Development of chitosan/cycloolefin copolymer and chitosan/polycaprolactone active bilayer films incorporated with grape seed extract and carvacrol

Abstract

[EN] Chitosan (CH) bilayer films were obtained by casting polycaprolactone (PCL) or cycloolefin copolymer (COC) onto the CH film surface. Active components, such as grape seed extract (GSE, 5%, w/w) and carvacrol (CV, 10%, w/w), were incorporated into the bilayers. Film samples were characterized as the release behavior of CV in ethanol, antioxidant activity, water vapor permeability (WVP), tensile properties, and optical characteristics. The contact angles of COC and PCL chloroform solutions on the CH-based film surface were also analyzed to evaluate the potential wettability of CH films with PCL or COC solutions. A lower release rate was observed in COC-based bilayer films when compared to PCL-based bilayers. Film samples including GSE and CV showed radical scavenging activity, reducing the radical between 10-15%. The PCL or COC layers on CH improved the WVP, while GSE also negatively affected WVP. The combination of GSE and CV in the bilayer film formulations enhanced the films' tensile properties. All film samples showed an internal transmittance value of around 80%.