Last week, hundreds of thousands of people lost their electricity… and the food stored in their refrigerators. But before the ice storm, researchers were already thinking about creating a tool that could have saved several foods from waste: a spoiled meat detector.
A piece of fresh meat, poultry or fish will generally keep for two to four days in the refrigerator. Despite their rapid degradation, there is “no test” to detect spoiled foods or regulations, says assistant professor of electrical and biomedical engineering at Concordia University, Steve Shih.
“There are no regulations in Canada on what spoiled meat is, other than using your nose to smell the meat and see if it has a bad smell. And that’s a big problem, because the meat can go bad without us being able to smell it. »
When it spoils, meat contains a toxin called putrescine. As its name suggests, it is responsible for foul odors, but can also cause headaches or heart palpitations. If consumed in too large quantities, it can also, in the long term, be responsible for colon cancer, warns Mr. Shih.
With his students, the director of the microfluidics laboratory Shih wanted to develop a sensor that would allow consumers to detect, beyond the smell, spoiled meat. “Like a pregnancy test”, the tool would be accessible, reliable and fast.
About the size of a strip of paper, it could be deposited by the consumer on the meat, or directly in the packaging by the retail chains. “I don’t know if supermarkets would like that, but that’s what we hope for consumers,” says Steve Shih.
A natural procedure
“We can consider the biosensor as a protein that attaches to putrescine, and then emits a green color. If the sensor stays white, there is no putrescine, so the meat is edible. If it turns green, it is not fit for consumption.
At the end of March, a Montreal researcher warned that fresh foods are contaminated with a chemical found on their labels. But adding this sensor to the packaging does not present any risks, reassures Mr. Shih.
“We wouldn’t say we can use it in packaging if it was unhealthy. All the elements that make up the sensor, the paper and the protein, are natural, insists the researcher.
Not yet on the market
The object is still at the prototype stage. Detection, which takes one to two hours, is still too slow. Mr. Shih would like that wait to be reduced to just “five minutes”.
For that, the process needs to be streamlined, says Jay Pimprikar, who co-authored the study. For now, a small piece of meat must be placed in a physiological solution, and rest there. It is then this solution which is deposited on the sensor. Eventually, this step will no longer be necessary, and it will suffice to place the sensor directly on the meat.
The researchers also aim to expand the range of foods for which the sensor works. For now, it is only usable on beef. But Shih is optimistic about widespread use, as putrescine is also found in chicken or fish.
To obtain even more precise results, the member of the Research Chair in Microfluids for Biological and Chemical Analysis at Concordia University would like to extend the analysis to molecules other than putrescine, which are also responsible for the degradation of meat.
Mr. Shih’s detection method could also prove useful beyond the kitchen walls. The professor believes, with the same protocol, to be able to detect heavy metals in water that are dangerous to health, such as mercury, copper or cobalt.
This content is produced in collaboration with Concordia University.