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United States Department of Agriculture

Agricultural Research Service

Title: Geosmin causes off-flavour in arctic charr in recirculating aquaculture systems

item Houle, Stephanie
item Schrader, Kevin
item Lefrancois, Nathalie
item Comeau, Yves
item Kharoune, Mourad
item Summerfelt, Steven
item Savoie, Arianne
item Vandenberg, Grant

Submitted to: Aquaculture Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/25/2010
Publication Date: 2/1/2011
Citation: Houle, S., Schrader, K., Lefrancois, N.R., Comeau, Y., Kharoune, M., Summerfelt, S.T., Savoie, A., Vandenberg, G.W. 2011. Geosmin causes off-flavour in arctic charr in recirculating aquaculture systems. Aquaculture Research. 42:360-365.

Interpretive Summary: Arctic charr cultured in recirculating water systems were found to contain an “earthy” off-flavor. The compound geosmin was detected in the fish flesh and determined to be the cause of this off-flavor.

Technical Abstract: The “earthy” and “muddy” off-flavors in pond-reared fish are due to the presence of geosmin or 2-methylisoborneol (MIB) in the flesh of the fish. Similar off-flavors have been reported in fish raised in recirculating aquaculture systems (RAS); however, little information is available regarding the cause of these off-flavors. Our hypothesis was that earthy and muddy off-flavor compounds, previously found in pond-raised fish, are also responsible for off-flavors in fish raised in RAS. In this preliminary study, we examined water, biofilms in RAS, and fillets from cultured arctic charr (known to have off-flavors and requiring depuration) using instrumental (solid-phase microextraction procedure and GC-MS) and human sensory analyses. Geosmin was present in the samples taken from the biofilter and on the side-walls of the tanks. MIB was only found in low levels in the samples. The GC-MS results indicated the presence of geosmin in the fillets (1,095 ng kg-1), but lower levels were found in the water (56.3 ng L-1). Sensory analyses also detected an earthy flavor (i.e., geosmin presence) in the fillets, and, therefore, it appears that geosmin is the main compound responsible for the off-flavor in RAS. Further studies are being performed to identify microorganisms responsible for geosmin production in RAS.

Last Modified: 07/26/2017
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