Cross-linked gelatin film enriched with green carbon quantum dots for bioactive food packaging

Dialdehyde Persian gum (PG) was applied to reinforce the physicomechanical properties of gelatin films through cross-linkage. Carbon dots (CDs) from grape leaves were incorporated into the system to fabricate nanocomposites. Adding oxidized PG to gelatin and CDs up to 5 % improved tensile strength. The solubility of the oxidized PG/gelatin film increased with the addition of CDs. The water vapor transmission of the gelatin film decreased through cross-linking. Adding CDs to the films reduced UV transfer rates but increased the antioxidant activity from 16.66 to 94.08 %. The oxidized PG/gelatin film with CDs showed antibacterial activity against Escherichia coli and Staphylococcus aureus. The fabricated films showed no cell cytotoxicity. Observed decreases in TVB-N and TBARS values, in trout fillets coated with the film containing 30 % CDs, resulted in extended shelf life up to 4 days. Cross-linked gelatin incorporated with CDs offers various applications in the food industry due to its functional properties.