Investigation of a novel smart and active packaging materials: Nanoparticle-filled carrageenan-based composite films

In this study, curcumin, zein, epigallocatechin gallate (EGCG) and carrageenan were used to fabricate curcumin-zein-EGCG-carrageenan (CZEC) layer-by-layer nanoparticles. These nanoparticles were embedded within carrageenan films to form composite films with enhanced antioxidant activity and smart responses. Light scattering, micro-electrophoresis, FTIR, and SEM were used to characterize the size, charge, interactions, and morphology of CZEC nanoparticles. The optical, mechanical, morphological, spectroscopic, thermal, and other functional attributes of the films were evaluated. The CZEC nanoparticles were uniformly dispersed within the carrageenan matrices, and improved their UV barrier (2.4-11.1 A mm^-1), mechanical (7.09 %-9.35 %), and thermal resistance properties. The films exhibited a color change, from yellow to red, in response to an increase in pH (2.0-12.0) or ammonia concentration (8.0 mM). The films also displayed relatively high DPPH (79.46 %) and ABTS (73.34 %) free radical scavenging activities. Finally, the composite film exhibited the ability of monitoring and extending the freshness of packaged fish.