Key aroma compounds of Chinese dry-cured Spanish mackerel (Scomberomorus niphonius) and their potential metabolic mechanisms.

Abstract The key aroma compounds of six commercially available dry-cured Spanish mackerel (Scomberomorus niphonius, DCSM) were identified using electronic nose (E-nose), gas chromatography–olfactometry (GC-O), and two-dimensional gas chromatography–time-of-flight mass spectrometry (GC × GC–TOFMS). A total of 38–55 aroma compounds were identified, and 21–26 of them, which presented high flavor dilution factors based on aroma extract dilution analysis, were quantified. Lastly, 9–14 key aroma compounds with high odor-active value, including 3-methyl-1-butanal, octanal, 1-octen-3-ol, nonanal, cis-4-decenal, ethyl caproate, (E)-2-octenal, (Z)-2-nonenal decanal, 3-methyl-1-butanol, 1-heptanol, 3-octanone, 2-octanol, and 6-methyl-5-hepten-2-one, were identified as the key aroma contributors in DCSM. Results also indicated that a longer dry-curing time would promote the generation of aroma compounds. The metabolism analysis implied that the auto-oxidation/oxidation of unsaturated fatty acids, such as oleic and linoleic acid, and the enzymatic degradation of L-leucine might be potential metabolic mechanisms.