Enhancing chitosan-zein films with Bergenia ciliata extracts toward smart food packaging

Abstract This research aims to develop chitosan-zein protein films supplemented with Bergenia ciliata (Bc) extract, a traditionally important medical herb of Himalayan origin. The film’s physicochemical, mechanical, antioxidant, and antimicrobial properties were systematically explored. The opacity of chitosan film increased from 2.42 ± 0.97 to 10.32 ± 1.44 upon introducing zein (Z) protein in chitosan (Cs) in a 1:2 ratio (w/w); conferring enhanced UV-blocking attributes. Incorporating B. ciliata extracts in the chitosan-zein film (Cs-Z-Bc) under optimized conditions further increased the opacity to 16.27 ± 1.03 without compromising the tensile strength. The α-diphenyl-β-picrylhydrazyl scavenging activity of the Cs-Z-Bc film was found to be 97.07 ± 1.09%. Additionally, these optimized films displayed significant antimicrobial efficacy, with zones of inhibition of 11.4 mm measured for gram-positive strains like C. subtilis and S. aureus and 11.2 mm and 11.1 mm for E. coli and K. pneumoniae (gram-negative) bacterial strains. The film also showed excellent biodegradable properties. The shelf life study of Himalayan cheese was significantly increased when wrapped with the film. These findings suggested that B. ciliata extract-fortified chitosan-zein films can be an excellent food packaging material.