pH-Sensitive Starch-Based Packaging Films Enhanced with Wild Blackberry Extract

• DOI: 10.3390/pr13041148
• Publication Date: 2025-04-10T14:47:41Z
• Authors: Kristina Cvetković; Aleksandar Lazarević; Sandra Stamenkovi...; Simona Dordevic; Dani Dordevic; Ivana Karabegović; Bojana Danilović

This study aims to develop and evaluate pH-sensitive food packaging films, based on starch and enriched with aqueous wild blackberry extract (Rubus sp.). The extract was selected for its high anthocyanin content due to color changes in different pH environments. Extract analysis revealed a dry matter content of 23 mg/mL and a polyphenol concentration of 21.10 mg GAE/g (dry extract), with high antioxidant activity, measured to be an 86.57% DPPH radical neutralizer. Films were produced with wild blackberry extract at concentrations of 0%, 5%, 10%, and 15%. The analyses determined the barrier, mechanical, physical, and intelligent properties of biodegradable films. The introduction of the extract resulted in a substantial rise in water content (9.6–21.36%), swelling capacity (35.27–43.06%), dissolution rate in water (288.05–459.89%), and permeability to water vapor (1.99–3.69 × 10−10 g/(Pa × m × s)). The bioactive compounds in the extract enhanced the films’ antimicrobial and antioxidant properties, with the highest effectiveness observed in the film containing 15% extract. These starch-based films, enriched with aqueous wild blackberry extract, demonstrated strong potential for packaging foods prone to pH changes during fermentation, such as fruits, dairy products, meat, and fish.