Alterations in fatty acid composition and volatile compounds in muscle of large yellow croaker Larimichthys crocea fed different dietary lipid sources

Abstract

A 12-week feeding trial was performed to evaluate the impacts of different dietary lipid sources on the fatty acid composition and volatile compounds in muscle of large yellow croaker Larimichthys crocea (initial body weight: 36.87 ± 0.32 g). The 6.5 % of fish oil, soybean oil, palm oil, vegetable oil blend (soybean oil: palm oil = 1:1), rapeseed oil and linseed oil were added respectively to formulate six isonitrogenous (46 % crude protein) and isolipidic (13 % crude lipid) experimental diets, which were named as FO, SO, PO, BO, RO and LO respectively. Results showed that dietary vegetable oils significantly reduced the contents of arachidonic acid (ARA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in muscle. While the highest levels of linoleic acid (LA), palmitic acid (PA), oleic acid (OA) and linolenic acid (ALA) were found in fillet of fish fed SO, PO, RO and LO respectively. Among the 39 identified volatile compounds in fillet, 23 were significantly affected by replacement of dietary fish oil with vegetable oils. Fish fillets in different treatments were mostly characterized by distinct volatiles and odours. Principal component analysis and Pearson’s correlation analysis indicated that some volatiles had strong positive correlations with main fatty acids in muscle, for example, (E)-2-pentenal, 1-penten-3-ol, etc. In conclusion, replacement of dietary fish oil by vegetable oils changed the volatile compounds in muscle of large yellow croaker, which could be ascribed to the modifications of muscle fatty acids induced by dietary vegetable oils.