An EU project entitled ‘SpaceTaste’ is to investigate ways of reducing the musty, earthy flavour (‘off flavour’) of fish farmed in recirculating aquaculture systems (RAS). A good solution has not yet been found, despite repeated studies of 'off flavour' in farmed fish.
What is ‘off flavour’?
‘Off flavour’ refers to unwanted flavours and/or smells in food. In the case of aquaculture products, it usually means the musty, earthy taste caused by geosmin and 2-methyl isoborneol (MIB) in fish tissue. ‘Off flavour’ occurs in fish farmed in land-based aquaculture production systems with high nutrient levels, such as pond systems and RAS.
‘Off flavour’ in farmed fish is economically bad for the aquaculture industry. The unpleasant taste means that consumers buy less fish. Furthermore, it is expensive to remove ‘off flavour’ before bringing the product onto the market.
The project has identified three priority areas to reduce ‘off flavour’ in fish farmed in RAS:
- Prevention strategy: reducing the microbial production of geosmin and MIB in aquaculture production systems;
- Curative strategy: removing geosmin and MIB from fish cultivation water;
- Alternative strategy: optimising the purification process.