Innovative and environmentally safe composites based on starch modified with dialdehyde starch, caffeine, or ascorbic...

Biodegradable films based on starch modified with ascorbic acid or caffeine and dialdehyde starch (DS) were evaluated towards their applications in the food packaging industry. The morphology of the films surface was observed with SEM and AFM. The chemical structure was examined with ATR-FTIR spectroscopy and X-ray diffraction. The mechanical, thermal and barrier properties of the films were examined. The cross-linking and hydrophobic effect of dialdehyde starch on starch-based films was proven. Vitamin C addition prompts the crystalline structure formation and improves the hydrophilicity and antioxidant activity of the starch blends. Caffeine addition results in higher starch film hydrophobicity, whereas caffeine combined with DS reduces crystalline order in starch. Both caffeine and ascorbic acid incorporation influence the film stiffness, and dialdehyde starch causes an increase in brittleness. The high susceptibility to biodegradation and good antioxidant activity confirms the potential application of examined systems in the packaging industry.