Cellulose Nanocrystals Modulate Curcumin Migration in PLA-Based Active Films and Its Application as Secondary Packaging

This study presents the development of poly(lactic acid) (PLA)-based biocomposite films incorporating algal cellulose nanocrystals (CNC) and curcumin (CUR) using a customized solution casting machine, where CUR serves as a bioactive agent. Two different types of biocomposites were fabricated with and without CUR, aiming to investigate the impact of varying CNC concentrations (0, 0.5, 1, and 2 wt %) while maintaining a constant CUR concentration of 2 wt %. The overall and specific migration (OM and SM) study was performed using aqueous food simulants. PLA films containing CNC/CUR were tested for SM, whereas those containing only CNC were tested for OM. Through a comprehensive analysis, it was observed that the inclusion of CNC increased the OM rate of the biocomposite films, but it remained below the permissible limits. Notably, during storage at 40 °C, the CUR-incorporated PLA/CNC active films demonstrated an accelerated CUR migration compared to PLA/CUR films, with migration kinetics fitting best to the Korsemeyer–Peppas model. As attributed, CUR-incorporated active films exhibited superior UV-light blocking, antioxidant, and antimicrobial properties. The physical and chemical properties of developed biocomposites were characterized by TGA, DSC, FTIR, XRD, WVTR, and WCA. The curcumin-incorporated biocomposite films displayed their potential as secondary packaging for cut potatoes, highlighting their potential for active sustainable food packaging solutions.