Yes, the off-flavor components can affect the taste of the fish meat. Off-flavor is not a problem in all the RAS production, but it can be an issue in RAS when the system is highly loaded. Because of the high level of re-cycling and the small rate of new water coming into the system, there is a risk of off-taste coming from flavor-producing bacteria living in the biofilter and the biofilm in the system. One component is geosmin that you smell in rain in the summer or detect when eating vegetables but having the component in the fish is most often disliked by consumers.
The off-taste problem does not affect smolt and post-smolt production as these fish are transferred for grow-out at sea sites. The off-flavor component will disappear quickly once the fish are growing at sea. In the land based grow-out systems however, the off- flavor components can be an issue. The removal of geosmin in fish on land is carried out by having the fish in clean geosmin-free water for 7-10 days. This prosses is called purging or depuration and removes the off-flavor components from the fish tissue and fat.
AKVA group´s Research & Development team is working together with world-leading experts to prevent the formation of off-taste in land based aquaculture. The results are promising, and we are developing new methods of managing off-taste.