Changes in volatile compounds of pomfret and grass carp during different storage periods

Pomfret and grass carp were chosen as representatives of sea and freshwater fish, respectively to investigate odor changes by electronic nose (E-nose) and changes in volatile flavor components during chilled storage by gas chromatography-mass spectrometry (GC-MS). The results showed that e-nose could distinguish the odor of different species of fish at different storage periods, and the odor changes of grass carp were much more obvious. A total of 22 and 19 volatiles were identified in pomfret and grass carp, respectively, during refrigeration, mainly consisting of aldehydes, alcohols, esters, and putrefactive compounds etc. The major volatiles of fresh pomfret were 1-penten-3-ol, 1-octen-3-ol, hexanal, heptanal and 2-octenal, while the major volatile of grass carp was caproic acid methyl ester. There were different changes in odorous components of pomfret and grass carp during refrigeration. The putrefactive compounds of pomfret were mainly trimethylamine and 3-methyl-butanol, and the contents of most aldehydes and alcohols showed a decreasing tendency. The fat oxidation products decanal, 1-octen-3-ol, hexanal and nonanal were found to be the main volatiles of grass carp stored for two and four days. Moreover, fewer putrefactive compounds were detected during the late storage period. The above results noted that growing environment, lipid oxidation and microbial spoilage may influence the odor of sea fish and freshwater fish during cold storage. © 2016, China Food Publishing Company. All right reserved.