Biodegradable food packaging could alert eaters that their food is spoiling by changing colour.
Date labels put on perishable foods are often poor predictors of when food will become dangerous to eat, which can lead to both food waste and food poisoning, says Benedetto Marelli at the Massachusetts Institute of Technology.
So, he and his colleagues decided to create packaging that can react to changes in the food it contains to better indicate when it has gone bad.
They made four films similar to …