Development of Alkali‐Modified Starch and Konjac Glucomannan Antibacterial Films Loaded With Cinnamon Essential Oil for Sustainable Food Packaging

ABSTRACT Although the starch‐based polysaccharide material has the advantages of environmental protection, its high hydrophilicity and low mechanical strength limit its practical application in the field of packaging. In this study, the biodegradable antibacterial composite films were successfully produced by modifying starch and konjac glucomannan (KGM) with sodium hydroxide and loading with cinnamon essential oil (CEO). The characterization results of the composite films showed that after alkali treatment of starch and KGM, a more dense network structure could be established with CEO through hydrogen bonding and electrostatic interaction. Compared with the starch/KGM composite film, the tensile strength of the composite film was increased by 36%, the surface hydrophobicity was improved by 14.9%, and the ultraviolet transmittance was reduced by 20%. Furthermore, the incorporation of CEO endowed the films with remarkable antibacterial properties, enabling their application in strawberry preservation to extend postharvest shelf life. After 5 days of sealing, the strawberries showed no decay and maintained a vitamin C content of 135 mg/100 g. Accordingly, the modification of starch and KGM by sodium hydroxide could improve the hydrophobicity and mechanical properties of the composite film, which could be used as an effective strategy for designing biodegradable polysaccharide composite packaging materials.