Geosmin causes off‐flavour in arctic charr in recirculating aquaculture systems |
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| Authors: | Stéphanie Houle Kevin K Schrader Nathalie R Le François Yves Comeau Mourad Kharoune Steven T Summerfelt Arianne Savoie Grant W Vandenberg |
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| Institution: | 1. Département des sciences animales, Université Laval, Québec, QC, Canada;2. United States Department of Agriculture, Natural Products Utilization Research, Agricultural Research Service, University of Mississippi, University, MS, USA;3. Université du Québec à Rimouski, Rimouski, QC, Canada;4. Biod?me de Montréal, Montréal, QC, Canada;5. Department of Civil, Geological and Mining Engineering, école Polytechnique de Montréal, Montréal, QC, Canada;6. Département de Génie de la Production Automatisée, école de Technologie Supérieure, Montréal, QC, Canada;7. The Conservation Fund Freshwater Institute, Shepherdstown, WV, USA |
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| Abstract: | The ‘earthy’ and ‘muddy’ off‐flavours in pond‐reared fish are due to the presence of geosmin or 2‐methylisoborneol in the flesh of the fish. Similar off‐flavours have been reported in fish raised in recirculating aquaculture systems (RAS); however, little information is available regarding the cause of these off‐flavours. Our hypothesis was that earthy and muddy off‐flavour compounds, found previously in pond‐raised fish, are also responsible for off‐flavours 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‐flavours and requiring depuration using instrumental solid‐phase microextraction procedure and gas chromatograph‐mass spectrometry (GC‐MS)] and human sensory analyses. Geosmin was present in the samples taken from the biofilter and on the side walls of the tanks. Two‐methylisoborneol was only found in low levels in the samples. The GC‐MS results indicated the presence of geosmin in the fillets (705 ng kg?1), but lower levels were found in the water (30.5 ng L?1). Sensory analyses also detected an earthy flavour (i.e., geosmin presence) in the fillets, and, therefore, it appears that geosmin is the main compound responsible for the off‐flavour in RAS. Further studies are being performed to identify the microorganisms responsible for geosmin production in RAS. |
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| Keywords: | geosmin off‐flavour arctic charr recirculating aquaculture systems |
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