Functional polysaccharide-based film prepared from chitosan and β-acids: Structural, physicochemical, and bioactive properties

Abstract

β-Acids are natural antibacterial and antioxidant ingredients, obtained from supercritical CO2 hop extract. In this study, β-acids/chitosan complex films were prepared using the casting method. Complex films were characterized using scanning electron microscopy (SEM), atomic force microscope (AFM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction analysis (XRD). Structure analysis revealed that β-acids can be successfully combined with the chitosan matrix. Mechanical tests demonstrated that the tensile strength of the films showed a significant upward trend (1.9 MPa to 9.6 MPa) with increase in β-acids content (0.1%–0.3%). Interestingly, the chitosan-based films showed excellent UV barrier capability below 400 nm. The release of β-acids from the film followed Fickian diffusion (n < 0.45). In addition, the complex films inhibited the growth of five food-borne pathogens (Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Salmonella enteritidis and Listeria monocytogenes). This study highlights the promising nature of composite film as a desirable alternative for active packaging.