Development of intelligent/active food packaging film based on TEMPO-oxidized bacterial cellulose containing thymol and anthocyanin-rich purple potato extract for shelf life extension of shrimp

An intelligent and active film was developed based on 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-oxidized bacterial cellulose (TOBC) containing thymol (THY) and anthocyanin-rich purple potato extract (ANT). The microstructure, thermal stability, water vapor permeability, mechanical property and UV protection performance of TOBC-based films were evaluated. Scanning Electron Microscopy (SEM) and Atomic Force Microscope (AFM) results show the additions of THY and ANT bring about the uneven distribution of TOBC fibers with slightly increased surface roughness. Meanwhile, the introduction of THY and ANT could increase the thermal stability, UV protection and water vapor barrier property of TOBC with slightly decreased tensile strength. The prepared ANT exhibits a pH-sensitive activity, and it endows the fabricated TOBC/THY/ANT film with colorimetric response ability to volatile ammonia. TOBC/THY/ANT film also exhibits good antibacterial and antioxidant activities. Particular finding is that TOBC/THY/ANT film possesses simultaneously freshness real-time monitoring and good shrimp preservation abilities. The antioxidant, antibacterial and color response performances of TOBC/THY/ANT film were measured for three cycles in order to prove its recycling ability. These unique features of TOBC/THY/ANT film demonstrate the potential in commercial shrimp packaging with freshness real-time monitoring.