Exploring the Relationship of Antioxidant Characteristics and Fatty Acids with Volatile Flavor Compounds (VOCs) by GC-IMS and GC-O-MS in Different Breeds of Pigs

The volatile organic compounds (VOCs) are the main flavor constituents of different pig breeds, which have positive effects on the quality evaluation of pork. This study aimed to clarify the effects of lipid oxidation on characteristic VOCs in different breeds of pigs. The fatty acid composition and antioxidant characteristics of the Ningxiang (NX) pig, Rongchang (RC) pig, Duroc × Wujin (DW) pig, and Duroc × Landrace × Yorkshire (DLY) pig were determined. The VOCs from these four pig breeds were analyzed by gas chromatography-ion migration spectrometry (GC-IMS) and solid-phase micro-extraction-gas chromatography-olfactory mass spectrometry (SPME-GC-O-MS). A total of 49 volatile compounds were identified by GC-IMS, whereas GC-O-MS detected 97 volatile components, including aldehydes, alcohols, ketones, acids, and esters. Among these, aldehydes and alcohols were the predominant categories. The results showed that RC breed pork had the highest fatty acid content, whereas NX breed pork exhibited the highest antioxidant activity. Among the VOCs from these four pig breeds, tridecanal showed a strong positive correlation with antioxidant capacity (T-AOC) and vitamin E, which was mainly reflected in NX. Furthermore, the key VOCs across the different pig breeds were mainly related to unsaturated fatty acids, such as C20:3n6, C18:1n9c, and C18:2n6c. In conclusion, the antioxidant characteristics of NX pigs are closely associated with their unique volatile flavor profile, while the characteristic flavor compounds across different pig breeds are primarily influenced by the composition and oxidation of unsaturated fatty acids.