Antioxidant-Rich Biodegradable Films: Incorporating Date Phenolic Extracts into Polyvinyl Alcohol Biofilms for Strawberry Preservation

This study evaluates the development and characterization of polyvinyl alcohol (POVA) films incorporated with phenolic extracts from two varieties of dates, Barhi, Medjool, and their potential application in strawberry packaging. Total phenolic content (TPC) and antioxidant activity (DPPH) were assessed for aqueous and ethanolic extracts of Barhi and Medjool dates. Barhi exhibited higher TPC and DPPH than Medjool, with 10.53 mg/g and 65.83%, respectively, in its ethanolic extract, compared to Medjool’s 7.39 mg/g and 50.63%, respectively. POVA films incorporating Barhi ethanolic extract (POVA/BE) demonstrated the highest TPC (3.58 mg GAE/g) and antioxidant activity (53.68%) compared to other films. The physical properties of the films, including thickness and water vapor permeability (WVP), were evaluated, POVA/BE showing improved barrier properties with a WVP of 88.75 ×10⁻¹⁰ g H₂O/m s p.a. Compared to pure POVA, POVA/BE films also showed superior mechanical properties, with a tensile strength of 69.69 MPa and elongation at break of 66.72%. Additionally, strawberry storage trials demonstrated that POVA/BE films minimized weight loss, maintained higher firmness, TSS, TTA, and vitamin C content over 14 days of storage, with weight loss of 8.00%, TSS of 4.84%, and vitamin C retention at 111.77 mg/100g. These results suggest that POVA films containing Barhi extracts offer enhanced antioxidant activity, mechanical strength, and barrier properties, making them a promising biodegradable packaging solution for extending the shelf life of perishable foods like strawberries.