An intelligent bilayer film based on blue honeysuckle berries and Artemisia Sphaerocephala Krasch. Gum for Cyprinus carpio preservation and indication.

The demand for extended shelf life and food safety in the food industry continues to rise. At the same time, the environmental burden of traditional plastic packaging materials is becoming increasingly serious. Therefore, in this study, an intelligent bilayer film with a pH-sensitive inner indicator film based on Artemisia Sphaerocephala Krasch. Gum (ASKG) and blue honeysuckle berries anthocyanin (BHBA), and an antimicrobial outer film composed of polyvinyl alcohol (PVA) and cinnamon essential oil (CEO) were developed. SEM cross-sectional images showed a clear interface of the bilayer films, demonstrating the successful binding of the inner and outer layers; FTIR and X-ray results showed the binding and interaction of the components. The properties of the bilayer film were significantly enhanced with the increase of BHBA content. Compared to ASKG-BHBA film, the tensile strength of the bilayer film with 18 % anthocyanins increased by 143.66 %, elongation at break increased by 60.92 %, and showed excellent water resistance as well as water vapour barrier, thermal stability, free radical scavenging activity (increased by 14.7 %), and antimicrobial activity (inhibition circle diameter increased by 53.79 % and 57.98 %, respectively). In addition, the ASKG-BHBA and bilayer films exhibited excellent UV-vis light barrier, pH sensitivity and responsiveness to ammonia vapour. Freshness tests applied to Cyprinus carpio showed that the intelligent film could monitor the fish's freshness in real time and extended the shelf life by 1 to 3 days compared to the control. According to preliminary calculations, the cost of producing the bilayer film is about 0.1499 USD/piece. The bilayer film is expected to meet the market's dual demand for food safety and environmental protection and realize a wide range of applications in fresh food preservation and quality monitoring in the future.