Improving Sodium Alginate Films Properties by Phenolic Acid Addition

Currently, packaging materials constitute a group of the most commonly used products. Natural polymers are widely tested as potential packaging materials to replace traditional plastics. Sodium alginate is eco-friendly and reveals effective film-forming properties whereas tannic acid has been proposed as a sodium alginate cross-linker. Thin films of sodium alginate/tannic acid were obtained by solvent evaporation. Interactions between the components were determined as well as the maximum tensile strength and color change after contact with different solutions. Improvement in the physicochemical properties of the obtained films was noticed. Moreover, such films showed antioxidant properties. It may be assumed that materials based on a sodium alginate/tannic acid mixture are promising alternatives to traditional packaging materials.

Keywords: films; food packaging; sodium alginate; tannic acid.