Multifunctional trilayer films based on gelatin-dextran incorporated with defatted rice bran-derived carbon dots for scallop preservation

Single-layer films lack sufficient mechanical, barrier, and controlled-release properties. Thus, a three-layer gelatin/gelatin-dextran/gelatin film incorporated with defatted rice bran-derived carbon dots (DRB-CDs) was prepared to overcome these issues and preserve scallops. DRB-CDs were non-toxic to HaCaT cells (<2 mg/mL). They enhanced the film's thermal stability and formed hydrogen bonds with the matrix polymer. Increasing the DRB-CDs concentration improved the film's UV-blocking, antioxidant, and antimicrobial properties. Adding 3 % DRB-CDs reduced the film's water vapor permeability by 35 %, increased the tensile strength 2.09-fold, and increased the elongation at break 1.15-fold. The three-layer structure enabled the sustained release of DRB-CDs in food simulants. Scallops wrapped with 3 % DRB-CDs-loaded films showed enhanced chemical and microbial stability, extending their shelf life by ≥6 days. In conclusion, this study proposes a sustainable and effective active packaging strategy using food-byproduct-derived nanomaterials to maintain seafood quality, showing significant potential to replace petroleum-based packaging.