Gelatin/Carrageenan-Based Functional Films with Carbon Dots from Enoki Mushroom for Active Food Packaging Applications

Enoki mushroom-derived carbon dots (mCDs) were fabricated using a facile hydrothermal method to prepare gelatin/carrageenan-based active food packaging films. The mCDs were characterized by UV light spectroscopy, photoluminescence spectroscopy, and transmission electron spectroscopy. They showed high antioxidant activity with negligible cytotoxicity toward mouse fibroblast L929 cells and were evenly dispersed in the gelatin/carrageenan polymer matrix to form a compatible composite film. The addition of mCDs produced a highly transparent film with significant improvement in mechanical properties without much changing the water vapor permeability and hydrophobicity of the film. The release of mCDs from the composite film depended on food simulant solutions, and the release rate was highest in aqueous solution and 10% ethanol. In addition, mCD-added gelatin/carrageenan films exhibited strong antioxidant activity as determined by DPPH and ABTS methods. Therefore, the mCD-blended gelatin/carrageenan-based films with improved physical and functional properties can be used in active packaging applications to extend the shelf life of food products.