Film based on chitosan and wood vinegar with superior antioxidant, UV-shielding, and bacteriostatic properties for food packaging

This study proposed a new film-forming system on wood vinegar (WV)/chitosan (CS) by replacing the traditional chitosan solvent with wood vinegar based on its richness in organic acids and phenolic organic compounds. A film material with excellent antioxidant, UV-shielding and bacteriostatic properties was successfully prepared. Notably, the optimized film has specific mechanical properties (tensile strength 12.97 MPa, elongation at break 38.15 %), superior antioxidant properties (scavenging of DPPH and ABTS radicals of 95.2 % and 99 %, respectively), UV shielding (up to 100 %) in the region of 200 nm–400 nm and excellent bacteriostatic properties (inhibitory circle diameter of up to 8.5 mm and 23 mm for Escherichia coli and Staphylococcus aureus , respectively). The prepared film could effectively reduce browning and water evaporation from apples (about 56.5 % reduction within 24 h), and decrease the peroxide value of food oil (about 45.2 % reduction within one month comparing with the commercial plastic wrap) during storage. This study provides ideas for the innovative preparation of CS films and the feasibility of sustainable development and utilization of WV. • Wood vinegar/chitosan-a novel antioxidant active packaging system. • Biofilm with natural sources and a simple preparation process. • Functional films with superior biodegradability, bacteriostatic, and UV-shielding properties. • Effective as a food packaging film to extend the shelf life of apples and canola oils.