Enhanced sodium alginate-Based active packaging films via sonication, CaCl2 crosslinking, and patchouli essential oil incorporation

Abstract

This study explored the development of enhanced sodium alginate (SA)-based active packaging films using a synergistic approach that combines sonication, calcium chloride (CaCl₂) crosslinking, and incorporation of patchouli essential oil (PEO). The fabrication of the films involved optimized sonication (5 min at 50 % amplitude), internal crosslinking with 2 % CaCl₂, and 1 % (w/v) PEO. The resulting film (S5/C2/PEO) exhibited significant (p < 0.05) improvements in tensile strength (31.8 MPa), reduced water vapor permeability (2.11 × 10⁻¹¹ g m⁻¹ h⁻¹·Pa⁻¹), and enhanced thermal stability. FTIR analysis revealed intensified hydrogen bonding, indicating the successful integration of PEO and structural reinforcement via Ca²⁺ crosslinking. A qualitative in vivo preservation test on cherry tomatoes demonstrated mold inhibition by the S5/C2/PEO film over four days of storage, in contrast to rapid spoilage in the control. Although these antimicrobial results are preliminary and based on visual assessment, they underscore the potential of the film as a biodegradable active food packaging solution. Future studies should incorporate quantitative microbiological and sensory analyses to validate its efficacy and address the potential aroma transfer.