Fully transparent and flexible antibacterial packaging films based on regenerated cellulose extracted from ginger pulp

Full transparent and bendable multifunctional composite films were successfully prepared using regenerated cellulose extracted from ginger pulp. Ginger pulp was chemically treated to obtain the highly purified cellulose. The purified cellulose was dissolved in DMAc/LiCl and regenerated in coagulants such as water, ethanol, and acetone to produce transparent cellulose films with high flexibility. Zinc oxide nanoparticles (ZnO NPs) and curcumin were further incorporated into the regenerated cellulose films to give antioxidant, antibacterial, and UV barrier properties. The regenerated cellulose film prepared in ethanol (RCE) showed the highest tensile strength of 51.4 MPa as well as the highest transmittance of 70.0% at 280 nm (UV) and 90.1% at 660 nm (visible light). The RC film incorporated ZnO NPs and curcumin (RC/ZC) imparted strong antioxidant and antibacterial activities. The antioxidant activity of the RC/ZC films ranged from 56% to 64% but there is no significant difference by types of coagulants. In addition, the RC/ZC films showed strong antibacterial activity of more than 99% against six bacteria.