Analysis of key fishy odorants in crucian carp (Carassius auratus) and yellowfin seabream (Acanthopagrus latus).

Fishy odor is a critical factor affecting the sensory quality and consumer acceptance of aquatic products. However, systematic differences in the composition of fishy odor compounds between freshwater and marine fish remain unclear. To address this gap, this study elucidated the composition of fishy odor compounds in freshwater crucian carp (Carassius auratus) and marine yellowfin seabream (Acanthopagrus latus) through comprehensive analysis of their volatile compounds. The key fishy odorants were identified using headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) for qualitative and quantitative analysis of volatile components, together with the application of odor activity value (OAV), gas chromatography-mass spectrometry-olfactometry (GC-MS-O), as well as aroma recombination and omission experiments. A total of 32 volatile compounds were identified from crucian carp, predominantly aldehydes (283.48 μg/kg), alcohols (144.57 μg/kg), and ketones (116.95 μg/kg). In contrast, 31 volatile compounds were identified from yellowfin seabream, mainly aldehydes (215.17 μg/kg) and hydrocarbons (881.20 μg/kg). Except for hydrocarbons, the concentrations of volatile compounds in crucian carp were higher than those in yellowfin seabream, and 2-methylisoborneol (2-MIB), a known earthy-musty odorant, was detected in crucian carp. Six key fishy odorants in crucian carp included: (E,Z)-2, 6-nonadienal, nonanal, (E,E)-2, 4-decadienal, (E,E)-2, 4-nonadienal, 1-octen-3-ol and hexanal. In yellowfin seabream, four critical odorants were identified: (E,Z)-2, 6-nonadienal, nonanal, (E,E)-2, 4-decadienal and (E,E)-2, 4-nonadienal. The volatile profiles differed markedly between the two species. Compared with the marine yellowfin seabream, the freshwater crucian carp exhibited a more intense odor profile with a more complex composition of fishy odorants.