Off-flavour in Nile tilapia (Oreochromis niloticus) cultured in an integrated pond-cage culture system

Thai farmers are shifting to cage farming in ponds due to drastic fluctuations in production in river cages resulting mainly from deteriorating water quality and diseases. Cage culture of tilapia in ponds has its merits but it is not immune to off-flavour problems. This study compares the levels of off-flavour compounds: geosmin and 2-methylisoborneol (MIB), in Nile tilapia (Oreochromis niloticus) cultured alone in ponds (T1), alone in pond cages (T2), in ponds with caged catfish (T3), and in pond cages with catfish in ponds (T4). Off-flavour levels of caged tilapia in the Ping River were similarly determined for comparison. Analysis of geosmin and MIB by HS-SPME-GC/MS revealed that fish in all pond treatments were found to be off-flavoured. At harvest, Nile tilapia in pond cages had significantly higher geosmin and MIB levels (P