Investigating the impact of the key processing stages on flavor components and lipid flavor formation of Tibetan dried pork slice

This study aimed to explore the aroma formation mechanism of Tibetan dried pork slice by investigating changes of their volatile compounds and lipid molecules across four key processing stages (mincing, seasoning, drying, and baking). E-nose analysis revealed significant differences in the odor profiles of dried pork slice at different processing stages. Furthermore, the drying and baking processes significantly enhanced the odor profiles of dried pork slice. The GC-IMS detected 61 volatile compounds, among which PLS-DA highlighted nine key contributors to the final flavor profile: ethyl 2-hydroxypropanoate-M, butanal, propanal, 3-methyl butanal, benzaldehyde, 1-nonanal, 1-hexanal-D, (Z)-2-pentenal, and 2-methylpyrazine. Additionally, the four processes significantly changed the content and composition of lipid molecules analyzed through LC-MS. Glycerolipids and phospholipids metabolism were identified as the primary metabolic pathway during the processing stages. Triglycerides (TG) and phosphatidylcholine (PC), such as TG (13:1/13:1/13:1), TG (17:0/18:1/18:1), TG (13:1/21:4/21:4), TG (12:0/12:0/19:3), TG (16:0/22:1/22:1), PC (18:4e/18:5) and PC (18:3/22:6), played a vital role in the generation of aroma compounds. Furthermore, the correlation between the lipid molecules and the key volatile compounds suggested the role of lipid oxidation, the Maillard reaction, as well as the interaction between these reactions in the aroma formation of dried pork slice. Therefore, this study provides the first evidence that lipid oxidation in the drying and baking stages is a critical factor in the aroma evolution of Tibetan dried pork slice. These findings provide a scientific basis for understanding the flavor formation mechanism and inform the development of optimized processing strategies for Tibetan dried pork slice. • Drying and baking process enhance umami in Tibetan dried pork slice. • TGs content significantly increase during drying and baking. • Oxidation of lipids caused by drying and baking formed the main flavor.