Using a credit card-sized device called a microfluidic chip, the researchers have developed a way to test for histamine—a potentially toxic compound—without the need to use complex chemical additives to the fish.
Histamine is a naturally occurring organic compound found in a range of products, including fish and red wine. A known allergen, histamine concentrations can increase when food spoils, leading to potentially fatal food poisoning.
More efficient than other methods
Associate Professor Claire Lenehan, a lecturer in forensic and analytical chemistry, said the purpose-built microfluidic chip, which resembles a credit card, is fitted with electrodes that detect histamine levels as a sample passes through a tiny pipe in the plastic device.
“We extract different compounds from the fish in liquid form, and these compounds will pass through the device at different rates,” said Lenehan.
“We can tell what compounds are histamine, and how much histamine is contained in the sample, based on the rate at which the compounds pass through the device.”
Lenehan, who built the chip with Flinders PhD candidate Leigh Thredgold, said the method was a much more efficient and cost-effective way to test for histamine levels in fish.
“At the moment the extraction of compounds takes longer than the actual analysis because you have to pulverise the fish, add a chemical to turn it into a different chemical and then test it,” she said.
“It’s an indirect testing method because you’re not actually detecting histamine at all; you’re detecting a product of histamine.
“Our method is a much simpler way because all you do is extract the sample and pipette it into the device without having to chemically treat it first.”
Useful for allergy sufferers
In addition to preventing food poisoning, the device could also be used by consumers who are allergic to histamine, Lenehan added.
“For the seafood industry, our method is a simple, cost-effective and rapid way to monitor food quality and reduce the incidence of food poisoning.
“It could also be marketed to consumers who have histamine sensitivity because they can use the device to test a product before they consume it.”
The research has just been published in the international journal Analytical Methods.