Intelligent Packaging Must Turn Freshness Signals into Decisions, Not Just Colors

A team at Kyushu University has presented a smart film for refrigerated mutton that combines two freshness signals: a colour shift in normal light and fluorescence under 365-nanometre UV light. The matrix is based on casein and includes modified anthocyanins from black soybean seed coats plus the porous material ZIF-67. Ammonia and other volatile basic compounds released during spoilage trigger the response.