Sodium Alginate-Pectin Biopolymer Film With Essential Oil Impregnated Bio-Derived Silica for Active Packaging...

Plastic-based food packaging is widely used for food preservation and transportation because of its low density and high durability. However, it possess significant environmental and health challenges. Consequently, the synthetic polymers used in food packaging should ideally be replaced with biodegradable and cost-effective biopolymers. This study focuses on three key concepts of sustainable food packaging, namely the use of bio-based materials for film production, the development of water-soluble films, and waste valorization. A hybrid film is prepared by incorporating biomaterial-derived silica (b.SiO₂) modified with essential oil (EO) into a sodium alginate/pectin (SA/P) polymer matrix. The intermolecular interaction between the SA/P, glycerol, and chemically derived b.SiO₂ revealed excellent film-forming ability and flexibility. The SA/P-b.SiO₂-EO film revealed an increased mechanical strength (46.82 MPa), high thermal stability, controllable water vapor permeability (9.2 × 10^-11 gm^-1s^-1Pa^-1) and an increased water contact angle (51.4°) compared to the SA/P-only film. Furthermore, the b.SiO₂ combined with EO resulted in a polymer film demonstrating significant packaging performance, ensuring the strawberries remain safe for an extended duration (7 days). The SA/P-b.SiO₂-EO films showed considerable activity via inhibiting the bacterial (S. aureus and E. coli) growth rate. Thus, the EO-modified b.SiO₂ in SA/P films improves the functional, barrier, and antibacterial properties, which highlighting it as a viable sustainable alternative for food packaging applications.