Ultrasonic-Assisted Stewing Enhances Chicken Soup Flavor by Promoting Flavor Precursor Release and Key Aroma Compound Formation

Chicken soup is widely appreciated for its nutritional value and flavor. This study investigated the effects of ultrasonic-assisted stewing (UAS) on flavor and non-volatile compounds (NVCs) using gas chromatography-mass spectrometry (GC-MS) and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis. GC-MS identified 39 volatile organic compounds (VOCs). At 120 min of stewing, the total VOCs concentration in the UAS group reached 150.08 mg/kg, approximately 5.10-fold that of the control group (29.41 mg/kg). Multivariate analysis combined with odor activity values further screened 10 differential VOCs. Aroma recombination and omission tests confirmed that 7 key VOCs, including (E)-2-octenal and (E,E)-2,4-decadienal, contributed to the meaty and fatty sensory attributes. UPLC-MS/MS analysis detected 5032 NVCs across 20 categories, among which 322 key differential NVCs, including small peptides, fatty acids, and nucleotides, showed significant differences between the UAS and control groups. Overall, UAS enhanced the flavor complexity of chicken soup by facilitating the release of flavor precursors, including small peptides, nucleotides, and lipid-derived NVCs, and promoting the formation of key VOCs. This study provides theoretical and technical support for the application of UAS in soup processing.