Characterization and identification of pork flavor compounds and their precursors in Chinese indigenous pig breeds by volatile profiling and multivariate analysis

Chinese indigenous pigs are favored for their rich flavor, which is generated through complex reactions involving lipid-oxidation-related flavor precursors. In this research, we characterized the aroma compounds and fatty acids of representative Chinese pig breeds by gas chromatography-olfactometry-mass spectrometry (GC-O-MS) and GC-ion mobility spectrometry (GC-IMS) with multivariate analysis. A total of 79 volatile compounds were identified, among which 15 compounds were selected as odorants in pork. According to multivariate statistical analysis, some odorants, including hexanal, 1-octen-3-ol, 2,3-octanedione, (E, E)-2,4-decadienal and dodecanal could be discriminative compounds explaining breed-originated differences in flavor profiles. As confirmed by partial least squares regression (PLS-R), some fatty acids, including C18:1n9c, C22:6n3 and C18:3n3, were major precursors for the formation of rich flavor in indigenous pig breeds. These results revealed that fatty acids and volatile compounds were breed-dependent, and the differences in flavor were related to the variance in the fatty acid content.