Effects of dietary replacement of fish oil by vegetable oil on proximate composition and odor profile of hepatopancreas and gonad of Chinese mitten crab (Eriocheir sinensis).

Five different diets with different ratio of fish oil to vegetable oil were prepared. The biological index and proximate composition of Eriocheir sinensis fed with different diets were compared, and then sensory analysis, electronic nose (E-nose) and headspace-solid phase micro-extraction combined with gas chromatography-mass spectrometer (HS-SPME-GC-MS) analysis were applied to determine the odor profile of E. sinensis. The results showed that partial replacement (50%-75%) of fish oil by vegetable oil (FO/VO) was beneficial to the weight increment, nutrition accumulation, and odor-active compounds (OACs) formation of E. sinensis. A total of 7 and 11 OACs were detected in the hepatopancreas and gonad, respectively, these OACs contributed greatly to the overall odor profiles of E. sinensis when the dietary replacement levels were at 50% and 75%, respectively. The results could provide the guide for dietary fish oil replacement as well as improving the odor quality of E. sinensis. Practical application The objective of this research is to compare the effects of dietary replacement of fish oil by vegetable oil on proximate composition and odor profiles of E.sinensis. The results obtained from this study would not only chose an optimal dietary replacement level and serve as a useful database for the odor of female and crabs, but also provide some guide for the improvement of Chinese mitten crab aquaculture.