Toward a Fully Edible Sensor Showing If Frozen Food Has Previously Thawed

When you’re standing in the frozen food aisle, it’s nearly impossible to know whether that Salisbury steak has thawed and refrozen — a process with potentially harmful consequences. So, researchers reporting in ACS Sensors have designed a food-grade device from edible materials, including table salt, red cabbage and beeswax, that lets you know. The proof-of-concept sensor provides a color readout when it’s warmed above a specific temperature, which is tunable from -58°F to 32°F. Keeping food ...