Revolutionary food safety test saving shellfish industry time and money


A food safety test recently developed by scientists at Cawthron Institute and the UK's Centre for Environment, Fisheries and Aquaculture Science (Cefas) is proving valuable to shellfish industry and consumers.

A variety of commercial shellfish species are now tested for Paralytic Shellfish Toxins (PSTs) using a quicker, simpler, and more sensitive test. Aquaculture farmers and regulators are thrilled with the innovation.

New Zealand Oyster Industry Association President and Biomarine Chief Executive Jim Dollimore said the new test helps to avoid past situations where levels of some toxins have been sufficient to close shellfish harvest areas and trigger expensive testing – which came up negative, meaning production was put on hold unnecessarily.

"It's [the PST test] really improved our credibility among our customers, and the aquaculture and shellfish industry worldwide,” said Mr Dollimore.

Produced by microscopic algae, PSTs can naturally accumulate in filter-feeding shellfish such as mussels, oysters and scallops. These toxins pose a human health risk so tests are conducted regularly to protect public health and to ensure access to international markets.

Exporters commission these tests before they send their goods to market.

Cawthron marine toxin chemist and Safe New Zealand Seafood programme co-leader Dr Tim Harwood said. "Although several methods existed to monitor these toxins, they were time consuming and complex.

"We had been performing related research under the Safe NZ Seafood programme and saw the value in providing a test that was faster and more accurate. Our PST test has changed the game."

Work started on the new test back in 2013. It’s the result of international collaboration and rigorous research

The test uses LC-MS (liquid chromatography-mass spectrometry), an analytical chemistry technique that separates, detects, and identifies particular compounds of interest.

Ministry for Primary Industries specialist advisor for seafood Brian Roughan said, "It's sound science and a testament to the calibre of scientists at Cawthron who coordinate[d] this programme and developed this method."

Cawthron has obtained approval from the Ministry for Primary Industries to use it as part of the New Zealand marine biotoxin-monitoring programme and Dr Harwood is now looking for the rest of the world to follow, "We would like to get international acceptance for the method.

"True success is when other labs around the world acknowledge how good it is and start using it.”

A collaborative study is currently underway. This study involves different labs around the world testing the method and analysing samples, before reporting the results back to Cawthron for review. With results so far looking positive, the Cawthron developed Paralytic Shellfish Toxin test looks set to become a shellfish industry mainstay.

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