Analysis of Dynamic Changes in the Flavor of Cooked Crayfish during Frozen Storage by Headspace Solid-Phase Microextraction Coupled with Gas Chromatography-Mass Spectrometry Combined with Electronic Nose

This study aimed to investigate the effect of frozen storage time on the flavor of cooked crayfish. Headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) was used to detect the types and contents of volatile components in the meat and hepatopancreas of crayfish during the frozen storage, and the key components causing the flavor deterioration of crayfish were identified based on odor activity values (OAV). The results showed that the electronic nose could clearly distinguish the differences in odor between crayfish with different freezing times. The contents of alcohols, aldehydes, ketones, nitrogen oxides, alkanes, and sulfides in the meat and hepatopancreas increased with storage time. After 4 months of frozen storage, the key components related to flavor deterioration in the meat were nonanal and pentanal, while those in the hepatopancreas were hexanal and nonanal. After 12 months of frozen storage, the key components related to flavor deterioration in both the meat and hepatopancreas were hexanal, heptanal, nonanal, pentanal, 1-octen-3-ol, and 2,3-octanedione. Sensory evaluation with compounding different concentrations of the key odor components revealed that the off-flavor intensity increased continuously with frozen storage time. A quantitative method for detecting the key odor components was established, which could be used to evaluate the flavor changes of cooked crayfish during the frozen storage. In summary, the flavor of cooked crayfish deteriorated during frozen storage. This study provides a reference for controlling the flavor deterioration of cooked crayfish during frozen storage.