A konjac glucomannan composite film embedding proanthocyanidin-grafted chitosan and carvacrol@ZIF-8 nanoparticles for synergistic antioxidant/antibacterial packaging

Novel dual sustained-release film with antioxidant/antibacterial synergy. • PACS grafting enables persistent antioxidant activity. • CV@ZIF-8 nanoparticles provide prolonged antibacterial release. • Enhanced barrier, mechanical and UV-shielding properties. • Effectively preserves strawberry quality and extends shelf life. Few bio-based active packaging films simultaneously achieve sustained antioxidant and antibacterial functions, making a dual sustained-release system highly desirable. To extend postharvest fruit shelf life, this study developed an active packaging film based on konjac glucomannan (KGM). A dual-release antioxidant and antibacterial system was constructed by introducing proanthocyanidin-grafted chitosan (PACS) and carvacrol-loaded ZIF-8 nanoparticles (CV@ZIF-8). The resulting KPCZ-3 film exhibited a tensile strength of 34.36 MPa, a water vapor permeability of 2.72 g·mm·m −2 ·day −1 ·kPa, and an oxygen permeability of 1.27 × 10 −3  g·s −1 ·m −2 . In strawberry preservation tests at 25 °C, the film synergistically delayed quality deterioration and maintained optimal sensory and nutritional quality for over 4 days. In addition, the film showed good biodegradability and biocompatibility. These results indicate that KGM/PACS/CV@ZIF-8 films, as novel degradable active packaging, have promising application prospects. Download: Download high-res image (159KB) Download: Download full-size image