The technique, which has been pioneered at Purdue University, is designed to estimate the numbers of microbes present in a food or liquid sample to ascertain any potential threats present, according to researchers behind the project.

Arun Bhunia, a microbiologist at Perdue, told FoodProductionDaily.com that the development, which forms part of an ongoing research project funded by the US department of agriculture (USDA), may have a number of industrial bio security uses.

He claimed that improvements to Hazard Analysis and Critical Control Points (HACCP) during food production, was just one of the areas that processors may benefit from by using the technology.

"Certainly, this can be used with the finished products to ensure that the products are safe to deliver for retail distribution or consumption," Bhunia said.

The technology is designed to test mammalian cells, which release varying amounts of signaling chemicals when harmed. This action is then measured through the use of both optical equipment and computer software to identify the amount of harmful microbes present within a food or liquid sample.

"This method can determine the pathogenic potential of the live microbes or active toxins instantly that are capable of causing diseases in consumers," Bhunia said. "Other methods may not be able to provide that information".

Fellow Purdue researcher Pratik Banerjee claimed that the technology is particularly effective at recognising miniscule levels of Listeria monocytogenes, and other food-borne contamination such as Bacillus.

Listeria is one of the most dangerous food borne pathogens. It multiplies at low temperatures and survives refrigeration. Fewer than 1,000 organisms can cause sickness to humans, sometimes leading to more serious illness.

In order to identify these pathogens, the Mammalian cells are put into a collagen gel, which the researchers claim is adept at capturing particles of various sizes, before being put into multi-well plates. Each well can then be used to test a different individual sample, allowing for simultaneous sample reviews.

These live cells, also known as biosensors, are able to identify harmful pathogens, while also ignoring inactive or harmless organism, according to Banerjee.

"Some analogous tests lack this capability, making them prone to false alarms and entailing a relatively lengthy incubation period to grow out any living microbes," he stated. "The new technology's discerning power also could help optimize processes to kill harmful microbes or deactivate toxins."

The researchers said that the new technology could offer mobility and versatility benefits due to the use of the well plates, which can be easily transported to locations like food processing plants for on-site testing.

Test limitations

The researchers added that their current goal was to ensure that cells can survive in the well-bound gel beyond the current time limit of four to six days. Bhunia claims that the aim would be for a time-span of two weeks, a period he said was necessary to maximise the commercial value of the product.

However, he added that research was ongoing, and as a diagnostic test, the technology could also be used for testing clinical specimens too.