Layer-number-controlled Fe-tea polyphenol metal-phenolic network-coated PLCL/gelatin electrospun membranes for active preservation of yellow sweet cherries

Layer-controlled Fe-TP coating endows PLCL/Gel fibers with favorable physical properties. • Fe-TP coating confers potent antioxidant and antibacterial activities and excellent biocompatibility. • Fe-TP/PLCL-Gel 4 exhibits optimal preservation performance for yellow sweet cherries. To address postharvest fruit spoilage from microbial contamination and oxidation, biodegradable PLCL/gelatin electrospun membranes were functionalized with layer-number-controlled Fe-tea polyphenol (Fe-TP) networks via layer-by-layer assembly. Fe-TP deposition increased fiber diameter, improved hydrophilicity, and enhanced mechanical strength while maintaining flexibility. Increasing the number of assembly cycles enhanced TP release and antioxidant activity, delayed degradation, and improved antibacterial activity against Gram-positive and Gram-negative bacteria. Cytocompatibility and hemolysis assays indicated favorable biosafety. SEM and leakage assays suggested membrane disruption and intracellular leakage as possible antibacterial mechanisms. In yellow sweet cherry preservation, the Fe-TP effectively delayed decay. Although Fe-TP/PLCL-Gel 8 exhibited stronger antibacterial and hydrophilic performance, the Fe-TP/PLCL-Gel 4 achieved the best overall balance of mechanical properties, release, safety, and preservation efficacy, with a day-7 decay rate of only 1.85% ± 3.21%, versus 50.00% ± 5.56% for PE control. This layer-optimized multifunctional electrospun membrane offers a highly effective, promising material for fruit preservation. Schematic diagram of experimental process and mechanism. Download: Download high-res image (122KB) Download: Download full-size image