Characteristic volatile flavor components of in-pond raceway system in the muscle of channel catfish (Ictalurus punctatus)

In order to investigate the characteristic volatile flavor components in the muscle of channel catfish (Ictalurus punctatus) by in-pond raceway system (IPRS), and the traditional pond system (TPS) served as control. The volatile flavor components of I. punctatus selected randomly under the two modes were extracted and identified by the headspace solid phase microextraction combined with comprehensive two- dimensional gas chromatography-time of flight mass spectrometry, and the characteristic components were determined by ROAV (relative odor activity value). The results showed that 49 and 50 components were identified under the IPRS and TPS, respectively, which were mainly composed of aldehydes, hydrocarbons, alcohols and lipids. The relative contents of alcohols and ketones by IPRS were higher than those by TPS, and 1-pentanol, 1-penten-3-ol, vinyl acetate, 2-nonone, 2,3-octanedione, 1,3-pentadiene and n-pentadecane were significantly higher or very significantly higher than those of TPS (P<0.05 or P<0.01). Some aldehydes, such as hexanal, tended to present unpleasant odor when the content was high, the advantage of IPRS in the study were obvious. The characteristic volatile flavor components by IPRS were composed of 1-octen-3-ol, hexanal, heptanal, octanal, 2,6-nonadienal, nonanal, decanal, 2,4-decadienal and (E, E)-2,4-nonadienal, among them, the heptanal and 2,6-nonadienal were the particular components. In conclusion, the culture mode had a great influence on the volatile flavor components and relative contents, The composition of volatile flavor components under IPRS was better than that under TPS, which was suitable for intensive and high-density cultivation of I. punctatus.