Active bio-foam packaging based on sodium alginate incorporated with vanillin for extending the shelf life of cherry tomatoes

As fresh produce easily undergoes postharvest decay, eco-friendly and active packaging is an emerging technology for maintaining the safety and quality of fresh produce. This study focuses on the development of an active and biodegradable packaging foam made from sodium alginate (SA) incorporated with the natural antimicrobial vanillin (VAN) to enhance the shelf life and quality of fresh produce. The effects of VAN concentrations (0, 0.25, 0.50, 0.75 % w/v) on the chemical, morphological, mechanical, and antimicrobial properties, as well as the biodegradability and release kinetics of the SA-based bio-foam (SAVs), were systematically explored. The incorporation of VAN improved the mechanical properties and reduced the water absorption of SAVs. The bio-foam exhibited strong antimicrobial activity against both gram-negative (E. coli) and gram-positive (S. aureus) bacteria as well as the postharvest fungus (B. cinerea) with complete biodegradability within 20 days. The SAV-0.50 formulation was applied in storage studies of cherry tomatoes, significantly extending their shelf life by inhibiting microbial growth and maintaining color, firmness, TSS, and pH. These results emphasize the potential of SA-based bio-foams as eco-friendly, sustainable packaging solutions for the preservation of fresh produce.