Automated sample preparation speeds up off-flavour research in the aquaculture industry

Recirculating aquaculture systems’ are increasingly used for largescale fish production, but monitoring of fish tissues is needed to ensure that they do not accumulate ‘off-odours’ in these closed-circuit systems. We talked to Robert Harrington, Research Associate at the Aquaculture Research Institute (ARI) at the University of Maine, about how he’s using Centri to monitor geosmin and 2-methylisoborneol.

The challenge of monitoring off-odours in fish

Geosmin and 2-methylisoborneol are odorous chemicals naturally produced by bacteria commonly found in recirculating aquaculture systems. Although naturally occurring, when they accumulate in fish tissues, they can give rise to an unpleasant ‘off-odour’, which is unappealing to consumers.

The challenge is therefore to identify geosmin and 2-methylisoborneol in the fish tissues before the product is shipped – but these odorants are easily absorbed into the tissue, making extraction difficult.

Techniques such as liquid–liquid extraction or solid-phase extraction are commonly used in combination with sensitive detectors to reach the low detection limits stipulated in many regulations. However, they tend to use large volumes of solvents, which are expensive and pose health & safety concerns for analysts.