Decoupling chemical and structural-driven function on barrier properties of PVA-lignin blends

Area of Science:

• Materials Science
• Polymer Chemistry
• Food Science

Background:

• Polyvinyl alcohol (PVA) is a versatile polymer with potential applications in food packaging.
• Kraft lignin, a byproduct of the paper industry, possesses antioxidant properties.
• Developing sustainable and functional food packaging materials is crucial for reducing food waste.

Purpose of the Study:

• To create polyvinyl alcohol (PVA)-kraft lignin nanoparticle (KLNP) composites with improved barrier and antioxidant functionalities.
• To investigate the effect of processing methods (casting vs. electrospinning) on material properties and performance.
• To evaluate the efficacy of these composites in preserving pork meat quality.

Main Methods:

• Kraft lignin was converted into nanoparticles (KLNPs) via self-assembly.
• PVA-KLNP composites were prepared using casting and electrospinning techniques.
• Material properties (UV-shielding, water barrier, antioxidant activity via DPPH assay) and food preservation efficacy (lipid oxidation, MDA inhibition) were assessed.

Main Results:

• Casted PVA-KLNP films exhibited enhanced UV-shielding and water barrier properties.
• Electrospun PVA-KLNP membranes showed increased surface wettability and higher antioxidant scavenging efficiency (10% more than casted films).
• Casted films reduced lipid oxidation by 71%, while electrospun membranes achieved 56% malondialdehyde (MDA) inhibition, primarily due to lignin's active properties.

Conclusions:

• PVA-KLNP composites demonstrate tunable barrier and antioxidant properties dependent on processing and lignin concentration.
• Electrospinning offers a route to incorporate higher KLNP loadings, enhancing antioxidant activity for food preservation applications.
• These functional composites show promise for active food packaging, contributing to reduced food spoilage.