Synergistic Effect of Plasticizer and Cross-Linking Agent on the Properties of Finger Millet Starch-Based Film

Abstract

Edible films can be used for food packaging to extend the shelf life of foods and protect them from exposure to moisture, microorganisms, pathogens, and bacteria. In the present study, the effect of plasticization and cross-linking, which are modification approaches for upgrading the properties of starch, are investigated. Glycerol and sorbitol are used as plasticizing agents, and succinic acid is used as a cross-linking agent. The results demonstrate that the addition of glycerol and sorbitol to the film-forming solutions reduces brittleness and increases peeling ability and flexibility upon drying. Furthermore, the film matrix supports improvements in water vapor permeability (WVP), swelling index (SI), and mechanical properties. The glycerol-based finger millet starch (FMS) films exhibits better thermal stability than the sorbitol-based FMS film. The microscopic images of the films show that the use of glycerol in the film improves compactness and homogeneity compared to sorbitol-based FMS films.