Eco-friendly, antibacterial, antioxidant, ultraviolet blocking sodium alginate-gelatin films loaded with clove essential oil for food packaging

Abstract

This study aims to develop an eco-friendly active packaging film to preserve perishable food. The film was prepared using natural polymers like sodium alginate and gelatin. Further, Clove oil was added to these films to improve their antioxidant and antimicrobial properties. The films’ transmission was low, i.e., ~ 18.79% in 315–400 nm, lower, i.e., 14.41% in the UV region of 200–400 nm, and lowest, i.e., 12.21% in 200–280 nm with a band gap of ~ 3.52 eV, showing the effectiveness of films in shielding UV light. The films were hydrophilic and showed a low water vapor transmission rate. The packaging films showed thermal stability and reduced swelling. Freeze-thaw and high-temperature annealing significantly improved the film’s mechanical properties (Y = 10.39 MPa and σ = 23.37 MPa). The Chorioallantoic Membrane (CAM) assay in the chick model showed the films’ biocompatibility. After 28 days, the films were completely biodegradable in soil, providing a sustainable solution for food packaging. Active packaging film showed significant antibacterial properties against Gram-positive S. aureus (colony-forming unit (CFU) reduced from 92 ± 4.2 to 3 ± 0.2, i.e., 96.74 ± 5.13% inhibition) and Gram-negative E. coli (colony-forming unit reduced from 106 ± 6 to 95 ± 4.11, i.e., 96.13 ± 3.41%). These films showed significant antioxidant activity and effectively delayed the decay of bananas (Musa acuminata), making them a promising solution for food packaging with excellent UV blocking, antimicrobial, and antioxidant properties.

Graphical abstract