Incorporation of curcumin extract with lemongrass essential oil into the middle layer of triple-layered films based on furcellaran/chitosan/gelatin hydrolysates - In vitro and in vivo studies on active and intelligent properties.

Triple-layered, pH-sensitive and active films based on furcellaran (FUR), chitosan (CHIT) and gelatin hydrolysates (HGEL) were obtained for the first time. Curcumin ethanol extract (CUR) enriched with lemongrass essential oil (LEO) in three concentrations was added to the middle layer of the film. SEM and AFM analysis confirmed the formation of 3 layers, and CUR-LEO was evenly dispersed in the 2nd layer. The addition of CUR-LEO influenced the color of the surface and improved the UV blocking properties of the film. However, the mechanical and water vapor barrier properties remained unchanged. The CUR-LEO demonstrated antibacterial properties against bacteria and fungi. The antioxidant activity of the films increased along with the increasing concentrations of CUR-LEO. The presented films were able to effectively extend the storage life of tomatoes. Moreover, the colored films had the monitoring freshness effect with a distinct color change during carp storage.