Bio-Based Alginate Films Incorporating Bacterial Nanocellulose and Grape Seed Extract for Enhanced Food Packaging

The development of sustainable, active food packaging materials is essential for reducing plastic waste and improving food preservation. This study investigated the fabrication and characterization of bio-based films composed of sodium alginate (Na-alginate), bacterial nanocellulose (BNC), and grape seed extract (GSE) as a natural antioxidant. Films were prepared via casting solutions with 2% Na-alginate, 1% and 2% of BNC, glycerol as a plasticizer, and varying GSE concentrations (0, 0.5, 1, and 2% <i>w</i>/<i>w</i>). The films' physicochemical properties, including thickness, mechanical strength, water vapor permeability, antimicrobial and antioxidant activity (DPPH assay), were evaluated. To assess practical applicability, blueberries were packaged in these films and stored at 4 °C for four weeks, with spoilage, weight loss, and visual quality monitored. The results demonstrated that GSE significantly enhanced the films' antioxidant capacity, with 1% GSE achieving an optimal balance between mechanical integrity and bioactivity. Blueberries packaged in GSE-enriched films exhibited lower spoilage, reduced weight loss, and maintained better visual appearance compared to controls. These findings suggest that Na-alginate/BNC/GSE films possess potential as biodegradable active packaging materials for extending the shelf life of perishable fruits.