Characterization of off-flavor compounds in ready-to-heat roasted catfish after reheating by sensomics approach

Gas chromatography-electronic nose (GC-E-Nose), gc-ion mobility spectrometry (GC-IMS), and gc-olfactory-mass spectrometry (GC-O-MS) techniques, along with odor recombination and omission experiments, were employed to characterize the off-flavors in commercially available ready-to-heat roasted catfish after reheating. A total of 19 (DR), 11 (HR), and 21 (YR) characteristic compounds were identified across the three samples. The 19 characteristic compounds from the DR group were reconstituted to develop recombination and omission models. The resulting model demonstrated the highest similarity (84.98 %) to the original sample while retaining some odor information from the other two sample groups. The 12 key off-flavor substances were identified through the omission model and were subsequently subjected to multivariate recombined. The contribution of these off-flavors was further validated via omission testing. The results indicated that the primary off-flavors in reheated ready-to-heat roasted catfish were attributed to hexanal, heptanal, (E)-2-hexenal, octanal, 3-methyl-1-butanol, 1-octen-3-ol, and (E,E)-2,4-heptadienal. This characterization of off-flavors in ready-to-heat roasted catfish post-reheating will contribute to the regulation of the product's flavor quality.