Abstract: In this study, headspace solid phase microextraction coupled to gas chromatography-mass spectrometry (HS-SPME-GC-MS) was used to analyze the types and relative contents of volatile flavor substances in Takifugu bimaculatus during cold storage at 0 or 4 ℃ so as to explore the change of volatile substances in the fish during cold storage. The results showed that the fuzzy mathematics gave high sensory scores for Takifugu bimaculatus cold stored for 1–3 days, and reached the upper limit of consumer acceptance on day 7 and 9 for 4 and 0 ℃, respectively. Principal component analysis (PCA) and linear discriminant analysis (LDA) of the electronic nose data showed clear differences in the volatile flavor substances in T. bimaculatus cold stored for different periods of time, which was consistent with the results of HS-SPME-GC-MS. Forty-eight volatile substances were detected, including hydrocarbons, alcohols, aldehydes, esters, aromatic compounds and nitrogen- and sulfur-containing heterocyclic compounds. The fresh fish flesh smelled fishy smell but refreshing. After 11 days of refrigeration, the fishy smell became stronger, and rancid and sour odors appeared.?Nitrogen- and sulfur-containing heterocyclic compounds and aldehydes were the major compounds responsible for the flavor deterioration. Odor activity value (OAV) analysis showed that 1-octene-3 alcohol, hexanal, octanal, nonaldehyde and 2,3-octandione were the key flavor substances of the fish during refrigeration storage. PCA was used to construct the comprehensive evaluation model for volatile flavor substances: T = 0.83T1 + 0.15T2, and the evaluation results were significantly negatively correlated with the sensory evaluation results (P < 0.01). In conclusion, electronic nose combined with HS-SPME-GC-MS can be used to discriminate the differences in the volatile flavor components of T. bimaculatus during cold storage, which may provide a theoretical reference for investigating the changes of volatile flavor compounds in T. bimaculatus during cold storage.

Key words: Takifugu bimaculatus; volatile flavor components; headspace solid phase microextraction-gas chromatography-mass spectrometry; electronic nose; odor activity value