Polylactic acid aerogel with antibacterial, early warning and heat preservation functions applied to fresh trays

Fresh trays could not provide efficient protection and detection to the fresh foods during the transportation and sale processes due to its less functions. To address these challenges, one type of multifunctional fresh tray with antibacterial and detection properties was fabricated by the combining of two types of functionalized polylactic acid (PLA) aerogels, PLA/carvacrol (PLA/CA) aerogel and PLA-red cabbage anthocyanin (PLA-RCA) aerogel. The PLA/CA aerogel prepared by in situ encapsulation strategy exhibits a strong antioxidant effect with the free radical clearance rate of 69.57 % at 12 h, and a significant inhibitory effect on Staphylococcus aureus and Escherichia coli due to the existence of CA. The PLA- RCA aerogel prepared via the solute self-assembly strategy demonstrates a detection property due to the existence of RCA. Meanwhile, the microfiber structure of PLA aerogel provided more reaction sites for RCA which results in a fast response to ammonia in 5 s. Therefore, the novel fresh tray could not only extend the shelf life of food but also monitor the status of food in real time. Overall, the preparation of the novel fresh tray by the functionalization of PLA aerogel can provide a feasible solution for the storage and detection of fresh food.