No more use-by dates on milk?

Consumers may not have to rely on expiration dates or their sense of smell to determine whether milk has gone bad thanks to a new sensor from Washington State University researchers. The sensor can 'smell' if milk has gone bad before the product is opened, but has no direct contact with it.

"If it's going bad, most food produces a volatile compound that doesn't smell good," said Shyam Sablani, Professor at WSU's Department of Biological Systems Engineering. "That comes from bacterial growth in the food, most of the time. But you can't smell that until you open the container."

It consists of chemically coated nanoparticles that react to the gas produced by milk and the bacterial growth that indicates spoilage, explained Sablani. The sensor detects these volatile gases and changes colour.

While it is still in its early stages, this development could replace expiration dates, which are based on best-case scenarios and only accurate if a product has been consistently stored at the correct temperature.

Currently, the sensor only shows if milk is spoiled or not, but the researchers aim to develop a way to visually show how long a product has before it spoils. Sablani hopes to integrate the sensor into a milk bottle's plastic cap to help predict remaining shelf life.

"We'll have to work with the industry to make this work. But we're confident that we can succeed and help improve food safety and shelf life for consumers," he said.

The research was published in the journal Food Control.

Image credit: ©stock.adobe.com/au/Valentyn Volkov