New patch technology may help consumers detect spoiled food

TORONTO — To throw or not throw away is often the question when someone checks a package of food that may be past its sell-by date.

A team of researchers at McMaster University is perfecting a patch printed with harmless DNA molecules capable of detecting bacteria like E. coli or salmonella. The transparent patch would be attached to a package and could be scanned with a smartphone or other device, said mechanical-biomedical engineer Tohid Didar.

The patch changes colour under ultraviolet light if there is contamination present.

“We see this as an alarm system for you to know there might be something,” he said at the recent Canadian Meat Council food safety conference held in Toronto.

“Maybe we will get to a time when we don’t have an expiration date on that packaging. We can use it to see if it is good to eat or not. If we can get there this could avoid a lot of waste,” he said.

This could also save time sending products to a laboratory to do cultures that could take 16 to 48 hours to complete and analyze.

“It costs a lot of money for manufacturers to recall contaminated products,” he said.

McMaster researchers and private companies are working on other intelligent food packaging technology. A new food wrap is under development that could prevent pathogens or biofilm from adhering to packaging.

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