spectrometry

Abstract

The quality of pork, such as intramuscular fat (IMF) content and flavor, can affect the acceptance of the consumer. Many studies have reported on the pork quality of Chinese local and commercial pigs (for example Large White (LW) pigs). The Jianhe White Xiang (JWX) pig, one of the Chinese Xiang pigs, is known for its high IMF and pork flavor. However, studies investigating the characterization and difference of lipids and metabolites between the JWX and LW pork are limited. Herein, we performed metabolomic and lipidomic profiling of JWX and LW pork by high-performance liquid chromatography–tandem mass spectrometry. The IMF and meat redness (a*) of the JWX pork were significantly higher than those of the LW pork. Metabolomic profiling revealed that 118 out of 501 polar metabolites, such as carnitine, amino acids, sugar, and dipeptide, were significantly different between the two types of pork. Additionally, the screened metabolites were mainly related to carnitine synthesis, phospholipid metabolism, sugar metabolism, and amino acid metabolism. Lipidomic profiling identified 100 of 376 lipids, which contained carnitine, diglyceride, triglyceride (TG), sphingomyelin, cardiolipin, fatty acid, phosphatidylcholine (PC), and phosphatidylethanolamine (PE), which were significantly different between the two types of pork under the positive and negative ion modes (variable importance in projection (VIP) > 1, p < 0.05, and fold change (FC) > 2 or FC < 0.5). All of the different TG substances were up-regulated in the JWX pork, and their carbon chain length was longer than that of the residual TGs. In addition, the JWX pork had more double bonds of PC and PE substances than LW pork. Thus, our findings provide comprehensive metabolomic and lipidomic profiles between the JWX and LW pork and a basic understanding on increasing the pork quality.