Smart Food Sensor Detects Packaged Food Contamination
Tuesday, September 22nd, 2020 | 915 Views
MIT engineers have designed a Velcro-like food sensor, made from an array of silk microneedles, that pierces through plastic packaging to sample food for signs of spoilage and bacterial contamination.
The sensor’s microneedles are moulded from a solution of edible proteins found in silk cocoons, and are designed to draw fluid into the back of the sensor, which is printed with two types of specialised ink. One of these “bioinks” changes colour when in contact with fluid of a certain pH range, indicating that the food has spoiled; the other turns colour when it senses contaminating bacteria such as pathogenic E. coli.
The researchers attached the sensor to a fillet of raw fish that they had injected with a solution contaminated with E. coli. After less than a day, they found that the part of the sensor that was printed with bacteria-sensing bioink turned from blue to red — a clear sign that the fish was contaminated. After a few more hours, the pH-sensitive bioink also changed colour, signaling that the fish had also spoiled.
Such smart food sensors might help head off outbreaks such as the recent salmonella contamination in onions and peaches. They could also prevent consumers from throwing out food that may be past a printed expiration date, but is in fact still consumable.
“There is a lot of food that’s wasted due to lack of proper labelling, and we’re throwing food away without even knowing if it’s spoiled or not,” says Benedetto Marelli, the Paul M. Cook Career Development Assistant Professor in MIT’s Department of Civil and Environmental Engineering. “People also waste a lot of food after outbreaks, because they’re not sure if the food is actually contaminated or not. A technology like this would give confidence to the end user to not waste food.”
As seen on ScienceDaily
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