The warmed-over flavor (WOF) can significantly impair the flavor quality of prepared foods, leading to reduced consumer acceptance. This study investigates the molecular composition of WOF and the alterations in lipid molecules during the heating-cooling-reheating process of bowl-steamed Tan lamb, employing a comprehensive analytical approach. By integrating GC-MS and GC-IMS analyses, 11 WOF-related compounds were identified, including furan, 2-pentyl-, and 2-pentanone. UPLC-MS/MS analysis revealed that phospholipids and triglycerides, particularly TG 49:4
O and PG 34:2, play a critical role in the formation and retention of WOF. These lipids exhibited a negative correlation with WOF, indicating that lipid degradation is the primary cause of WOF formation. The results of this study provide a theoretical foundation for the targeted inhibition of WOF in prepared foods.