Multifunctional Peanut Shell-Derived Carbon Dots/Chitosan-Polyvinyl Alcohol Composite Films for Preservation of Fruits

Food loss of agricultural products has become a major global challenge that urgently requires effective solutions. This study developed multifunctional composite films by integrating peanut shell-derived carbon dots (CDs) into chitosan (CS)/polyvinyl alcohol (PVA) matrices. The CS/PVA composite film containing 5% CDs (CP/5%CDs) exhibited significant improvements in ultraviolet shielding, mechanical strength, water vapor barrier properties, and thermal stability, attributing to the formation of a dense film structure and effect of hydrogen bonding interactions among film components. Notably, this composite film exhibited exceptional antioxidant capacity with 80.19% DPPH and 99.20% ABTS radical scavenging rates. And this composite film showed potent antibacterial capacity through photocatalytic ROS generation, exceeding 94% inhibition against both Escherichia coli and Staphylococcus aureus under light irradiation. Furthermore, when applied in strawberry preservation trials, the CP/5%CDs film effectively extended shelf life, demonstrating practical potential for perishable food packaging applications. Practical Applications This research could be used to develop safer and more sustainable food-packaging materials for fresh produce. The film helps slow spoilage by blocking UV light, reducing moisture loss, and limiting bacterial growth. It may offer food industries and consumers an eco-friendly option to keep perishable fruits fresher for longer.