Chitosan-based films with incorporated supercritical CO2 hop extract: Structural, physicochemical, and antibacterial properties

摘要

Chitosan-based films with incorporated supercritical CO2 hop extract (HE) were developed and evaluated regarding structural, physicochemical, and antibacterial properties. The morphological and spectroscopic analyses have confirmed successful incorporation of HE into the polymer matrix, which affected films' structure and visual appearance. The presence of HE has caused a reduction in the hydrophilic character of films, but also provided a complete UV light blockage at wavelengths below 350 nm. Furthermore, a declining trend of tensile strength (from 14.4 MPa to 6.4 MPa) and Young's modulus (from 218.8 MPa to 26.9 MPa), as well as an ascending trend of elongation at break (from 10.7% to 35.1%), have been observed after the extract incorporation. The total phenolic content in the films was up to similar to 13 mg(GAE) g(film)(-1). Besides, the HE-loaded films exhibited antibacterial activity against foodborne pathogen Bacillus subtilis.