Preparation and Performance Exploration of Emoji Intelligent Tags

Judging the freshness of food by detecting gases within food packaging is more accurate than traditional methods that rely on production dates. This paper explores the influence of substrate and solution concentration on label performance using a solution with indicating properties derived from anthocyanins found in black goji berries. The “emoji” labels were printed on filter paper utilizing an inkjet printing technology, employing a 25 mg/mL concentration of anthocyanin solution. The effectiveness of these labels was evaluated through color changes when applied to fish meat samples. The “Emoji” label sensitively detects changes in environmental pH to determine the spoilage status of fish flesh after 10 h of storage under a constant temperature of 30 ℃. This innovative smart label offers convenience, intuitiveness, and vividness, demonstrating significant potential for application in the realm of meat food packaging.