Smart biopolymer based on rice husk extracts and Pinhão failure applied as an interlayer for sliced mozzarella cheese

Food packaging plays a crucial role in preserving food and beverage quality. Biodegradable polymers from renewable materials offer an effective alternative to reduce the environmental impact of non-biodegradable plastics. This study aimed to develop a smart biopolymer (active and intelligent) using agribusiness by-products like rice husk and Pinhão failure (Araucaria angustifolia). The film was created using the casting method and analyzed for its physical, mechanical, antioxidant, and intelligent properties, including color changes at different pH levels, thickness, transparency, and biodegradability. The film, 0.23 ± 0.01 mm thick, had a tensile strength of 0.69 ± 0.09 MPa, maximum force 7.60 ± 0.09 N, 86.06 ± 0.15% transparency, and 17.76 ± 0.05% moisture, enabling biodegradation within 10 days. The water vapor permeability (WVP) of the film was (1.08 ± 0.01) × 10⁻⁸ gH₂O (Pa·s·m) ⁻¹. The coloration of the film obtained values of L* 71.23 ± 0.50, a* 12.11 ± 0.13, b* 41.14 ± 0.17, and color changes at various pH levels demonstrated potential for smart packaging as a freshness indicator, particularly for foods prone to spoilage at alkaline pH. The Pinhão extract contributed phenolic compounds (57.47 ± 2.5 mg GAE.g⁻¹), providing antioxidant properties and thermal resistance up to 200°C. When applied to mozzarella cheese as an interlayer, the film performed comparably to synthetic plastic Low-Density Polyethylene (LDPE), proving its suitability as a sustainable replacement. This study highlights the potential of Pinhão failure extract in developing biodegradable and smart packaging for food preservation.

Highlights

• A flexible film was developed using extracts from agricultural by-products.
• The film exhibited pH-sensitive color changes and antioxidant activity.
• The biopolymer biodegrades within 10–12 days.
• The film serves as an alternative to synthetic interlayers used in mozzarella.