Development of electrospun nanofiber membranes based on ZIF-8 MOF loaded tea polyphenols with pH-responsive release capabilities for food preservation

The traditional packaging of food lacks a controlled-release mechanism, resulting in a relatively low preservation efficiency of the food. The development of controlled-release packaging can effectively solve this problem. In this study, based on the acid responsiveness collapse of ZIF-8, a nanomaterial, tea polyphenols@ZIF-8 (TZ8, ZIF-8 with tea polyphenols encapsulated) with pH-responsive release of tea polyphenols (TPs), was prepared, then polyacrylonitrile/TZ8 nanofiber membranes (PT8-NF) were fabricated in combination with electrospinning. The release of TPs could be controlled based on the pH changes that occurred during food spoilage and deterioration. When the pH is 5, the release rate can reach a maximum of 73.41 %. The membrane also had excellent antibacterial, antioxidant and biocompatibility properties. Its inhibitory effect on E. coli and S. aureus is both over 99 %, and it has an inhibitory effect on the formation of their biofilms. The scavenging rates of the two free radicals, DPPH and ABTS, were the highest, reaching 86.55 % and 91.61 % respectively. After co-cultured with the membrane for 48 h, the L929 cell's survival rate was all above 90 %, and the highest hemolysis rate was only 0.81 %. The membrane was used to preserve strawberries and salmon. At 25 °C, the shelf life of strawberries was successfully extended to 8 days, and at 4 °C, the shelf life of salmon was successfully extended to 12 days.