Antimicrobial and Antioxidant Activity of Chitosan/Hydroxypropyl Methylcellulose Film-Forming Hydrosols Hydrolyzed by Cellulase

The aim of this study was to evaluate the impact of cellulase (C) on the biological activity of chitosan/hydroxypropyl methylcellulose (CH/HPMC) film-forming hydrosols. The hydrolytic activity of cellulase in two concentrations (0.05% and 0.1%) was verified by determination of the progress of polysaccharide hydrolysis, based on viscosity measurement and reducing sugar-ends assay. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging effect, the ferric reducing antioxidant power (FRAP), and microbial reduction of Pseudomonas fluorescens, Yersinia enterocolitica, Bacillus cereus, and Staphylococcus aureus were studied. During the first 3 h of reaction, relative reducing sugar concentration increased progressively, and viscosity decreased rapidly. With increasing amount of enzyme from 0.05% to 0.1%, the reducing sugar concentration increased, and the viscosity decreased significantly. The scavenging effect of film-forming solutions was improved from 7.6% at time 0 and without enzyme to 52.1% for 0.1% cellulase after 20 h of reaction. A significant effect of cellulase addition and reaction time on antioxidant power of the tested film-forming solutions was also reported. Film-forming hydrosols with cellulase exhibited a bacteriostatic effect on all tested bacteria, causing a total reduction.