Preparation of antimicrobial and antioxidant gelatin/curcumin composite films for active food packaging application

The functional gelatin/curcumin composite film was prepared using an emulsifier, sodium dodecyl sulfate (SDS). The composite films were characterized using field emission scanning electron microscopy (FE-SEM) and Fourier transform infrared spectroscopy (FTIR). The FE-SEM test results showed that curcumin was evenly distributed in the gelatin polymer matrix to form a flexible composite film with a smooth surface. The addition of 1.5 % of curcumin improved the UV blocking effect by more than 99 % at a loss of 5.7 % of transparency compared to neat gelatin films. The addition of curcumin (up to 1 wt%) significantly improved mechanical and water vapor barrier properties. Also, the gelatin/curcumin composite films exhibited remarkable antimicrobial activity against foodborne pathogenic bacteria, E. coli and L. monocytogenes, and showed strong antioxidant activity comparable to ascorbic acid. Antibacterial and antioxidant gelatin/curcumin composite films with improved UV protection, water vapor barrier and mechanical properties have high potential in active food packaging applications.