Characterization of the aroma profile and dynamic changes in shrimp sauce with different storage time based on E-nose, GC-IMS and GC-MS

Shrimp sauce is a traditional fermented condiment whose aroma profile evolves during storage. This study systematically evaluated the aroma characteristics of shrimp sauce storage for 3 months (SA-A), 1 year (SA-B), and 2 years (SA-C) using sensory analysis, electronic nose (E-nose), gas chromatography-ion mobility spectrometry (GC-IMS), and headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS). Sensory evaluation revealed that SA-A had a stronger fruity and roasted aroma, while SA-B and SA-C more intense saucy and fishy odors. E-nose sensors W1W (sulfur-organic compounds) and W2W (aromatic and sulfur-containing volatiles) most effectively differentiated SA-A from the longer-aged samples. GC-IMS detected 42 volatile compounds, with high fingerprint similarity between SA-B and SA-C. GC-MS identified 78 volatile, whose total first increased and then decreased with storage. Heterocyclic, acids, and alcohols were major aroma contributors. Based on relative odor activity value (rOAV), 22 key aroma substances were identified. Pearson correlation analysis revealed that fishy odor correlated strongly with 3-methyl-1-butanol、dimethyl disulfide、propionic acid、tetramethylpyrazine and 2-methyl-3,5-diethylpyrazine. Conversely, 4-methylvaleric acid, 2-methylpyrazine, and 2,5-dimethylpyrazine correlated negatively with saucy aroma but positively with fruity and roasted aromas, whereas butyric acid was strongly associated with shrimp aroma. These results offer valuable insights into how storage duration influences the aroma quality of shrimp sauce. • Multi-technique analysis revealed dynamic volatile changes during storage. • SA-A showed a distinct profile with stronger fruity and roasted aromas. • 22 key aroma compounds characterized shrimp sauce over time. • Established correlations between sensory attributes and volatile compounds.