Gelatin/potato starch edible biocomposite films: Correlation between morphology and physical properties

Abstract

The paper presents the results of studies of the microstructure morphology and the operational properties of the gelatin/potato starch/glycerol edible biocomposite films varying in the starch content from 0 to 50wt% prepared by casting film-forming solution and dying at 36°C for 15h. The biocomposite films were shown phase separated heterogeneous morphology with the gelatin matrix as a continuous phase and microgranules of starch as a minor phase. It is found that when the starch content ≤ 30wt% the phase separation mechanism is nucleation and grow, whereas the starch content > 30wt% then the spinodal decomposition is the dominant mechanism. The work focuses on findings the influence of the phase separation mechanisms on the size of starch granules during the drying process, as well as the impact of these mechanisms on optical, frictional, mechanical, thermal and water-barrier properties.

Keywords: Biocomposites; Edible films; Gelatin; Morphology; Phase separation; Potato starch.