Low-density polyethylene/curcumin melt extruded composites with enhanced water vapor barrier and antioxidant properties for active food packaging

In this study, active biocomposite films of low-density polyethylene (LDPE) containing 5% wt. of curcumin, a natural chemical produced by some plants, are developed by melt extrusion and hot pressing. The detailed study of the physicochemical properties of the formed films demonstrates that the curcumin molecules, homogeneously dispersed in the whole volume of the LDPE matrix, cause a notable increase in the thermal stability of the LDPE polymer, without altering its thermal processability. At the same time the LDPE's water vapor barrier properties are significantly improved, while an effective antioxidant scavenging activity is observed against the 2,2-diphenyl-1-picrylhydrazyl free radicals (DPPH center dot). These results indicate that the developed active films based on the combination of LDPE and curcumin, following industrially applied preparation methods, are ideal candidates for active food packaging applications.