How accurate are the food expiration dates?
McMaster researchers hope to make use-by dates obsolete through smart packaging technology
Have you ever wondered if that cup of yogurt or tray of chicken in the back of the fridge is still safe to eat, even if it’s a few days past its use-by date?
Researchers at McMaster University hope to make expiration dates a thing of the past through a range of packaging and food testing technologies that signal whether products are spoiled or contaminated with pathogenic bacteria like E. coli, listeria and salmonella.
Tohid Didar, one of the researchers behind an article published April 30 in Nature Reviews Bioengineering, said the effort aims to reduce food waste, prevent recalls and stop the spread of food-borne illness.
Didar, a biomedical engineer and entrepreneur, is part of a team that’s spent seven years developing a range of food monitoring technologies.
“Food waste is a major issue,” Didar said in an interview. “In Canada we waste about $40 billion worth of food every year and our per-capita food waste is more than the U.K. and the U.S.”
Didar, also an assistant engineering professor at McMaster, said smart packaging technologies could save hundreds of billions of dollars globally each year, more than justifying the upfront costs.
“Contaminations and recalls have a lot of impacts,” Didar noted. “The brand gets affected. Health care gets affected and it’s a lot of waste.”
The McMaster team has developed a product called Sentinel Wrap, a plastic wrapping with printed DNA molecules that detect pathogens. The application can be used to monitor spoilage in meat, cheese and produce, providing a more reliable indicator of food safety, compared to an expiration date.
“I see a day that there are no dates printed on any of these packages,” said Didar.
Instead, smart packaging sensors would indicate a green or red signal to show whether a product is safe. Researchers are also developing a hand-held test to help food producers isolate specific lots of spoiled goods before they reach the market, eliminating recalls.
Another innovation is called labon-a-package, a tiny self-activating test placed into trays of chicken, red meat or fish, for example, that produces a visible signal when a product has spoiled.
There’s also a sprayable, food-safe gel containing beneficial organic bacteriophages that help to eliminate bacterial contamination. Didar said the gel can be applied to food products at the packaging stage, to plants and crops on the farm, or even fed to livestock in a joint effort to prolong shelf life and reduce animal antibiotic use.
Didar said smart packaging is a better indicator compared to an expiration date.
“The producers tend to be very conservative. They want to make sure they put a date where they’re 100 per cent sure the food is still good to consume. But that food could still be good for another two days or three days. We think if we have proper sensors, we could get rid of that static expiration date and have a more dynamic (system).”
Didar acknowledged food producers may be reluctant to accept higher packaging costs amid the current climate of food inflation.
“The issue we’re dealing with is the food prices are going up and what is happening is, when we talk to the food producers, they don’t want to add to the price of the packaging, even if it’s two or three pennies,” said Didar. “But when a recall happens, everyone gets affected.”
Didar said governments and policymakers have the power to mandate the use of smart packaging.
“I feel like there’s a need for more support to bring it to the retail stage, because it’s going to add to the cost of the packaging. But if you do what we call a sustainable return on investment — that’s environmental return, social return, all of that as a whole society — we think that adding a couple of pennies to the price of the packaging is definitely worth trying this.”
Didar said the research team has engaged with food producer partners in the U.K. and Germany as well as the Canadian Food Inspection Agency, to explore ways to bring innovative food packaging and testing strategies to market.
“We are trying our best to ensure that this can be scaled up and the price makes sense,” he said.
Didar noted automobiles and home appliances already contain smart sensor technology that detect when something is awry.
“Why shouldn’t we make food and food packaging smarter?”