Zein/Shellac Composite Films with Limonin and Resveratrol: Characterization and Application for Strawberry...

Area of Science:

• Materials Science
• Food Science
• Polymer Science

Background:

• Active packaging is crucial for extending the shelf life of perishable foods.
• Zein and shellac are natural polymers with potential for food packaging applications.
• Incorporating bioactive compounds can enhance the functional properties of packaging films.

Purpose of the Study:

• To fabricate an active film based on a zein/shellac matrix incorporating limonin (LM) and resveratrol (RES).
• To evaluate the mechanical properties, water vapor permeability (WVP), antioxidant, and antibacterial activities of the developed films.
• To assess the efficacy of the active film in preserving strawberries and extending their shelf life.

Main Methods:

• Coaxial electrospinning was used to fabricate zein/shellac composite films with varying concentrations of LM and RES.
• Films were characterized for mechanical properties (tensile strength, elongation at break, elastic modulus) and WVP.
• Antioxidant capacity was assessed using DPPH, ABTS, and FRAP assays.
• Antibacterial efficacy was tested against *E. coli* and *S. aureus*.
• Strawberry preservation was evaluated using the fabricated films as packaging.

Main Results:

• The ZSLM4R film demonstrated favorable mechanical properties (EBA: 28.91%, TS: 0.93 MPa, EM: 40.76 MPa) and a WVP of 1.55 g mm/m². h. kPa.
• Incorporation of LM and RES significantly enhanced the antioxidant capacity of the films, with ZSLM4R showing high free radical scavenging activity (DPPH: 68.14%, ABTS: 89.69%).
• The composite film exhibited strong antibacterial activity against *E. coli* and *S. aureus*.
• ZSLM4R packaging effectively extended the shelf life of strawberries compared to controls.

Conclusions:

• Limonin and resveratrol-incorporated zein/shellac composite films show promise as active packaging materials.
• These films possess enhanced antioxidant and antibacterial properties, contributing to improved food preservation.
• The developed active films offer a viable eco-friendly alternative for extending the shelf life of perishable produce.