Characterization of different meat flavor compounds in Guangdong small-ear spotted and Yorkshire pork using two-dimensional gas chromatography–time-of-flight mass spectrometry and multi-omics

In China, indigenous pigs are popular due to their excellent meat quality and unique flavor. In this study, the unique flavor was investigated using Guangdong small-ear spotted pig (GD) and their hybrid progeny, which produced high-end pork in the Chinese market. Two-dimensional gas chromatography-time-of-flight mass spectrometry (GC × GC-TOF MS) was used to analyze and quantify volatile organic compounds (VOCs) in the two pork types for identifying the unique flavor of these very popular pigs. The flavor is imparted by alkanes, aldehydes, ketones, and ethers. Flavor imparting compounds mainly include methyl isobutyl ketone, octane, pentane, and 3-ethyl-2, 2-dimethylheptane. High levels of volatilization of such compounds generated ethereal, acetonic, sweet, and green odors in the pork of GD. Hybrid offspring of Chinese and Western pig breeds can also inherit such special aromas, which are sometimes even more intense, with increased meat yield. Multi-omics analysis of the transcriptome and metabolome showed that AMD1 (Adenosylmethionine Decarboxylase 1) affects the p-cresol content by regulating the polyamine pathway, affecting the unique flavor of GD. This study revealed the unique flavor composition of GD, analyzed the advantages of species hybridization, and thus, provides a new direction and theoretical basis for pork quality improvement.