Abstract:Cod skin is a valuable marine food resource，yet its off-odor components remain unclear，limiting product development. Headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry （HS-SPME-GC-MS），gas chromatography-olfactometry-mass spectrometry （GC-O-MS），odor activity value （OAV） analysis，recombination，and omission experiments were used to investigate key odorants in cod skin. Results showed that total of25 volatile compounds were identified，among which octanol，1-nonanol，（E，Z）-2，6-nonadienal，nonanal，2-nonanone，1-tridecene，6-methyldodecane，2，6-dimethylundecane，naphthalene，decanal，3，5，5-trimethyl-1-hexene，1-octen-3-ol，myrcene，9-methyl-1-undecene，2-undecanone，geranylacetone，2，4-di-tert-butylphenol，and octanal were detected by GC-O-MS with distinct odors. Recombination and omission experiments showed that the reconstituted sample matched the grassy，metallic，meaty，and fatty notes of cod skin，while deviations were observed in sweet，fishy，and mushroom-like attributes. Triangular tests further confirmed decanal as a key contributor to fishy and fatty notes，octanal to grassy note，and （E，Z）-2，6-nonadienal and 1-octen-3-ol to mushroom-like note. This study identified the components contributing to grassy，metallic，meaty，and fatty flavors in cod skin，and partially clarified those responsible for sweet，fishy，and mushroom-like odors，providing a reference for understanding and improving the aroma of marine food resources.