Researchers at McMaster University in Canada have created a new packaging tray that can signal when salmonella or other dangerous pathogens are present in packages of raw or cooked food such as chicken.

The new technology will enable producers, retailers and consumers to tell in real time whether the contents of a sealed food package are contaminated without having to open it, preventing exposure to contamination while simplifying cumbersome and expensive lab-based detection processes.

The prototype tray, shaped like a shallow boat, is lined with a food-safe reagent that allows a built-in sensor to detect and signal the presence of salmonella. The technology can readily be adapted to test for other common food-borne contaminants, such as E. coli and listeria.

“This is something that can benefit everyone,” says researcher Akansha Prasad, the co-lead author of a paper that describes the invention, published in the journal Advanced Materials. “We’re hoping this technology will save lives, money and food waste.”

There is a lot at stake with food safety, says researcher Shadman Khan, co-lead author on the paper. “We wanted to develop a system that was reliable, quick, affordable and easy to use.”

The sloped sides of the tray direct juices to a sensor embedded in a window at the bottom. Users can scan the underside of the sealed package with a cellphone and know immediately whether the food is contaminated without additional lab work.

Having easy, instant access to such information would allow public health authorities, producers and retailers to trace and isolate contamination quickly, reducing potentially serious infections and cutting back significantly on food waste by identifying precisely which lots of food need to be recalled and destroyed, compared to broad recalls that end up wasting unspoiled foods.

Further, the researchers say, protecting consumers from contaminated foods will create significant health-care savings.

Globally, there are about 600 million cases of food-borne illness every year, largely attributed to the consumption of pathogen-contaminated food products.

The McMaster researchers and their colleagues have been working for several years on related technologies, all aimed at creating simple, inexpensive tools to prevent and detect food contamination.

Their work is part of McMaster’s Global Nexus School for Pandemic Prevention & Response.