ZIF-8-Reinforced Biodegradable Composite Modified Atmosphere Packaging Membranes for Fruit Packaging

Area of Science:

• Materials Science
• Polymer Science
• Chemical Engineering

Background:

• Modified atmosphere packaging (MAP) is crucial for extending the shelf life of fresh produce.
• Traditional MAP materials often lack optimal gas selectivity and mechanical properties.
• Biodegradable polymers offer sustainable alternatives but require functional enhancement.

Purpose of the Study:

• To develop a novel biodegradable equilibrium modified atmosphere packaging (EMAP) membrane with enhanced gas selectivity.
• To incorporate Zeolitic Imidazolate Framework-8 (ZIF-8) into a polylactic acid (PLA) matrix to improve CO2/O2 selectivity and gas permeability.
• To evaluate the packaging performance, mechanical properties, and safety of the developed PLA/PEG@ZIF-8 membrane for food preservation.

Main Methods:

• Synthesis of a biodegradable polylactic acid (PLA) matrix incorporating Zeolitic Imidazolate Framework-8 (ZIF-8) nanoparticles.
• Fabrication of the PLA/PEG@ZIF-8 composite membrane for equilibrium modified atmosphere packaging (EMAP).
• Characterization of gas selectivity (CO2/O2), gas permeability, water vapor transmission rate, mechanical properties (tensile strength, elongation at break), hydrophobicity, swellability, UV-blocking, and cytotoxicity.

Main Results:

• The PLA/PEG@ZIF-8 membrane achieved a high CO2/O2 selectivity of 6.35 with favorable gas permeability.
• Enhanced mechanical properties, including improved elongation at break and tensile strength, were observed.
• The membrane demonstrated reduced water vapor transmission rate, retained hydrophobicity and swellability, and exhibited improved UV-blocking.
• Cytotoxicity assays confirmed negligible zinc ion migration and cell viability exceeding 97%, ensuring material safety.
• Packaging cherry tomatoes with the membrane significantly extended their shelf life by inhibiting microbial growth and nutrient loss.

Conclusions:

• The developed PLA/PEG@ZIF-8 EMAP membrane offers superior CO2/O2 selectivity and enhanced packaging performance.
• The membrane exhibits excellent mechanical and barrier properties, making it suitable for food preservation applications.
• This novel biodegradable packaging material shows significant potential for extending the shelf life of high-respiration fresh produce, contributing to sustainable food preservation technology.