Functional chitosan/starch composite films enriched with Aloe vera extract for antimicrobial and antioxidant...

Functional chitosan/starch composite films enriched with aloe vera extract were developed as sustainable active packaging materials using a one-pot preparation method and optimized by response surface methodology (RSM). The effects of chitosan, Dioscorea esculenta starch, and aloe vera extract concentrations on key film properties were systematically evaluated. The optimum formulation, consisting of chitosan (2 wt%), starch (2 wt%), and aloe vera extract (0.461 wt%), exhibited a swelling degree of 27.379%, tensile strength of 92.853 MPa, and elastic modulus of 881.614 N/m². Structural analyses confirmed homogeneous physical integration of aloe vera extract within the polymer matrix, resulting in reduced crystallinity, improved surface hydrophobicity, and lower water vapor permeability. The optimized films showed significantly higher antioxidant activity, achieving DPPH• and ABTS•+ radical scavenging efficiencies of 52.46% and 95.83%, respectively, and demonstrated broad-spectrum antimicrobial activity. Shelf-life studies on chicken and shrimp confirmed the practical effectiveness of the films, as evidenced by higher firmness, lower weight loss, balanced pH, reduced microbial growth, and lower protein degradation during refrigerated storage. Additionally, the films exhibited favorable biodegradation behavior, reaching >80% degradation after 45 days in soil burial tests. These results highlight the potential of aloe vera-enriched chitosan/starch films as multifunctional and biodegradable active packaging materials.