Colour-changing wrap could let you know when food has spoiled

Date labels found 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, according to Benedetto Marelli, a 2018 and 2021 principal investigator at the Abdul Latif Jameel Water and Food Systems Lab (J-WAFS) at the Massachusetts Institute of Technology. Benedetto and his colleagues have created a biodegradable plastic-like wrap made from silk which changes colour when exposed to rotting foods. Benedetto received a 2018 J-WAFS Seed Grant for his project 'Printed silk-based colorimetric sensors for food spoilage prevention and supply chain authentication', which developed 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.