Development of multifunctional films based on chitosan, nano silica and hops extracts

Abstract

• Hops extracts introduced into film with excellent properties. • The multifunctional film based on biopolymer. • The structural, physicochemical, and functional properties on films were investigated. • Multifunctional films process good biological activity and mechanical properties. Multifunctional films were developed by chitosan (CS) and nano silica (NS) with different concentrations (w/v, 0.05%, 0.10%, 0.15%, 0.20%) of hops extracts (HE). The effects of NS and/or HE on the structure, physicochemical and biological activities of CS membranes were studied. Multifunctional films were assessed by using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Structure analysis has proven successful incorporation of NS and HE into CS film. The physicochemical properties of the polymer matrix can be greatly changed by incorporating NS and/or HE. Obviously, the presence of NS could make the tensile strength show an upward trend (5.27–11.91 MPa), and the elongation at break also shows the same trend (42.23–68.98%). Furthermore, CS-NS film significantly improved barrier properties against water vapor permeability ( p < 0.05) and UV light. Bioactive analysis displayed that CS-HE and CS-NS-HE films both owned excellent antioxidant and antibacterial capability. Among these films, CS-NS-HE presented the lowest moisture content, water solubility and WVP, whereas the highest tensile strength and biological activity. This study suggests CS-NS-HE film would have broad application prospects in active food packaging materials that require strong water resistance and excellent mechanical properties.