Smart Sticker Can Tell If Your Food Is Spoiling.. Here’s How

A new smart freshness sticker made using anthocyanin, a natural pigment extracted from red cabbage, can indicate the quality of certain food products through colour changes. The process involves extracting anthocyanin using purified water and citric acid, then applying the solution to cellulose paper or biodegradable polymers. When placed on foods such as paneer, the sticker changes colour based on the freshness of the product.

A yellow or green colour indicates that the food is fresh, while orange or pink suggests that its quality is declining. A red or darker shade indicates that the food is approaching spoilage. Such stickers are reportedly being used by businesses in several parts of China, while researchers are exploring ways to connect them with smartphones in the future. However, the sticker should be viewed only as a screening tool, not as a definitive test of food safety. Its key objective is to help reduce unnecessary food waste.